


Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC
Issued by NWS Raleigh/Durham, NC
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944 FXUS62 KRAH 270420 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 1220 AM EDT Thu Mar 27 2025 .SYNOPSIS... Canadian high pressure will build across the Carolinas through tonight, then offshore on Thursday. A warm front will lift northeast across the Carolinas and Middle Atlantic on Friday, with following Bermuda high pressure that will extend across the South Atlantic states through the weekend. && .NEAR TERM /THROUGH TONIGHT/... As of 1045 PM Wednesday... Surface observations show a majority of locations light and variable to mostly calm winds. With the combination of mostly clear skies, good radiational cooling will continue into Thursday morning. Latest statistical guidance largely agrees with the afternoon forecast, with temperatures dropping into the lower to mid 30s across of much of central North Carolina. A Frost Advisory remains in effect for the Piedmont, western Sandhills, and northern and central Coastal Plain. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... As of 310 PM Wednesday... Following the shortwave trough that will move across and offshore the nrn Middle Atlantic and Northeast by the start of the period, a nwly polar jet now directed into NC will retreat newd and across the lwr Great Lakes and nrn Middle Atlantic, within a regime of rising heights that will maximize there through early Fri. At the surface, ~1027 mb Canadian high pressure now centered over the mid MS Valley will crest over the Carolinas early Thu, then move offshore by afternoon-evening. Within the return flow regime to its west, a sharp frontal zone will retreat from the TN to OH Valleys. The aforementioned rising heights and developing, return sly/sswly surface flow will yield warming over cntl NC, with high temperatures mostly in the mid-upr 60s. While a band of mostly frontogenetically- forced stratiform rain will lift across the TN Valley and srn Appalachians, only virga is expected by the time it reaches the nw NC Piedmont Thu night, where it will be falling from ~7-8 thousand ft ceilings atop a deeply dry sub-cloud layer. Light swly stirring and variably cloudy skies Thu night should keep low temperatures in the 40s. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... As of 200 PM Wednesday... Friday and Saturday: Aloft, the sub-tropical ridge will progress ewd across the region Fri/Fri night, as a potent srn stream s/w tracks ewd across the srn Plains/lwr MS Valley. The s/w will then continue enewd across the Deep South/TN Valley on Sat. At the surface, high pressure off the Carolina coast will slowly migrate ewd toward Bermuda Fri-Sat, with increasing sly return flow advecting warm, moist air into the area. Expect generally dry weather to prevail, although a disturbance aloft could result in some rain along the VA border on Fri, with moderating temperatures and increasing low-level moisture. Saturday night through Wednesday: Aloft, the aforementioned srn stream s/w will continue lifting enewd across the region Sat night- Sun night, while a pair of trailing nrn stream shortwaves move ewd from the Intermountain West to the Great Lakes. The srn stream s/w will move off the Southeast US coast on Mon, while one of the nrn stream shortwaves continues ewd across the Great Lakes and Northeast US. There are still some difference in the medium-range guidance wrt the evolution of the two shortwaves Mon/Tue and the overall upper level pattern thereafter, with the EC and GFS completely out of phase with one another by Wed/Wed night. At the surface, a low pressure system will develop over the cntl Plains Sat/Sat night, with some model differences already showing up (whether there will be one low (GFS) or two (EC)) and impacting the track of the system as it moves across the cntl and ern CONUS through Mon night/Tue. Despite these differences, there is fairly good agreement over central NC, with a warm front lifting nwd across the area Sat night/Sun morn and the cold front moving in from the west Mon eve/night and settling south of the area by Tue morning. Arctic high pressure will ridge swd into the area in the Wake of the front for Tue/Tue night, but how long it sticks around remains uncertain at this time. Convection: Chances for showers/storms will increase Sat night and persist through Sun and possibly into early Sun night, associated with the srn stream s/w aloft. A brief lull in convective activity is expected mid/late Sun night as the s/w exits the area, with another round of showers and better chance for storms moving across the area along/ahead of the front Mon/Mon night. All of central NC is currently in a Day 6 15% area from the SPC for Mon/Mon night, so will be keeping a close eye on how the forecast evolves and the potential for some strong to severe storms across the area. Tue should be largely dry and the weather for Wed remains uncertain at this time. Temperatures: Above to well above normal temperatures are expected through Mon night, warmest Sun night (lows upper 50s to mid 60s) and Mon (highs mid 70s to low 80s). && .AVIATION /06Z THURSDAY THROUGH MONDAY/... As of 1220 AM Thursday... There is high confidence in VFR conditions through the 24-hour TAF period. Winds be rather light to start the period, then slowly veer to be out of the west and southwest Thu afternoon between 5 and 8 kt. Winds will be south to southwest Thu night around 5 kt. Outlook: A period of LLWS may be possible Fri and Sat morning, however, it appears marginal at this point. VFR should largely prevail through Sat. Showers and storms will be possible Sun and Mon with our next frontal system. It may also be quite breezy on Mon. && .FIRE WEATHER... As of 1045 PM Wednesday... ...INCREASED FIRE DANGER HAS BEEN ISSUED FOR THURSDAY AFTERNOON AND EVENING... The combination of low relative humidity of 20 to 30 percent and dry fuels will continue a risk of adverse fire behavior over central North Carolina. While winds are not expected to be strong, gusts around 15 mph are expected during the afternoon, continuing the enhanced fire danger conditions. Gradually recovering RHs through the weekend will mitigate the relative higher threat of increased fire danger through Thu. && .RAH WATCHES/WARNINGS/ADVISORIES... Frost Advisory from 4 AM to 9 AM EDT Thursday for NCZ007>011- 021>028-038>043-073>078-083. && $$ SYNOPSIS...MWS NEAR TERM...Helock/Swiggett SHORT TERM...MWS LONG TERM...KC AVIATION...Kren FIRE WEATHER...Helock/Swiggett/MWS