Area Forecast Discussion
Issued by NWS Wakefield, VA
Issued by NWS Wakefield, VA
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960 FXUS61 KAKQ 051931 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 331 PM EDT Fri Jul 5 2024 .SYNOPSIS... High pressure lingers offshore with building heat and humidity today and Saturday. Daily chances of mainly afternoon and evening showers and thunderstorms continue into next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... As of 330 PM EDT Friday... Key Messages: - Excessive Heat Warnings remain in effect through the evening for much of the area with Heat Advisories elsewhere. - Isolated to scattered afternoon and evening storms are possible. Potential for a few storms in the piedmont to become severe. - Temperatures remain very warm overnight. High pressure continues to sit off the SE this afternoon while a weak stationary front is situated well the NW. Aloft, a ridge is in place from the Gulf coast to the Mid-Atlantic with a trough dipping into the upper Midwest. A moist airmass is in place, allowing dewpoints to climb into the upper 70s. Latest mesoscale analysis indicates PWs over 2" along the coast and 1.5-2" in the piedmont. Temps have risen into the mid to upper 90s this afternoon. Dangerously high heat indices are evident with latest obs, which show widespread values near 110 (a few sites have occasionally shown 112 even). Thus, the Excessive Heat Warning and Heat Advisories will continue into the evening. Latest radar shows convection initiating in SW VA with 1 or 2 small showers starting to show along the SW border of the FA. Not expecting widespread storms this evening, but will see scattered convection primarily through the NW half of the FA. CAMs continue to favor the late evening time period for the majority of precip. Areas W of the bay have 20-40% PoPs (highest in SW) through the rest of the afternoon, then PoPs increase to 40-55% for areas W of I-95 after sunset. Later tonight, may see isolated showers/storms along northern counties. There is a marginal risk for severe storms along the western tier of counties. While shear is not favorable, plentiful MLCAPE (1500-2000J/KG) and decent low level lapse rates will allow a chance for damaging wind gusts with stronger storms. Scattered to broken cloud cover is expected to remain in place overnight, which will aid in keeping overnight temps rather warm. Lows tonight will be in the upper 70s. A few locations along the coast may not even drop lower than 80F. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... As of 650 AM EDT Friday... Key Messages: - Very hot conditions continue into Saturday with heat indices of up to around 110F possible along portions of eastern Virginia and northeast North Carolina with 102-107F farther west and across the Eastern Shore. - Scattered storms are possible Saturday afternoon into Saturday night. The upper ridge breaks down some by Saturday allowing the upper trough and a weakening cold front to approach from the NW. Meanwhile, an upper level low lingers off the Southeast coast. PW values remain very high Sat (2-2.2" with locally higher values). Additionally some stronger mid- level flow approaches from the NW. This could result in some better storm organization, which may allow for some stronger storms. That being said, the more likely threat from showers/storms will be heavy rain given the very moist environment. The most favorable region for some locally heavy rain appears to be across southern/SE VA and NE NC at this time. However, widespread rainfall totals of 0.5-1.0" appear possible from Mecklenburg NE to the Northern Neck. Localized higher totals are possible. Storm coverage farther W appears more conditional with mainly the NAM being the outlier with higher coverage in this area. A cold front approaches the area but stalls, allowing for PoPs to continue overnight Sat night and into Sun with the highest PoPs across SE VA/NE NC. Showers/storms gradually move offshore Sun night. Given morning lows in the upper 70s to around 80F across E portions of the FA Sat morning, it won`t take much heating for temps to rise into the 90s with afternoon highs in the mid 90s W to the mid-upper 90s E. Dew points remain very high Sat in the mid 70s W to the upper 70s E. Given the combination of heat and humidity, the heat indices may rise to around 110F across portions of E/SE VA and NE NC with 105-108F farther west (102-105 across the far W Piedmont) and across the Eastern Shore. Extensions of the Excessive Heat Warning or additional Heat Advisories through Sat are possible depending on forecast trends. Will note that the challenging aspect of Sat is that storms are expected to be more widespread in coverage. If they happen early enough, the rain cooled air and cloud cover may keep temps cooler than currently forecast. If this happens, heat indices may be lower than and/or a shorter duration than currently forecast. Even so, Heat Advisories (at a minimum) are likely for most of the area. DESI probs are not as high for Sat as they are for Fri with 20-40% chances for heat indices >109F across SE VA/NE NC. With the convection allowing for rain cooled air, lows Sat night will be cooler than tonight in the lower 70s W to mid 70s along the E of I-95. Highs Sun in the upper 80s to lower 90s with lows Sun night in the low-mid 70s expected. Heat indices will be cooler on Sun (95-100F). && .LONG TERM /MONDAY THROUGH FRIDAY/... As of 500 AM EDT Friday... Key Message: - Slightly above normal temperatures and very humid conditions continue through next week. - Remaining a bit unsettled with a chance for mainly afternoon and evening showers and storms each day. Not as hot through the period, but high temps will still be slightly above normal ranging from the upper 80s to lower 90s (most in the lower 90s). Humidity sticks around with dew points in the 70s continuing through the week. Additionally, with lee troughs and/or weak frontal boundaries in the vicinity of the region, expect chances for mainly afternoon/evening showers/storms each day. Heat indices will mainly range from the mid 90s to lower 100s through the week. Warm and muggy nights continue as well with lows ranging from the upper 60s to mid 70s. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... As of 150 PM EDT Friday... Scattered CU (VFR CIGs around 7000-10000 ft) have started building in from SW to NE this afternoon and will continue to expand across the region into the evening. Isolated to scattered showers and storms are possible this afternoon into this evening. Highest coverage in storms will likely be west of local terminals. Confidence in coverage is too low to go with more than VCSH/VCTS at RIC/SBY. Mostly cloudy skies move in tonight with MVFR (and potentially IFR) CIGs possible across portions of SE VA and NE NC as well as SBY. A weakening and slow moving cold front settles into the region Saturday. This will bring a higher chance of afternoon/evening showers/storms. This front settles near the coast Sunday and washes out, with a remnant boundary lingering over the area Monday/Tuesday. Unsettled weather continues through the week with daily chances for showers/storms. && .MARINE... As of 330 AM EDT Friday... Key messages: - Southerly winds increase later this afternoon into tonight, with Small Craft Advisories now in effect for the coastal waters, lower Chesapeake Bay, and Currituck Sound. - There is a moderate rip risk across area beaches today and Saturday. Early this morning, winds are generally out of the S to SSW and range around 10 to 15 knots. Seas are 3-4 ft with waves 1-2 ft in the Bay. SSW winds shift to the SSE and increase later this afternoon into this evening as a cold front begins to slowly approach from the NW, tightening the gradient over the waters. Winds will first increase across the southern waters this afternoon, with the higher gusts spreading north later through this evening. Latest local wind probs show the best potential for 25 knot gusts (70-80% chance) out 20 nm with lower probabilities closer to the coast. In addition to the wind, seas will also increase to around 5 feet later this afternoon into tonight. SCAs are now in effect for the lower Chesapeake Bay and Currituck Sound this afternoon through this evening and the coastal waters this afternoon into tonight. Similar conditions are expected on Saturday, with winds again ramping up later Saturday afternoon into Saturday night. Additional SCAs may be needed for this timeframe. Lighter winds are then expected Sunday into early next week as the cold front dissipates over the local waters. A moderate rip current risk in place for all beaches today with the moderate threat expected to continue through Saturday. && .CLIMATE... No record highs or record high mins were set today/July 4th. Record High Temperatures Fri and Sat (July 5-6) 7/5 7/6 - RIC 102/2012 105/1977 - ORF 98/2012 102/1881 - SBY 102/2012 102/2010 - ECG 100/2012 99/2012 Record High Minimum Temperatures Through Sat (July 4-6) 7/5 7/6 - RIC 79/2012 80/2012 - ORF 80/1999 80/1999 - SBY 81/2012 77/2012 - ECG 77/2018 78/1999 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...Heat Advisory until 8 PM EDT this evening for MDZ021>024. Heat Advisory from 11 AM to 8 PM EDT Saturday for MDZ021>024. NC...Heat Advisory until 8 PM EDT this evening for NCZ102. Heat Advisory from 11 AM to 8 PM EDT Saturday for NCZ012>017- 030>032. Excessive Heat Warning until 8 PM EDT this evening for NCZ012>017-030>032. VA...Heat Advisory until 8 PM EDT this evening for VAZ048-060-061- 099-100-509-510. Heat Advisory from 11 AM to 8 PM EDT Saturday for VAZ062- 064>069-075>090-092-093-095>098-511>525. Excessive Heat Warning until 8 PM EDT this evening for VAZ062- 064>069-075>090-092-093-095>098-511>525. MARINE...Small Craft Advisory until 10 PM EDT this evening for ANZ632>634. Small Craft Advisory until 1 AM EDT Sunday for ANZ650-652-654. Small Craft Advisory until 1 AM EDT Saturday for ANZ656-658. && $$ SYNOPSIS...RMM NEAR TERM...AM SHORT TERM...RMM LONG TERM...RMM AVIATION...AM/RMM MARINE...AJB CLIMATE...