textproduct: Wakefield

WHAT HAS CHANGED

Forecast update. No major forecast changes.

KEY MESSAGES

1) Warmer this afternoon with scattered afternoon and evening showers and thunderstorms.

2) Shower and thunderstorm chances continue through the weekend with hot and humid weather expected, especially on Saturday. Dry weather and slightly cooler temperatures return early next week.

3) A warming trend is expected by the middle of next week, with more significant heat possible by later in the week heading into the holiday weekend. Shower/thunderstorm chances remain very low through Wednesday.

DISCUSSION

As of 250 PM EDT Friday...

KEY MESSAGE 1...Warmer this afternoon with scattered afternoon and evening showers and thunderstorms.

Latest analysis reveals Bermuda surface high pressure still centered well offshore, with zonal flow aloft east of the Rockies. Temperatures at 18z are well into the 80s to low 90s on breezy low-level S-SW flow. Two areas of showers have also developed; the first to our W-NW in association with an approaching shortwave trough, with decent agreement CAMs continue to hint that showers and storms will continue to focus along the lee/pre-frontal trough to our W/NW. The second area of showers is across central and eastern NC along the afternoon seabreeze, with these showers expected to weaken with time as they push into SE VA through mid-late afternoon.

Scattered showers and thunderstorms will continue across northeast NC into far SE VA through early evening. Given relatively modest instability and weak shear, expect storms to remain below severe limits for the most part, but some gusty winds are possible. Meanwhile, chances for showers and storms ramp up across northern and western portions of the area late this afternoon, with isolated- scattered convection potentially spreading E or SE during the early part of tonight before diurnal weakening occurs. With the heat and humidity, a few stronger storms capable of producing highly localized damaging wind gusts cannot be ruled out, especially given increasing 500mb flow in advance of a shortwave trough to our NW. SPC has maintained a Marginal Risk for severe storms (Level 1 out of 5) across northern portions of the FA, including the Richmond metro.

Given increasing moisture and with weak disturbances crossing overnight, will maintain a low end chance for showers through the night. Lows mainly in the 70s.

KEY MESSAGE 2...Shower and thunderstorm chances continue through the weekend with hot and humid weather expected, especially on Saturday. Dry weather and slightly cooler temperatures return early next week.

The upper level flow gradually shifts from W to NW over the weekend in response to strong ridging building upstream over the Northern Plains. Meanwhile, a series of shortwaves will drag a cold front through the area late Sunday or Sunday night. Convective timing and areal coverage of storms once again remain conditional upon overnight and early morning upstream MCS activity. High-res guidance continues to suggest that overnight convection or at least stabilizing convective outflows/debris cloudiness will track near or just north of the area Saturday morning. This likely portends some lingering cloud cover and a reinforced stable outflow pool across the northern half of the FA, effectively delaying boundary layer destabilization and maintaining a stronger convective capping inversion through much of the day. Consequently, SPC has maintained a Marginal Risk (Level 1 of 5) across northern sections.

Farther south, minimal impacts over the southern half of the area will allow for more in the way of sunshine, and subsequent late day destabilization ahead of an approaching (stronger) afternoon shortwave, which will trigger convection. A very warm to hot and moderately humid airmass will drive DCAPE values into the 1000-1500 J/kg range along and south of US-460 into SE VA and eastern NC, making the southern half of the area a bit more conducive to severe weather. For that reason, a Slight Risk (Level 2 of 5) has been nudged SE slightly, but remains in place south and east of a Lawrenceville-Wakefield-Newport News line, including most of Hampton Roads and NE NC. Given decent W-WNW flow aloft and 25-35 kt of 0-6km bulk shear, organized clusters or line segments, capable of producing localized damaging wind gusts will be the primary threat. Storm motions should generally be progressive enough (15-20 kt) to limit the widespread flash flood threat, though brief hydro issues cannot be ruled out if convection coalesces over urban areas.

Convective coverage is expected to be a bit less on Sunday and confined more to southern and western portions of the FA as the front begins sinking south through the area and the low-level flow becomes N-NE across northern portions of the FA. Though once again, potential for damaging wind gusts persists across Hampton Roads into NE NC, albeit a bit earlier in the day through around sunset. Dry and fairly pleasant weather for the end of June is expected on Monday, with temps in the mid- upper 80s and noticeably lower humidity as high pressure builds toward the area from the NNE.

KEY MESSAGE 3...A warming trend is expected by the middle of next week, with more significant heat possible by later in the week heading into the holiday weekend. Shower/thunderstorm chances remain very low through Wednesday.

Upper heights gradually rise for the latter half of the week into the holiday weekend. Multi-model consensus continues to show an anomalously strong heat ridge building E from the mid- south toward the southeast coast late next week. This will lead to a warming trend for the late week period. After seasonable temps Tuesday, a pronounced warming trend develops with temperatures well into the 90s to around 100F possible from Wednesday-Friday (especially if the ridge builds farther east and lingers toward the central Appalachians like the latest ECMWF/EPS shows). It appears as if there is a decent chance for 105F+ heat indices across a decent portion of the area by late next week as well.

However, it must be noted that local mid-Atlantic climatology suggests that reaching air temps in the 95-100+F range requires either deep boundary layer mixing or a strong downsloping component, both of which would naturally mix out Td well below the NBM values. In terms of rain chances, strong high pressure overhead, plenty of sunshine, and dry, downslope flow do not lend themselves to high rain chances. The only real opportunity for showers and storms in this pattern would be with "ring of fire" type convective complexes, and this keeps rain chances quite low through the extended period. This will all be better resolved as we get closer. The bottom line is that preparations should be made now for another period of very warm to hot temperatures/heat indices late next week into the 4th of July weekend.

AVIATION /19Z FRIDAY THROUGH WEDNESDAY/

As of 255 PM EDT Friday...

VFR conditions in place across area terminals to begin the 18z TAF period, with S-SW winds of 5-10 kt, and occasional gusts to 15-18 kt. SCT CU with bases around 5 kft AGL this afternoon into this evening, Some isolated showers or storms have developed near the KORF/KECG terminals, with additional isolated to widely scattered showers/storms possible area- wide late this afternoon and this evening. Rain chances are too low to mention in PHF TAF attm, but did add vicinity wording at RIC/SBY this evening into the early morning hours Saturday. Isolated showers and storms may persist tonight, but confidence in precip is low. However, expect we will see some MVFR to IFR CIGs late tonight into Sat AM, as moisture increases ahead of the next system.

Outlook: There is a better chc of showers/tstms on Saturday afternoon and evening across the entire area, and low-end shower/storm chances continue on Sunday (mainly S/SE terminals). Prevailing conditions will be VFR outside of sub-VFR conditions in convection. VFR conditions are expected to return by the beginning of next week as a cold front moves south of the forecast area.

MARINE

As of 240 PM EDT Friday...

Key Messages:

- Sub-SCA marine conditions expected into early next week, outside of any thunderstorm activity late today and again Saturday ahead of a weakening cold front.

Sfc high pressure centered near Bermuda is favoring a continuation of sub-SCA conditions across our local waters today. S or SW 10-15 kt winds prevail through early Sunday as a slow-moving frontal boundary approaches from the N. Briefly elevated winds are possible this evening into early tonight, especially on the ocean, with a few gusts to 20 kt likely. Otherwise, briefly higher winds and waves are possible with any shower or storm today through Sunday. The front drops into the waters Sunday morning, with winds shifting to the NE. There isn't much CAA to work with so winds are likely to remain below SCA thresholds. The one caveat would be the solution depicted by the NAM which shows a stronger low and tighter pressure gradient Monday. If this were to occur, stronger NE winds would be realized with widespread SCA conditions. Still, this is not favored at this time. A typical summertime pattern is expected mid-late next week with generally light flow, isolated afternoon/evening thunderstorms, and hot temps.

Seas hover in the 2-3 ft range through most of the forecast period, potentially up to 4 ft on the ocean tonight. Waves in the bay/rivers sound of 1-2 ft or less. Have adjusted the rip current forecast to "Low" for all beaches through the weekend. While just outside the rip current forecast period, Monday could approach "Moderate" with 9- 10 sec periods and onshore flow.

AKQ WATCHES/WARNINGS/ADVISORIES

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