textproduct: Wakefield

WHAT HAS CHANGED

All discussion sections updated for the overnight forecast package.

The Slight Severe Risk for Thurs has been expanded south to the VA/NC border.

KEY MESSAGES

1) Storm chances increase Thursday evening, continuing overnight and potentially into Friday. Strong to severe storms possible Thurs evening.

DISCUSSION

As of 320 AM EDT Wednesday...

KEY MESSAGE 1....Storm chances increase Thursday evening, continuing overnight and potentially into Friday. Strong to severe storms possible Thurs evening.

A warm front will lift north of the area today. As such, temps will be a bit warmer than yesterday with highs in the low 90s. Otherwise, a pretty decent day today with mostly sunny skies and a light breeze. Heating up more tomorrow with highs in the mid to upper 90s and heat indices mostly around 100 but up to 104 in the southeast. SW flow also increases as the pressure gradient tightens ahead of a cold front, leading to breezy conditions with gusts of 25-30mph for most of the day tomorrow.

Storm chances increase during the late afternoon and evening hours Thursday, though there's still some uncertainty in what kind of coverage we will get out of this system. Thursday evening/night has trended drier with more sparse coverage in the GFS, Canadian, and NAM with only the ECMWF keeping the higher coverage. Current thinking is that there will be at least widely scattered storms Thurs night, particularly across western and central portions of the FA. There is the potential for some of these storms to be strong to severe, but the window for this will be kind of narrow (7-10ish). With hot, humid conditions during the day, instability likely builds to the 1200-2000 J/kg range. But with the timing of storms likely later in the evening, storms will have to work with waning instability that could be under 1000 J/kg by 10pm (based on the LREF mean). Shear should be decent enough to support a few stronger storms, though nothing substantial (maybe 30-35kt). Main threat from these storms would be severe wind gusts as evidenced by nearly 1000 J/kg of DCAPE that the guidance depicts. The SPC has designated a Slight risk for all of our VA and MD counties with a Marginal in NC.

There's still a fairly wide range of solutions from the models about what will happen Friday. The ECWMF is holding onto its solution of redeveloping tropical remnants from the gulf into an area of low pressure that tracks across NC and out to sea. This would mean the potential for moderate to heavy rainfall during the day Friday particularly across the south. The Canadian also has this sfc low, but a bit weaker, a bit faster, and with a bit less moisture. It mostly limits the rain to SE portions of the area. The GFS is much drier for Friday as it never develops the sfc low and it pushes Thursday's front and the associated moisture south of the area. Regardless, rain should be pushing out of the area by Friday evening. Dry conditions and near-average temperatures then prevail for the weekend. Unsettled conditions potentially return early next week with the approach of another cold front.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

As of 650 AM EDT Wednesday...

VFR conditions prevail for the 12z/17 TAF period. Overcast skies gradually clear out early this morning as a warm front lifts north of the area. Light winds mostly out of the SW (some variation in direction at ORF), then turning SE at 5-10kt this evening.

Outlook: Showers/storms possible Thu evening into early Fri with lingering showers and embedded storms into Fri afternoon. Drier conditions/VFR conditions return late Fri into the upcoming weekend.

MARINE

As of 320 AM EDT Wednesday...

Key Message:

- Benign marine conditions today.

- Small Craft Advisories are in effect for all of the waters later tonight into Thursday night due to increasing SW winds and seas ahead of a strong low pressure system.

- Gale conditions are possible for the far offshore waters off the NC coast. A Gale Watch has been issued for late Thursday afternoon into Thursday night.

Early this morning, a warm front is draped over the far southern waters. This front will continue to lift north across the entire area as we head through the morning hours. Winds are primarily out of the SE, averaging 5 to 10 knots. Seas average 2 to 3 feet and waves in the Chesapeake Bay average 1 to 2 feet.

Benign/sub-SCA conditions are expected throughout the daytime hours today with a S to SE wind averaging 5 to 15 knots (highest in the afternoon/evening). The gradient tightens tonight into early Thursday ahead of the next front, with winds become SW and increasing to 15 to 20 knots. Winds increase further after sunrise Thursday through much of the day, especially along the immediate coast where we will see the best mixing. Winds may gust up to 30 knots by Thursday afternoon along the coast. Small Craft Advisories are in effect for the Chesapeake Bay and lower James River beginning tonight and for the remainder of the waters beginning Thursday morning. For the far offshore waters, especially the waters south of the VA/NC border, gusts to 35+ knots will be possible during the late Thursday afternoon timeframe into Thursday night. The highest gusts will be confined to the southeastern portion of the NC offshore zone, with local wind probs showing a ~50% chance for gale gusts across this location. As a result, a Gale Watch has been issued for this zone. We will also need to watch the potential for strong to severe thunderstorms Thursday evening into Thursday night which may bring local wind gusts of 40+ knots. During the Thursday- Thursday night timeframe, seas build to 4 to 6 feet nearshore and 5 to 8+ feet offshore. The cold front drops across the local waters on Friday with winds shifting to the N/NW behind the front (sub-SCA). Winds diminish Saturday into Sunday as high pressure builds into the area. Winds and seas may increase again Sunday night into early next week as another system approaches the region.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 1 AM Thursday to 1 AM EDT Friday for ANZ630-631. Small Craft Advisory from 1 AM Thursday to 7 AM EDT Friday for ANZ632-634. Small Craft Advisory from 7 AM Thursday to 7 AM EDT Friday for ANZ633-650-652-654-656-658. Small Craft Advisory from 7 AM to 7 PM EDT Thursday for ANZ635>637. Small Craft Advisory from 4 AM Thursday to 7 AM EDT Friday for ANZ639. Gale Watch from Thursday afternoon through late Thursday night for ANZ688.