textproduct: Wakefield

WHAT HAS CHANGED

Full discussion updated. No significant changes to the forecast.

Aviation section for 12Z TAFs updated

KEY MESSAGES

1) Frost Advisory in effect through mid-morning today for south-central VA and interior portions of southeast VA and northeast NC. Dry and seasonably mild otherwise through mid- week.

2) A strong cold front brings chances for rain Thursday-Friday, but any potential for appreciable rain is low. Much cooler temperatures follow behind the front.

DISCUSSION

As of 310 AM EST Tuesday...

KEY MESSAGE 1...Frost Advisory in effect through mid-morning today for south-central VA and interior portions of southeast VA and northeast NC. Dry and seasonably mild otherwise through mid-week.

Chilly early this morning with temperatures in the upper 30s to lower 40s. Calm winds and mostly clear skies are allowing for decent radiational cooling conditions, though the position of the nearby high pressure system isn't 100% ideal for a very cold night. Regardless, am expecting temps to drop a few more degrees through sunrise. Frost is possible away from the coast, though will tend to focused in rural and sheltered locations. A Frost Advisory is in effect for interior southern VA and NE NC where the growing season is still ongoing.

After the chilly morning, temps should warm quickly, leading to a very nice day with clear skies, a SW wind, and highs in upper 60s to lower 70s. Not as cold tonight with lows in the 40s for most. Another seasonably mild day is on the way for Wednesday with sky cover and temperatures very similar to today. Could see some increase in clouds late in the day as low pressure begins to take shape well NW of the region.

KEY MESSAGE 2...A strong cold front brings chances for rain Thursday- Friday, but any potential for appreciable rain is low. Much cooler temperatures follow behind the front.

A big change remains on the horizon as we approach late week. A shortwave trough is forecast to dive southward out of the north- central CONUS Wednesday, with a larger longwave trough and embedded upper low setting up shop over most of the eastern CONUS by Thursday and Friday. While some precip is possible Thursday and Friday, the main focus will be the much cooler temperatures that overspread the area behind the associated frontal passage. Thursday looks to be the last "mild" day for a while with pre-frontal high temps in the mid 60s NW to lower 70s SE. A series of cold fronts then crosses the local area Thursday evening and overnight, bringing those much cooler temps by Friday. At this time, forecast highs Friday are only in the 50s, with lower 50s for the northern and northwest tier of our CWA (mainly N and NW of a Farmville- Richmond- Salisbury line). The large upper trough remains parked over most of the eastern CONUS Saturday and this still looks like the coolest day of the period: highs only in the lower 50s for the entire area and even some potential for upper 40s across the N and especially the lower MD Eastern Shore. Some semblance of troughing remains in place Sunday, so those cool temps are expected to persist. Overnight lows also dip to around freezing for most locations away from the coast, with even some upper 20s possible in the Piedmont. Gusty winds could make these temps feel even chillier. A very gradual moderating trend is possible starting early next week.

Regarding the precip potential Thursday-Friday, the synoptic pattern is not very favorable for appreciable rainfall. The sfc low passes W to E through the northern Mid-Atlantic Thursday, with the main trough axis lagging well behind these sfc features. The overall moisture also appears limited with the westerly flow aloft. Still, at least some light rain or showers are expected later Thursday into Friday, particularly N of the I-64 corridor and especially on the lower MD Eastern Shore. Expected/forecast QPF is only on the order of a tenth or two per the latest NBM and ensemble guidance, and even these amounts could be on the generous side. Probs for a half inch of QPF have cratered to <5-10%, so any sort of beneficial rain is unlikely at this point. Conditions dry out for the weekend, though those aforementioned gusty (NW) winds are likely to persist in the Friday-Sunday timeframe as the pressure gradient remains compressed over the area.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

As of 620 AM EST Tuesday...

VFR conditions prevail through the 12z/10 TAF period. Mostly sunny today with light and variable winds early becoming SW 5-10 kt in the late morning and afternoon. Light/calm winds return tonight.

Outlook: VFR conditions are expected to continue through the middle of the week. A cold front approaches from the west Thursday, with rain showers possible by later Thursday and Friday. Some short- lived sub-VFR conditions are possible with the frontal passage, along with some gusty NW winds and markedly cooler conditions behind the front for Friday and the weekend.

MARINE

As of 310 AM EST Tuesday...

Key Messages:

- Benign marine conditions prevail through Thursday.

- An extended period of strong NW winds and elevated seas are likely Friday into the weekend. However, confidence with respect to the strength of the wind and exact timing remains low.

High pressure is centered over southern VA and Carolina coastal plain early this morning. The wind is less than 10kt, out of the NW across the northern tier of the local marine area, and out of the NE across the southern tier of the area. Seas range from 2-3ft in the coastal waters, to 3-4ft in the offshore waters, with 1-2ft waves in the Ches. Bay. High pressure prevails across the region through Wednesday, before moving offshore Wednesday night into Thursday. Sub- SCA conditions are expected during this timeframe. There is a weak dry cold front that crosses the coast tonight. The wind becomes WSW today and increases to 10-15kt across the Ches. Bay and ocean ahead of this boundary this aftn and early evening, before becoming N ~10kt, then NE 5-10kt behind the front later tonight into early Wednesday morning. High pressure becomes centered in vicinity of the northern Delmarva Wednesday with the wind becoming light and variable across the northern tier of the marine area, and ENE 5-10kt across the southern tier of the area. The wind then becomes SE 5- 10kt Wednesday night and then S followed by SW Thursday and increasing to 10-15kt as the high moves farther offshore and as a cold front approaches from the NW. Seas remain to 2-3ft nearshore and 3-4ft offshore today, and then 2-3ft for most of the local Atlantic zones through midweek. Waves in the Ches. Bay will be 1 to occasionally 2ft Tuesday through midweek.

Low pressure and a strong cold front push across the coast and offshore Thursday night into Friday, with an extended period of CAA into the weekend. This should allow for decent mixing as a colder airmass overspreads relatively warmer SSTs. 00z/10 EPS probs for wind gusts at or above 34kt increase to generally 30-60% later Friday into early Saturday, and then to >60% Saturday aftn/evening. Meanwhile, the 00z/10 GEFS probs are negligible. Local wind probs for wind gusts at or in excess of 34kt are on average ~20% for the Ches. Bay Friday night through Saturday evening, 20-50% for the coastal waters, and 40-60% for the offshore waters. Taking a more traditional analysis, the 00z/10 ECMWF/GFS/CMC have 925mb wind speeds reaching a max of ~30kt a few hours either side of 00z Sunday (7PM Saturday). This also occurs as 925mb temperatures dive to ~0C along with pressure rises of +4-6mb/6hr, which could help boost the wind a few knots higher into gale criteria. Combining this with the probabilistic guidance, the scenario (at least as of this cycle) favors an extended period of SCA conditions Friday into the weekend, with a period of gale force gusts possible later Saturday/Saturday evening as the coldest air aloft arrives. However, it is still far enough in advance that confidence in exact details remains low. Seas potentially build to 5-7ft in the coastal waters and 7-9ft beyond 20nm, with 3-5ft waves in the Ches. Bay.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...Frost Advisory until 8 AM EST this morning for NCZ012>014-030. VA...Frost Advisory until 8 AM EST this morning for VAZ079>081- 087>089-092-528-529. MARINE...None.