AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
326 PM EDT WED SEP 29 2010

.SHORT TERM...(THROUGH FRIDAY NIGHT)...
THE MODELS ARE IN GOOD AGREEMENT OVER THE NEXT COUPLE OF DAYS AND
INDICATE THE HIGHLY AMPLIFIED UPPER PATTERN REMAINING IN PLACE OVER
THE CONUS WITH A BROAD TROUGH OVER THE EASTERN STATES AND RIDGING
OUT WEST. PRIMARY UPPER FLOW WILL BECOME WEST AND NORTHWEST OVER
THE REGION AS THE MEAN UPPER TROUGH AXIS SHIFTS EAST. AT THE
SURFACE...TC NICOLE WILL QUICKLY LIFT NORTH OVER THE EASTERN HALF
OF THE FLORIDA PENINSULA TONIGHT...OUT ACROSS THE WESTERN ATLANTIC
WATERS...THEN BACK ASHORE OVER THE CAROLINAS TOMORROW. PLENTY OF
DEEP LAYER DRY AIR AND SUBSIDENCE OVER THE LOCAL AREA WILL KEEP THE
ENVIRONMENT SUPPRESSED THROUGH THIS PERIOD. THE ONLY MENTION OF
SHOWERS WILL BE THROUGH THE TONIGHT PERIOD AS WE REMAIN JUST ON
THE WESTERN FRINGE OF THE LARGE MOISTURE PLUME STREAMING NORTH
FROM TC NICOLE. A BLEND OF THE NUMERICAL GUIDANCE KEEPS ISOLATED
TO SCATTERED SHOWER PROBABILITIES THROUGH THIS FIRST PERIOD.
BEYOND THIS PERIOD...DEEP LAYER DRY AIR WILL ADVANCE FURTHER EAST
ACROSS THE CWA...WHICH WILL DECREASE THE MOISTURE AND RAINFALL
CHANCES INTO THE WEEKEND. A BLEND OF THE GUIDANCE OUTPUT HIGH
TEMPERATURES REACHING THE MID 80S WITH LOWS DIPPING INTO THE UPPER
50S TO MID 60S.

.LONG TERM (SATURDAY THROUGH NEXT WEDNESDAY)...
UPPER LEVEL PATTERN WILL REMAIN AMPLIFIED ACROSS THE EASTERN HALF OF
THE NATION. WHAT A DIFFERENCE A WEEK CAN MAKE IN TERMS OF
TEMPERATURE. IT WAS JUST A FEW DAYS AGO THAT WE CONTINUED TO SEE
WELL ABOVE AVERAGE SUMMER-LIKE HIGH TEMPS IN THE MIDDLE 90S. NOW THE
EXTENDED FORECAST IS FOR BELOW NORMAL TEMPS...AND AT TIMES WELL
BELOW NORMAL READINGS. GLOBAL MODELS IN AGREEMENT IN BRINGING
ANOTHER STRONG SHORTWAVE TROUGH SOUTHWARD FROM THE GREAT LAKES
DURING THE UPCOMING WEEKEND. THIS ENERGY WILL CLOSE OVER THE OHIO/TN
VALLEYS...AND THEN HOLD IN PLACE THROUGH THE EARLY PORTION OF NEXT
WEEK.

OVERALL...THE POSITION OF THIS TROUGH/CLOSED LOW WILL KEEP MOST OF
THE SIGNIFICANT WEATHER (IN TERMS OF RAINFALL POTENTIAL) TO OUR
NORTH AND EAST. HOWEVER...THE BIG IMPACT WILL BE THE INFLUENCE OF
THE ASSOCIATED COLD POOL ALOFT ON OUR TEMPERATURES. HIGH TEMPS ON
SATURDAY WILL BE NEAR NORMAL WITH THE SYSTEM STILL WELL TO OUR
NORTH...THEN BY SUNDAY AND MONDAY...WE DROP BELOW NORMAL. HIGH TEMPS
OVER OUR NORTHERN ZONES FROM DOTHAN TO ALBANY MAY STRUGGLE TO REACH" onClick="return popup(this, 'notes')">REACH
80 EARLY NEXT WEEK...DESPITE AMPLE SUNSHINE. OVERNIGHT LOWS WILL
ALSO TAKE A TUMBLE WITH WIDESPREAD 50S. IT IS CERTAINLY POSSIBLE
THAT BY SUNDAY AND MONDAY NIGHTS...A FEW NORMALLY COLDER SPOTS WILL
REACH THE UPPER 40S.

ANOTHER POTENTIAL IMPACT WILL BE MARINE WINDS/SEAS. THE NORTHERLY
FLOW OF COOLER AIR WILL BRING RATHER BREEZY CONDITIONS TO THE
NORTHEAST GULF OF MEXICO. GFS AND ECMWF DO NOT COMPLETELY AGREE ON
THE DETAIL OF THE SURFACE PATTERN...WITH THE GFS SHOWING A MUCH
TIGHTER GRADIENT...AND SOLID ADVISORY LEVEL CONDITIONS FOR EARLY
NEXT WEEK...AND THE ECMWF BEING LESS AGGRESSIVE. HAVE GONE WITH A
BLEND OF THESE TWO RELIABLE GUIDANCE SUITES UNTIL BETTER AGREEMENT
IS REACHED...HOWEVER EVEN THIS BLEND BRINGS NEAR ADVISORY LEVEL WIND
TO OUR WATERS FOR SUNDAY NIGHT THROUGH TUESDAY.

&&

MARINE...MODERATE NORTHERLY FLOW WILL PERSIST ACROSS THE
MARINE AREA THROUGH THE REMAINDER OF THE WEEK AS THE TROPICAL
STORM NICOLE...CURRENTLY SOUTH OF THE KEYS...TRACKS NORTHEAST
OVER THE SOUTHERN AND CENTRAL FLORIDA PENINSULA OVER THE NEXT
COUPLE OF DAYS. A FEW PERIODS MAY REACH CAUTIONARY LEVELS AS THIS
TROPICAL FEATURE PASSES THE MARINE AREA WELL TO THE EAST. WITH THE
OFFSHORE FLOW IN PLACE...EXPECT THE HIGHEST SEAS TO REMAIN FURTHER
OFFSHORE AND AWAY FROM THE IMMEDIATE COASTAL AREAS. WINDS AND SEAS
MAY BECOME CHOPPIER IN AND AROUND MODERATE SHOWERS AND STORMS OVER
THE NEXT COUPLE OF DAYS...MAINLY OVER THE BIG BEND WATERS.

&&

.AVIATION...
+SHRA/+RA AND A DENSE CLOUD SHIELD ARE CONTINUING TO IMPACT VLD AND
THE ERN PORTION OF THE REGION. CIGS AND VIS WILL REMAIN AT IFR OR
LIFR IN +RA. RADAR TRENDS INDICATE THAT THE +SHRA/+RA WILL PERSIST
FOR AT LEAST 2-3 MORE HRS. +RA HAS MANAGED TO STAY CONFINED TO THE
ERN PORTION OF THE REGION AND HAS NOT IMPACTED THE ABY OR TLH
TERMINALS THIS AFTERNOON...BUT MORE CLOUDS FROM THE SHIELD TO THE
EAST ARE BEGINNING TO IMPACT THOSE TWO TERMINALS. FOR NOW...THE WRN
TERMINALS OF DHN AND ECP STILL REMAIN CLOUD FREE WITH VFR
CONDITIONS. OVERNIGHT...EXPECT CIGS/VIS TO CONTINUE TO DETERIORATE
AT VLD...POSSIBLY BOTTOMING OUT TO AIRPORT MINIMUMS. BR WILL ALSO
DEVELOP AT ABY AND POSSIBLY TLH IN THE EARLY MORNING HOURS AS WELL.
VFR SKIES WILL EVENTUALLY PREVAIL MID MORNING FOR ALL TERMINALS.

&&

.FIRE WEATHER...
DRY CONDITIONS WILL PERSIST THROUGH EARLY NEXT WEEK FOR MUCH OF THE
REGION...PROMPTING A RED FLAG WARNING FOR THURSDAY AFTERNOON AND A
FIRE WX WATCH OF FRIDAY AFTERNOON FOR THE WESTERNMOST PORTION
OF THE FL PANHANDLE. CONDITIONS WILL BE DRY ACROSS SRN AL AND SRN GA
OVER THE NEXT FEW DAYS AS WELL...HOWEVER...RELATIVE HUMIDITY VALUES
WILL STAY SLIGHTLY ABOVE CRITICAL FIRE WX LEVELS. WARNINGS AND
WATCHES ARE POSSIBLE EVERY AFTERNOON THROUGH AT LEAST EARLY NEXT
WEEK FOR PORTIONS OF THE FL PANHANDLE.
About these ads