textproduct: Wakefield

WHAT HAS CHANGED

Updated aviation discussion for the 00z TAFs. No significant forecast changes.

KEY MESSAGES

1) Mainly dry weather, slightly below average temperatures, and lower humidity to end the week and start the weekend.

2) A typical summertime pattern returns by late this weekend and early next week, with near average temperatures and increasing shower/storm chances starting Sunday and continuing through early next week.

DISCUSSION

As of 300 PM EDT Friday...

KEY MESSAGE 1...Mainly dry weather, slightly below average temperatures, and lower humidity to end the week and start the weekend.

An upper level trough lingers over New England and Atlantic Canada this afternoon, with another trough over the upper Midwest. This places the Mid-Atlantic region in dry NW flow on the leading flank of an upper ridge. At the surface, weak high pressure is centered over the region. Quite pleasant for the end of July with temperatures in the mid/upper 80s and dewpoints in the upper 50s to mid 60s. Partly sunny with SCT afternoon CU. Humidity will likely come up a bit this evening, especially near the coast as the flow becomes onshore. One last dry day (but warmer/more humid) on Saturday as upper heights build a bit as the ridge and surface high nudge offshore and the LLVL flow becomes southerly. Highs near 90F w/ aftn dew pts rising into the mid-upper 60s.

KEY MESSAGE 2...A typical summertime pattern returns by late this weekend and early next week with increasing shower/storm chances starting Sunday and continuing through early next week.

The pattern becomes more unsettled late in the weekend into early next week as a slow moving UL trough approaches from the west. At the same time, a weak cold front approaches from the north, but will remain north of the local area through Monday (and likely wash out by Tue). With the approaching trough and Bermuda high pressure well offshore, deep-layered S to SW flow will prevail. This will allow rich Gulf moisture to overspread the area on Sunday and remain over us early next week. PWs surge from a comfortable 1-1.4" on Saturday to 2.2-2.4" by late Sunday/Sunday night. Scattered to potentially numerous showers/tstms are expected Sunday. The highest precip chances will initially be across south-central VA during the aftn (as the deep moisture arrives here first). Showers and tstms should gradually spread NE through the evening (though it may very well remain dry near the immediate coast and on the eastern shore). Showers/tstms are likely across the entire area on Monday as a lead shortwave potentially tracks over the area. Monday appears to be the day with the highest convective coverage during the period. The trough dampens a bit from Tuesday/Wednesday, but scattered showers and tstms are still expected during the aftn/evening on both days as weak SW flow aloft continues and deep moisture remains nearby. Given the environment and relatively weak unidirectional flow aloft and tall/skinny CAPE, there will be a threat of localized flash flooding each day. Temps dip down a little below average during the early week period thanks to the cloud cover and multiple rounds of rain.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

As of 720 PM EDT Friday...

VFR conditions prevail through the 00z/01 TAF period. High pressure remains over the area with FEW lingering CU clouds this evening. These will dissipate as daytime heating is lost after sunset. From then, mostly clear skies are expected throughout the night. Winds will drop to AOB 5 kt and shift more SSW overnight. Mainly SCT CU develops once again Saturday with primarily SSW 5-10 kt winds inland and trend from SSW to SSE along the coast.

Outlook: VFR/dry Saturday night through Sunday morning as high pressure settles offshore. Shower/tstm chances return on Sunday and Monday as a slow moving upper trough approaches the area, and linger into Tuesday/Wednesday. Periodic sub-VFR conditions are possible during this time, mainly from early morning stratus, and brief vsby restrictions in heavy rain.

MARINE

As of 300 PM EDT Friday...

Key Messages:

- A brief period of elevated S/SE winds are possible later Saturday afternoon into Saturday night as high pressure settles offshore.

- Another brief period of SCA conditions is possible Sunday night into Monday as a trough approaches from the west.

Sfc high pressure is still in control over the local area this afternoon, leading to light winds generally 5kt or less. Seas are 2ft or less. High pressure will slide offshore late tonight, resulting in the return of southerly sfc flow by tomorrow morning. The next frontal system that will impact the area will be approaching, leading to an tighter pressure gradient between the low over the midwest and the high pressure offshore. SSE winds increase Sat evening to 15-20kt, then diminish back to 10-15kt late Sat night through early Sunday. A brief SCA will likely be needed for the bay for the Sat evening timeframe. Seas and waves build to 3ft. South winds increase again Sunday night, again to 15-20kt. Winds likely remain elevated through Monday night. During that time, seas will be able to build to 4-5ft.

Showers and storms will be possible daily from Sunday through at least early next week, mostly in the afternoons. Severe risk is low at this time, but stronger storms could still have strong wind gusts. Heavy rain is the primary threat.

AKQ WATCHES/WARNINGS/ADVISORIES

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