992 FXUS62 KRAH 071722 AFDRAH AREA FORECAST DISCUSSION National Weather Service Raleigh NC 1220 PM EST Tue Dec 7 2021 .SYNOPSIS... The cold front that moved across our area on Monday night will settle across coastal GA and SC through tonight. Cool high pressure will swing across the OH Valley today and move into the Northeast on Wednesday. Weak waves of low pressure will develop along the front tonight and move northeastward along and off the Carolina coast late tonight and Wednesday. High pressure will return Wednesday night through Thursday, before moving offshore on Friday. && .NEAR TERM /TODAY AND TONIGHT/... As of 1000 AM Tuesday... The latest surface analysis shows the cold front that moved across central NC overnight is now off the NC coast. Strong cold advection behind the front with gusty winds early this morning have begun to relax from west to east. In the wake of the front, multiple cloud layers are present and moving across the Carolinas, ranging from widespread cloudiness across the Coastal Plain and southern Piedmont and Sandhills to mostly clear skies across the Triad and far northern Piedmont. Dry weather is expected across central NC through sunset with chilly temperatures and variably cloudy and changing skies. A region of moisture at around 4kft will spread north across much of the area resulting in a good deal of stratocumulus clouds, already widespread in the south and east and spreading north late this morning and afternoon. Cold advection today and low level thickness values that dropped to 1306m at GSO with the morning RAOB will result in highs today that will be about 20 degrees cooler than yesterday and 5 degrees below average. Highs will range in the upper 40s across the Triad and VA border counties to around 50 in the Triangle and the lower 50s in Fayetteville. North winds at 10 to occasionally 15 mph with a few gusts up to 20 mph his early this morning will relax and become northeast at 5 to 10 mph this afternoon before veering to light east toward sunset. -Blaes Meanwhile, a mid/upper trough will dive SE from southern Canada into the Great Lakes region today and tonight, while a weak surface low develops along the front stalled to our south. As the 850 mb front lifts back north across our region, isentropic lift will result in light showers moving into southern and eastern zones as early as late this afternoon and this evening. Rain will become more widespread overnight as the surface low moves just off the SE NC coast and the mid/upper trough approaches from the west, with decent upper divergence and vorticity advection. The best moisture and lift will be across the south and east, so have likely POPs generally along and east of US-1, decreasing to low chance in the far NW. Overcast skies should help keep lows tonight slightly above normal, in the upper-30s to lower-40s. -Danco && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... As of 355 AM Tuesday... Rain will continue on Wednesday morning before quickly ending from west to east in the afternoon as the coastal low pulls away. Models continue to trend faster with the exit of precipitation so adjusted the forecast accordingly, and the region should be largely rain-free by late Wednesday afternoon. Unfortunately considering the drought, the overall trend in the models continues to be drier with this system, and storm total QPF amounts now only range from a quarter to half inch in the Coastal Plain and Sandhills to very little if anything in the far northern Piedmont. The faster exit of clouds and precipitation also caused me to bump up forecast highs a bit on Wednesday, ranging from lower-50s in the south and west to mid-40s in the far NE. As the center of a ~1025 mb high pressure system moves close to the region Wednesday night, clear skies and light winds will result in ideal radiational cooling conditions. Thus forecast lows range from the mid-20s in the coolest spots to lower- 30s in the SE. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 327 AM Tuesday... Weak surface ridging will build over the area on Thursday with cool easterly flow expected for much of the day. This will result in a continued period of below normal temperatures ranging from the upper 40s in the north to the low 50s in the south. Meanwhile, zonal flow aloft will gradually take on a more southwesterly component Thursday night into Friday morning, with several weak impulses forecast to move through the western Piedmont during the day on Friday. Antecedent dry conditions and BL dewpoints ranging from the 30s to the 40s will preclude noteworthy rainfall during this time period. Also worth noting: the strongest moisture transport and fgen forcing ahead of these waves remains west of the mountains. As such, PoPs will remain in the 15-20 percent range during the day Friday, trending toward a dry forecast Friday night. The forecast for Saturday through Monday remains a bit uncertain, as there are still conflicting signals regarding a trough and surface cold frontal passage at some point this weekend. GFS and its family of ensemble members have been consistent in their depiction of a fairly progressive trough moving through NC late Saturday into Sunday. The EC/Canadian and their respective ensemble solutions agreed on a longwave trough west of the mountains, but depicted a closed low developing at the base of the trough with a much slower introduction of precip into the area. The aforementioned EC/Canadian solutions were present in the 06.12Z runs but have since reverted back to the GFS/GEFS solution with this morning's 07.00Z runs. I'm going to hang onto the highest precip chances late Saturday into Sunday per the GFS/GEFS, but also allow them to linger into part of Sunday in the event a perturbation develops at the base of the trough along the lines of the EC/Canadian solutions. As for temperatures, a gradual warming trend can be expected Friday through Sunday ahead of the approaching cold front, with a drop back closer to normal post FROPA early next week. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... As of 1220 PM Tuesday... TAF period: VFR conditions will continue through the afternoon and evening hours, although low VFR ceilings will be present at many sites. Low pressure will develop along the North Carolina coast tonight, and as that occurs, MVFR ceilings and rain will expand from south to north. The edge of precipitation should be very close to the Triad, and have added VCSH at GSO but not at INT. Other sites should have steady rain develop late tonight into Wednesday morning. There is high confidence that IFR cigs will occur at FAY/RWI/RDU through the morning. Rain should diminish at RDU later in the morning, but will continue into the afternoon at RWI/FAY. Outlook: Rain and restrictions will come to an end Wednesday afternoon, with VFR conditions expected Wednesday night, Thursday, and Thursday night. A chance of rain will return to the forecast Friday and remain through Sunday, with the most likely chance for rain coming Saturday night. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Blaes NEAR TERM...Blaes/Danco SHORT TERM...Danco LONG TERM...Leins AVIATION...Green