textproduct: Wakefield

WHAT HAS CHANGED

A Severe Thunderstorm Watch has been issued for the northern half of the forecast area through this evening, with a southward expansion possible later.

Increased chance in heavy rainfall and strong to severe storms Tuesday as remnants of an MCV moves across the area.

KEY MESSAGES

1) Showers and storms return this evening, with some storms potentially becoming strong to severe.

2) Another chance for showers and storms returns Tuesday afternoon into evening, with the potential for heavy downpours and isolated strong to severe storms.

3) A more summer-like pattern takes hold Wednesday night into the weekend.

DISCUSSION

As of 320 PM EDT Monday...

KEY MESSAGE 1...Showers and storms return this evening, with some storms potentially becoming strong to severe.

Latest wx analysis shows a warm front lifted through the area this morning, now residing north of the Commonwealth. This front has helped temperatures get to the lower to mid 90s with dewpoints in the upper 60s to lower 70s. Breezy southerly winds have increased this afternoon behind the front due to a well-mixed profile, with gusts up to 30 mph. This evening, a cold front will approach the area, providing a forcing mechanism for shower and storm development. With the warm dewpoints, ample amounts of instability with MLCAPE values around ~1500 J/kg are presently noted. Better shear values are observed just to the north of the area, but the limited amount present (~25-35 kt) will allow for storm growth. PWAT values have increased across the area to >1.5", which could also result in localized flash flooding in urban and poor drainage areas. Decent low level lapse rates from the very warm surface temperatures favor the potential for cold-pool dominated storms with water-loaded downdrafts. Damaging winds are the primary threat with any storm, although cannot rule out large hail. The northern half of the area from a line roughly west to east across Farmville/Chesterfield/ Mathews/Accomac are now under a Severe Thunderstorm Watch until 9 PM. The timing of the convection will likely begin late afternoon to early evening in the piedmont and reaching the RIC metro around 7-8 PM. Further south, a cap on the environment with less favorable conditions leaves more uncertainty on how strong storms will be. Any storms would reach SE VA late evening around 9-10 PM, which is a less than favorable time for severe storms due to the loss of daytime heat. If the environment is able to sustain storms, a downstream Severe Thunderstorm Watch may be needed for portions outside the current watch.

KEY MESSAGE 2...Another chance for showers and storms returns Tuesday afternoon into evening, with the potential for heavy downpours and isolated strong to severe storms.

The aforementioned cold front will be slow to move out of the area and a subsequent surface low will form along the front and slide across the area Tuesday as an MCV. With the front slowly crossing the area Tuesday, warm temperatures in the mid to upper 80s and dewpoints in the lower 70s across the SE VA/NE NC will keep sufficient instability levels throughout the day. PWAT values will quickly rebound with values >2.0" for areas along the Ches. Bay and Atlantic Coast. Localized areas could see an additional 1.00-2.00" of rainfall, with more widespread values of 0.50-1.00" of rainfall across a large portion of the area Tuesday, on top of any rainfall tonight. While any and all rain is beneficial, there is a concern for areas of flash flooding, especially the urban and poor drainage areas. SPC has introduced a Marginal Risk of severe storms (level 1 of 5) as isolated storms may become severe with damaging winds. There is still some uncertainty with storm development, but the 12z models have came into better agreement with training showers and possible storms.

KEY MESSAGE 3...A more summer-like pattern takes hold Wednesday night into the weekend.

A drier airmass will take over behind the cold front, keeping Wednesday dry. Temperatures won't be much cooler though, with highs near normal in the mid to upper 80s across the area Wednesday. By Wednesday night, winds will quickly shift back to the SE-S and bring back normal June humidity amd temperatures. For the remainder of the week, a more typical summertime pattern sets up for late week. Mainly seasonable temperatures are expected, with diurnally driven, scattered late-day and evening showers and storms possible each day. Expect highs mainly in the upper 80s and low 90s, with overnight lows in the 60s to near 70.

AVIATION /19Z MONDAY THROUGH SATURDAY/

As of 155 PM EDT Monday...

VFR conditions continue through early evening at all terminals. Gusty southwest winds has picked up across all terminals (gusts to 25 kt), and will decrease this evening to 5-10 kt. Scattered showers/storms will move west to east across the area this evening. There is still some uncertainty with the arrival time, but SBY and RIC have the highest chance in seeing degraded flight conditions from these storms, as storms will likely lose momentum as they move eastward given the late time of day. Have included 3 hour TEMPOs for RIC and SBY beginning 23z and 00z respectively, while maintaining PROB30s for ECG and ORF from 01z-04/23. Storms look to fall apart before reaching ECG, so have maintained VCSH for these terminals. Behind the storms, there will likely be patchy low stratus/fog in areas that received rainfall. Low-end MVFR CIGs have been included for RIC and SBY after 06z/23 through sunrise.

Outlook: Additional flight restrictions from more showers/storms Tuesday is likely, especially across the SE terminals as a front and surface low moves across the area. Mainly dry/VFR Wednesday. Late day showers/storms possible Thursday and Friday.

MARINE

As of 320 PM EDT Monday...

Key Messages:

- Small Craft Advisories are in effect for all waters through tonight with gusty S-SE winds ahead of an approaching system.

- Sub-SCA conditions are expected for much of this week.

Afternoon weather analysis shows a low pressure system tracking across eastern OH and western PA. The pressure gradient ahead of the low has tightened over the waters allowing winds to increase out of the S around 15 kt with gusts up to 20 kt across the bay and 25kt across the ocean. Waves are much lower than expected with 1-2ft across the bay and 2-3ft across the ocean. Through the rest of the evening and into tonight, the pressure gradient will continue to tighten and winds will increase to 20-25kt with some gusts approaching 30kt. The highest confidence in these 30kt gusts are across the ocean waters north of the VA/NC border. Small Craft Advisories have been issued and are in effect for all waters, now including the Sound and southern coastal waters, as hi-res guidance continues to gusts around 25kt. Seas will also increase to 3-4ft across the bay and 4-5ft across the ocean. In addition to the wind, strong to severe thunderstorms are possible late this afternoon and into tonight. These storms could pose the risk of gusts greater than 34kt and a waterspout cannot be ruled out especially across the the far north.

The low will track north and a weak cold front will pass across the waters tomorrow. Winds shift to the NW by late tomorrow afternoon/ evening behind the front, and may increase slightly tomorrow night. Will note that additional SCA maybe needed as models continue to hint on gusts nearing 20kt. Local probs have increased to 50% of gusts greater than 18kt across the bay tomorrow evening/night. Prevailing sub-SCA conditions are expected the rest of the week as high pressure returns.

Rip current risk has been downgraded for today to moderate due to reports and the waves being lower than expected. The rip risk looks to be low through much of this week.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 1 AM EDT Tuesday for ANZ630>634-654- 656-658. Small Craft Advisory until 10 PM EDT this evening for ANZ635>637-639. Small Craft Advisory until 4 AM EDT Tuesday for ANZ650-652.