Area Forecast Discussion
Issued by NWS Wakefield, VA
Issued by NWS Wakefield, VA
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027 FXUS61 KAKQ 292014 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 414 PM EDT Sat Jun 29 2024 .SYNOPSIS... Heat and humidity build through Sunday ahead of an approaching cold front. Strong to severe storms and locally heavy rain will be possible Sunday afternoon into Sunday night. The front pushes south of the area Monday morning, bringing cooler temperatures and lower humidity Monday and Tuesday. Heat and humidity return later in the week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... As of 350 PM EDT Saturday... - Key message: mainly precip-free tonight, but warm and very humid. The latest WX analysis indicates a WSW flow aloft over the region, in between a broad upper ridge centered across the SE CONUS, and a strong upper trough over central Canada into the upper midwest. At the sfc, the pressure pattern is starting to transition as a bit of a lee trough is developing well inland, with high pressure well off the coast of New England, and low pressure over Lake Superior. It remains quite humid this aftn with dew pts generally near 70F to the lower 70s well inland to the mid-upper 70s near the coast. Heat indices range from the upper 90s to ~103F. Isolated showers continue over eastern NC, and will generally stay there into the early evening, but will maintain PoPs to around 15 over interior NE NC. CAMs are not very excited about any showers/storms through early evening, but will keep a slight chc over the far NW for where the upper heights are a bit lower closer to the approaching upper trough. The models also depict some weak sfc troughing advancing to the E of the mountains later tonight. With the winds turning to the SSW this evening/overnight, it will remain warm and very humid keeping min temperatures in the mid to upper 70s. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... As of 355 PM EDT Saturday... Key messages: - A Heat Advisory has been issued for portions of the area Sunday where confidence is highest at reaching heat indices of at least 105F. - The potential is there for strong to severe storms Sunday aftn/early evening, likely transitioning more to a heavy rain threat later Sunday night. An upper trough and a strong cold front (for this time of year), will approach the area from thr NW Sun, crossing the region Sun night through Mon morning. Ahead of the front, S/SW low level flow will allow hot and very humid conditions to continue. The typical mid morning peak in dew pts will tend to see them avg from the mid 70s to perhaps around 80F along the Albemarle sound in NE NC, before mixing out a few degrees during the aftn. There remain some uncertainties regarding an earlier than usual shower/storm development between 15-18Z, and this could limit the temperatures to some extent. Right now, this appears most likely over the northern portions of the CWA so have left them out of the Advisory for now. Even in areas within the Advisory over central and southern VA, there will be a chc for some spotty showers/tstms by mid/late morning but the thinking is that the anomalously high dew pts should push heat indices towards 105F rather quickly. While the potential for morning convection exists, the main threat for sctd to numerous storms will be in the aftn and into the overnight hours, probably in 2 rounds (earlier with storms well ahead of the front and overnight with additional forcing from the front itself). The greatest severe threat will be in the aftn/early evening ahead of the front with ML CAPE to 1000-1500 J/Kg and will primarily be from damaging winds given increasing mid level flow with shear to 30-35 kt. Thus, there is a Slight risk for severe storms for just about the entire FA, and a Marginal risk for most of NE NC where shear is a bit less. Locally heavy rainfall is expected, especially E of I-95 across VA, where PWs will approach 2.25", and the latest HREF shows 10-30%+ for 3" of rain in 3 hr. WPC continues with a Marginal ERO for much of the region. Pcpn will taper off and end from NW to SE from late Sun night through Mon morning. Lows Sun night will range from around 60F over the far NW to the lower 70s far SE. Pcpn will push SE of NE NC by Mon aftn, with N winds ushering much drier and cooler air into the region during the day. The sky will become mostly sunny (with lingering clouds over the SE) with highs in the upper 70s to mid 80s. Clear or mostly clear and comfortable Mon night, as sfc high pressure builds in from the N. Lows will be mainly in the upper 50s to mid 60s. Similar setup for Tuesday, as the sfc high settles across the region with highs upper 70s to lower 80s at the coast to the mid 80s inland with comfortable dew pts. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 415 AM EDT Saturday... High pressure will bring dry weather through mid week. Mostly sunny and generally comfortable on Tue with highs mainly in the lower to mid 80s. Hotter conditions and more humidity returns for Wed, then very hot and humid for Thu and Fri. Highs in the mid 80s to lower 90s Wed, and in the mid to upper 90s on the Fourth of July and Fri (lower 90s over the Lower MD and VA ern shore both days). With dewpoints climbing back into the upper 60s to lower 70s both days, there is the potential for heat indices over 100. There also will be a chance for aftn tstms both days. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... As of 235 AM EDT Saturday... High pressure centered off the New England was leading to light E/ESE flow at area terminals early this morning. As a result, stratus and lower SC were developing over portions of the region. Guidance continues to favor low-end MVFR, but cannot rule out patchy pockets of IFR stratus, esply in/near central VA (including RIC) until around 12Z this morning. Not expecting much in the way of VSBY restrictions. A few showers are also possible at ECG through this morning. For this aftn, mainly dry conditions expected though a very brief shower or storm is possible at any terminal. SCT CU again redevelops with a 7-12 kt S or SE wind. Mainly dry conditions continue into tonight, with just an isolated threat of a shower or storm. Sctd to numerous showers/tstms are likely Sun aftn through Sun night, some of which could be strong to severe. High pressure and drier conditions return for later Mon morning through Tue. && .MARINE... As of 220 PM EDT Saturday... Key messages: - A High Rip Risk for eastern shore (VA/MD) beaches today, with moderate Rip Risk for SE VA & NE NC. Moderate Rip for all beaches Sunday. - A brief period of SCA level winds is expected in the bay late this afternoon and this evening, and a Small Craft Advisory is in effect during this period. - A period of SCA conditions is very likely for most of the waters on Monday with northerly winds behind a cold front. High pressure is centered off the New England coast early this aftn. The wind is mainly SE 10-15kt, with some lingering 3-4ft swell over the ocean. High pressure sinks S off the coast tonight. There is a period of channeling across the Ches. Bay late this aftn and evening, with a SSE wind of 15-20kt with gusts to 25kt. SCAs for the Ches. Bay remain in effect from 4 PM to 1 AM. Elsewhere, expected a SSE wind of 10-15kt with gusts to 20kt. The wind shifts to SSW later tonight and diminishes to 10-15kt. Seas should remain 3- 4ft tonight, but could touch 5ft out near 20nm off the MD coast, with 2-3ft waves in the Ches. Bay. A rather strong cold front for summer approaches from the NW Sunday. The wind should generally remain SW 10-15kt out ahead of the front. However, some strong to severe tstms could bring some locally stronger wind gusts. A decent CAA surge will follow the cold front late Sunday night into early Monday morning with a NNW wind of 15-25kt. Seas build to 3-5ft, with 2-4ft waves in the Ches. Bay. SCAs are likely for the Ches. Bay, lower James, and Currituck Sound, and potentially the coastal waters S of Cape Charles. The wind remains N 10-15kt Monday aftn, and then becomes NE 10-15kt Monday night into Tuesday as high pressure builds SE toward the New England coast. Seas slowly subside to ~3ft. High pressure settles S off the coast by the middle of next week with the wind becoming southerly. A high rip current risk continues through this evening for the northern beaches with a moderate S. A moderate rip current risk is forecast for all beaches Sunday. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...Heat Advisory from 11 AM to 6 PM EDT Sunday for NCZ012>017- 030>032. VA...Heat Advisory from 11 AM to 6 PM EDT Sunday for VAZ065>069- 079>090-092-093-095>098-512>520-522>525. MARINE...Small Craft Advisory until 1 AM EDT Sunday for ANZ630>632-634. && $$ SYNOPSIS...LKB NEAR TERM...LKB SHORT TERM...LKB LONG TERM...AM/TMG AVIATION...JDM/TMG MARINE...AJZ