Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KRAH 150842 AFDRAH AREA FORECAST DISCUSSION National Weather Service Raleigh NC 341 AM EST Sun Dec 15 2019 .SYNOPSIS... Broad high pressure will extend across North Carolina today into Monday, with deepening low pressure expected to move north of the area on Tuesday and bring a cold front across the region. && .NEAR TERM /THROUGH TONIGHT/... As of 240 AM Sunday... Quiet weather is expected to finish the weekend and start the work week. Broad high pressure extends from Minnesota south into Missouri and southeast into Florida. The high will slide east today, but be somewhat eroded by developing low pressure across the Southern Plains. A warm front that will develop off the surface low will extend to the northeast, but stay north of North Carolina overnight. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... As of 240 AM Sunday... The low will take its time moving east, not making its way much farther east than Mississippi by Monday afternoon. Over the last several days, models have continued to show the warm front remaining north of North Carolina on Monday as well, except for a few GFS ensemble members showing rain falling just south of the Virginia- North Carolina border. Have bumped up cloud cover a bit across the region, but still think that this entire period will be dry. Brought highs on Monday down a degree or two considering the increased cloud cover, but with the area still in the warm sector, nearly all locations should rise into the 60s. Monday night will see high pressure retreat off the coast ahead of a developing mid tropospheric trough over the Ohio Valley. Increasing clouds and strong surface WAA will play havoc with temperatures and some spots could end up flirting with record warm min temperatures early Tuesday morning. Steady or slowly rising temperatures area- wide were already drawn into the digital forecast in this scenario and I see no reason to change that thinking. The main story with this approaching trough is precip chances, this time around p-type will not be an issue. Taking a look at this morning`s 00Z deterministic and probabilistic guidance, timing remains relatively on track showing precip moving into the Triad between 06Z-12Z Tuesday and into the Triangle closer to 12Z. PoPs were adjusted accordingly to match these timing trends. && .LONG TERM /TUESDAY THROUGH SATURDAY/... As of 341 AM Sunday... Precip should be ongoing at nearly all sites by Tuesday morning, rapidly ending from west to east around 00Z Tuesday. Not going to introduce thunder at this point but most models agree that there should be about 100-300 J/KG SBCAPE in the warm sector just prior to FROPA. This also lines up well with SPC general thunder mention for Day 3. More concerning is the nearly 40kts of 0-1km shear and 90kts of 0-6km shear, suggesting the potential for weakly rotating showers/storms. Most of the shear is fairly unidirectional in nature but certainly something worth monitoring as we get closer. Precip tapers off as mentioned Tuesday night into Wednesday, with surface high pressure/dry weather building in Wednesday through Friday. The forecast for next weekend remains uncertain as there have been inconsistencies from run to run of the ECMWF and GFS as well as their respective ensemble counterparts. GFS and GEFS solutions have been depicting a very deep upper trough and associated surface low moving through the Southeast. EC and ECENS have maintained a similar idea but much less intense. Today`s 00Z ECMWF is depicting and even weaker upper trough than before, but does continue the idea of weak coastal cyclogenesis off the South Carolina coast. This solution would bring some rain to the area Saturday and Sunday but nothing significant. NBM PoPs during this period are near climo and until a more clear consensus can be reached, sticking with its low impact forecast for next weekend with slight chances of rain and above freezing temperatures seems like the best approach. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... As of 1210 AM Sunday... 24 hour TAF period: Although some patchy high clouds are possible during the daytime hours, it should be a very quiet period with little cloud cover and light southwest winds. Looking ahead: Some MVFR cigs assoc with cloud may develop across the western Piedmont Monday morning. Flight conditions will then enter of period of reduction late Monday through Tuesday assoc with low clouds and rain chances with the next front. Look for improving flight conditions by Tuesday night in the wake of that front. -NP && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Green NEAR TERM...Green SHORT TERM...Green/Leins LONG TERM...Leins AVIATION...Green/np is the U.S. government's official web portal to all federal, state and local government web resources and services.