Area Forecast Discussion

WHAT HAS CHANGED

Updated aviation discussion for 18z TAFs.

Freeze Watches have been issued for many areas along/west of I-95 Monday night into Tuesday morning.

KEY MESSAGES

1) Increased fire danger possible on Monday.

2) Cold tonight with lows dropping back into the 30s and 40s. Frost and/or freeze conditions are looking increasingly likely Monday night into Tuesday morning, with the best chances for freezing temperatures roughly along/west of I-95.

3) A warming trend is expected through mid to late week. Rain chances remain low until perhaps the weekend.

DISCUSSION

As of 300 PM EDT Sunday...

KEY MESSAGE 1...Increased fire danger possible on Monday.

Only minimal rainfall has fallen across the area this afternoon, with total amounts ranging from ~0.10-0.20". Showers will continue to weaken as they drift to the east later this afternoon. The combination of the very dry fuels, RH values crashing into the 20 to 25% range (possibly teens in spots), and gusty NW winds will likely lead to an increased fire danger across much of, if not all of the area on Monday. One possible limiting factor is that a secondary cold front will be dropping south across the area, potentially allowing for increased cloud cover and possibly slightly higher RH values. Winds will likely be too low for a Red Flag Warning, though the best potential would be in North Carolina.

KEY MESSAGE 2...Cold tonight with lows dropping back into the 30s and 40s. Frost and/or freeze conditions are looking increasingly likely Monday night into Tuesday morning, with the best chances for freezing temperatures roughly along/west of I-95.

For tonight, temperatures will drop into the mid to upper 30s for many inland locations as high pressure briefly builds overhead, allowing for strong radiational cooling. Cannot rule out some patchy frost, especially for the typically cooler spots.

For tomorrow night, strong high pressure builds over the region, allowing for even better radiational cooling compared to tonight. Temperatures will likely fall into the low to mid 30s for many inland areas. Upper 20s are even possible across our NW counties and the typically colder locations. It should be noted that MOS guidance is as low as the lower 20s across our far NW. With such a dry airmass in place combined with little to no wind Monday night, would not be surprised to see temperatures drop even more than what is currently in the forecast. A Freeze Watch has been issued for much of the area roughly along and west of I-95 where there is the best potential to see sub-freezing temperatures. Even though the airmass will be quite dry, frost formation temperatures (<36F) are expected for much of the area away from the coast and Frost Advisories will likely be needed as a buffer around any Freeze headlines.

KEY MESSAGE 3...A warming trend is expected through mid to late week. Rain chances remain low until perhaps the weekend.

Tuesday afternoon the high pressure will slide off the SE coast allowing temperatures to moderate (though still remaining below average, especially on the coast and the Eastern Shore). Then through the middle to the end of the week temps return back above normal with highs into the 70s and 80s. As for rain chances, they continue to to remain quite minimal. As for rain chances this week, a cold front drops into the area on Wednesday, bringing at least the chance for showers and potentially isolated thunderstorms. Neither the 12z EPS or GEFS are impressed with this system, only averaging ~0.10" of QPF (at most). A potentially stronger system impacts the region this weekend, bringing another chance for rainfall. The ensembles have slightly higher QPF with this second system, but this still does not appear to be a drought buster.

AVIATION /19Z SUNDAY THROUGH FRIDAY/

As of 200 PM EDT Sunday...

A cold front has crossed the local area with gusty NW winds in its wake. A line of light rain showers has passed RIC and will continue to move east into the remaining sites over the next couple of hours. MVFR CIGs (bases ~3000 feet) and potentially brief MVFR VSBYs will be possible as the showers move east. Otherwise, we are already seeing clearing across the western half of the area, with dry/VFR conditions expected at all sites by this evening. Winds become gusty late Monday morning into Monday afternoon as a secondary cold front drops south across the area.

Outlook: Conditions remain VFR through Tuesday. Another front may drop south across the area Wednesday, bringing at least a low-end chance for rain showers and increasing cloud cover. VFR conditions Thursday into Friday.

MARINE

As of 300 PM EDT Sunday...

Key Messages:

- Solid SCA conditions will decrease this evening with sub-SCA conditions tonight.

- Another cold front will cross the area Monday. Additional SCA are likely for the Chesapeake Bay Monday afternoon into evening.

A strong upper air trough across the eastern CONUS has pushed a cold front across the local waters this afternoon. The front has brought solid SCA conditions across all local waters and a period of gusts to 34+ kt. Winds have begun decreasing slight, and all SMWs have expired at this point. Winds are NW 20-25 kt with gusts to 30 kt in the southern waters and mouth of the Ches. Bay and 10-15 kt with gusts to 20 kt in the northern coastal waters. Waves and seas have built to 2-5ft and 4-6ft, respectively. Winds will shift to be west- SW by late tonight around 5-10 kt.

Another cold front will cross the area Monday afternoon, with a subsequent northerly surge following for Monday afternoon and Monday night. At this time, the Ches. Bay has the best potential for additional SCA flags. Winds will increase during the day to 15-20 kt with gust to 25 kt, peaking in the evening. High pressure passes across the region Tuesday and settles offshore by mid to late week, with a weak backdoor cold front potentially nudging into the area by later in the week. Sub-SCA conditions expected to prevail aside from Tuesday night/early Wednesday when a SSW increases to 15-20kt across the Ches. Bay/lower James and coastal waters, bringing the potential for low-end SCAs for the Ches. Bay and lower James. 3-4ft seas Monday should subside to 2-3ft by Tuesday, with 2-3ft waves in the Ches. Bay Monday/Monday night subsiding to 1-2ft Tuesday. Seas build to 3-5ft later Tuesday night/early Wednesday with 2-3ft waves in the Ches. Bay, subsiding to 2-3ft/1-2ft later in the week.

AKQ WATCHES / WARNINGS / ADVISORIES

MD...Freeze Watch from late Monday night through Tuesday morning for MDZ021>024. NC...None. VA...Freeze Watch from late Monday night through Tuesday morning for VAZ048-060>062-064>069-075-079-080-509>513-515-517- 519-521. MARINE...Small Craft Advisory until 7 PM EDT this evening for ANZ630>634-650-652-654. Small Craft Advisory until 4 PM EDT this afternoon for ANZ635>637-639. Small Craft Advisory until 10 PM EDT this evening for ANZ656- 658.