textproduct: Wakefield

WHAT HAS CHANGED

Rain chances have increased from tonight through Monday, particularly across southern portions of the area. Temperatures have trended cooler for Sunday and Monday as well. Coastal Flood Statements have been issued for the VA and MD Eastern Shore along the Ches Bay for this evening's high tide. Small Craft Advisories have been issued for Sunday afternoon into Monday across the Ches Bay and southern coastal waters.

KEY MESSAGES

1) Scattered showers and thunderstorms continue through Monday with the possibility of a few storms becoming strong to severe today.

2) Below normal temps are expected through the first half of the week before warmer temperatures return by the middle to later part of the week.

DISCUSSION

As of 315 PM EDT Saturday...

KEY MESSAGE 1...Scattered showers and thunderstorms continue through Monday with the possibility of a few storms becoming strong to severe today.

Latest surface analysis depicted a cold front across southern VA with N/NW winds north of the front and W winds south. Scattered showers and storms continue to develop along the front across far SE VA/NE NC and the lower Ches Bay this afternoon with a few additional showers well north of the front across far northern portions of the FA. Aloft, an upper level low across the Midwest will slowly move SE into KY/TN by Sun before slowly drifting south Mon. Will the surface cold front is expected to move well into SC by Sun, an effective 500mb W/E oriented frontal boundary aloft (best viewed at 500mb) from the aforementioned upper level low is modeled to stall across southern VA from this evening into Mon. This feature will be the forcing mechanism for the scattered to numerous showers and storms from later this afternoon into Mon.

The first wave of scattered showers and storms moves in from W to E later this afternoon into this evening. This convection has the best chance of becoming strong to severe given the favorable time of day and DCAPE of 800-1000 J/kg. However, MLCAPE is modeled to remain generally weak (500-1000 J/kg) with the greatest shear generally displaced to the north of the convection. This combined with the W/NW surface winds appear unfavorable for widespread severe weather. However, strong to perhaps severe storms remain possible with damaging winds the primary hazard. SPC has maintained a marginal risk for severe storms across the entire FA today to account for that potential. The severe threat diminishes this evening as low level instability becomes less favorable. A sub-tropical airmass continues to pump moisture into the area overnight with PWAT values of 1.8-2.2" (locally higher possible) expected from late this afternoon/evening through Sun. This will allow for tall, skinny CAPE profiles which support the potential for heavy rain. At the same time, showers and storms look to become nearly stationary along the aforementioned stalled frontal boundary aloft. As such, the potential for locally heavy rain and flash flooding increases tonight through Sun generally along and south of I-64. While CAMs continue to disagree with the exact morphology of convection, individual models show the potential for localized rainfall totals of 3-5". As such, WPC has maintained a marginal risk for excessive rainfall across the entire FA today and along and south of I-64 Sun. There is even a small sliver of slight risk across the far souther portions of the FA Sun. The best chance for flooding is across urban and low-lying areas. Uncertainty increases Mon as some models show showers/storms continuing across the local areas while others have the frontal boundary farther south and mostly dry conditions locally. As such, kept NBM PoPs which have a 60-85% chance along and south of I-64 Mon (and dry conditions across the Eastern Shore). In any case, unsettled weather continues through Mon with drier conditions returning Tue through midweek. Will note that SPC has a 15% chance for severe weather next Fri (July 17), however, considerable uncertainty remains at this time.

KEY MESSAGE 2...Below normal temps are expected through the first half of the week before warmer temperatures return by the middle to later part of the week.

Given widespread cloud cover and precip Sun and Mon, temps have trended cooler. Highs are now expected to struggle to warm above 80F in some locations both days with most locations in the 70s for the majority of both days. Will note that temps could be quite cool Mon night/Tue morning if cloud cover moves out of the area given high pressure overhead. Currently have lows that night in the 60s inland. However, some adjusted models show the potential for widespread lower 60s and even locally upper 50s. A return to normal temps arrives Tue with a warmup expected Wed-Fri as a ridge centered across the central CONUS expands towards the local area. Highs in the mid-upper 90s are possible Wed-Fri with heat indices around 100F each day.

AVIATION /19Z SATURDAY THROUGH THURSDAY/

As of 215 PM EDT Saturday...

SCT-BKN CU continue across the area this afternoon with a few showers noted across the NW Piedmont and scattered showers/storms across the lower Ches Bay and far SE VA/NE NC. PoPs gradually increase from W to E later this afternoon into this evening with increasing coverage of scattered showers and storms. A cold front aloft becomes stationary across southern VA tonight into Mon. This will allow for enough forcing aloft for scattered to occasionally widespread showers and embedded storms from later today through Sun (potentially into Mon). However, exact timing of showers and storms remains uncertain at any given taf site with rounds of showers and storms favored over a long duration light rain. As such, have PROB30s for thunderstorms late this afternoon into this evening. Will note that gusty winds are possible with stronger storms. From tonight through Sun, think the predominant precip type will be showers as opposed to storms. However, enough elevated instability could allow for occasional periods of embedded thunderstorms over the next 24 hours. Otherwise, CIGs remain generally VFR this afternoon apart from brief drops to MVFR (~2500-3000) across SE VA/NE NC. CIGs lower to MVFR mainly after midnight and remain MVFR through the remainder of the 18z taf period apart from SBY which could see improvement to VFR by around 14z. Will note that some model guidance has SBY dropping to IFR CIGs from 6-14z Sun. As such, CIGs may trend lower for that terminal. Winds remain light and variable.

Outlook: Shower and storms chances continue into Monday for all terminals except SBY. MVFR CIGs will continue to be possible as well. Drier conditions arrive late Mon into the middle of next week with improving conditions.

MARINE

As of 315 PM EDT Saturday...

Winds across the local waters have shifted to the WNW this afternoon ahead of and along a weak front that is moving across the area. Isolated showers with one or two embedded thunderstorms have developed across the Chesapeake Bay and coastal waters near the Capes this afternoon, though gusts within these showers have remained below MWS criteria so far. Winds generally range between 5- 10 kts outside of these showers. Waves in the Bay are 1 ft or less, while seas in the coastal waters are being measured between 2-3 ft this afternoon.

Winds veer to the NNE late tonight into Sunday morning, as weak CAA nudges into the area and high pressure builds to the north. The frontal boundary then becomes hung up across the Carolinas late Sunday into Monday. NE/ENE winds of 15-20 kt with gusts up to 25 kt look increasingly likely during this period, and guidance is suggesting that these elevated winds will linger into midday Monday as a weak low pressure system develops and slides along the slow- moving front. A Small Craft Advisory has been issued for the Bay starting tomorrow afternoon, with the Middle Bay dropping off early Monday morning and the lower Bay (including the mouth of the Bay) remaining through Monday evening. Additionally, an E-SE swell should build to 4-6 ft (highest across the NC coastal waters) Sunday evening into early Monday, with 3-4 ft waves possible across the lower Chesapeake Bay. Have issued an SCA for the coastal zones south of Parramore Island starting early tomorrow night through Monday evening for 5 ft seas. Winds diminish Monday night, as high pressure builds down over the local waters. Generally benign marine conditions return for Tuesday and look to prevail through late week.

A Moderate Rip Current risk continues across the northern beaches today, with a Low Rip Risk persisting across the southern beaches. Increasing onshore flow and building seas will result in a moderate rip risk for all beaches tomorrow as winds become elevated and onshore, lingering into Monday. Lingering strong E-NE wind waves will maintain a moderate rip risk Monday for the northern beaches. Meanwhile, a building, longer-period swell (~7 sec) will result in a high rip risk across the southern beaches.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 5 PM Sunday to 4 AM EDT Monday for ANZ630-631. Small Craft Advisory from 5 PM Sunday to 7 PM EDT Monday for ANZ632-634. Small Craft Advisory from 10 PM Sunday to 5 PM EDT Monday for ANZ654. Small Craft Advisory from 10 PM Sunday to 10 PM EDT Monday for ANZ656-658.