textproduct: Wakefield

WHAT HAS CHANGED

Turning much colder Thursday with gusty NW winds behind tonight's cold front. Coastal low pressure brings increasing potential for some wintry weather to portions of the area on Sunday.

KEY MESSAGES

1) A strong cold front crosses the area late tonight into Thursday. Spotty light rain showers are possible tonight along with breezy westerly winds behind the front.

2) Turning colder Thursday and Friday. Below normal temperatures are expected from Thursday night into early next week. Mainly dry through Friday, there is a low-end chance for some light precipitation on Saturday.

3) Low pressure develops off the Southeast coast on Sunday with the potential for wintry precip across portions of the area. Uncertainty remains very high regarding specific impacts.

DISCUSSION

As of 650 PM EST Wednesday...

KEY MESSAGE 1...A strong cold front crosses the area late tonight into Thursday. Spotty light rain showers are possible tonight along with breezy westerly winds behind the front.

The first round of showers has moved offshore this evening. Additional light showers remain possible later tonight ahead of a strong cold front. However, confidence continues to decrease with the latest CAMs showing little (if any) additional showers. Given the trend for drier conditions overnight, CAMs no longer have any wintry mix and just have plain rain. Any rain moves offshore by Thu morning as drier air moves in behind the front. Overnight low temps range from the mid 20s in the Piedmont to the mid 30s along the coast. Additionally, winds become W and breezy overnight behind the front with gusts up to 20-25 mph possible.

KEY MESSAGE 2...Turning colder Thursday and Friday. Below normal temperatures are expected from Thursday night into early next week. Mainly dry through Friday, there is a low-end chance for some light precipitation on Saturday.

Skies clear quickly from west to east Thursday morning. Gusty NW winds are expected in the wake of the surface cold front. Deep mixing and very dry air aloft will allow afternoon RH values to fall below 30% despite high temperatures only in the 30s to low 40s. Wind chills likely do not get out of the 20s for the NW half of the area and only in the low to mid 30s SE. Winds decrease Thursday night with lows falling into the teens to low 20s under clear skies. High pressure to the south moves offshore on Friday but temperatures remain on the cool side in the 40s. A bit warmer Saturday ahead of the cold front with highs ranging from the mid 40s NW to the upper 50s SE. There is a slight chance for a shower or two across the NW half of the area but moisture is limited. Turning cold once again Saturday night with lows in the mid 20s to low 30s.

KEY MESSAGE 3...Low pressure develops off the Southeast coast on Sunday with the potential for wintry precip across portions of the area. Uncertainty remains very high regarding specific impacts.

Attention then turns to Sunday as a deep trough digs southward toward the central Gulf Coast. Surface low pressure forms off the SE coast Sunday morning and lifts NE. 12z guidance has mainly continued the trend of the overnight models to favor a stronger surface low closer to the coast. The GFS and its ensembles are the most bullish with increasing probabilities for impactful/accumulating snowfall, focused across the SE half of the area. The ECMWF and EPS snow probs are lower but have trended towards the stronger low pressure/closer to the coast scenario over the last few cycles. With a low track near or offshore, expect plenty of cold air to be in place ahead of the surface low. At this time, it appears that p-type will be in the form of snow with perhaps some mixed precip possible near the coast depending on how close the low tracks. There are many moving parts to this portion of the forecast so users are encouraged to stay up to date with the latest forecasts as the specifics of the upper level and surface pattern become clearer over the next 24-48 hours. Very cold air moves into the region behind this system with below normal temperatures expected to linger through mid week.

AVIATION /00Z THURSDAY THROUGH MONDAY/

As of 645 PM EST Wednesday...

VFR conditions are expected to prevail through the 00z TAF period. Widespread cloud cover persists overnight before clouds clear from W to E Thu morning. While most of the clouds are expected to have VFR CIGs, a few pockets of MVFR CIGs are possible across SE VA/NE NC and the Eastern Shore between 6-12z. However, confidence was too low to reflect in the TAFs. Light showers have moved offshore this evening. While there remains a low chance for a few isolated, light showers overnight across mainly the Eastern Shore, confidence is quite low. Otherwise, mostly sunny skies are expected by Thu afternoon. SW winds around 10 kt this evening will become W or WNW 10-15 kt with gusts 20-25 kt behind a strong cold front late tonight, continuing through Thursday.

Outlook: VFR conditions are expected Fri with some potential for MVFR CIGs on Sat. Cannot rule out a few rain or snow showers Sat, mainly across the Piedmont. Another system approaches the region Saturday night and potentially impacts the region on Sunday with snow or a rain/snow mix and flight restrictions possible.

MARINE

As of 300 PM EST Wednesday...

Key Messages:

- Strong northwesterly winds are expected tonight through Friday morning. High-end SCA conditions are expected with Gale conditions possible, particularly Thursday night.

- Tidal anomalies remain low for the foreseeable future and low water conditions are possible in the lower Chesapeake Bay and James River by Friday.

Breezy conditions are ongoing over the local waters this afternoon ahead of an approaching cold front. SW winds are around 15kt and gusts up to 20kt. Latest buoy obs indicate seas of 3-4ft N of Cape Charles and 2-3ft to the south. While the afternoon is falling just short of criteria, the SCA for the northern coastal waters is still in effect into tonight since seas/winds will come back up ahead of and behind the cold front.

The aforementioned front will pass over the waters late tonight into early tomorrow morning. Winds abruptly switch to the NW behind the front and increase to 20-25kt with gusts around 30kt. SCAs go into effect for all of the marine zones later tonight. Since this is a fairly strong front with a 35-40kt LLJ, there could be a couple of hours right before sunrise with gale force gusts as it passes through. However, these should be brief and sporadic in nature since there does not appear to be strong enough mixing during that time period to bring those stronger winds to the surface. Will issue SMWs if necessary. NW winds of 20-25kt continue through the day Thurs, increasing to 25-30kt Thurs night with an another push of CAA. Prevailing winds may be a bit lower on the upper rivers and Currituck Sound, but are expected to reach SCA criteria regardless. Have maintained the Gale Watch for the coastal waters north of Cape Charles for the Thurs night period. Local wind probs have actually trended down a bit and now only show ~50% for the waters N of Parramore Island and <20% as far south as Cape Charles. Given the marginal nature, the downward trend in probs, and the fact that it is still over 24 hours out, decided to hold off on any upgrades at this point. Winds relax to ~15kt on Friday and return to the SW as high pressure slides by to the south. SW winds increase again to 20- 25kt Friday evening into Saturday morning ahead of another cold front.

Seas ramp up again tonight to 3-5 ft as winds increase behind the cold front. Seas increase further Thursday night to 4-6 ft, with 3-5 ft waves possible in the Chesapeake Bay as well. Seas diminish to 2- 3ft Friday, increasing again to around 4ft Fri night. Waves in the bay will be around 2ft Friday, then 2-3ft Fri night. Will also note the potential for Low Water Advisories in the in the lower Chesapeake Bay, James River and York River Fri and especially Sat.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 1 AM Thursday to 7 AM EST Friday for ANZ630>632-634-638-656-658. Small Craft Advisory from 4 AM Thursday to 7 AM EST Friday for ANZ633. Small Craft Advisory from 1 AM Thursday to 4 AM EST Friday for ANZ635>637. Small Craft Advisory until 7 PM EST Thursday for ANZ650-652- 654. Gale Watch from Thursday evening through Friday morning for ANZ650-652-654.