Marine Weather and Tide Forecast for Boswell's Corner, VA

NEAR TERM /UNTIL 6 AM TUESDAY MORNING/
Northeasterly winds around Canadian high pressure continue to advect very dry air into the area, with dew points now in the single digits across the northern half of the area. This dry air continues to slowly eat away at the shield of snow, with lower visibilities now confined to the far southwestern part of the CWA Rates haven't been too heavy, so lower elevation road impacts appear to be fairly minimal. Still would expect peak amounts, perhaps locally in the 4 to 6 inch range, along the ridges from Highland to Nelson (coldest temperatures and longest duration of snow). Some guidance lingers snow into the early evening along the I-64 corridor. However, the shortwave trough axis will be moving east, and low levels will continue to dry out. Doubt there will be much additional accumulation after 5 PM or so. High temperatures occurred in most areas early this morning, with temperatures continuing to fall the remainder of the day.

The surface high will move overhead tonight. Winds will likely become light to calm, although there will be some residual low level flow given the narrow/elongated orientation of the high. Clouds may also hang around until the second half of the night. Even without maximized radiational cooling, the cold advection and very low dew points will still allow most areas to drop into the teens. The urban cores and bayshore will stay in the lower 20s. Some of the colder valleys could drop into the single digits, especially where there is snow pack. Any residual moisture or slush will likely freeze on untreated surfaces.

SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/
The surface high will slide off to the south and east Tuesday.
Despite return flow by afternoon, cold air will remain in place, with most areas staying in the 30s during the day. Dry weather is expected, although a shortwave trough aloft will increase mid and high level clouds.

The pressure gradient will tighten Tuesday night as a clipper-type low moves into the Great Lakes. This could bring gusts into the 30 to 40 mph range on the ridges, and keep a light southerly wind in place in the lower elevations. Clouds will also continue to thicken. However, it may not be enough to stop the temperatures from dropping back into the 20s. Some precipitation may approach from the west but most likely holds off until after sunrise. Most of the warm advection precipitation will remain along and west of the Allegheny front, although some models bring some light precipitation across northern parts of the area. There is a small chance this could be a wintry mix if it starts early enough. Otherwise it would just be rain as temperatures rise into the 40s with gusty south-southwest winds.
Even in the Alleghenies, temperatures will likely rise above freezing in most spots, which may result in some rain mixing at times, and any snow accumulations limited to the higher ridges.

The low will move into the St. Lawrence Valley Wednesday evening as the mid and upper trough axis dives toward the region. Upslope moisture will change fully to snow in the Alleghenies. There remains some spread on how much moisture will be available, but at least several inches of snow is probable. Winds will also increase, potentially to near Wind Advisory caliber on the highest peaks.
Therefore some near-blizzard conditions can't be ruled out. Wind chill values will also drop into the 0 to 10 degree range in this area. Winds won't be quite as gusty in the lower elevations, and little precipitation will spill east of the Alleghenies. Temperatures will drop back into the mid 20s to mid 30s.

LONG TERM /THURSDAY THROUGH MONDAY/
The long term period will start off on Thursday with troughing along the East Coast, ridging along the West Coast, and west-northwesterly flow across much of the CONUS between those two features. A strong area of low pressure is expected to track toward the Canadian Maritimes on Thursday, with strong cold advection ensuing in its wake over the Northeast/Mid-Atlantic. A few snow showers may linger to the west of the Allegheny Front, but dry conditions are expected further east. It will be a chilly day, with high temperatures in the 30s and lower 40s for most (20s mountains). Winds may gust to around 20-30 mph out of the northwest, making it feel even colder.

West-northwesterly flow will continue aloft across much of the CONUS to end the week. Guidance suggests that multiple clipper-like systems may track toward the area out of Canada. Forecast spread remains large with these systems, but at least the Alleghenies should experience chances for snow. Further east, mainly dry conditions are expected, but some snow could also be possible Friday into Friday night depending on how those systems track. Guidance favors well below normal temperatures, with highs likely struggling to get out of the 30s this coming weekend.

AVIATION /19Z MONDAY THROUGH SATURDAY/
Snow continues to produce IFR conditions in CHO. While the snow may continue until the 22-00Z time frame, continuing advection of dry air will result in improving visibility and ceilings. Dry weather and mid to high level ceilings continue into the evening elsewhere. Northeasterly winds are already showing signs of decreasing, with gustiness ceasing after sunset. As Canadian high pressure builds in, winds turn light overnight.

VFR conditions continue for Tuesday and Wednesday. As high pressure moves off the coast, winds shift to southerly on Tuesday, picking up in intensity during the late afternoon to evening period with gusts to around 15 to 20 knots. Further upticks in wind are expected for Wednesday ahead of a fast moving clipper-like system. Gusts up to 20 to 30 knots are possible before winds shift to westerly late Wednesday behind the associated cold front.

VFR conditions are expected on both Thursday and Friday. Winds will be gusty out of the northwest on Thursday, and then lighter out of the west on Friday.

MARINE
In the wake of a cold front, north to northeast winds have likely peaked and will gradually decline through the remainder of the day.
Small Craft Advisories are in place through this evening for all waters, and through tonight for the southern waters. High pressure will slide across the area Tuesday, providing lighter winds that will quickly become southerly. The gradient increases by Tuesday evening as this high exits the coast. Small Craft Advisories will likely be required for Tuesday night, especially along the bay. Strong southerly winds continue Wednesday in response to a quick-moving low pressure system in the Great Lakes. Gusts up to 25 to 30 knots are possible this period. The associated cold front will cross Wednesday night, while advisory conditions will remain likely.

Small Craft Advisories appear likely on Thursday within northwesterly flow. A few Gale gusts can't be ruled out during that time. Sub-SCA level westerly winds are expected on Friday but will increase Friday night.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Small Craft Advisory until 6 PM EST this evening for MDZ008.
VA...Winter Weather Advisory until 5 PM EST this afternoon for VAZ025-026-036>038-503-504-507-508.
WV...Winter Weather Advisory until 5 PM EST this afternoon for WVZ505-506.
MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ530- 531-535-536-538-539.
Small Craft Advisory until 2 AM EST Tuesday for ANZ532-533- 540>542.
Small Craft Advisory until 6 AM EST Tuesday for ANZ534-537-543.