Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 031740 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 1240 PM EST Sat Dec 3 2016 .SYNOPSIS... High pressure will continue to build SE into the region this afternoon and tonight. The high pressure will extend from NY state south through the Carolinas Sunday as a coastal front develops. A storm system will move from the Gulf Coast states into the Southeast states early in the week increasing the chance of rain. && .NEAR TERM /THROUGH TONIGHT/... As of 1110 AM Saturday... Mostly sunny skies in the east and partly sunny skies in the west will be dominate into the afternoon. The cirrus/cirrostratus may occasionally thicken up in the western areas to produce mostly cloudy to cloudy skies by mid to late afternoon. CAA continues as the 1030mb surface high centered over the Midwest to the Ohio Valley builds toward NC. This high will slide slowly east and will eventually extend down the eastern seaboard Sunday delivering chilly air into the region from the north. Highs this afternoon are forecast to top out between 50 and 55 N to S with the north breeze around 10 mph adding a briskness to the air. Readings in the upper 40s may hold on across the far northern Piedmont if the high clouds thicken. Tonight... high cloudiness will overspread the region as the system developing over northern Mexico and Texas spreads deep mid/upper moisture NE. Lows should hold in the 35-42 range due to the thickening cloudiness. There is a low chance of measurable (0.01) light rain very late tonight over the western Piedmont. Temperatures will be well above 32; therefore, high confidence of liquid if anything falls. && .SHORT TERM /SUNDAY THROUGH MONDAY/... As of 405 AM Saturday... Low chance pops move into Central NC Sunday, ~30% chance west ranging to slight or no pops in the east where the relatively dry subcloud layer will be deeper. Thick clouds will further hold temps down, and expect highs from the mid 40s NW (beneath the most pronounced combination of thick clouds and cool/stable low levels) to the lower 50s SE. The arrival of a 40+ kt low level jetlet across GA/SC/NC Sun evening along with strengthening IVT will result in a ramping up of moist upglide and overall forcing for ascent, in tandem with the departure of the surface ridge, making the low levels vulnerable to saturation. Expect rain coverage to increase to likely in the NW CWA and categorical south/southeast Sun evening, followed by a slow exit later Sun night as the low level jetlet shifts to our east and deep moist upglide shuts down. Rainfall from late Sun through Sun night could approach 0.25-0.50", higher in the south. Expect lows from around 40 NW to mid 40s SE. Monday will be a transitional day with high pressure moving off the coast, a weak wave along the coast and new high pressure moving into the mid-Atlantic region from the Ohio Valley. The upshot of this is that we will move from more of an in-situ damming situation to more of a hybrid scenario but northeasterly winds across the area and chances for precipitation early in the day with a lull later on. The cold air damming should keep temperatures down around 50 degrees in the Triad with middle 50s across the southeast. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 325 AM Saturday... Tuesday the Miller B scenario takes full effect a pair of lows on either side of the wedge parked over the Piedmont. Precipitation should begin early Tuesday morning and continue all the way through Tuesday night before the system starts to move off to the northeast. Accumulations for this event should be over an inch and possibly up to two inches. Temperatures will be tricky and dependent highly upon the track of the coastal low. With fairly high confidence, the Triad should stay cold throughout the day under the wedge with highs possibly only in the upper 40s. The bigger uncertainties in the temperature forecast lay in the south and east where highs could be as much as 60 degrees. Wednesday and Thursday will be dry and a little warmer on the front side of a longwave trough bisecting the continent. Highs in the 60s. By Thursday night, models begin to diverge on timing and available moisture leading to two very different possible scenarios for Thursday night into Friday. The GFS solution has a very progressive trough and a drier solution which brings very cold temperatures into the area on Thursday night. The ECMWF solution is slower and wetter which means warmer temperatures hanging around longer Thursday night. For now we are taking the dry, colder forecast so expect temperatures below freezing both Thursday and Friday nights with Friday being the coldest as very anomalous thickness values move into the area and bring low temperatures down into the 20-25 degree range. && .AVIATION /18Z SATURDAY THROUGH WEDNESDAY/... As of 1240 PM Saturday... High confidence in VFR conditions through around 09Z/Sunday, then CIGS will lower between 09Z-18Z Sunday into the MVFR range west. VSBYS remain VFR with a chance of light rain arriving around 12z in the west, then most likely after 18z/sunday in the east. OUTLOOK FOR LATE SUNDAY THROUGH WEDNESDAY. Confidence is high that conditions will become IFR to LIFR Sunday evening/night and remain into Monday with periods of rain and drizzle. LIFR TO IFR conditions are expected Monday night and Tuesday with the storm system arriving from the SW and the cold air damming over the region. Rain should taper off Tuesday night but IFR/LIFR conditions may hold through daybreak Wednesday, followed by improvement to VFR by midday Wednesday. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...Badgett SHORT TERM...Hartfield LONG TERM...Ellis AVIATION...Badgett is the U.S. government's official web portal to all federal, state and local government web resources and services.