textproduct: Wakefield

WHAT HAS CHANGED

- Updated discussion and key messages

KEY MESSAGES

1) Mostly sunny and cooler this afternoon. Another cold night tonight, with additional Frost/Freeze headline potential for late tonight/early Thu AM.

2) Remaining mainly dry through the middle of next week. Temperatures Friday-Sunday will be mostly above average but still seasonable, followed by a well above normal period Monday- Wednesday.

DISCUSSION

As of 920 AM EDT Wednesday...

KEY MESSAGE 1...Mostly sunny and cooler this afternoon. Another cold night tonight, with additional Frost/Freeze headline potential for late tonight/early Thu AM.

Strong high pressure (~1037mb) is centered across central NY state, with a W-NW flow aloft in association with a subtle upper level trough off the mid-Atlantic and NE coast. The sky is clear, and conditions are quite dry with RH values still at or below 50% over most of the region. Very dry with full sunshine expected this afternoon, but high temperatures will be about 10 degrees below average inland, and ~15 degrees below normal closer to the coast. RH values will once again be quite dry well inland, while the cool onshore flow will allow for somewhat higher values closer to the coast. Overall though, fire WX concerns are not high enough to warrant any IFDs, given that the places with wind closer to the coast will see higher RH values while the drier inland zones will generally have winds at or below 10 mph.

Previously referenced sfc high builds east, becoming centered along the coast of New England and ridging down the mid-Atlantic coast into the coastal Carolinas. This setup favors better radiational cooling and less mixing overnight for inland areas, as the pressure gradient slackens a bit more. Additionally, the onshore flow allows for some limited moisture return in lower levels, resulting in some slightly higher dew pts, especially along the coast. Farther inland, lower T/Td depressions and high RH along with the diminishing winds make frost formation significantly more likely, with forecast lows in the low- mid 30s. Persistence-based forecast meshes well with statistical guidance, leading to increased confidence that frost/freeze headlines will be needed for inland areas. Lows are marginal, so right now it would appear that this would most likely be handled with Frost Advisories, though some localized Freeze Warnings in our far western piedmont zones and the MD eastern shore.

KEY MESSAGE 2...Remaining mainly dry through the middle of next week. Temperatures Friday-Sunday will be mostly above average but still seasonable, followed by a well above normal period Monday-Wednesday.

After a cold start, temperatures rebound closer to average Thursday as the sfc high gradually weakens and shifts farther off the coast. The next upper level trough moves from the upper midwest to eastern Canada and New England Fri into Sat, with a weakening cold front dropping S into the mid-Atlantic. This will bring more clouds Saturday, but most models keep the area dry (as does the NBM). Temperature warm into the 70s for most areas Friday, but then will cool off a bit by Sunday on the ern shore and near the coast as the low level flow turns back to onshore. Beyond that, next week will be very warm with highs well into the 80s, possibly around 90F Tue-Wed. The already dry conditions are very likely worsen in the medium range, as rain chances are basically zero through the middle of next week. 00Z/08 model ensembles show < 50% chc for 0.50" of total rainfall through the end of next week, as the SE upper ridge continues to keep any significant rain chances well N and W of the region.

AVIATION /13Z WEDNESDAY THROUGH SUNDAY/

As of 200 AM EDT Wednesday...

Mainly VFR conditions prevail for the next several days. Mainly SKC today and this evening, with some stratocumulus potentially moving into SE VA and NE NC overnight. CIGs would likely be low end VFR to MVFR is this scenario does occur. Otherwise, gusty NE winds continue along the coast, especially at ORF/ECG, while winds inland will be E-NE at 10 kt or less. Diminishing winds tonight all areas.

Outlook: Somewhat elevated E-NE winds at ORF/ECG Thursday, but easterly winds will be less than 10 kt elsewhere. Dry with VFR conditions through Saturday- there is a weakening cold front Saturday that will bring some clouds, but rain chances look very limited.

MARINE

As of 245 AM EDT Wednesday...

Key Messages:

- Winds remain elevated this morning and into the afternoon before the gradient starts to relax later today and into tonight.

- Elevated seas will maintain SCA on the ocean from tonight through at least late Thu night/Friday, and possibly into the upcoming weekend.

Strong high pressure (~1035 mb) is set up across the eastern Great Lakes, while an area of low pressure is east of the Florida Peninsula in the north Atlantic. The gradient across our area remains tightened, and with the high pushing down a good amount of cold air, winds remain strong across the local waters this morning. Marine observation sites are measuring 20-25 kts with gusts of 25-30 kts across the Bay, with winds of 20-25 kts with gusts to ~30 kts in the southern coastal waters. Winds are a touch weaker in the northern coastal waters, but still remain within SCA criteria. Seas have started to come up, with seas ranging from 3-6 ft (lowest in northern waters, highest in southern waters). The aforementioned high will shift offshore today and tonight, but remain stretched across the Mid-Atlantic and Southeast, which will maintain a NE wind across the local waters. The gradient will begin to relax during the day today, though SCA winds and wind gusts are still expected across the Lower Bay and southern coastal waters through at least the afternoon due to a channeling effect. While winds will start to come down today into tonight, seas will remain elevated due to the long fetch of NE winds. There is a good chance that seas across the southern waters over perform, as that is common in this NE wind regime. The prolonged period of ENE winds will keep seas elevated in the coastal waters and mouth of the Chesapeake Bay through at least Friday, so the SCA has been extended through then, and may need to be extended into the early weekend even as winds turn offshore Friday and Saturday.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...High Surf Advisory until 4 PM EDT this afternoon for NCZ102. VA...High Surf Advisory until 4 PM EDT this afternoon for VAZ098. MARINE...Small Craft Advisory until 10 AM EDT this morning for ANZ630- 631-635>637. Small Craft Advisory until 10 PM EDT this evening for ANZ632- 633. Small Craft Advisory until 8 AM EDT Friday for ANZ634-650-652- 654-656-658. Small Craft Advisory until 4 PM EDT this afternoon for ANZ638.