Area Forecast Discussion
Issued by NWS Wakefield, VA
Issued by NWS Wakefield, VA
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679 FXUS61 KAKQ 261854 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 254 PM EDT Wed Jun 26 2024 .SYNOPSIS... A cold front approaches the area this evening and crosses the region tonight into Thursday, bringing the a chance for showers and thunderstorms. High pressure builds north of the region late Thursday through the end of the week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 130 PM EDT Wednesday... Key Messages: - Scattered showers and thunderstorms develop late this afternoon into tonight, with a few storms potentially being strong or severe with damaging wind gusts to primary threat. - Some beneficial rain is likely across northern portions of the area, although it will be hit and miss due to the nature of the storms. Early afternoon wx analysis shows quasi-zonal flow over the Mid- Atlantic with an upper trough over the Great Lakes (extending south into the mid-MS River Valley). At the surface, high pressure is centered off the Carolina coast with a lee trough across VA. There is a cold front which is still well to our NW. Temperatures have risen into the 90s area-wide, with dew pts in the mid-upper 60s inland/lower-mid 70s near the coast. Heat indices are generally 100-104F, but have seen a couple of spots near the SE VA coast touch 105F. Skies are partly to mostly sunny with a 10-15 mph SW wind. Forecast soundings show that the boundary layer remains capped prior to some height falls arriving this evening and especially tonight. Still think that a few tstms will develop in the higher elevations of W/NW VA near that lee trough by 3-5 PM and push into NW portions of the area by early evening. Expect tstms to actually become more widespread after 7-8 PM as the better height falls arrive. Any storm will be capable of producing damaging wind gusts given very strong sfc heating, a deep well mixed boundary layer, and some mid-level drying. In fact, forecast soundings from most models continue to show DCAPE values of 1200-1500 J/kg through this evening. Storms will likely be ongoing (mainly along/N of I-64) through ~3 AM (though the severe threat diminishes after 12-1 AM) as a 30-40 kt southwesterly LLJ may help the convection hold on a bit longer than we normally see. There are hints that the convection may get a bit farther south than previously expected. Still, locations south of a Farmville-Petersburg- Norfolk line will likely see little to no rain through Thursday morning, with localized rain totals in excess of 1" likely north of I-64. Could definitely see a few totals of 2" across northern portions of the FA. Convection gradually diminishes in coverage early Thu AM. Lows tonight will mainly be in the upper 60s to mid 70s. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 255 PM EDT Wednesday... Key Messages: - A few thunderstorms are possible across SE VA/NE NC Thursday afternoon-evening. - Seasonally hot on both Thursday and Friday. The cold front slowly pushes south across southern VA and NE NC Thursday as high pressure and a drier airmass build into the northern tier of the area. Showers/tstms are expected to redevelop along the boundary Thursday afternoon with the highest chc across SE VA and NE NC. However, there is some uncertainty with respect to where convection develops on Thu (mainly regarding whether it will be in srn VA/NE NC or just to our south). Coverage/placement of tstms Thursday aftn will depend on the evolution of overnight convection. High temperatures return to seasonally hot levels ranging from the mid 80s to near 90F. Showers/tstms largely dissipate or move to our south by late Thursday evening, although some isolated activity could linger into the early overnight hours over far srn VA/NE NC. High pressure builds across New England Thursday night into Friday following the frontal passage. Lows Thursday night fall into the mid 60s-lower 70s. Easterly flow Friday will keep highs in the lower to mid 80s along the coast, and seasonally hot inland with highs in the upper 80s to around 90F. Surface high pressure initially settles off the coast Friday night into early Saturday, with some moisture returning as a weak warm front lifts through the area. Therefore, there is a slight chc to low chc of showers and perhaps a tstm from central VA and the Piedmont to the MD Eastern Shore Friday night into early Saturday morning. Lows Friday night are mainly in the upper 60s to mid 70s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 255 PM EDT Wednesday... Key Messages: - Heat rebuilds across the region Saturday and Sunday and with more humidity, with dangerous heat indices likely across parts of the area on Sunday. - Scattered showers and thunderstorms are possible later Sunday afternoon into Sunday night ahead of a cold front. - A brief break in the heat is likely early next week before very hot weather potentially returns by Independence Day. The heat builds back over the local area this weekend as high pressure settles off the Southeast coast and the low-level flow once again increases out of the SW. 850mb temps rise to around 20C on Saturday, and to 20-22C on Sunday. This will support high temps in the mid 90s both days. Aftn dewpoints will be in the lower to mid 70s (mid 70s mainly toward the coast) during peak heating on both days. This is supported by the deterministic guidance and MOS guidance, but is below the mid 70s-80F shown by the NBM (which is likely too high especially given how dry it has been). Resultant heat indices are in the 100-105F range on Saturday, and 105-109F for much of the CWA Sunday. Isolated to widely scattered tstms are possible on Saturday afternoon (mainly W of I-95), with a better chc of showers/tstms later Sunday afternoon into Sunday night as the cold front drops through the region. A slight reprieve in the heat is likely early next week in the wake of the cold front as the 12z/26 EPS and GEFS continue to depict below average 850mb temperature anomalies Monday and Tuesday. However, the ensemble guidance also surges the heat back into the region by the middle of next week just prior to Independence Day with forecast highs well into the 90s for much of the area. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... As of 130 PM EDT Wednesday... VFR/mainly dry with SCT cumulus through 22-00z. A cold front then approaches from the NW this evening and drops into the region tonight. There is a 40-60% chc of evening/overnight tstms at RIC/SBY, a 30-40% chc at ORF/PHF, and a 15-20% chc at ECG. The most likely timing for tstms is between 00-06z at RIC/SBY, and from 03-08z at PHF/ORF. A few tstms could produce strong wind gusts (to 30-50 kt) along with brief IFR/LIFR flight restrictions in heavy rain. Overall coverage of showers/tstms diminishes after 06z/2 AM. Some MVFR stratus is possible between 08-15z Thursday morning, but CIGs should otherwise remain VFR through the period. This front will be slow to push through southern VA and NC NE Thursday with a 30-50% chc of redeveloping aftn/early evening showers/tstms (highest at ECG...with lower chances at ORF). High pressure and dry conditions return Friday into Saturday. There is another decent chance for showers/tstms later Sunday into Sunday night. && .MARINE... As of 130 PM EDT Wednesday... SW winds mainly 5-15 kt will become S and increase to 10-20 kt with gusts up to 25 kt by late this aftn into this evening in advance of a cold front. Waves will build to 2-3 ft in the Bay, and seas will build to 3-5 ft in the coastal waters. So, SCAs are in effect for the mouth of the Bay, all coastal waters and the Currituck Sound from thru 1 AM (4 AM north of Parramore Island). That weakening cold front will push through the region late tonight into Thu aftn. NE winds expected late Thu night through Fri morning, then E and SE winds for Fri aftn into Sat morning, as high pressure slides by to the north then off the srn New England coast. Low rip current risk is forecast for all beaches today and Thu. Moderate rip risk on Friday. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 1 AM EDT Thursday for ANZ633-634- 654-656-658. Small Craft Advisory until 4 AM EDT Thursday for ANZ650-652. && $$ SYNOPSIS...AJZ/ERI NEAR TERM...ERI SHORT TERM...AJZ/ERI LONG TERM...AJZ/ERI AVIATION...ERI MARINE...JDM/TMG