AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 905 PM EST Sun Feb 12 2012 DISCUSSION...00 UTC surface analysis shows a 1031 MB HIGH centered across Northwestern Alabama. The PRESSURE GRADIENT across the South was continuing to relax AS this high pressure area spreads eastward with winds becoming near CALM across much of the region. With these lighter winds tonight and clear skies temperatures have plummeted into the MID and upper 30s across much of the region with a FEW locations already at the freezing mark by 01z. Vapor imagery and 500 mb analysis shows the large cold TROUGH that was in place across the Eastern CONUS now shifting to a position more across the Canadian Maritimes. SHORTWAVE ridging was spreading eastward across the Central CONUS and into the Southeast. Some Pacific MOISTURE was streaming across the Gulf of Mexico and this has led to the development of an area of CLOUD cover across the Central Gulf Coast States. The primary forecast concern tonight again is with the temperatures. The forecast is complicated by the arrival of some cloud cover from the west. Model data shows a gradual and slow moistening of the 500-300 mb layer across the southern half of the region by morning and this would LIKELY serve to limit how far temperatures would drop overnight. Feel very confident about winds being essentially calm overnight, so with the very dry and cold airmass that is in place, temperatures away from the cloud cover should easily be in the lower 20s by morning based on the latest observations and model data. After watching TEMPERATURE trends over the last couple of hours, have decided to adjust temperatures up slightly in the Florida Big Bend, but still keep minimum values in the lower 20s as it is expected the cloud cover will have some but not much of an effect on temperatures before SUNRISE. Aside from that adjustment, not additional changes are planned with the forecast this evening. Have a great NIGHT! && .AVIATION...VFR conditions will are expected to prevail through the TAF period with mainly light winds. However, mid and upper level cloudiness appear to be increasing from the southwest well ahead of the model guidance, but this will be more of a concern to overnight LOW temperatures than to Aviation concerns. && .MARINE...Winds and SEAS will continue to diminish this evening and into the overnight hours as high pressure moves nearer to the marine area. Expect low winds and seas to persist into Monday before increasing again on Tuesday.