Monthly Archive

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
745 PM EST Tue Jan 31 2012

SYNOPSIS...
AT UPPER LEVELS...
DOWNSTREAM from TROUGH from WRN Great Lakes SWWD into CNTRL Plains
and Desert SW, the large scale longwave pattern remains fairly
zonal and progressive with multiple, short waves embedded within the
MEAN FLOW across the Great Lakes and weaker ones across AZ and Gulf
Coast.

During the next 24 HRS, a WSW split flow regime develops with NRN
stream portion of trough tracking from Great Lakes THRU New England
and SRN stream component moving from Desert SW to Wrn Gulf before
lifting NEWD, deamplifying and phasing with Nrn stream trough across
MS/OH Valleys reaching MID-Atlc region early Thurs. Overnight into
early Wed, srn stream SHORTWAVE will move from AZ to TX to LA while
under increasingly SW steering flow, Gulf shortwave moves NEWD
across NE Gulf region.

AT LOWER LEVELS...
Analysis showed HIGH off Carolina Coast with an east-west oriented
RIDGE WWD through Srn GA, and a weak cold FRONT in KS and OK.
24-hour PRESSURE falls over the NW Gulf of Mexico and along
the Gulf Coast suggest the beginning of the development a weak LOW
pressure system over the western Gulf of Mexico. During the next 24
hrs, low is forecast to move east Wednesday and Thursday ahead of a
weak short wave (currently over the southwest U.S.). Advancing
UPSTREAM trough will drag weak cold front ESE and (under zonal flow
very slowly) aligned from OH Valley thru TN Valley and N TX Wed
morning. In response, ridge just N of FL will drift S and E and
weaken.

Despite the low being so weak, the models forecast ample deep layer
MOISTURE and large scale lift to support a large area of RAIN. This
reflected in model time heights, i.e. GFS TAE with 0.70 inch PWAT at
00z Wed increasing to 1.51 inch at 00z Thu down under one-inch at
18z Thurs. Expect RAINFALL totals for this event to RANGE from a
quarter of an inch over N FL and S Central GA to an inch along the
FL Panhandle Coast. There could be ISOLATED amounts of up to 3
inches, mainly Panhandle Coastal areas. Although there may be enough
INSTABILITY and lift to support some thunderstorms (mainly near the
coast and over the Gulf coastal waters). Rain chances will decrease
from NW-SE on Thursday AS a weak frontal system (with slightly drier
AIR) moves into the area. As this front stalls Thursday NIGHT and
Friday, slight rain chances will return to the region. behind the
front, high pressure will build over the area.

&&

.SHORT TERM...(Rest of Tonight through early Wednesday)
Increasing mid and high clouds spreading NEWD ahead of Gulf system
will be countered by VEERING light low level winds and high DEW
points. Expect patchy to areas of FOG to develop especially ERN
counties, farthest from clouds and where gradients the weakest.
Will add patchy fog to Ern counties. Expect lows from around 50
inland to near 60 coast.

&&

.AVIATION (through 00z Thursday)...Mid and upper level cloudiness
continues to spread from west to east across the region and low
level clouds will move in overnight with CIGS around 5kft. Periods
of MVFR CIGS and VSBYS are also expected before daybreak along with
SCATTERED showers mainly at ECP and DHN. After daybreak, patchy
light to occasional moderate rain will overspread the area from
southwest to northeast throughout the remainder of the TAF period.
Winds will be light from the southeast to south.

&&

.MARINE...
Winds and SEAS will continue to drop below exercise caution levels.
The next CHANCE for near-ADVISORY level conditions will be Thursday
night and Friday.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
830 PM EST Sun Jan 29 2012

UPDATE...
A dry cold FRONT passed earlier this morning, leaving colder
temperatures behind it. Lows tonight will be at or below freezing
across most of the region with colder areas dipping into the upper
20s and urban areas such AS downtown Tallahassee staying a little
warmer. HIGH PRESSURE is now building across the area and is raising
the pressure GRADIENT, increasing WIND speeds over the water. Winds
tonight over the marine area will be from the northeast at 15 to 20
knots, which requires a cautionary headline. RAIN chances will
increase later this week by Wednesday, and Thursday will see a
CHANCE of thunderstorms.

&&

.AVIATION (Through 00Z Tuesday)...
VFR conditions will prevail through the entire TAF period with very
light or CALM winds at NIGHT, and E to NE winds between 5 and 10 KTS
during the day on Monday. Sky conditions will have virtually no
impact on aviation, with just patches of high CIRRUS which will
LIKELY be BKN at ECP from time to time

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
914 PM EST Wed Jan 25 2012
...Slight Risk of Severe Storms Continues for Thursday Evening
through MID-morning Friday...
UPDATE...

Regarding severe STORM chances Thursday and Thursday night, not
much has changed with the latest 18z guidance. It is a bit
concerning that the 18z NAM forecasts SBCAPE values AS HIGH as
500-1000 j/kg during the late afternoon and evening hours
coincident with increasing LOW and deep layer SHEAR values over
parts of southeast Alabama and the eastern panhandle. We expect a
SQUALL line to enter the western zones during the late afternoon
to early evening hours with damaging straight line winds the main
threat, although an ISOLATED TORNADO cannot be ruled out given the
increasing low level shear. The 18z local hi-res ARW run does show
some strong to severe cells moving onshore in the vicinity of
Panama City during the evening hours, and this bears close
watching. The highest threat of severe weather for the local area
is located across southeast Alabama, the Florida panhandle, and
southwest Georgia, but the threat could extend as far east as
Tallahassee and Albany as well during the overnight hours.

&&

.AVIATION...
Based on PERSISTENCE from last night and MOS guidance, IFR or lower
conditions are expected at all airports with fog developing during
the late night hours. All terminals with the exception of DHN are
expected to see ceilings below airport minimums starting between
06z and 09z. Fog will diminish and ceilings will lift after
SUNRISE. VFR conditions are expected after the fog and ceilings
lift with winds out of the south from 10 to 15 KTS gusting to 25
kts. Some CONVECTION may start to approach KECP and KDHN near the
end of the TAF period, but most of it should occur beyond this TAF
forecast period.

&&

.MARINE...
Southeast winds will begin to increase ahead of a strong cold FRONT
tonight. This front will bring increasing winds, SEAS, and
thunderstorms to the coastal waters Thursday afternoon through
early Friday. Some of these storms could be severe. Winds will
shift to the west Friday behind the cold front with exercise
caution or low end ADVISORY conditions possible until winds and
seas subside later in the day on Friday. A return to WINDY
conditions is expected again on Sunday.

Tornado damage in Center Point, Alabama, from early morning storms on Mon., Jan. 23, 2012.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1015 PM EST Tue Jan 24 2012


.UPDATE...A tricky FOG forecast is on tap once again tonight. It
is being complicated by an assortment of CLOUD cover at different
levels across the forecast area. Starting with a surface analysis,
it seems AS though a stalled FRONT continues to linger from near
KPAM-KMAI-KTMA, or roughly bisecting our forecast area from SW-NE.
To the north of this front, dewpoints drop off sharply into the
upper 40s and lower 50s, while the LOW-level AIR mass south of the
front is still quite moist (dewpoints 60-65F). The area south of
the front is where we would have the best CHANCE of seeing some
fog development tonight. Indeed by 02z, Apalachicola (KAAF) had
already reported a 1/4SM VISIBILITY and Perry (K40J) had reported
visibility as low as 1/2SM.

HI-resolution model guidance including the 4km WRF and NAM runs,
as well as the HRRR, show the fog initially developing near the
coast and then slowly expanding inland. This seems quite logical,
although it will probably not be a uniform south-to-north
evolution. The aforementioned cloud cover will play a role in
keeping some areas devoid of fog much longer. The latest IR
satellite shows MID-upper level clouds eroding quickly over the
last several hours east of the Apalachicola River, and this is
where the initial Dense Fog ADVISORY was placed for our Florida
zones (02-13z valid time). To the north in Georgia, we coordinated
the advisory area with WFO JAX. BKN-OVC low clouds situated west
of Thomasville and Moultrie should limit the westward extend of
fog in our SW GA zones. Additionally, the front is expected to
slowly drift south overnight, and drier air will slowly work
towards the FL-GA border. Thus, the temporal extent of the fog in
SW GA may be limited to pre-SUNRISE, and the initial advisory for
our GA zones was limited to 02-10z.

Looking ahead to the THUNDERSTORM potential Thursday NIGHT, things
still seem generally on TRACK with previous thinking. SPC SWODY3
places areas west of a DHN-MAI-AAF line in a Slight Risk for
severe thunderstorms. The 25.00z NAM run continues to be a blend
of the 25.12z runs of the faster ECMWF and slower GFS. It brings
some convective PRECIPITATION into our western areas around 03z
Friday (10pm EST Thursday Night). Forecast soundings indicate
about 500 j/kg of near-surface CAPE closer to the Gulf coast, with
a lot of the CAPE profile concentrated in the lowest 3-4km AGL" onClick="return popup(this, 'notes')">AGL.
Therefore, while the forecast CAPE values are not overwhelming,
the more compact CAPE region would favor greater low-level
accelerations. SHEAR profiles are, as is typical of the cool
season, quite favorable for organized thunderstorms. In fact, a
lot of the shear in the 0-3km layer will LIKELY be concentrated in
the lowest 500m AGL. There is some concern about southeasterly
FLOW ahead of the approaching front not being the most favorable
pattern for MOISTURE return. However, this may be negated by
fairly warm water temperatures with both of our offshore buoys at
71F this evening. Bottom line, there will be a lot of low-level
shear and a lot will ultimately depend on the lapse rates and CAPE
profiles in the lowest 3-4km. The HWO wording will be modified
this evening to indicate a bit more concern.


&&

.AVIATION [through 00z Thursday]...With front lingering along the
I-10 corridor overnight, low cigs/VSBY may be an issue for KECP,
KTLH, and KVLD. To the north, enough dry air is expected to keep
conditions VFR through the forecast period. Best chance for
conditions near airport mins will be KVLD by morning. Slightly
better conditions expected to the west. Clouds will gradually lift
through the morning with VFR conditions everywhere by the afternoon.


&&

.MARINE...A Marine Dense Fog Advisory has been issued for all of
our coastal waters within 20 NM of shore until 16z Wednesday. This
was the result of a FEW surface observations near the coast
reporting visibilities below 1 mile, as well as NUMEROUS HIGH-res
models showing strong indications of fog. The fog is expected to
lift around mid-morning with enough mixing in the marine boundary
layer to dissipate the dense fog. With offshore buoys SSTs running
at 71F, fog is not a concern for the offshore zones.

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE 
TALLAHASSEE FL 1017 PM EST Mon Jan 23 2012


.UPDATE...The thin band of RAIN and thunderstorms has been pushing
gradually into our forecast area this evening from west to east,
reaching a EZM-ABY-MAI-ECP line by around 0230z. This activity has
advanced ahead of the main cold FRONT, which extended from just NW
of Atlanta to far southern Mississippi. A much drier AIR mass was
noted behind the front, with dewpoints 35-45F on most surface OBS.
HIGH-resolution model guidance, including all flavors of the 4km
WRF AS well as the HRRR, dminishes this activity to just ISOLATED
showers around 06z. This seems to match recent RADAR and LIGHTNING
trends, and makes sense with a lack of strong LOW-level forcing.
We used a 3-HR POP trend with hourly weather GRIDS to time the
PRECIPITATION trends in the very near term (0-6hr).

The other concern tonight is FOG potential. One area of fog was
already developing in the WAKE of the precipitation across SE
Alabama and the far western Florida Panhandle. KTOI and KCEW (both
just outside our forecast area) have reported visibilities as low
as 1/4SM in the past hour or so. Therefore, as the rain moves out
of our northwestern areas we will probably see some fog develop.
This may be abbreviated somewhat by the arrival of the main front
later tonight and therefore some drier air. As such, confidence
was not high enough in true dense fog (1/4SM or less) developing
to issue any ADVISORY in our AL zones and adjacent FL/GA zones.
Meanwhile, some of the high-resolution guidance and VSREF
probabilities indicate some potential for dense fog over Apalachee
Bay and into our eastern Big Bend counties as well, particularly
after 06z. There is uncertainty in those locations related to the
dense MID level CLOUD cover BLOWING off the CONVECTION to the
west. Also, no observations in that area have any restricted
VISIBILITY at this time. It isn`t inconceivable that a Dense Fog
Advisory may be needed later tonight, but confidence is not high
enough at this juncture to accurately place one.

Some minor tweaks were made to the weather and POPS into tomorrow
afternoon as well. Our 18z local 4km WRF-ARW, and to a lesser
extent the 12z SPC WRF-NMM, indicate some more focused afternoon
THUNDERSTORM activity around the rim of Apalachee Bay, from near
Apalachicola up towards Tallahassee and Madison. This seems to be
related to some enhanced onshore FLOW off the cooler waters as the
land areas heat up. PoPs were nudged up 5-10% in aforementioned
corridor. WRF forecast soundings show about 1000 j/kg of MLCAPE in
the afternoon, so THUNDER seems like a good bet south of wherever
the stalled cold front sets up.


&&

.AVIATION [through 00z Wednesday]...Tricky TAF package for the
overnight hours into Tuesday. Approaching cold front is forecast
to stall along the I-10 corridor all day Tuesday, creating impacts
for KTLH, KECP, and KVLD. SCATTERED showers and will impact KDHN,
KABY, and KECP for the next several hours before the activity
weakens. MVFR conditions expected at these sites through the
NIGHT. Conditions will improve through the day for the northern
terminals, which will be well north of the front. Farther south,
after patchy fog and low cigs overnight, conditions will LIKELY
only improve to near Alt. Arpt. thresholds during the day.
Isolated thunderstorms are possible during the afternoon.


&&

.MARINE...Considered a Marine Dense Fog Advisory for nearshore
waters from Apalachicola to the mouth of the Suwannee River.
However, despite a 63 degree dewpoint, Keaton Beach was holding
steady with a 2F dewpoint DEPRESSION, and there was no evidence of
any fog having developed yet at any coastal observations. This
will need to be monitored closely during the overnight. Subdued
SEAS and winds will continue through Wednesday when there should
be a gradual increase in southeasterly winds as a low develops
along the Texas Gulf coast. A front still looks to arrive late
Thursday Night, and advisory level winds and seas will be possible
just before and after the front. The front also looks to be
accompanied by some thunderstorms.

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TALLAHASSEE FL
850 AM EST SAT Jan 21 2012


.NEAR TERM (REST OF TODAY THROUGH TONIGHT)...
MID/upper level SHORTWAVE IMPULSE continues to quickly translate
eastward from the lower MS valley toward the southern
Appalachians/Carolinas this morning. TROUGH axis now extends from
western TN to northern MS, noted by significant drying/SUBSIDENCE in
its WAKE over AR/northern LA. At the surface, the cold FRONT is
aligned ahead of the upper trough axis from eastern TN, southwest
through northern AL/central MS.

Large scale forcing/synoptic ascent ahead of the upper trough
combined with surface focus, and a general WAA regime ahead of the
cold front is forcing a solid line of CONVECTION over north-central
AL, and more SCATTERED variety convection further south and east
across AL/GA.

A large TORNADO WATCH box remains in effect just to our north across
central AL/GA related to this convection. SPC continues to OUTLOOK a
slight risk of severe weather co-located with this watch and also
extending a bit further south into portions of our SE AL/SW GA
zones.

The location of this slight risk zone still appears appropriate
after analyzing the latest output from our ENSEMBLE suite of CAM
(convective allowing models). Good agreement among these models
showing the potential for organized and rotating updrafts in the
vicinity of our far northern zones (mainly along the north of a line
from Dothan to Albany) later this morning through early this
evening. Will continue to monitor, but it does appear that the
window for the best severe potential will close off fairly early
this evening AS the shortwave impulse and resulting synoptic
forcing/SHEAR profiles shift past our area. With this quick exit of
the most favorable conditions, the potential to support severe
thunderstorms further south, especially along and south of the I-10
corridor appears LOW. However, will continue to monitor trends in
case the threat area needs to be briefly adjusted south. Either way,
the low level JET will be east of our area by 00-02Z with upper
HEIGHT rises/anti-cyclonic FLOW building in from the west. Therefore
some POPS will remain in the forecast overnight, but the threat for
severe weather looks to be over shortly after dark.

The forecast emphasis by later this evening will have shifted from
severe weather potential to dense FOG potential. Appears that a very
favorable setup for a dense fog event is in the making across a vast
majority of the forecast area. The cold front will be stalling over
or just north of our AL/GA zones tonight, allowing a continued
moist/southerly flow off the Gulf of Mexico. CURRENT forecast
dewpoints crossing the nearshore waters tonight are 2-5 degrees
higher than the surface water TEMPS. This is a good setup for
ADVECTION fog to move ashore/spread inland. Combine this with
an already favorable setup due to the general NVA/subsidence
overhead in the wake of the shortwave, and dense fog is a good bet.
All available HI-res guidance are picking up on this potential, and
the SREF probabilities for fog are very HIGH. The potential for
dense fog should SET in fairly early...by 03-05Z south of the I-10
corridor and expand quickly inland after midnight. Will continue to
highlight this potential in the GRIDS for the morning update.

&&

.MARINE...
Southerly winds will prevail through Monday along the western edge
of surface high PRESSURE. A weak front will pass over our coastal
and offshore waters late on Monday allowing winds to shift to the
north, and eventually to the east as high pressure builds in north
of our area. Winds and SEAS are not expected to increase
significantly with the passage of the front. At this time, no
headlines are expected through mid-week.

&&

.AVIATION (THROUGH 12Z SUNDAY)...
Areas of IFR VIS/CIG should slowly lift through 15Z. Scattered
showers and thunderstorms are expected to develop into our NW areas
by early afternoon. South to southwest winds will increase during
the day with frequent gusts over 20 knots. There remains a threat
for ISOLATED severe storms around DHN and ABY. THUNDERSTORM activity
should diminish during the early evening, but will quickly be
replaced by a potential WIDESPREAD fog event, which is expected to
develop earlier in the NIGHT and be more widespread than what we are
see this morning. The potential appears quite high at this point for
a widespread IFR or lower event at all terminals. The setup is
favorable for early fog development for KECP and KTLH, possibly
before 03-04Z, with fog rapidly spreading inland after midnight.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
315 PM EST Mon Jan 16 2012

SHORT TERM [Tuesday through Wednesday NIGHT]...The short term
period will be encompassed by a frontal passage. The cold FRONT in
question currently stretches from eastern Ontario to northern
Missouri, and then arcs westward through southern Kansas. A
frontal wave developing along the front in the central Plains is
expected to grow into a surface low as a low amplitude upper level
TROUGH ejects into the Plains. The rapid CYCLOGENESIS in the Great
Lakes and up the ST. Lawrence Seaway, along with the progressive
zonal flow aloft, should help drive a cold front into the Gulf
Coast region late Tuesday Night and early Wednesday.

Tuesday: Despite some gradually increasing CLOUD cover, especially
above 10,000 feet, it still looks like a pretty warm day. There is
good agreement amongst the NAM, GFS, and GEM that 850mb TEMPS will
SURGE up into the +13C to +14C RANGE. Even if the TEMPERATURE
profile in the low-levels ends up being closer to the moist
ADIABATIC lapse rate, it would still LIKELY result in highs in the
low-to-mid 70s. The southeastward progression of POPS was delayed
relative to previous forecasts, and it wouldn`t be entirely
surprising to see most of the area staying dry prior to 00z Wed.
There may be a FEW showers in the THETAE ADVECTION MAX near the
coast, as is hinted at by our local 4km WRF-ARW, but confidence is
not high enough to portray that scenario yet.

Tuesday Night: The cold front finally pushes into our area. Timing
differences on the 16.12z SET of models are much less than in
previous model runs. For this forecast package, we used ENSEMBLE
approach. SREF and GFS Ensemble means have roughly the SAME timing
with the front entering our Alabama zones (NW corner of our area)
around 06z Wednesday, and reaching a TMA-TLH-AAF line by 12z.
Likely PoPs were included behind the front on Tuesday Night, where
the bulk of the PRECIPITATION will occur. ISOLATED THUNDER was
included as well, with MUCAPE 200-400 j/kg and equilibrium level
around -25 to -30C. For temperatures, we used a non-DIURNAL trend
as they will likely be almost steady ahead of the cold front for
much of the night.

Wednesday: As the front quickly exits the area, precipitation
should come to an end. It will be a cooler day with highs closer
to seasonal normals (low-to-mid 60s). Light FREEZE possible for
Wednesday Night.


&&

.LONG TERM [Thursday through next Monday]...Extended forecast
period will begin Thursday with a rather unamplified upper level
pattern across the CONUS, consisting of broad riding over the
inter-mountain west and broad troughing over the eastern half of
the nation. Wednesday`s cold front will be well to our south by
Thursday morning with high pressure building in from the north in
its WAKE. Some slight disagreement among the global guidance suite
as to the position of the surface high, with the GFS building the
CENTER overhead, and the the ECMWF/Canadian showing the high
center up over the Carolinas. The GFS would be a colder solution
Wednesday night, as the high position would favor a better
radiational cooling setup. Will not deviate much from the MEX
numbers for now which bring the normally colder inland spots down
into the lower 30s. A solution closer to the EC/Canadian will
lower the potential for significant coverage of subfreezing temps.
Overall pattern becomes quite zonal in nature for Friday with just
a weak shortwave riding the flow across the central portions of
the country. Influence of this energy will hold off until Saturday
providing a dry and warm final day of the workweek. Friday should
see highs well into the 60s to around 70 degrees away from the
immediate coast, where onshore flow off the cooler shelf waters
will hold temps in the lower/mid 60s.

GFS/ECMWF do not agree on the evolution of shortwave energy by the
time it arrives here in the SE part of the CONUS. GFS is very
progressive, passing the energy over us, and off the SE coast by
Saturday evening. The GFS solution has very little, if any, surface
REFLECTION associated with this energy, and only a CHANCE of a few
showers. ECMWF is slower and stronger with its shortwave. This
solution does show a surface reflection/front moving into our
northern areas Saturday night. For now did not choose to follow this
solution which would keep SHOWER chances in the forecast Saturday
night. In fact, will continue to follow the GFS pattern through the
early portion of next week, as the ECMWF becomes somewhat
questionable. GFS keeps our area with a general southerly low level
flow underneath a zonal to ridged upper level pattern. This would
suggest above NORMAL temperatures for Sunday and Monday. Can not
rule out a few isolated showers embedded with the southerly flow,
however a generally dry forecast will also be shown.


&&

.MARINE...The descending ASCAT pass at 1914z showed much of the
coastal waters (except the two eastern nearshore segments) with
15-20 KNOT winds. In fact, there were some values around 20kt in
our western offshore zone. Both of the buoys just outside our
marine zones were reporting 17-19kt winds, so the scatterometer
data is probably pretty accurate. Thus, winds have been slower to
decrease than models have indicated. The "Small Craft Exercise
Caution" headline will be continued into Tuesday morning for all
but the two eastern nearshore segments. Although the central
segments may see winds decrease briefly in the evening, they are
expected to increase once again after midnight. After a brief
lull, there are likely to be SCEC conditions again late Tuesday
Night and early Wednesday as the cold front comes through. With
respect to sensible weather, we added patchy FOG to the nearshore
zones from 18z Tuesday to 18z Wednesday where RH was above 85% in
the forecast GRIDS. This timeframe encompasses a surge of higher
dewpoints in the 60-62F range (compared with observed water temps
of 58F and 56F at Panama City and Apalachicola respectively).


&&

.AVIATION [through 18z Tuesday]...Mid and upper clouds will
continue to impact area terminals into Tuesday. However,
prevailing conditions are expected to remain VFR. There is some
possibility of brief MVFR conditions at KECP and KDHN after 12z
Tuesday.


&&

.FIRE WEATHER...Relatively moist onshore flow will continue into
Wednesday ahead of an approaching cold front. This will keep
HUMIDITY values well above critical levels, as well as provide some
RAINFALL late Tuesday into Wednesday. Much drier AIR will push in
behind the front for Thursday with humidity values dropping into the
20s for much of the region.

MAX/MIN TEMPERATURE AND PRECIPITATION TABLE FOR
SOUTHEAST AL...EASTERN FL PANHANDLE ...
SOUTHWEST GA AND FL BIG BEND
NATIONAL WEATHER SERVICE TALLAHASSEE FL
722 PM EST MON JAN 16 2012

HIGH TEMPERATURE TODAY
LOW TEMPERATURE PAST 18 HOURS
24 HOUR PRECIPITATION ENDING AT 7PM EST / 6PM CST


.BR TAE 0116 E DH19/TAIRZX/DH19/TAIRZP/PPDRZZ
:
:AIRPORT OBSERVATIONS - EASTERN TIME ZONE
:AS OF 7PM EST
:
:                                 MAX   MIN
:                                 TEMP  TEMP   PCPN
TLH  : TALLAHASSEE              :  69 /  28 /  0.00
AAF  : APALACHICOLA             :  65 /  36 /  0.00
40J  : PERRY                    :  72 /  30 /  0.00
CTY  : CROSS CITY               :  71 /  26 /  0.00
JAX  : JACKSONVILLE INTL        :  68 /  30 /  0.00
ABY  : ALBANY                   :  69 /  33 /  0.00
VAD  : MOODY AFB                :  68 /  31 /  0.00
VLD  : VALDOSTA                 :  71 /  32 /  0.00
BGE  : BAINBRIDGE               :  70 /  34 /
BIJ  : BLAKELY                  :  66 /  28 /
MGR  : MOULTRIE                 :  68 /  34 /
TVI  : THOMASVILLE              :  68 /  34 /
:
.END


.BR TAE 0116 C DH18/TAIRZX/DH18/TAIRZP/PPDRZZ
:
:AIRPORT OBSERVATIONS - CENTRAL TIME ZONE
:AS OF 6PM CST
:
:                                 MAX   MIN
:                                 TEMP  TEMP   PCPN
ECP  : PANAMA CITY NW INTL ARPT :  66 /  34 /  0.00
PAM  : TYNDALL AFB              :  67 /  35 /  0.00
VPS  : EGLIN AFB ASOS           :  64 /  37 /  0.00
CEW  : CRESTVIEW ASOS           :  68 /  30 /  0.00
PNS  : PENSACOLA REGIONAL ASOS  :  69 /  43 /  0.01
MAI  : MARIANNA                 :  69 /  32 /  0.00
MOB  : MOBILE ASOS              :  72 /  43 /  0.00
DHN  : DOTHAN                   :  68 /  34 /  0.00
OZR  : OZARK - CAIRNS AIR FIELD :  68 /  34 /  0.00
LOR  : FT RUCKER HELIPORT       :  69 /  29 /  0.00

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
910 PM EST Fri Jan 13 2012

NEAR TERM (Tonight)...
The back edge of the CIRRUS was rapidly pushing eastward across our
western zones at 02z and will be a non-factor on our minimum TEMPS.
The surface HIGH centered along the western Gulf coast this evening
will move little overnight. Thus, despite a very dry airmass in
place along with clearing skies, ideal radiational cooling
conditions will not occur. However, we are still expecting
unseasonably cold temperatures with inland areas dropping into the
MID to upper 20s. The only question continues to be whether some
locations experience a hard FREEZE (25 degrees or less for 2 or more
hours). Temperatures at 00z were already a FEW degrees below MOS
guidance where we are forecasting lows in the 25-26 degree RANGE.
This would encompass a large portion of the eastern Big bend. Will
be updated GRIDS and zones shortly along with issuing a Hard Freeze
WARNING for Jefferson, Madison, Inland Taylor, Lafayette and Inland
Dixie counties from 08z until 14z Saturday.

&&
SHORT TERM (Saturday through Sunday NIGHT)...The MEAN eastern
trough will be maintained through Saturday night as a pair of weak
shortwaves move through the base. While neither of these
shortwaves will push colder air in the region, they will serve to
slow the moderation of the airmass currently in place. After a
cold start tomorrow morning, high temperatures are forecast to
REACH the upper 50s by mid-afternoon. Another freeze will be
possible Sunday night as the surface high remains in a favorable
position for radiational cooling. Forecast temps are 4 to 5
degrees warmer than tonight with lows from 30 to 35 away from the
coast.

Heights will begin to rise on Sunday as the upper trough lifts
northeast and an upper ridge begins to build in from the west.
This will allow temperatures to continue moderating with highs in
the lower to mid 60s. Low temperatures should remain above
freezing Sunday night.

.LONG TERM (Monday through next Friday)...The large scale
longwave pattern commences fairly amplified. This is highlighted
in the NRN stream by weak troughing across WRN states and extreme
Wrn Atlc and ridging in between. SRN stream with weak troughing
PAC Coast to TX and ridging EWD into extreme Wrn Atlc. At surface,
high along NC/VA coast with ridge axis SWWD into Apalachee Bay.
Low in Canada N of MN with cold front Swwd into Colorado. This
place local area in very dry pattern.

During the rest of the period, Wrn upper trough digs Ewd while Srn
stream upper ridge moves offshore with Srn flow becoming nearly
zonal and stays so before weak troughing approaches shifting flow to
SWLY on Fri. Second upper trough over Gulf digs rapidly ESE Tuesday
and Tuesday night. At surface, Above troughs push surface low moves
to Srn Great Lakes kicking high into Atlc. Assocd cold front with
limited INSTABILITY dragged rapidly SEWD with deep SLY flow setup
from Gulf. GFS and ECMWF similar in timing and intensity of
front pushed THRU CWA Tues night exiting Wed morn ERN most zones
bringing SCT shwrs and a few tstms Tues AFTN into early Wed. In its
wake, strong high builds SEWD from Srn Plains Ewd spreading a
reinforcing shot of cold and very dry air across local region Wed
into Fri. By end of period high pushed offshore with next low moving
NEWD into TN valley dragging trailing cold front to Wrn Gulf. In
response, onshore flow with increasing chances of RAIN commences
again across local area by end of Fri.

Forecast will show Sct POPS Tues aftn into Wed. Otherwise NIL pops
thru period. Ahead of the front MIN temps will be around 10 degrees
above CLIMO Mon and Tues nights dropping to at or below climo Wed
and Thurs nights and may reach freezing in coldest locales. MAX
temps commence at least 10 degrees above climo on Tues dropping to
at or below climo on Wed then inching up to a few degrees above
climo by Fri. Average inland min/max temps are 39/62.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
911 PM EST Thu Jan 12 2012

NEAR TERM (TONIGHT)...
Cold ADVECTION will drop TEMPS steadily through the NIGHT and the
freezing line should stretch from Ocilla GA southwest to TLH and
west to ECP by 12Z. Total FREEZE durations across our Southeast AL
zones MAX out at about 5 hours over Coffee County. Winds will also
stay up all night, although we will lose the gusts. Wind chill
readings will be down into the 20s northwest of a line from VLD to
TLH to PAM. Inland portions of the FL Panhandle, Southeast AL and
adjacent portions of Southwest GA will see minimum wind chill
readings in the lower 20s around SUNRISE, just shy of advisory
criteria.

&&

.MARINE (FRIDAY THROUGH NEXT THURSDAY)...
Small craft advisory conditions have returned to the marine area
this evening in the WAKE of a cold front. Elevated winds and SEAS
will persist into Friday morning before high pressure begins to move
back over the water resulting in diminishing winds and seas.
Generally light winds and low seas are expected throughout the
weekend AS high pressure hovers just northwest of the marine area.

&&

.AVIATION (THROUGH 00Z SATURDAY)...
Winds have shifted to the west and northwest at all TAF sites except
VLD where the front was just about to push through at 01z. Wind
speeds will continue to be in the 10 to 15 KT RANGE and gusty until
06z to 09z before diminishing to around or under 10kts for the
remainder of the forecast period. Aside from a SCATTERING of low
level clouds, expect only CIRRUS to stream over the region tonight
and Friday.

&&

.FIRE WEATHER...A very dry airmass will settle in across the region
through the weekend, with RH values dropping into the lower 20s
Friday and Saturday afternoons. Durations of critical RH will be
right around 3 to 4 hours across SE AL/SW GA for both days. Will
leave the Fire WX WATCH for Friday afternoon unchanged and add a
Watch for Saturday afternoon. Dispersions across Florida should
remain below 75, with no headlines needed.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
237 PM EST Wed Jan 11 2012

SYNOPSIS...18 UTC surface analysis shows a 998 MB occluded surface
LOW across Central Kentucky. The cold FRONT that moved through our
region today was moving across Southeastern Georgia and Northeastern
Florida. A somewhat drier and cooler airmass had moved in across the
region this afternoon, however, a much more substantive, albeit dry,
cold front is surging southeast across the Plains and will be moving
through the region tomorrow resulting in another shot of cold
temperatures for the weekend.

Vapor imagery and upper AIR data show the upper low across the
Southeastern U.S. starting to pivot northeastward into the Carolinas
AS a deeper TROF amplifies and surges southeastward across the HIGH
Plains. This is the next step in the overall evolution of the
pattern across the CONUS toward an amplifying TROUGH in the Eastern
CONUS and a building RIDGE across toward the Pacific Northwest.

&&

.NEAR TERM...(TONIGHT).
Post frontal cloudiness across the region will slowly thin and
dissipate overnight leaving a period of mostly clear skies overnight
with cool temperatures in the low to MID 40s. Some of the model
guidance indicates some patchy FOG potential, most LIKELY due to the
moist ground conditions and relatively light winds overnight. Even
with patchy fog possible, do not anticipate any significant issues,
especially when compared with the foggy conditions experienced
earlier this week.

&&

.SHORT TERM...(THURSDAY THROUGH SATURDAY).
The airmass behind this morning`s cold front does not have much in
the way of cool air behind it, but the cold front projected to pass
through late Thursday afternoon and evening will bring much colder
and drier air to our region for Friday and Saturday, with a light
FREEZE possible Friday and Saturday mornings. Although the deep
layer MOISTURE with this front does not look particularly
impressive, the NAM, NAM MOS, and CONVECTION allowing NWP guidance
forecast a solid (but thin) line of RAIN with the front. The GFS MOS
continues its trend of POP of 10 percent. As a compromise we are
forecasting a 30 percent CHANCE of light showers (QPF .05 inches or
less). Ahead of the cold front Thursday, highs will REACH" onClick="return popup(this, 'notes')">REACH the upper
60s north to mid 70s south. Highs will only be in the 50s Friday and
Saturday. Strong winds aloft will likely mix down to the surface as
strong WIND gusts (25-35 KT) Thursday.

.LONG TERM...(SUNDAY THROUGH WEDNESDAY).
This ridge is then expected to essentially camp out over the region
for the remainder of the weekend into the beginning of next week,
keeping TEMPS about 5-10 degrees below climatological values until
highs get back to NORMAL by Sunday and Monday. By Tuesday and
Wednesday (as this Ridge slides off to our northeast), it appears
that a rather diffuse low PRESSURE system will enter our region from
the west, bringing with it the next chance of rain along with above
normal temps. At this time, there appears very little in the way of
dynamical or thermodynamical support for this system, so any strong
to severe storms do not appear to be in the cards at this time.

&&

.AVIATION...Ceilings have lifted to VFR or SCATTERED out across the
region. Expect this to be the case through much of the overnight
hours. The potential exists for an MVFR VISIBILITY restriction at
VLD before SUNRISE. As the cold front approaches on Thursday,
SCT-BKN clouds are expected around 3500ft, though some guidance
indicates the potential for a brief MVFR CEILING before the frontal
passage. After the front moves through, BREEZY northwest winds up to
25 knots can be expected during the daytime hours.

&&

.MARINE...Winds will continue at ADVISORY levels into the early
evening hours before briefly diminishing. However, SEAS are expected
to remain near advisory levels into Thursday afternoon. Winds will
increase one again on Thursday afternoon and evening in the WAKE of
a strong dry cold front. High pressure will build back near the
marine area on Friday allowing for winds and seas to diminish into
the weekend.

&&

.FIRE WEATHER...The breezy conditions and good mixing Thursday and
Friday will lead to unusually high DISPERSION values each afternoon.
The combination of low relative HUMIDITY and high dispersions values
could pose a risk for Red Flag conditions Friday, and possibly
Saturday.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
830 PM EST Tue Jan 10 2012

...There is a slight Risk of Severe Storms Tonight THRU Wed morning
for SE Ala and for the FL Panhandle...

.SYNOPSIS...
Around 7-730 pm, some small MESO-scale feature moved thru southern
Georgia generating brief but strong WIND gusts with multiple trees
down across Decatur County.

AT UPPER LEVELS...
The large scale split FLOW pattern this Tues evening is highlighted
in NRN stream by troughing over WRN states and broad ridging EWD to
ERN seaboard. Conversely, SRN stream more amplified with ridging Wrn
and Ern states and deep TROUGH in between with 553DM closed LOW over
NE TX. Potent SHORTWAVE approaching LWR MS Valley.

Over the next 12-18 HRS, this low will progress EWD to MS/AL in
response to Nrn stream trough amplifying over Nrn Rockies/Plains.
Assocd speed MAX approaching 80KT and ahead of H5 low PROGGED to
eject NEWD across SRN AL/FL Panhandle and gradually weaken AS upper
low opens up. Shortwave moves from Lwr Ms Valley thru TN Valley and
strong cooling and HEIGHT falls over LA/MS this evening that will
push EWD into the Wrn CWA overnight.

AT LOWER LEVELS...
Analysis shows an occluding 1006 MB low centered over SE AR with a
QUASI-STATIONARY boundary located from this low ESE to across
S/CNTRL Al/SRN GA ewd to Atlc. The warm sector continues to be
marked by weak INSTABILITY (MU Capes 250-500 j/kg) but strong SHEAR
(06km 60-70kt). Another quasi-stationary coastal FRONT had SET up
about 50 NM or so south of the FL Panhandle/AL Coast. The result is
that the true surface-based instability continues to be well
offshore and will prove difficult to go NWD toward the Gulf Coast
rest of tonight. In fact,UPSTREAM radars earlier indicated that
thunderstorms struggled to develop in the warm sector of Ern LA/MS
due primarily to weak lapse rates, extensive CLOUD cover and limited
instability. In fact, this extensive cloud cover emanating from
ongoing upstream convective clusters kept local conditions mostly
CLOUDY and cooler on Tuesday.

&&

.REST OF TONIGHT INTO EARLY WEDNESDAY.
Elevated thunderstorms will be possible towards midnight over
interior sections with best forcing occurs as the upper low
approaches the area. The primary forecast question will be the
potential for severe weather but this looking less and less LIKELY.
With CURRENT OVERRUNNING over cold front producing extensive
cloudiness and warm MID layers, chances of generating enough
instability to produce WIDESPREAD surface based land thunderstorms
not HIGH. Regional meso-analysis seems to confirm that the area for
best surface-based instability will remain along the coast and
especially offshore and will likely only gradually pivot northward
toward the Gulf Coast States as the surface low continues to
occlude, deepen and lift northward into Nrn AL by 12Z Wed dragging
cold front to Lwr Ms Valley later tonight and across our CWA on Wed.

Still looks like a low CAPE/high shear generally linear event.
The kinematic fields and 500 mb height falls remain reasonably
impressive locally as the upper low drives ENE through SRN AL with
cooling aloft helping to raise DEW points to near 60F...before
lifting into N GA on Wednesday allowing for some destabilization.
However,lapse rates meager restricting MU Cape to below 500 j/kg and
this will focus along a very narrow axis directly ahead of the
cold front. However, somewhat veered but still strong LLJ near 50kts
crosses Ern Gulf states with strong warm sector moving progressively
NWD. Overall, all this kinematic and dynamical forcing will likely
be unable to overcome the prohibitive thermodynamic environment at
the surface for more than ISOLATED severe weather. Based on upstream
events, even the CHANCE of non-severe storms is diminishing with
time. If any strong and especially any severe weather occur, it
looks to be confined to coastal areas of the FL Panhandle/WRN Big
Bend and especially over the adjacent coastal waters where where
shear is greatest and where some storms may contain ROTATION
producing brief damaging winds. Cannot completely discount an
isolated TORNADO. Thunderstorms look to begin around 3AM EST Wrn
counties and ending around SUNRISE Ern most counties. SPC still has
area in a 15% chance of severe wind gusts and a 5% chance of
tornadoes.

One thing that is clear is that it will RAIN, so POPS remain at 100
percent across much of the area. Significant rains are not
anticipated, but it should be a good soaking rain with most areas
receiving between 0.75 and 1 inch by Wednesday, the bulk of which
should FALL prior to sunrise. Temperatures overnight will be quite
warm given the thick cloud cover. Increasing boundary layer winds
will keep FOG from becoming the problem experienced in recent
nights. The rain will end from west to east Wednesday morning,
followed by clearing skies and slightly drier AIR behind the cold
front. Temperatures will return to near average on Wednesday.

&&

.MARINE...Winds and SEAS will be on the increase rest of tonight
with a period of ADVISORY level conditions starting west to east.
These conditions should continue through Wednesday Afternoon before
diminishing.

&&

.AVIATION...
Cold front will approach and begin to cross the area through the
NIGHT. Large expanse of light to moderate rain has been impacting
KECP...KTLH...and KVLD the past FEW hours with generally periods of
MVFR cigs/VIS. Appears this main area of rain will be pushing east
by the early morning hours, however anticipate another round of
showers and a few thunderstorms to move through associated with the
actual cold front. Therefore rain will be in the forecast through
the majority of the night for all terminals. Expect a gradual
lowering of the cigs through the overnight with widespread MVFR and
tempo IFR conditions after midnight. Cold front will cross KDHN and
KECP during the late night hours, and the remaining eastern
terminals during the first few daylight hours of Wednesday.
Anticipate a few hours of MVFR cigs post-frontal, followed by
conditions improving to VFR for the afternoon hours.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
935 PM EST Mon Jan 9 2012


.UPDATE...
02Z Water vapor and H4 RUC analysis shows a complex upper level
pattern in place across the CONUS this evening. Main northern stream
FLOW arrives across the Pacific NW while ridging up into SC Canada.
This flow then dives back to the southeast forming longwave
troughing across the NE states and eastern Canadian Provinces. Other
feature of note, and most important to our forecast is a large
cut-off upper LOW spinning over TX. WV imagery shows abundant
MID/upper level MOISTURE streaming east/NE ahead of this feature
along the northern Gulf Coast. Synoptic support ahead of the low is
combining with deep WAA pattern to produce a large area of showers
and storms along and south of the LA coastline. This weather will
enter our forecast later Tuesday and Tuesday NIGHT, however for the
rest of the overnight, our weather will remain dry and QUIET,
outside of areas of FOG. 00Z KTLH SOUNDING shows a fairly dry
profile in the middle and lower levels this evening, however the
upper level moisture mentioned above can be seen overriding the
region above around 400mb. This moisture will be lowering with time
overnight resulting in a mostly CLOUDY forecast for your Tuesday.

Once again, fog will be the main forecast concern during the early
morning hours. HI-res guidance is generally hinting toward better
fog potential in the western zones associated with a developing weak
southerly flow. While some fog is certainly possible overnight, the
areal coverage and PERSISTENCE of the fog does not appear AS
impressive as previous nights. This is especially true noting the
amount of mid/HIGH level clouds overspreading the region which
should have some influence in slowing the radiative process. Still a
bit early in the evening to determine the degree to which this
higher level moisture will impact the fog forecast, so will not make
any significant changes with this update package.

Temperatures appear on TRACK with lows generally dropping into the
lower to middle 50s. Will expect a FEW mid/upper 40s over toward the
SE big bend and Suwannee River Valley in closer proximity to the
surface high.
...(TUESDAY THROUGH THURSDAY).
The 12 UTC model suite remains on track, bringing a strong cold
FRONT through our forecast area Wednesday morning. The NAM is still
a little slower than the global models, but the global models are a
bit slower than their previous runs so the timing differences are
smaller than 24 hours ago. With strong Q-G forcing and ample deep
layer moisture, there is almost no question as to whether or not it
will RAIN here, it`s just a matter of when. Our POP for Tuesday
night/Wednesday morning is about 80%, but this will probably come up
to near 100% in subsequent forecast packages once the timing becomes
more certain. Our STORM total QPF for this even is about an inch
areawide, but of course a few locations could get double or triple
this amount in the heavier storms. Temperatures behind this cold
front will not be very cold, and lows Thursday morning will return
to near average (lower to mid 40s) with mostly clear skies and a dry
airmass in place. A stronger (but dry) cold front will pass through
our forecast area Thursday afternoon and evening, but will not
arrive in time to prevent high temperatures from reaching the upper
60s to lower 70s.

Not much has changed with regard to the severe weather potential for
Tuesday night and Wednesday morning. All indications continue to
suggest another high-SHEAR/low CAPE environment for our region as
the SQUALL line moves through. The SPC subjective Convective
OUTLOOK the 09 UTC SREF, and our local objective severe weather
PROBABILITY forecasts show the chances for severe storms at about 5%
within 25 miles of a point. This looks reasonable based on our
experience with such cases. There may have been a subtle change in
the model forecast WIND profiles, which now suggest a less curved
HODOGRAPH (but still strong shear magnitudes). This would indicate
more of a threat for damaging wind gusts in LEWPs, and still
possibly a weak, short-lived TORNADO. This is more LIKELY where the
greatest SBCAPE coincided with the squall line, which right now
appears to be the FL Panhandle (west of the Apalachicola River). By
tomorrow the high-resolution NWP guidance will have the event within
its forecast time, and we will be able to examine UPDRAFT speeds and
HELICITY to confirm the overall severe weather threat.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
849 PM EST Thu Jan 5 2012

.UPDATE...
The main concern for the overnight period is the potential for
dense FOG. The AIR mass has modified quite a bit compared to 24
hours ago with a significant increase in boundary layer MOISTURE.
HIGH PRESSURE is forecast to be centered near the area with clear
skies and light winds. The condensational pressure deficits are
forecast to be quite LOW by our local HI-res ARW AS well as the
NAM and RUC, especially over the southern half of the forecast
area. Correspondingly, the guidance consensus shows the highest
dense fog probabilities over the Florida zones as well as extreme
southern Georgia and southeast Alabama. This area was already
forecast to have the greatest fog coverage late tonight by the
previous shift, and added some general dense wording with the
evening update. Confidence is not yet high enough to go with a
dense fog ADVISORY, but the NIGHT shift will monitor in case it
becomes necessary.