textproduct: Wakefield

WHAT HAS CHANGED

-Updated the aviation section for 12z TAFs

-The Slight Risk for severe wx was trimmed back to just north of the NC border. Most of the area is still in the Slight Risk area, but areas along and south of the NC border are now in a Marginal Risk .

KEY MESSAGES

1) Hot and humid conditions with heat indices around 105F expected through the rest of the week. Heat Advisories remain in effect for the entire area excluding eastern Currituck/OBX and the MD Beaches.

2) There are daily chances for thunderstorms through Saturday. Some storms may be strong to severe with damaging winds gusts and large hail.

DISCUSSION

As of 240 AM EDT Thursday...

KEY MESSAGE 1...Hot and humid conditions with heat indices around 105F expected through the rest of the week. Heat Advisories remain in effect for the entire area excluding eastern Currituck/OBX and the MD Beaches.

Records will be challenged today as this heat wave peaks. The backdoor front draped along the coast will lift back to the north as a warm front and the strong UL ridge will remain anchored just to the west. Actual temperatures should max out in the upper 90s to around 100 this afternoon with heat indices peaking between 105 and 108. Unlike yesterday, this includes coastal areas since the sfc flow will return to the SW. Heat Advisories are already in effect for inland portions of the area (extended from yesterday) and advisories for the coastal zones (excluding OBX and MD Beaches) go into effect at 11am. The ridge starts to break down and a cold front will approach from the north going into Friday, but heat advisories will likely need to be extended for at least the southern half of the FA. Afternoon clouds and storms ahead of the front will likely limit temps across the north. "Limit" of course being a relative term since highs are still expected to reach the low 90s. Meanwhile, southern counties will have another day of near 100F temps and heat indices over 105. There will finally be some relief from the heat on the north side of the cold front over the weekend. Temps on Sat are a bit uncertain given the early morning frontal passage, but highs will generally be in the 80s with some lingering 90s across the far south Sat.

KEY MESSAGE 2...There are daily chances for thunderstorms through Saturday. Some storms may be strong to severe with damaging winds gusts and large hail.

Another round of weak shortwaves traveling down the ridge will bring another day of potential thunderstorms. Like the last couple of days, there is low confidence in coverage and high confidence that anything that does form could be severe. If storms are able to initiate, it would likely be late afternoon for the far NE, then progressing SE through the late evening hours. Once again, damaging wind gusts are the main threat. The Day 1 SPC outlook did trim the slight back to just above the NC border with a marginal risk for along and south of the border.

The most favorable overlap of forcing, shear, and instability is expected Friday. At the surface, the aforementioned front to our north will finally make appreciable progress and descend into our local area. Aloft, NW flow will remain in place and progressively strengthen as the associated trough drops southward along the NE/Mid- Atlantic coast, increasing the deep-layer shear. This all suggests a legitimate severe wx threat for the majority of the area Friday, with the potential for several fast-moving clusters capable of widespread damaging winds, along with isolated supercells and large hail. There is a slight risk for the entire area Friday.

The risk for storms (and any potential severe weather) Saturday is dependent on where the front is situated during peak heating. After the front moves through, the risk for severe weather becomes negligible as a much drier airmass filters in across the region through at least early next week.

AVIATION /12Z THURSDAY THROUGH MONDAY/

As of 645 AM EDT Thursday...

Patchy dense fog has spread across much of the area this morning and has impacted most of the terminals. Luckily, visbilities are already improving at the SE terminals and RIC has stayed in MVFR range so far. Restrictions are expected to linger the longest at SBY, but should clear up around mid- morning. VFR should then prevail through the remainder of the 12z TAF period. Late evening thunderstorms are possible once again, but likely won't reach terminals until after 00z. Did go ahead and add Prob30 groups for RIC and SBY for this evening.

Outlook: A stronger cold front is set to pass through the area Friday night into Saturday. The front will likely trigger scattered thunderstorms Friday as it slowly sags southward. This may cause flight restrictions and strong wind gusts.

MARINE

As of 210 AM EDT Thursday..

Key Messages:

- South to southwest winds increase today and tonight ahead of a cold front. Conditions are expected to remain below Small Craft Advisory criteria, but there could be wind gusts ~15 knots at times in the Chesapeake Bay and ~20 knots across the coastal waters.

- A cold front drops south over the waters Friday night into Saturday morning. This will allow winds to turn northerly then northeasterly as high pressure builds into the area. Wind gusts may approach 20 knots late Friday night into Saturday.

Early this morning, a warm front is slowly lifting north across the waters. Winds are generally light (~5 knots or less) and are out of the S to SE. Seas average 2 to 3 feet, while waves in the Chesapeake Bay average around 1 foot.

Today, high pressure will remain situated well offshore. Meanwhile, a cold front will approach from the north/northwest. The pressure gradient will gradually tighten, leading to an increasing S to SW wind. By this evening and tonight, a few gusts of 15 to 20 knots will be possible, with the strongest gusts across the southern half of the coastal waters. Winds diminish later Thursday night into Friday, with SW winds generally averaging 5 to 15 knots. The cold front begins to drop south across the waters Friday night into Saturday morning with winds turning to the N and eventually NE later Saturday into Sunday. There will not be a strong pressure push behind the front, but pressure rises and slightly cooler/drier air filtering in over warmer waters will lead to the potential for gusts of 15 to 20 knots Saturday. NE winds become breezy Sunday into Sunday night, leading to the next potential for SCA conditions across a majority of the waters. Calmer, more benign conditions look to take hold for early next week as high pressure builds back over the region.

Afternoon and evening thunderstorm chances ramp up today, becoming even more widespread on Friday. Any storms will have the potential to be strong or severe with locally strong wind gusts, large hail, and potentially a few waterspouts. Mariners should keep a close eye on the forecast each day. Seas will average 2 to 3 feet through Saturday, before building to 4 to 5 feet Sunday into Monday. Waves in the Bay will average 1 to 2 feet, building to 2 to 4 feet on Sunday.

CLIMATE

No records were set on Wednesday, 9/2 at any of the climate sites. Record highs are possible today (Thursday, 9/3) at Norfolk, Richmond, and Elizabeth City.

Richmond: Record High:

Thu (9/3) 99/1984 Fri (9/4) 98/2023

Norfolk: Record High:

Thu (9/3) 97/1977 Fri (9/4) 96/1985

Salisbury: Record High:

Thu (9/3) 99/1930 Fri (9/4) 95/1944

Elizabeth City: Record High:

Thu (9/3) 97/2020 Fri (9/4) 98/1944

AKQ WATCHES/WARNINGS/ADVISORIES

MD...Heat Advisory from 11 AM this morning to 8 PM EDT this evening for MDZ021>024. NC...Heat Advisory until 8 PM EDT this evening for NCZ012>017- 030>032. VA...Heat Advisory from 11 AM this morning to 8 PM EDT this evening for VAZ075>078-084>086-098>100-521>525-530-531. Heat Advisory until 8 PM EDT this evening for VAZ048-060>062- 064>069-079>083-087>090-092-097-509>520-528-529. MARINE...None.