textproduct: Wakefield

WHAT HAS CHANGED

- Heat Advisory issued for interior central and eastern Virginia and northeast NC Wednesday

- Shower/storm chances increased some Saturday, especially inland

KEY MESSAGES

1) Hot and humid conditions expected this week, peaking Wednesday and Thursday. A Heat Advisory has been issued for portions of the area Wednesday. Isolated storms are also possible, but most locations are likely to stay dry.

2) Shower/storm chances increase late week as a cold front approaches. Seasonable temps forecast behind the front for the later half of the Labor Day weekend.

DISCUSSION

As of 235 PM EDT Tuesday...

KEY MESSAGE 1...Hot and humid conditions expected this week, peaking Wednesday and Thursday. A Heat Advisory has been issued for portions of the area Wednesday. Isolated storms are also possible, but most locations are likely to stay dry.

A late summer (or early fall, depending on what definition you prefer) heat wave remains on tap for the upcoming week. Currently seeing an early taste this afternoon with temps well into the 90s. Dew points are attempting to mix out into the 60s, so it doesn't feel too humid out despite the hot temps. Still expect the peak of the heat Wednesday and Thursday as the center of the upper-level ridge nudges east toward the TN Valley. There remains some uncertainty regarding a backdoor front later Wednesday afternoon which could temper the higher-end heat potential further E and especially along the immediate coast and the Eastern Shore. This would bring some onshore flow to these areas in the afternoon. Away from here, peak heat indices of around 105 degrees are expected by the late morning and afternoon. Therefore, a Heat Advisory has been issued for portions of central and eastern VA and northeast NC, minus those closer to the coast. That boundary lifts back N on Thursday and the sfc flow is likely to be S-SW for all the area, allowing for widespread 105+ heat indices. In fact, some areas in SE VA could near 110 F. A Heat Advisory is expected for the vast majority of our CWA and will likely issue this either tonight or tomorrow.

Regarding thunderstorm chances, isolated convection is expected both today and Wednesday. The 12z CAMs as a whole are not all that excited about either day, though areas across the N and especially NE (Eastern Shore, etc.) are most favored for any convection. Some of the CAMs and global models depict some stronger convection, perhaps in the form of linear segments, to the north of the local FA. It is not outside the realm of possibility that those storms dive south into the local area. Northwest flow aloft and strong instability means that any storms that do form will have the potential for strong winds and large hail. SPC has maintained the Marginal Risk for NE portions of the area today and tomorrow. Tomorrow's slight risk does clip northern portions of the area and was actually expanded a bit southward, though this risk remains highly conditional on the actual presence of storms.

KEY MESSAGE 2...Shower/storm chances increase late week as a cold front approaches. Seasonable temps forecast behind the front for the later half of the Labor Day weekend.

The strong ridge aloft starts to break down/flatten late in the week. Meanwhile, a sfc cold front will approach and pass through the area sometime Friday, likely late. An initial round of storms will be possible Thursday, but coverage still looks on the low side and these chances ultimately depend on where that backdoor front is situated. The most favorable overlap of forcing, shear, and instability is expected Friday. At the surface, the aforementioned front to our N 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 bonafide 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. SPC has maintained a slight risk for severe for the area. The risk for storms (and any potential svr wx) Saturday is dependent on where the front is situated during peak heating. PoPs from the NBM have increased compared to the previous forecast and this is likely due to the slower trend in the ECMWF and EPS.

A gradual relief from the heat begins Saturday and especially Sunday- Monday. Storm chances also decrease as strong high pressure builds in from the north. A first glance at the later half of the Labor Day weekend looks promising for those wanting favorable wx for outdoor activities.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

As of 145 PM EDT Tuesday...

VFR conditions prevail for the 18z/01 TAF period. SCT CU will develop/persist through the afternoon, with mainly clear skies tonight. While there remains a low chance for an evening or overnight shower or storm, expected coverage and confidence remains too low for any targeted mention in the TAFs. A light W/WSW this afternoon continues into tonight, before shifting to the N early Wednesday morning. Model guidance also suggests some MVFR CIGs could sneak into SBY just before 18z Wednesday.

Outlook: Predominately dry/VFR conditions through Wednesday. Shower and storm chances begin to increase Thursday afternoon/evening (and especially Friday) at all terminals ahead of the next cold front.

MARINE

As of 155 PM EDT Tuesday...

Key Message:

- High pressure remains centered offshore through much of the week leading to sub-Small Craft Advisory conditions.

- A cold front approaches the waters late in the week and may bring elevated winds.

A ridge axis is currently stretched across the SE this afternoon, which is promoting light SW winds. Seas are averaging between 1-2 ft, with waves in the Bay measuring 1 ft or less. The weak gradient will remain in place through late afternoon until a cold front buckles to the SW and approaches the far NE waters by early Wednesday morning. Ahead of the cold front, winds will shift to the S and increase to 10-15 kts. The front drops south to roughly the VA/NC border through the day Wednesday before lifting back to the north as a warm front Wednesday night into Thursday. In the wake of the front, winds turn around to the N-NE ~10 knots. A cold front will approach the region Thursday into Friday with strengthening flow ahead of and (especially) behind the boundary this weekend. This could bring elevated winds and the next potential SCA conditions. Guidance has trended a little lower with winds behind the front, with in-house wind probs suggesting a similar lower forecasted winds. With that being said, the water is very warm and with a cooler airmass moving over the area, this will likely lead to at least SCA conditions across the Bay. Shower and storm chances will ramp up during the late week period ahead of the front.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...Heat Advisory from 11 AM to 8 PM EDT Wednesday for NCZ012>017- 030>032. VA...Heat Advisory from 11 AM to 8 PM EDT Wednesday for VAZ064- 079>083-087>090-092-097-511>520-528-529. MARINE...None.