AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TALLAHASSEE FL 400 PM EST Fri Feb 10 2012 ...Much colder weather arriving this weekend... SHORT TERM (Tonight through Sunday NIGHT)... A MID/upper level shortwave trough will pivot rapidly eastward along the northern Gulf coast. Decent swath of synoptic support/QG forcing ahead of this energy will overspread the area this evening. This area of forcing is already supporting a large area of showers across southern LA/MS. Global and HI-res model consensus agrees that this area of showers will expand rapidly into our region this evening. The QG forcing will align with upper level JET energy to support the highest SHOWER concentration over the southern half of the area...and especially coastal areas eastward through the SE Big Bend. These areas are highlighted with high end 70% POPS, and an argument could easily be made for higher CATEGORICAL PoPs. POP GRADIENT will decrease to the north down to 40-50% up toward KDHN and KABY. Still do expect some of the showers to reach this far north, however some guidance members insist that the main area of showers will be more broken in nature north of the FL border. Even across the far south...this will be a high PoP...low QPF event, with highest RAINFALL amounts LIKELY remaining under 1/4 inch. This will be a quick hitting event AS the last of the organized showers are expected to be exiting the Suwannee River Valley/I-75 corridor by around 09Z. Surface based CAPE is essential NIL, and even elevated INSTABILITY is lacking. Showalter indices are all positive and will not include THUNDER mention. Low temperatures in the 40s. Saturday: Cold front will quickly pass east of the forecast area Saturday morning with a much cooler and drier airmass arriving on BREEZY NW winds. 850mb TEMPS will FALL below 0C over most areas by the end of the day. Despite the strength of the cold AIR...excellent DIURNAL mixing in the post-frontal environment will keep things seasonable for afternoon highs. Looking for highs to RANGE from the lower 50s north and west of a Dothan to Albany line, and range upward to the lower 60s over the SE Big Bend zones. As mentioned above it will be quite breezy for those with outdoor plans. NW winds sustained between 15 to 20 mph with gusts near 25 mph common. Saturday Night: The cold air will arrive quickly with the setting of the sun. At this time expecting temperatures by SUNRISE on Sunday to be generally in the upper 20s...with middle 20s possible across the far north. CURRENT statistical guidance shows lower/middle 20s for many locations, however, MOS guidance almost always is too low in these events with respect to the initial ADVECTION FREEZE...and have taken this BIAS into account. This will only prevent a hard freeze. Still anticipate a WIDESPREAD freeze even right down to the coast. Combine these temps with a steady northerly breeze and WIND chill reading will reach the upper teens to lower 20s. Will continue to monitor the situation in case a wind chill ADVISORY becomes necessary for early Sunday morning. Sunday/Sunday night: High pressure will settle southeast from the TN valley toward the forecast area. The airmass in place and less efficient mixing will result in a cool day. High temps will struggle into the lower 50s by the late afternoon. The close proximity of the high CENTER will cause any light afternoon winds will go nearly CALM quickly during the evening. These calm conditions combined with very dry low levels suggest temps will fall quickly after SUNSET. Expect to see normally colder areas fall below freezing potentially by late evening, and SET up a long duration freeze. This appears to be the night in which hard freeze conditions will be more likely. Low temps for normally colder areas may drop into the lower 20s...with most locations away from the immediate coast falling into the middle 20s. As is usual with radiational cooling...the immediate coast and more urbanized inland centers (such as downtown Tallahassee) should end up a FEW degrees warmer, but still below freezing. && .LONG TERM (Monday through next Friday)... We`ll see another cold day to start the extended period with possibly another widespread hard freeze Monday morning mainly east of the Apalachicola/Chattahoochee Rivers. Surface high pressure will be centered over the southeast CONUS with nearly zonal FLOW aloft on Monday. The high will rapidly move east making way for the next low pressure system that will bring a weak cold front with RAIN chances to the region on Tuesday. This front will stall over or just south of our FA late Tuesday/early Wednesday and then lift north as a warm front Wednesday/Wednesday night as a stronger low pressure system begins to develop over the southern plains. Showers/thunderstorms will begin to overspread the region during the Thursday/Thursday night time frame with the front forecast to push into the CWA on Friday. After below NORMAL temps for Monday, the rest of the extended period will have above seasonal temps. && .MARINE A weak area of low pressure will pass south of the forecast waters this evening. In the WAKE of this low, winds will increase from the Northwest later tonight and are forecast to reach advisory levels Saturday morning. These advisory level conditions will continue through Sunday morning. A period of GALE force gusts is possible Saturday night and this potential will need to be monitored closely. Winds and SEAS will decrease below headline criteria later Sunday into the early portion of next week. && .Aviation (through 18Z SAT)...Although VFR conditions should prevail through the bulk of this TAF period, gradually lowering Vfr level cigs will predominate the FCST for the remainder of this afternoon and throughout much of the evening hours. Widespread light rain is also expected to develop from SW to NE across the terminals, with possible periods of moderate rain and MVFR level VIS this evening at TLH, ECP, and VLD. Although some VFR level clouds could linger behind the cold front for a while, Saturday should be dominated by clearing skies, much cooler temps, and very gusty NW winds. && .FIRE WEATHER... Much cooler and drier air will be building in from the northwest on Saturday on gusty Northwest winds. This very dry air combined with sustained 15 mph or greater winds and Dispersions greater than 75 will result in a Red Flag WARNING for all of the Florida Big Bend and Panhandle on Saturday. However, even though relative HUMIDITY values will be extremely low over the SAME area on Sunday, will hold off on a Fire Weather WATCH until future ERC values can be determined. Over Southeast Alabama and Southwest and South Central Georgia, will issue a Fire Weather Watch for Sunday for expected long durations of relative humidity below 25 percent.