textproduct: Wakefield

WHAT HAS CHANGED

The forecast remains generally unchanged for today. There still remains some uncertainty regarding storm evolution this afternoon/evening.

The forecast has generally trended drier for the Monday- Wednesday timeframe.

KEY MESSAGES

1) There is a Slight Risk (2 out of 5) for severe thunderstorms across the entire area later this afternoon through the evening.

2) A cooler, drier pattern takes hold early this week. A return to warmer and more humid conditions and the potential for strong to severe thunderstorms Thursday

DISCUSSION

As of 330 AM EDT Sunday...

KEY MESSAGE 1...There is a Slight Risk (2 out of 5) for severe thunderstorms across the entire area later this afternoon through the evening.

Southerly flow and a more humid airmass (dewpoints in the upper 60s to lower 70s) returns area-wide today as a warm front lifts north across the area. Meanwhile, a cold front approaches from the NW this afternoon, before crossing the area tonight. This front, combined with an unstable airmass over the local area, will serve as the focus for strong to severe thunderstorms this afternoon-evening. Ahead of the front, MLCAPE values are forecast to increase to 1500- 2000 J/kg. In addition, model soundings continue to show steep low level lapse rates, which should result in substantial DCAPE (~1200 J/kg). Finally, compared to previous days, wind shear will be higher, averaging 30 to 40 knots. Given all of this, severe storms are likely this afternoon-evening, with damaging wind gusts of 60- 70+ mph being the main hazard. SPC has placed the entire forecast area in a Slight Risk (2 out of 5) for severe thunderstorms, with a 30% wind outlook covering a majority of the area. Weak 0-1 km SRH and high LCLs will limit any tornado potential, however a brief spin up cannot be completely ruled out, especially across NE portions of the area mainly due to localized land/marine interactions. As for hail, expect the potential for small hail, but large hail will likely be hard to come by due to marginal mid-level lapse rates. Finally, locally heavy rainfall may lead to isolated instances of flash flooding, especially over any urban areas. WPC has placed a Marginal ERO over the eastern half of the area. The progressive nature of the storms and drought conditions should keep the flooding threat limited. The cold front moves through a majority of the area tonight bringing drier air and ending the threat for any severe weather. However, in typical fashion for the summer months, the front likely near or just south of the local area allowing for unsettled conditions to continue into early next week.

Temperature-wise, highs climb back into the lower to mid 90s areawide (locally upper 90s). With the increasing humidity, heat index values increase back into the upper 90s to lower 100s. The highest heat indices will likely be east of I-85/95 and south of I- 64 and especially across southside Hampton Roads into northeast North Carolina. While a few ~105 degree heat indices may be possible, do not expect this to be widespread enough to warrant a Heat Advisory. In addition, the afternoon storms will put a quick end to the heat.

KEY MESSAGE 2...A cooler, drier pattern takes hold early this week. A return to warmer and more humid conditions and the potential for strong to severe thunderstorms Thursday.

Cooler conditions are expected through at least the first half of next week as an upper trough develops over the eastern half of the US. In addition, the front from today/tonight lingers near or just south of the area. The forecast has generally trended drier for Monday with only a small chance for a shower or storm across far S/SE portions the area, the majority of the area will remain dry. Much drier air (dewpoints in the 50s), near to slightly below average temperatures (low to mid 80s), and mostly sunny skies should make for pleasant and comfortable day. Clouds and rain chances expand back a bit further N/NW on Tuesday as the front to the south begins to lift north. The best rain chances (scattered showers/storms) on Tuesday will mainly be near/along the Albemarle Sound in NC with lower chances off to the N/NW. Temperatures stay in the lower 80s (upper 70s closer to the coast) on Tuesday with the increase in cloud cover, precipitation chances, and onshore flow. Warmer and more humid conditions return for the mid to later portions of the week as the trough begins to break down and a warm front lifts through the area. The Thursday-Friday timeframe likely becomes more active preciptation-wise as another front approaches and crosses the area from the NW. We are also watching for another severe weather potential, with SPC highlighting northern portions of the area in a day 5 15% severe weather outlook. In addition, temperatures may approach Heat Advisory criteria for portions of the area on Thursday.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

As of 640 AM EDT Sunday...

VFR conditions prevail into the early afternoon hours. Winds become southerly this morning, with occasional gusts to ~20 knots later this morning throughout the afternoon/evening. Thunderstorms develop around or after 21z across southern and western portions of the area, spreading east throughout the afternoon/evening. Some storms may be severe with damaging wind gusts being the main threat, winds may gust in excess of 35 knots with storms. PROB30 groups have been added to all sites due to the scattered nature of the storms and uncertainties on specific timing at each site. Storms taper to rain showers late in the period, especially closer to the coast. MVFR CIGs potentially develop late in the period.

Outlook: VFR/dry conditions return to all sites by later Monday morning . Becoming more unsettled on Tuesday, with the potential for MVFR CIGs, especially at the eastern TAF sites. Primarily dry/VFR conditions return for Wednesday through the first half of Thursday.

MARINE

As of 235 AM EDT Sunday...

Key Message:

- Small Craft Advisories in effect for the Ches. Bay this evening through tomorrow morning for SE winds of 15-20kt, becoming NW early tomorrow.

Southerly flow of 5-10kt is ongoing as of early morning obs. Seas are around 2ft and waves in the bay/rivers are 1ft or less. Winds will steadily increase today ahead of a cold front, turning SSE by mid-day. By the early evening hours, winds will be up to 15-20kt with gusts to 25kt over the coastal waters and bay (~15 over the rivers). SCAs are in effect for the bay starting at 21z. Decided against SCAs for the coastal waters since winds fall a bit short of criteria and seas are only forecast to increase to 4ft. Winds overall diminish slightly to ~15kt later tonight as the front passes through the area. However, convection associated with the front may include severe wind gusts, waterspouts, and small hail. Winds become northwesterly early Monday morning behind the front and will surge back up near 20kt through mid morning. Went ahead and ran the advisories out through the second surge for simplicity's sake, and because winds will still be near advisory levels overnight.

Winds will diminish pretty quickly Monday afternoon as high pressure builds in behind the front. Remaining benign through mid week with onshore flow of 5-10kt Tuesday then turning to the south for Wednesday. Another front late in the week may again bring elevated winds Thursday and Friday.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 5 PM this afternoon to 11 AM EDT Monday for ANZ630>632-634.