Marine Weather and Tide Forecast for Round Hill, VA

KEY MESSAGES
- Above average temperatures continue through Saturday before rain arrives by the night.

- High pressure moves in early next week, with persistent cool temperatures and fire weather risk.

DISCUSSION
KEY MESSAGE 1...Above average temperatures continue through Saturday before rain arrives by the night.

KEY MESSAGE 1 DESCRIPTION...

Not as warm today, but still with above average temperatures through Saturday. However, no daily records are anticipated as highs fall into the 80s. This does come with a continued elevated fire weather threat.

A large pattern shift occurs for the second half of the weekend as a cold front crosses the region late Saturday night. The degree of convective threat is more limited given the frontal passage is occurring in the middle of the overnight period. The forecast calls for additional shower activity into Sunday as the trough passes by overhead. The combination of extensive cloud cover, passing showers, and cold advection winds will yield highs only in the upper 50s to 60s (40s to mid 50s in the mountains).

KEY MESSAGE 2...Cooler air returns early next week, along with renewed fire weather concerns.

KEY MESSAGE 2 DESCRIPTION...

Upper troughing will pass overhead on Monday as high pressure builds to our west over the Ohio Valley. Northwesterly winds will continue to advect cooler and much drier air into the region. Monday will likely be the coolest day of the week, with forecast highs in the 50s for most (40s mountains, near 60 in Central Virginia). Relative humidity values are forecast to drop into the upper teens and 20s, which when coupled with northwesterly winds gusting to around 20-30 mph could lead to some fire weather concerns.

High pressure is forecast to build overhead Monday night. Clear skies and calm winds will result in ideal radiational cooling conditions. Temperatures are forecast to drop into the upper 20s to 30s across the entire area, which could result in some frost/freeze concerns.

High pressure then moves offshore on Tuesday, allowing winds to turn out of the south to southwest. Predominantly quiet weather conditions are expected for Tuesday through Thursday, along with a moderating trend in temperatures. High temperatures are forecast to reach into the 60s on Tuesday, and then 70s to near 80 on Wednesday and Thursday.

AVIATION /07Z FRIDAY THROUGH TUESDAY/

Northwest winds continue today with some gusts up to 22 kt possible. Stratocumulus ceilings around FL060 are possible at times through the day.

VFR conditions continue into Saturday before showers arrive late in the evening with a cold front. This will favor a return to sub- VFR conditions through the night and into Sunday as widespread light showers impact the area. A gusty northwesterly wind is expected behind the front on Sunday.

VFR conditions are expected on both Monday and Tuesday. Winds are forecast to be out of the northwest on Monday, and then southwest on Tuesday.

MARINE

New SCA has been issued for the northern and middle waters for NW winds gusting up to 25 kt for today.

Winds subside tonight before ramping back up the second half of Saturday. Southerly channeling effects ahead of a potent cold front will likely require Small Craft Advisories across all waters through Saturday night. Behind this strong cold front, additional advisories are likely needed on Sunday with gusts of 30 kt. Given the deeper mixing this time of the year, stronger gusts to gale force are possible.

Small Craft Advisories are likely on Monday as continued northwest winds flow 15-20 knots. Winds shift southerly on Tuesday as gusts fall below SCA guidelines by the early morning.

FIRE WEATHER
Elevated fire weather conditions will persist through Saturday due to above normal temperatures, low RH's and no wetting rain.
However, RH may be comparatively higher to Wednesday and Thursday, and winds not quite as strong.

Sunday...While some rain is expected late Saturday evening into Sunday morning, amounts of a tenth to two tenths of an inch will not be sufficient to increase 100-hr fuel moisture values significantly. More importantly, the precipitation duration is expected to be short-lived, generally 6 hours or less.
Furthermore, very strong gusty winds of 35 mph with potential for gusts as high as 45 mph will create renewed fire weather concerns despite marginal humidities and the light rainfall. The 10-hr fuel moisture values will likely drop rapidly through the day due to the drying effects of the strong winds and lowering humidity through the day.

Rest of next week...Much cooler temperature are expected Mon and Tue with a moderating trend in temperatures expected during the middle and second half of the week. Winds will be on light side thanks to high pressure overhead, but humidities will be marginally low to near critical levels. A dry pattern seems likely to continue with little to no rainfall.

CLIMATE

No more records are expected today or Saturday.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Small Craft Advisory from 11 AM this morning to 8 PM EDT this evening for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 11 AM this morning to 8 PM EDT this evening for ANZ530>533-535>542.
Small Craft Advisory until 4 AM EDT early this morning for ANZ531>533-538>541.