textproduct: Wakefield

WHAT HAS CHANGED

No significant changes to the forecast. The severe weather threat for Sunday remains with a 30% wind probability for much of the local area.

00z Taf was updated.

KEY MESSAGES

1) There is a Slight Risk (level 2 of 5) for severe thunderstorms across the area Sunday afternoon to late evening.

2) A cooler, somewhat unsettled pattern takes hold for early next week. Warmer and more humid conditions return for the mid to later portions of the week.

DISCUSSION

As of 340 PM EDT Saturday...

KEY MESSAGE 1...There is a Slight Risk (level 2 of 5) for severe thunderstorms across the area Sunday afternoon to late evening.

The stationary front that crossed the area overnight has stalled as a stationary front to our south. This front will push back north tonight, keeping temperatures mild overnight. This will also bring a chance of showers to to the far south near the Ablemarle Sound this evening. Overnight temps will be in the upper 60s to lower 70s.

Southerly flow and dewpoints in the 70s returns area-wide from the warm front lifting back north on Sunday. A strong cold front will cross the area Sunday night providing a strong forcing mechanism that will be able to overcome any environmental capping. Combined with the unstable airmass, scattered strong to severe thunderstorms are expected across the area. The latest model package continues to show MLCAPE values of 1500-2000 J/kg with steep lapse rates >6.0 C/km. Additionally, there will be more shear present that last night's storms with averages around 30 to 40 kts. Putting it all together, a Slight Risk (level 2 of 5) of severe storms remains over almost the entire local area. There was some collaboration with SPC about possibly upgrading to an Enhanced Risk, but after collaboration with SPC and neighboring offices, SPC has continued the Slight Risk. Cannot rule out an upgrade with future outlooks, given current model trends. The main threat with any storm is damaging winds gusts up to 60 mph+. A few discrete/supercells may also develop ahead of the main front Sunday afternoon-evening, bringing at least a low-end potential for large hail and even an isolated tornado. Finally, locally heavy rainfall may lead to isolated instances of flash flooding, especially over urban areas. Given the wind profiles, training storms are not expected and storms will likely move fast, so any flash flooding will be isolated. WPC has expanded the Day 2 ERO to cover the eastern half of the area, excluding the Eastern Shore in a Marginal Risk of flash flooding. The cold front moves through a majority of the area Sunday night bringing cooler/drier air and ending the threat for any severe weather. However, in typical fashion for the summer months, the front likely stalls near the coast allowing for unsettled conditions to continue into early next week.

Temperatures will increase behind the warm front overnight, with highs climbing back into the mid 90s for the area (lower 90s along the immediate coast) on Sunday. Although humidity builds back in, heat indices will likely remain below Heat Advisory criteria, but reaching the upper 90s to lower 100s Sunday afternoon. The potential for meeting Heat Advisory criteria is highest across southside Hampton Roads and into northeast North Carolina.

KEY MESSAGE 2...A cooler, somewhat unsettled pattern takes hold for early next week. Warmer and more humid conditions return for the mid to later portions of the week.

An upper trough develops over the eastern half of the US early next week. In addition, the front from Sunday lingers near eastern portions of the area bringing continued chances for showers or thunderstorms into Monday across S/SE portions of the forecast area. Rain chances/cloud cover likely expands a bit further N/NW on Tuesday. Cooler conditions are expected through at least the first half of next week with high temperatures Monday near to slightly below average, ranging from the lower 80s north to the upper 80s south (upper 70s to around 80 Eastern Shore). Temperatures may stay in the upper 70s for a majority of the area 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 next week as the trough begins to break down. Thursday may approach Heat Advisory criteria.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

As of 700 PM EDT Saturday...

VFR conditions are expected to prevail through the 00z/14 TAF period. Winds become light and variable tonight with clear skies. With a warm front lifting north tonight some patchy ground fog cannot be ruled out across the SE terminals, However, confidence to put fog in the taf is low at this time. Tomorrow winds increase out of the SW around 10 kt with gusts nearing 20 kt across the coastal terminals. Showers and thunderstorms (some severe) may impact the terminals after 20z. As of this update added PROB-30s for all TAF sides besides SBY. This is due to storms likely impacting the Eastern Shore around or past 00z tomorrow.

Outlook: Primarily VFR conditions are expected for Monday, though shower/storm chances may linger across S/SE portions of the area early. Becoming more unsettled on Tuesday, with the potential for sub-VFR CIGs, especially at the eastern TAF sites.

MARINE

As of 330 PM EDT Saturday...

Key Message:

- Mainly Sub-Advisory conditions expected through Sunday, with a surge of northerly winds bringing the potential for low-end SCAs Monday in the Bay. A stalled boundary had moved well south of the area, with weak sfc high pressure in place. E-NE winds average 5-10 kt this aftn, with seas only 1-2 ft and waves generally ~1 ft in the Bay. The winds remain ~10 kt or less overnight, and shift to the S. Another cold front approaches the region Sunday, bringing a round of thunderstorms (mainly late in the aftn/evening) that could contain locally severe wind gusts. Outside of storms, S-SE winds increase to ~15kt over the bay and rivers and 15-20kt over the coastal waters during the afternoon, becoming SW Sunday evening. Local wind probs are rather low for 18 kt sustained winds in the Bay (20-30%), and with the typical bias with southerly flow will not be issuing any headlines through Sunday, though SMWs will likely be needed with convection. Seas increase to 3-4ft, up to 5ft well past 20 nm. Winds turn to the W behind the front (~15kt) late Sunday night, then to the N Monday morning. Models tend to underestimate these northerly surges, and latest wind probs have increased to >50% over much of the Bay Monday morning as some of the high res models are starting to have an influence in the forecast. Too early to issue headlines, but think there is a good chance for short- lived SCAs for the Bay and possibly the sound and lower James Monday. Seas will average 2-4 ft Monday, and 2-3 ft in the Bay, with diminishing waves/seas by Mon afternoon.

Tides: Elevated southerly winds along with high astro tides will lead to minor/nuisance flooding into the MD eastern shore portions of the Bay Sunday evening/night.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...None.