textproduct: Wakefield

WHAT HAS CHANGED

- Updated Discussions.

KEY MESSAGES

1) Above normal temperatures with dry conditions prevail through Friday.

2) An unsettled weather pattern with cooler and wetter conditions is likely for this weekend, then gradually drying out and remaining cool next week.

DISCUSSION

As of 330 PM EDT Wednesday...

KEY MESSAGE 1...Above normal temperatures with dry conditions prevail through Friday.

The latest WX analysis indicates a broad upper level ridge over the western Gulf coast, extending NE through the TN Valley. Sfc high pressure is centered along/or just off the coast. There is still enough low level moisture that SCT-BKN cumulus have developed this aftn, though this should diminish over the next few hrs given the lower sun angle this time of year. Temperatures are mostly in the upper 70s to lower 80s with dew pts in the lower 60s, so overall a fairly pleasant end to September for the local area. For tonight, expect to see a lot of high clouds streaming over the the upper level ridge axis, some of this is already seen on satellite imagery. With the sfc high drifting offshore, a light southerly flow is anticipated. Some patchy fog can't be ruled out, but with the high clouds and light southerly flow, expect the coverage to be fairly limited (best chances across interior southern VA and NE NC). Lows will be in the upper 50s to lower 60s for most, ranging from as low as the mid 50s in the coolest piedmont locations to the upper 60s at the coast in the SE.

The ridge shifts to the east, becoming centered across the SE coast Thursday-Friday, allowing the sfc high to slide well offshore. Expect temperatures to become very warm Thursday and Friday as the low level S-SW flow increases; highs into the mid 80s to near 90F Thursday, with upper 80s to lower 90s Friday is about 10-15 F above average for the start of October and qualifies as "unseasonably warm". Have included record highs in a Climate section for Friday since Norfolk may be close (records are very unlikely elsewhere).

KEY MESSAGE 2...An unsettled weather pattern with cooler and wetter conditions is likely for this weekend, then gradually drying out and remaining cool next week.

An increasingly unsettled pattern looks to take shape for the weekend into early next week. A deep closed low currently over the Desert Southwest into the Intermountain West looks to open up on Thursday as it absorbs the mid-level remnants of TC Polo and lifts across the central and southern Plains. This system will eventually become absorbed into a northern stream trough digging across the interior Northeast into the northern Mid- Atlantic over the weekend. This will serve to dampen the Southeast ridge and allow an influx of Gulf and Pacific moisture across the Gulf Coast and Mid-South, likely reaching our region over the weekend. One signal common to all guidance, even this far out, is a notable increase in PWATs, with values reaching 1.5-2.0" by Saturday night/Sunday. While some model differences remain, trends are favoring pushing that front south through much of the area on Saturday, with the front then slowing or stalling Sat night, as additional, and likely more significant swaths of moisture ride along the front later in the weekend into early next week. While a mainly cloudy sky and some scattered showers are expected to accompany the initial frontal passage and wind shift on Saturday, the more widespread rainfall (and bulk of the QPF) is expected Sat night through Sunday. Periods of rain are then likely to continue into Sunday night before ending from NW to SE. There is still plenty of time to monitor the trends over the next several days, but locally heavy rainfall is certainly possible (although much of this would be beneficial given ongoing drought). 12Z/30 Ensemble probs for 1"+ of total rainfall are pushed farther north from the EPS (Euro) compared to the GEFS, which keeps 50% chances confined to to southern VA and NE NC.

In terms of temperatures, increased clouds/precip and onshore flow favor much cooler high temps over the weekend into early next week, with many areas struggling to get out of the mid- upper 60s both Saturday and Sunday (highs generally in the 70s across the far south). Latest models continue in good agreement showing a strong enough push of drier air associated with high pressure building in from the north into the middle of next week, leading to below normal temperatures with highs in the 60s and lows into the 40s and 50s Tue-Wed. The LREF robs even show some chance for lows into the upper 30s across the NW piedmont by Wed AM.

AVIATION /00Z THURSDAY THROUGH MONDAY/

As of 800 PM EDT Wednesday...

VFR conditions prevail through the 00z TAF period with high clouds tonight and FEW-SCT cumulus on Thursday. Some patchy fog is possible, but is generally not expected at the main terminals. Light S-SE winds become S-SW at 5-10 kt on Thursday.

Outlook: VFR with breezy S-SW winds on Friday. Rain chances increase over the area over the weekend ahead of an approaching low pressure system and a cold frontal passage. Flight restrictions are likely in rain and low clouds Sat night-Sun night/early Monday.

MARINE

As of 300 PM EDT Wednesday...

Key Messages:

-Sub-advisory marine conditions continue through the end of the week

-Small Craft Advisories are likely for at least the Ches. Bay early Sat behind a cold front.

High pressure remains over the local area this afternoon, leading to benign marine conditions. Latest obs show S/SE winds of 5 to 10kt and seas around 2ft. These conditions will persist this evening and overnight. High pressure will slide offshore tomorrow afternoon, which will allow for a slight increase in winds out of the SW on the backside of the high. Winds of 10 to 15kt expected. Breezy, but likely sub-advisory, conditions persist on Friday as the pressure gradient tightens ahead of a cold front. This initial cold front should push south Friday evening, leading winds to turn to the N/NE behind it. The incoming cool, dry air over the warm water combined with a still tight pressure gradient looks to cause a brief surge late Friday night into early Sat. Local wind probs for sustained 18kt winds are between 60-80% over the bay and up to 95% over the northern coastal waters. Seas will build to 3-4ft during this period with waves around 3ft in the bay. Winds should diminish to sub- advisory levels Sat afternoon, but will remain breezy out of the northeast through the rest of the weekend. Seas return to ~3ft and waves to ~1ft on Sunday. The 12z suite of models still points to a stronger cold front early next week, which will also likely result in SCAs.

CLIMATE

Record highs are unlikely Friday, though Norfolk may be close so for reference, they are listed below:

Record Highs for Friday Oct 2nd:

- RIC: 98 (2019) - ORF: 93 (2019) - SBY: 96 (2019) - ECG: 93 (1986)

AKQ WATCHES/WARNINGS/ADVISORIES

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