textproduct: Wakefield

WHAT HAS CHANGED

No significant changes.

KEY MESSAGES

KEY MESSAGE 1...Strong to severe thunderstorms are expected this this afternoon and evening, along with the potential for localized areas of flash flooding through tonight.

KEY MESSAGE 2...The threat of severe thunderstorms will linger into Wednesday and the potential for torrential rainfall to produce scattered instances of flash flooding will also increase through Wednesday night.

DISCUSSION

As of 700 AM EDT Tuesday...

KEY MESSAGE 1...Strong to severe thunderstorms are expected this this afternoon and evening, along with the potential for localized areas of flash flooding through tonight.

A few showers have developed and will move across the FA, especially eastern areas, between now and 10 am but the main show comes later this morning into this afternoon and evening ahead of a potent upper trough. Flow aloft strengthens considerably by the afternoon hours with 40-50 kt of flow noted at 500mb. Low level moisture also ramps up with PWAT values climbing back above 2". Instability is a bit more uncertain with clouds possibly hampering heating to some extent but models still show 2000- 3000 J/kg of MLCAPE across the area. Storm mode is also somewhat uncertain with the potential for a mix of linear segments and semi-discrete cells. All these factors point to a robust severe wx threat across the region. SPC has most of the area in a Slight Risk (level 2/5) with a sliver of Enhanced Risk (lvl 3/5) clipping far northern portions of the MD Eastern Shore. Could see the higher risk area being shifted a bit south and east in subsequent outlooks pending greater clarity on degree of cloud cover and storm morphology. As is typical for Mid-Atlantic July severe setups, the main threat will be from damaging winds but a tornado or two cannot be completely ruled out, especially across the N and NE portions of the region where the shear and low level helicity are progged to be strongest. The threat of severe storms should last well into the evening hours if not into early Wednesday morning. Additionally, the fast storm motion will largely preclude a widespread flooding risk. However, areas that get repeated storms late today into tonight due have a risk of flash flooding (SLGT ERO down to the VA/NC border).

KEY MESSAGE 2...The threat of severe thunderstorms will linger into Wednesday and the potential for torrential rainfall to produce scattered instances of flash flooding will also increase through Wednesday night.

The severe threat likely continues into Wednesday, but with the higher probabilities shifted to the south and east ahead of a southward-moving cold front. How convection evolves on Tuesday will also influence the degree of cloud cover and destabilization potential on Wednesday. That said, the flow aloft is forecast to remain rather strong. SPC has a Slight Risk outlined for our entire CWA (lvl 2/5).

Despite the ongoing drought conditions, Wednesday into Wednesday night is showing an increasingly confident signal for localized flooding, especially in urban and poor drainage areas. WPC has most of the area in a Slight Risk ERO again Wednesday with PWAT generally 2-2.25". Decent flow aloft should keep individual cells moving but training storms on top of the rainfall received Tuesday could cause scattered instances of flash flooding. All total, the QPF forecast through Thursday has generally 2-5" of rain from Richmond and Emporia eastward to SE MD and NE NC.

Some drier air finally moves back into the region Thursday and Friday but some showers and storms will remain possible, mainly across the southern and southeastern portions of the area.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

As of 0700 AM EDT Tuesday...

Starting off mainly dry and VFR for the start of the 12z TAF period but chances for storms quickly ramp up after 16z. Strong-severe storms are also possible, mainly after 18z, which could bring heavy rain, frequent lightning, and strong wind gusts. Outside of storms, winds today will become gusty out of the SW to 20-25 kt. Showers and thunderstorms will continue this evening and potentially into early Wed morning.

Outlook: Another round of showers and thunderstorms is expected Wednesday and Wednesday night, especially after 16z. Flight restrictions will be likely with the strongest storms. Rain and storm chances shift south by late week, but could still impact KORF/KPHF down to KECG.

MARINE

As of 340 AM EDT Tuesday...

- Small Craft Advisories have been issued for late today into Wednesday for most of the local marine area.

- Strong thunderstorms are possible today and Wednesday, primarily during the afternoons and evenings.

A warm front is lifting through the area early this morning. Breezy, sub-advisory level winds are turning to the SW south of the front. Latest obs show winds around 10kt with gusts around 15kt. Winds gradually increase today as the pressure gradient tightens ahead of a cold front. Sustained winds around 15kt expected during the morning, then approaching 20kt by late afternoon. Winds are expected to peak overnight at 20-25kt with gusts of 30-34kt over the bay, lower James, and coastal waters (15-20kt with gusts to 25kt over upper tidal rivers). A few gusts around 35kt will be possible past 20nm, especially for the southern zones. These conditions continue into Wed morning, then diminishing Wed afternoon and evening. SCAs are in effect for all marine zones (excluding the 20-60nm zones where SCAs are not issued) starting late this afternoon. Winds turn to the north behind the cold front Wed night into early Thurs and briefly surge back to 15-20kt. May end up needing another round of SCAs for the bay early Thursday for this. Lighter NE winds are then forecast Thurs afternoon into the weekend.

Multiple rounds of thunderstorms are expected over the next few days. Some storms may be severe with strong, erratic winds. Highest risk this afternoon and overnight would be across the northern waters. Storm coverage shifts south Wednesday into Thursday, turning into more of a heavy rain threat.

Seas build to 3-4ft by this evening as the winds pick up with waves in the bay increasing to 2-3ft. Seas of 4-5ft for southern nearshore waters and 5-6ft for the northern nearshore waters are forecast overnight (6-7ft offshore). Waves up to 4ft expected in the bay overnight. 5ft+ seas may linger as late as Wednesday night.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 4 PM this afternoon to 1 PM EDT Wednesday for ANZ630>632-634>637-639. Small Craft Advisory from 7 PM this evening to 1 PM EDT Wednesday for ANZ633. Small Craft Advisory from 4 PM this afternoon to 6 PM EDT Wednesday for ANZ650-652. Small Craft Advisory from 7 PM this evening to 6 PM EDT Wednesday for ANZ654-656-658.