


Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC
Issued by NWS Raleigh/Durham, NC
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465 FXUS62 KRAH 030826 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 426 AM EDT Thu Apr 3 2025 .SYNOPSIS... A front will remain quasi-stationary over the western Carolinas tonight, then dissipate on Thursday. Unseasonably strong and warm, sub-tropical high pressure will otherwise extend westward across the South Atlantic states through Sunday. && .NEAR TERM /THROUGH TONIGHT/... As of 836 PM Wednesday... Overview: Early evening radar and satellite imagery reveals abundant cloud cover across much of NC, with a few showers and isolated non- severe storms moving through the western Piedmont. The showers developed following the passage of a warm front that has mostly made it through the forecast area as of 00Z...with the only site remaining on the cool/stable side of the front being INT with a dewpoint of 51 whereas all other sites have dewpoints in the upper 50s to mid 60s. This is all setting the stage for a cloudy/mild night tonight. Precip chances: PoPs will be maintained across the western Piedmont through the remainder of the evening hours with a mention of showers and thunderstorms mainly from the Triad south to the SC state line. Several consecutive runs of the HRRR and other hi-res models insist that these showers will maintain themselves as they move northward. Instability is forecast to increase a bit through midnight per SPC mesoanalysis page, but a lack of strong forcing should keep them below severe thresholds. Eventually after midnight the BL should stabilize and these showers should dissipate, but quickly be replaced by areas of drizzle as strengthening isentropic ascent overspreads much of NC tonight. Drizzle may be seen as far east as the Triangle before daybreak, and a 15-20 percent mention of precip will be maintained in these areas as well. Temperatures: Expect lows to range from the low/mid 60s in the north, to the upper 60s in the south. It`s entirely conceivable that a few spots in the southern Coastal Plain may stay above 70 tonight. See climate records section below, including record warm minimum temperatures which could be jeopardized tomorrow morning. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... As of 205 PM Wednesday... * Thursday will begin a stretch of anomalously warm conditions with little overnight relief. Widespread low overcast, and perhaps some light drizzle, Thur morning will gradually lift/scatter from southeast to northwest through the morning into the early afternoon. Continued strengthening/expanding of the anomalous sub-tropical ridge over the southwest N. Atlantic, scattering cloud cover, and 12z low-level thicknesses 40m above normal for early April, will result in the first of several days of abnormal heat for central NC as temperatures rise into the upper 70s to mid/upper 80s. Warmest temps will likely be across the Sandhills into the eastern Piedmont and Coastal Plain where erosion low overcast occurs first. In the wake of the low overcast, diurnal heating of the already warm/moist airmass in place will result in moderate instability (1000-2000 J/kg of MLCAPE) mainly over the Piedmont. Proximity to the strong sub-tropical ridge may prevent much or even any deep convection, but isolated showers will be possible during the afternoon into the early evening hours. Among the latest 12z Hi-Res guidance, only the HRRR develops any deeper convection, likely since it has surface dew points closer to 70 degrees while mean 12z HREF dew points are closer to mid 60s during the afternoon. Light stirring southwesterly flow and potential redevelopment of some low overcast will result in another unseasonably warm night as temperatures only dip into the mid 60s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 420 AM Thursday... The weather pattern across central NC on Saturday will continue to be controlled by a subtropical high aloft that remains anchored east of FL and ridges up the Eastern Seaboard for one more day. Meanwhile a 1025-1030 mb surface high centered east of GA/SC and SW of Bermuda will slowly drift east. A cold front initially extended from eastern TX to the mid-MS Valley and Lower Great Lakes early Saturday will reach the TN Valley and northern Mid-Atlantic by early Sunday, as a wave of low pressure associated with a mid-level shortwave over the Southern Plains rides along the front. This will help to push Friday evening`s backdoor front well to our north, and with high pressure to our SE resulting in capping/subsidence aloft, Saturday looks dry and partly to mostly sunny. High temperatures will again be quite warm, mainly in the upper-80s to lower-90s, which is 15-20 degrees above normal and near the daily record highs for April 5 at GSO, RDU and FAY. Skies will turn mostly cloudy on Saturday night, and with southerly flow ahead of the approaching cold front, lows will be very warm and near record high minimums, only dropping to the mid-to- upper-60s. The Bermuda high will finally begin to break down and shift away from us on Sunday, in response to the mid-level southern stream wave pushing east and a broad northern stream trough digging into the Great Lakes. This will help push the cold front east through our region, as a wave of low pressure tracks along it. The frontal passage looks slow due to the SW flow aloft, and while the GFS is a bit faster than the ECMWF, both models are in pretty good agreement that it will gradually move east across central NC Sunday night into Monday, maybe even stalling out for a time. So continue likely to categorical POPs from Sunday afternoon into Monday. Precipitation may not completely clear our far SE until late Monday night if the ECMWF and many of its ensembles are correct. Some storms can`t be ruled out on Sunday and Monday, but at this time instability looks marginal, with CAPE on the ECMWF and GFS generally less than 500 J/kg, and their ensembles depicting very low probabilities of exceeding that. So despite strong winds aloft, the severe threat looks fairly limited at this time. Even outside of convection, GFS point soundings on BUFKIT indicate gusts of 25-35 mph will be possible during the day on Sunday. The bigger threat at this time looks to be heavy rain, and WPC has our region in a marginal (level 1 of 4) risk of excessive rainfall on Sunday/Sunday night, which lingers in our far SE on Monday. WPC total QPF for the event is in the 1-2 inch range, but the deterministic ECMWF and GFS both have stripes of 2-3 inches across a portion of central NC, and the 90th percentile QPF of their ensembles is in a similar range, indicating potential for isolated totals that high especially where any storms train. At the same time, this would provide some welcome drought relief as much of central NC is currently in D0 or D1 conditions. Sunday looks a bit cooler from cloud cover and precipitation chances, but still very warm with highs in the mid-80s to 90, which could still approach some records. Sunday night`s lows will again be quite mild (upper-50s to mid-60s) before we turn much cooler and close to normal on Monday (highs mid-60s to lower-70s, lows in the 40s). We finally dry out on Tuesday and skies turn sunny, as Canadian high pressure builds in from the NW and westerly flow aloft around the mid/upper low over the Great Lakes and New England pushes the cold front well to our east. A reinforcing cold front on Tuesday will bring a shot of even cooler, drier air with highs both Tuesday and Wednesday only in the upper-50s to mid-60s and dew points in the teens and 20s. As the surface high settles near the Appalachians on Tuesday night, went on the cooler side of guidance for temperatures as decent radiational cooling conditions and 1000-850 mb thicknesses only in the 1280-1295 m range will support widespread lows in the lower-to-mid-30s. Upper-20s will even be possible in outlying areas. This will result in some frost and freeze concerns. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... As of 205 AM Thursday... Widespread MVFR ceilings throughout cntl NC at 06Z may lower to IFR for a short time later this morning and be accompanied by periods of light rain and drizzle especially over the Piedmont in the few hours centered around 12Z. Ceilings should then gradually lift and/or scatter to VFR at FAY, RWI, RDU by early this afternoon, while IFR- MVFR ceilings will be slower to lift and disperse, likely not until mid to late afternoon, at GSO/INT. Sswly surface winds will strengthen and become frequently gusty to 20-25 kts by ~12-13, then remain so until diminishing around sunset. The exception may be at FAY, where an inland-moving sea breeze may maintain a little sly to ssely gustiness there until ~02-03Z this evening. Outlook: IFR-MVFR ceilings will likely redevelop Fri morning and again Sat morning, amid continued unseasonably moist/humid low-level flow. A strong cold front will be accompanied by a band of convection and flight restrictions, as it moves slowly east across cntl NC Sun night and Mon, possibly as early as late Sun afternoon at INT/GSO. && .CLIMATE... Record High Temperatures: April 3: KRDU: 91/1967 KFAY: 90/1934 April 4: KGSO: 86/1934 KRDU: 88/1934 KFAY: 93/1910 April 5: KGSO: 87/1942 KRDU: 90/1942 KFAY: 91/1942 April 6: KGSO: 89/2010 KRDU: 93/1967 KFAY: 91/2010 Record High Minimum Temperatures: April 3: KGSO: 64/1946 KRDU: 62/2000 KFAY: 65/1977 April 4: KGSO: 62/1999 KRDU: 63/2017 KFAY: 63/2017 April 5: KGSO: 60/2023 KRDU: 64/1910 KFAY: 64/2008 April 6: KGSO: 65/2023 KRDU: 69/2023 KFAY: 69/2023 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...MWS NEAR TERM...Leins SHORT TERM...Swiggett LONG TERM...Danco AVIATION...MWS CLIMATE...NWS