textproduct: Wakefield

WHAT HAS CHANGED

Updated all discussions. Latest guidance has trended wetter and shifted the axis of heavier rainfall somewhat farther northwest for Friday, with localized rainfall amounts in excess of 2 inches becoming increasingly possible, especially across eastern portions of the area.

KEY MESSAGES

KEY MESSAGE 1...Increasing clouds with a few light showers or sprinkles possible through this evening. Unseasonably warm conditions continue through Thursday.

KEY MESSAGE 2...Widespread moderate to locally heavy rainfall is expected Thursday night through Friday, with a few thunderstorms possible.

DISCUSSION

As of 230 AM EST Wednesday...

KEY MESSAGE 1...Increasing clouds with a few light showers or sprinkles possible through this evening. Unseasonably warm conditions continue through Thursday.

High pressure continues to shift farther offshore this afternoon as a cold front slowly approaches from the west. Cloud cover has increased more quickly than anticipated over much of the area. In addition, a few sprinkles and light rain showers have developed, especially across the southern half of the area, as moisture increases ahead of the next system. Expect this activity to remain generally light and spotty through this evening, with many locations staying dry. The increased cloud cover will likely limit additional warming this afternoon, although temperatures remain well above normal for early November.

Mostly cloudy skies are expected tonight as additional mid- level moisture streams into the region. Rain chances gradually increase across our western zones tonight, with the highest PoPs across far western Louisa, Fluvanna, and Prince Edward counties. Temperatures remain mild with lows generally in the upper 50s to lower 60s.

Another warm day is anticipated for Thursday as southerly flow increases ahead of the approaching front. High temperatures likely climb into the mid to upper 70s with a few locations across SE VA and NE NC approaching 80 degrees. Skies will remain mostly cloudy, and a few isolated showers or sprinkles will be possible during the day. However, the more widespread rainfall is expected to hold off until Thursday night.

KEY MESSAGE 2...Widespread moderate to locally heavy rainfall is expected Thursday night through Friday, with a few thunderstorms possible.

Confidence continues to increase in a widespread rainfall event Thursday night through Friday as a slow-moving cold front approaches and crosses the region. Rain should develop across western portions of the area late Thursday night before becoming more widespread Friday morning. The primary forecast challenge continues to be the placement and magnitude of the heaviest rainfall, particularly given the potential for a wave of low pressure to develop and track northeast along the frontal boundary Friday.

The latest 12z guidance has trended wetter, with the ECMWF shifting the axis of heavier precipitation a bit farther to the northwest compared to its previous runs. The 12z EPS has followed this trend, with increasing probabilities of exceeding both 1 and 2 inches across eastern portions of the area. The EPS mean now depicts rainfall amounts of 1.5 to locally over 2 inches across portions of SE VA and the MD Eastern Shore, with considerably lower amounts farther inland. Meanwhile, the 12z GFS remains notably wetter and farther northwest, depicting localized amounts of 3 to 4 inches from central VA northeastward toward the Eastern Shore.

There is a favorable environment for locally heavy rainfall, with PWATs forecast to increase to 200+ percent of normal for early November. In addition, guidance suggests a corridor of enhanced mid-level frontogenesis and strong ascent associated with the frontal boundary and a potential developing wave of low pressure. This could support a southwest to northeast oriented band of moderate to locally heavy rainfall, potentially persisting over some locations for several hours. While confidence in widespread rainfall has increased, uncertainty still remains regarding the precise location and intensity of this band. In general, rainfall amounts of 0.50 to 1.50 appears reasonable for much of the area with 1.5 to 2 inches or more possible across portions of eastern VA and the MD Eastern Shore.

A few embedded thunderstorms will also be possible Friday, particularly across SE VA and NE NC. Forecast soundings indicate increasing deep-layer shear, generally 30 to 40 kts, with modest surface based instability developing in the warm sector (~500 J/kg MLCAPE). While the environment could support a few stronger storms, widespread cloud cover and ongoing precipitation will likely substantially limit destabilization. As a result, organized severe weather is generally not anticipated, though an isolated damaging wind gust cannot be completely ruled out across far SE portions of the area.

Rainfall gradually diminishes from west to east later Friday afternoon into Friday night as the cold front pushes offshore. Drier and cooler conditions return for the weekend as northwest flow develops behind the front. High temperatures generally return to the 60s Saturday and Sunday with seasonably cool overnight lows.

AVIATION /19Z WEDNESDAY THROUGH MONDAY/

As of 1245 PM EST Wednesday...

MVFR stratus has developed across portions of central VA this afternoon (bases ~2500 ft), mainly impacting RIC. Expect the lower clouds to gradually lift over the next few hours, with VFR conditions returning to all terminals later this afternoon. Mid and high level clouds will continue to stream into the region ahead of an approaching cold front tonight into Thursday. The increased cloud cover should help to limit any fog development tonight, with VFR conditions expected to continue. A few showers showers are expected tonight into Thursday, especially across western portions of the area, but these will likely not be heavy enough to produce any VSBY issues. Cloud bases likely lower to MVFR Thursday morning across the west, mainly impacting RIC.

Outlook: Rain chances increase Thursday night into Friday, with widespread showers and isolated thunderstorms potentially resulting in periods of sub-VFR conditions. Conditions improve Friday night into Saturday, with VFR conditions generally anticipated for much of the weekend.

MARINE

As of 230 PM EST Wednesday...

Key Messages: Sub-SCA winds continue through Friday, but winds could reach SCA levels over the weekend in the wake of a cold frontal passage on Friday.

Another SCA event is possible early next week when a stronger front potentially crosses the waters.

High pressure remains anchored off the Mid-Atlantic coast this afternoon with generally light SE winds in the 5 to 10 kt range. The flow will gradually increase to 10 kts tonight into Thursday as a cold front approaches the area from the west. This will help turn winds more southerly, but the area of high pressure off the coast holds it position and the front should weaken and possibly dissipate before entering the coastal waters. This will keep the southerly flow to around 10 kts into the day on Friday. The onshore flow over the next 24 - 36 hours will push a little more swell toward the coast with seas increasing to 3 - 4 ft in the coastal waters.

The next upper trough approaches and deepens over the Great Lakes on Friday and swings a cold front into the Mid-Atlantic States. This will produce periods of showers and southerly winds around 10 kt. Once the cold front passes the area on Friday night, the winds will shift to the west and gradually increase later Friday into the day on Saturday. With good cold air advection developing in the wake of the front, expect winds to possibly reach up to 20 - 25 kt Saturday afternoon into the overnight hours. It is possible that SCA flags may be needed during that time period.

High pressure will build back into the area later on Sunday, but after this the forecast confidence drops as the models diverge between a possible southern stream weather system over the gulf coast possibly impacting from the south or another strong northern stream cold push from central Canada. Will continue to monitor develops for early next week over the coming days.

AKQ WATCHES/WARNINGS/ADVISORIES

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