textproduct: Wakefield

WHAT HAS CHANGED

The Flood Watch has been extended to noon Thursday from south central Virginia to the Virginia Eastern Shore including the Peninsula.

The Flood Watch has been extended to midnight tonight for Somerset, Wicomico, and Worcester counties in Maryland.

KEY MESSAGES

1) The threat of severe thunderstorms will continue this afternoon and the potential for torrential rainfall to produce scattered to numerous instances of flash flooding will increase tonight into Thursday.

2) Below average temperatures are expected Friday through the weekend, before trending back to seasonal for late July early next week. There is a general trend toward drier conditions through the weekend into early next week.

DISCUSSION

As of 345 PM EDT Wednesday...

KEY MESSAGE 1...The threat of severe thunderstorms will continue this afternoon and the potential for torrential rainfall to produce scattered to numerous instances of flash flooding will increase tonight into Thursday.

GOES water vapor channels depict a vigorous upper trough from the Great Lakes to the Northeast with the Mid-Atlantic at the base of the upper trough. Locally, there is a moist frontal band along the base of the trough producing persistent showers/tstms from southside to east central VA. The cold front is lagging to the NW, and scattered showers/tstms have developed from central VA to the MD Eastern Shore where there has been some better surface heating. The environment remains rather favorable for a few severe tstms with 40- 50kt of effective bulk shear and ~1500J/kg of MLCAPE. The main threat is locally damaging wind gusts, although a brief tornado/waterspout is possible near the coastlines. Additionally, locally heavy rain remains possible with PW values of 2.0-2.3".

Attention then turns to the heavy rain/significant flash flooding threat. Despite the ongoing drought conditions, there remains a confident signal for flash flooding, especially in urban and poor drainage areas. WPC has continued with a Moderate Risk ERO for tonight across much of Hampton Roads down into northern portions of NC. Much of the remainder of the area is in a Slight Risk ERO today. Decent flow aloft should keep individual cells moving but training storms on top of the rainfall received yesterday and overnight early this morning will likely cause scattered to numerous instances of flash flooding. The axis of heavier showers and storms shifts further to the SE on Thursday as the slow moving front gradually sinks south. WPC has continued a Day 2 Moderate ERO across northeast NC up to roughly the VA border and a Slight ERO across southeast VA. A Flood Watch continues for SE VA and NE NC through Thursday, and the Flood Watch from south central VA across the Peninsula to the VA Eastern Shore has been extended through noon Thursday. The Flood Watch from the RIC metro NW and N remains in effect through midnight as the heaviest rain should trend S/SE of this area later tonight. Additionally, the Flood Watch for portions of the Lower MD Eastern Shore has been extended through midnight to account for some scattered lingering convection that is capable of producing brief heavy rainfall across areas the received 2-4" last night.

All total, the QPF forecast through Thursday has generally 3-5", with locally higher amounts across southside Hampton Roads into northeast North Carolina.

KEY MESSAGE 2...Below average temperatures are expected Friday through the weekend, before trending back to seasonal for late July early next week. There is a general trend toward drier conditions through the weekend into early next week.

The trend is for the cold front to push south of the area later Thursday into Friday, but there is enough lingering moisture for at least some chc to low-end likely PoPs in far SE VA and NE NC. Rain chances then diminish to near to below climo for the weekend into early next week. Below average temperatures with highs in the lower to mid 80s are expected Friday through the weekend, with dewpoints even dropping into the lower to mid 60s across the northern tier of the area. Temperatures return to near seasonal averages early next week with increasing humidity.

AVIATION /00Z THURSDAY THROUGH MONDAY/

As of 740 PM EDT Wednesday...

Still mainly VFR conditions, with brief MVFR to IFR VSBYs in heavier showers near RIC/SBY at this hour. Showers will continue to impact RIC/SBY for the next few hours, bringing brief flight restrictions. Then, the precipitation shifts to SE VA/NE NC overnight, and a heavy rain threat is expected to develop (and last into Thu AM). Some thunder is also possible in SE VA/NE NC overnight with brief gusts to 30-35 kt in the stronger storms. Prevailing VSBYs will be MVFR at PHF/ORF/ECG after 02-04z, with periodic IFR/LIFR VSBYs likely through the night. Heavy rain potentially lingers across SE VA/NE NC into midday Thursday. CIGs will also lower to MVFR (and potentially IFR) tonight. Winds outside of convection will gust to 15-20 kts from the SW for a majority of the period, winds shift to the NNW as early as 04-06z across the north, but not until 10-14z over SE VA/NE NC, becoming NE all areas by Thu aftn.

Outlook: Generally drying out late Thursday, but a few additional SHRA and flight restrictions may linger at ORF/ECG into Fri AM. Mainly dry/VFR Friday-Saturday with a low chance for showers across the SE terminals.

MARINE

As of 250 PM EDT Wednesday...

- Small Craft Advisories are in effect for the local waters through this afternoon.

- Strong thunderstorms are possible again today and Thursday with gusty winds and reduced visibility from heavy rain likely.

A slow moving cold front crosses the area late tonight/early Thursday. Ahead of the front, SW winds peaked this morning, but remain elevated with current obs showing 10-15 kt with gusts to 25 kt across local waters. Seas are 3-5 ft across nearshore coastal waters (5-7 ft offshore) and 1-3 ft waves in the Ches. Bay. Winds will continue to diminish this afternoon and evening, but due to the gradual decline, Small Craft Advisories have been extended now through 4 PM for the Ches. Bay, tidal rivers, and Currituck Sound as frequent gusts above 20 kt are present. The SCA for the coastal waters remains in effect through 6 PM as 5 ft seas will linger behind falling winds. The cold front will cross the waters late tonight/early Thursday resulting in a brief northerly surge across the Ches. Bay around 2-8 AM Thursday with gusts around 20 kt. Local wind probs show a 30-50% chance of sustained 18 kt winds and a 70- 90% chance of gusts to 18 kt. A subsequent SCA is likely for the Ches. Bay following the expiration of the current advisory. Lighter NE winds are likely Thursday afternoon and into the weekend with 2- 3 ft seas and 1-2 ft waves.

Multiple rounds of thunderstorms are expected from this afternoon through Thursday. Some storms may be severe with strong, erratic winds and heavy rainfall capable of reducing visibility.

A Moderate Risk for Rip Currents is in effect across all local beaches today through Friday from increased swell and onshore flow on Friday.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...Flood Watch until midnight EDT tonight for MDZ022>025. NC...Flood Watch through Thursday evening for NCZ012>017-030>032- 102. VA...Flood Watch until midnight EDT tonight for VAZ048-060>062-068- 069-076>078-082-083-085-509>520-522. Flood Watch through Thursday evening for VAZ097-098-529>531. Flood Watch through Thursday morning for VAZ065>067-079>081- 084-086>090-092-099-100-523>525-528. MARINE...Small Craft Advisory from 4 AM to 10 AM EDT Thursday for ANZ630>632-634.