textproduct: Wakefield

SYNOPSIS

Benign weather is expected tonight into Saturday. A strong cold front crosses the the Mid-Atlantic late Saturday night into Sunday, with some accumulating snow possible Sunday. Arctic air moves in behind the cold front Sunday night, and provides a cold start to next week. The very cold temperatures do quickly give way to relatively milder temperatures for the middle to end of next week.

NEAR TERM /THROUGH SATURDAY/

As of 250 PM EST Friday...

Key Message:

- Mostly clear and chilly tonight with lows in the mid 20s to around 30F.

- Partly to mostly sunny and milder Saturday with highs in the upper 40s to mid 50s.

Weak high pressure is centered from the upper Ohio Valley to the northern Mid-Atlantic this afternoon. Meanwhile, a sheared apart shortwave trough and subtle surface low are sliding across the Carolinas through the base of a broad upper trough. Mid and high clouds are thinning across the region this afternoon and any radar returns (that produced little to no precip/light snow due to a dry sub-cloud layer) are largely pushing S of the local area. Temperatures this afternoon are generally in the mid 30s to around 40F.

Weak high pressure builds into the area tonight. Mostly clear with some increasing cirrus clouds across the N late. Forecast lows are in the mid 20s to around 30F. Quasi-zonal flow aloft will allow surface high pressure to slide offshore Saturday. Partly sunny N to mostly sunny S with an overall increase in cirrus clouds through the afternoon. Milder, but still slightly below to near average, with high temperatures ranging from the upper 40s N to mid 50s S.

SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/

As of 250 PM EST Friday...

Key Messages:

- An Arctic cold front crosses into the region Sunday, ushering in a much colder airmass Sunday night and Monday. Some snow is possible with the Arctic frontal passage, especially from the Neck to the Eastern Shore.

A vigorous upper trough digs across the central Appalachians Saturday night and then SE along the southern Mid- Atlantic coast Sunday along with an associated strong arctic cold front. A band of snow (may begin as rain) is expected to spread across the Northern Neck and MD Eastern Shore late Saturday night into Sunday morning. Farther SE, as of now, the situation looks to be cold air chasing moisture, which points toward a scenario of rain ending as a brief period of snow for Hampton Roads and NE NC. 12/12z ensemble probs are decently aligned with the GEFS bringing its >1" probs a touch further south than the EPS, but the main difference is that the GEFS has some low 1" probs for SE VA/NE NC, but this is an outlier compared to EPS/EC AI ens./CMC ens. The ECMWF shows 50-80% across the far north, while the GEFS is similar for the Northern Neck to the MD Eastern Shore with less back into the NW Piedmont. 3" probs are negligible for the local area. Forecast snow accumulation is in line with these with 1-1.5" in Dorchester MD, 0.5-1" for the Northern Neck and the rest of the MD Eastern Shore, and <0.5" nearly down to the US-460 corridor.

The main accumulation period based on current timing would be between 09-15z Sunday across the NE, and 12-18z Sunday farther S/SE. The front then exits offshore Sunday afternoon, possibly putting down a dusting of snow at the coast as precipitation quickly ends as a dry arctic airmass arrives from the NW (dewpoints falling into the single digits). Highs will range from the mid 30s across the N to the mid 40s in the SE. Temperatures drop quickly behind the front Sunday afternoon/evening. Northwest winds become rather gusty behind the front as well, leading to wind chills as low as the teens by mid evening. NW wind gusts of 25-35 mph are expected inland with 30-40 mph toward the coast.

Breezy conditions are forecast for Sunday night into Monday as an Arctic airmass and weakening but still 1035+mb high move into the region behind the cold front. NW wind gusts of 20-30mph will still be possible toward the coast Sunday night. The wind will relax farther inland, but still remain NW 5-10 mph through much of the night into early Monday morning. Temperatures drop quickly Sunday night as strong CAA ensues. Many locations could experience temperatures in the teens early in the night, dropping into the mid- teens (potentially colder) by sunrise. Even immediately near the coast, forecast lows are only around 20F. Wind chills will be in the single digits for the entire area. A Cold Weather Advisory will likely be needed for most, if not all, of the area Sunday night into Monday morning. The wind relaxes later Monday morning into the afternoon as high pressure builds across the region. Regardless, sunny and chilly with highs in the mid 30s.

LONG TERM /MONDAY NIGHT THROUGH FRIDAY/

As of 250 PM EST Friday...

- Moderating temperatures and mainly dry conditions are expected through the middle of next week.

High pressure weakens but remains over the region Monday night, and will be slow to move offshore Tuesday. Lows Monday night will likely drop to 20-25F inland (with some upper teens possible) with mid 20s to around 30F at the immediate coast. High temperatures moderate Tuesday, but remain below seasonal averages, and range from the lower 40s N to mid 40s S. A warming trend commences Wednesday once sfc high pressure is suppressed to the SE and the flow aloft becomes more zonal. Forecast highs moderate into the lower/mid 50s Wednesday, and around 60F Thursday. Lows will still be chilly and in the mid 20s to lower 30s Wednesday morning, and then mid/upper 30s Thursday morning. A cold front potentially pushes through the area Thursday night dropping temperatures back to near seasonal averages late week. Dry through Wednesday, with low rain chances returning later Thursday/Thursday night, before trending drier late week.

AVIATION /19Z FRIDAY THROUGH WEDNESDAY/

As of 150 PM EST Friday...

VFR conditions prevail as of 18z under SCT-BKN mid and high clouds as a weakening low pressure system tracks across the region. VFR conditions continue through the 12/18z TAF period. Mid and high clouds thin tonight with primarily clear/sunny conditions Saturday morning, followed by increasing high clouds Saturday aftn. The wind will be light and locally variable this aftn through tonight, and become SSW 5-10kt late morning into aftn Saturday.

A strong cold front crosses the region late Saturday night into early Sunday. This could bring a period of a rain/snow mix followed by all snow late Saturday night through midday Sunday along with brief flight restrictions. Turning much colder/drier with gusty NNW winds (25-35kt) Sunday afternoon. VFR conditions prevail Sunday night through Wednesday.

MARINE

As of 250 PM EST Friday...

Key Messages:

- Benign marine conditions are expected through the first half of the weekend.

- Gales are expected as a strong cold front moves across the local waters Sunday into Monday morning.

Afternoon weather analysis a weak high pressure over the area. With the high pressure in control benign marine conditions have been noted across all waters with light northerly wind between 5 to 10 kt. Seas remain low with around 1 ft waves across the bay and 2 to 3 ft waves across the ocean. Through tonight into Saturday a warm front is expected to move across the area shifting winds to the SW. Winds are not expected to increase much and marine conditions will remain benign. Winds on Saturday will be around 10 kt with perhaps some 15 kt sustained winds across the far northern ocean waters closer to where the front will stall. Seas will remain low with around 1 ft waves remaining across the bay and 2 to 3ft waves across the ocean.

All eyes then turn to Sunday where Gale force winds are expected across all waters. A strong cold front is expected to pass through the area stating as early as Sunday morning. Behind this front much colder and drier air will advect into the region. Extremely cold temperatures aloft will mix down to the surface across (relatively) warmer waters helping create very windy conditions. With decent model agreement in the cold temperatures aloft and with local wind probs showing 90%+ chances for wind gusts >= 34 knots a Gale Watch has been issued for all waters from Sunday morning to Monday morning. Winds are expected to be out of the NW between 30 to 35 kt sustained and gusts upwards of 40 to 45 kt. Over the upper rivers the winds may not be as high, however, winds will still be around 30 kt with gusts upwards of 35 to perhaps 40 kt. Seas will also increase, building to as high as 8 to 10 feet over the coastal waters and 5 to 6 feet in the Chesapeake Bay by Sunday night. By Monday morning, winds will gradually diminish, however, SCA will likely be needed for much of Monday due to seas remaining at 5+ feet and gusts could remain as high as 25 kt. Calmer conditions are then anticipated Monday night into the middle of next week as strong high pressure builds over the area.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Gale Watch from Sunday morning through Monday morning for ANZ630>634-650-652-654-656-658. Gale Watch from Sunday afternoon through Monday morning for ANZ635>638.