Marine Weather and Tide Forecast for Mason Neck, VA

NEAR TERM /THROUGH TONIGHT/
The hemispheric pattern this morning features a deep upper trough across eastern North America while ridging extends over much of the western portions of the continent. Within the southern stream, a stretched out positively-tilted trough anchors northwestern portions of the Mexico. This latter feature ends up bringing the local area the next chance for measurable rainfall.

The current surface analysis features high pressure extending from the Lower Mississippi Valley up into the Central Appalachians. Some westerly wind atop this anticyclone is noted in local observations, mainly in the 5 to 10 mph range. For areas that have been able to decouple and stay cloud-free, temperatures have plummeted into the teens. More specifically, this would include the central Virginia Piedmont and back into the Shenandoah Valley. Otherwise, a thickening mid-level cloud deck has been sinking southeastward from north of the Mason- Dixon Line. These clouds have helped keep temperatures up a tad with mainly 20s to near freezing values noted. Given the amount of upstream clouds, expect most to start off the day overcast.

Temperatures will continue to creep up from the cold readings the past several days. As cyclonic flow begins to weaken and mid/upper levels turn more west-northwesterly, temperatures in the air column rise by around 5 to 7C. However, this will not translate to such a warming at the surface as forecast soundings cap mixing at around 900 mb. Forecast highs are mainly in the upper 30s to mid 40s, with mainly 30s across the mountains. This comes with a mixed bag of sun and clouds.

Heading into tonight, southerly warm advection will allow temperatures to warm closer to freezing. Area-wide low temperatures are forecast to be in the mid/upper 20s in the cool spots to low 30s along and east of I-95. Winds aloft increase through the night, especially along the Allegheny Front. An enhanced 925-mb west-southwesterly jet tracks in which will bring raise ridgetop gusts to around 30 to 40 mph, locally nearing 45 mph. At this time, Wind Advisories are not expected given the small spatial area affected.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
Building heights ahead of the next weather maker tracking from northwestern Mexico into the Southern Plains will bring above average temperatures back to the region. By Sunday afternoon, 850-mb forecast temperatures rise to around 6 to 8C. While vertical mixing will not be able to tape into that pocket of milder air, high temperatures are expected to push into the 50s.
A few low 60s are also possible for areas south of I-66 in Virginia. Mountain locations are likely to see 40s to low 50s. A mainly westerly wind may be gusty at times during the afternoon.
Some gusts up to 20 to 25 mph are likely, slightly higher in the terrain. Clouds continue to increase through the day ahead of the next system. Unlike preceding systems, this comes from the southern stream which should keep this an all-rain event Sunday night into Monday.

Much of the area settles into the 30s overnight. If precipitation arrives a bit earlier, some mixed precipitation types are not out of the question. However, the current forecast packages favors a cold rain late Sunday night, continuing into Monday. The shortwave in question is rather progressive in nature as it tracks from western Kentucky to the New Jersey coast on Monday. Most areas will see around 0.10-0.25 inches of rain, locally around 0.50 inches along the Allegheny Front. The forecast highs have trended down on Monday owing to the clouds and rain in the area. Mainly mid/upper 40s are expected from U.S. 50 northward, with low to mid 50s to the south. Rain chances diminish into the evening and night for most except those in the Alleghenies. Nighttime lows mainly stay in the upper 30s to low 40s.

LONG TERM /TUESDAY THROUGH FRIDAY/
Global models show an amplifying upper level trough over the central CONUS Tue that swings across the Mid-Atlc and Northeast states Wed night-Tue while taking on a negative tilt. As a result, a strong surface low develops over the mid-South Tue along a stalled front in response to upper level divergence and strengthening jet dynamics. As dynamics improve Tue night-Wed, expect widespread soaking rain/showers over the area late Tue night with rain turning into snow over the mountains as heights fall substantially (~180 meters in 24 hrs). Note that the latest Euro is significantly deeper/sharper with this trough than the GFS. Expect a sharp drop in temperatures and an abrupt increase in winds immediately behind fropa. While instability is expected to be non-existent, magnitude of mid-level winds (~500 mb)
exceeding 110 kt, suggest potential for damaging post- frontal/non-convective winds. East of the mountains, it appears the precip exits quickly before cold air catches up, so it appears any snow showers will be confined to west of the Blue Ridge Mountains. Much colder and brisk conditions will follow for the second half of next week.

AVIATION /08Z SATURDAY THROUGH WEDNESDAY/
VFR conditions are expected at all terminals through the weekend. With high pressure passing by to the south and southwest, winds will largely be out of the west to southwesterly direction. Outside of KMRB which has seen an abrupt rise in gusts to 20 to 25 knots, other TAF sites are staying in the 5 to 10 knot range. Afternoon winds are expected to gust to around 15 knots today, with a further uptick into Sunday. Southwesterly winds increase on Sunday with afternoon gusts to 25 knots.

Rain overspreads the area late Sunday night into Monday. This will support IFR to MVFR conditions on Monday before this band of rain exits the area by the evening. Winds through the day on Monday will meander between southeast to southerly. Depending on how much cloud cover lingers into the night, some residual lower ceilings are possible.

Showers are possible Tue with rain or showers more definite Tue night into Wed morning. IFR/LIFR conditions appear likely Tue night into Wed. LLWS is also possible. FROPA expected late Wed with strong gusty of 30kt possible behind front.

MARINE
Small Craft Advisories continue through the early afternoon across the northern half of the Chesapeake Bay. Southwesterly gusts up to 20 knots are possible while these advisories are in effect. After a brief lull, southwesterly winds intensify this evening and night and into parts of Sunday. Small Craft Advisories are in place over most of the waters outside of the northern/central tidal Potomac and far northern Chesapeake Bay.
Sub-advisory caliber winds are expected for the second half of Sunday into Monday morning. However, another ramp up is likely on Monday across southern portions of the Chesapeake Bay in response to southerly channeling effects. This does appear to be on the brief side and restricted to only portions of the waters.

SCA conditions are likely Tuesday night through Thursday morning.
Gale conditions are possible Wed night.

FIRE WEATHER
While temperatures are rather cold, which typically mitigates rapid fire spread, a number of wildfires have recently broken out in the dry/gusty post-frontal environment. Winds do decrease in strength after dark with moderate nighttime recoveries expected.

For tonight into Sunday, a tight pressure gradient brings gusty winds to the area, primarily at higher elevations.
Southwesterly winds gust 20 to 25 mph across the area, with gusts around 30 to 40 mph expected at higher elevations.
Relative humidity values will be in the 40s and 50s for most of the area as southerly winds usher in moisture from the south.

A wetting rain comes in Monday across a vast majority of the region.

TIDES/COASTAL FLOODING
Tidal departures of around 1 ft below normal are expected today.
Departures will continue to recover tonight as winds diminish. Tidal departures recover to near normal by Sunday as winds shift to a more southerly direction.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Small Craft Advisory until 2 PM EST this afternoon for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 2 PM EST this afternoon for ANZ530>532-538>540.
Small Craft Advisory from 7 PM this evening to 6 AM EST Sunday for ANZ531>534-537>543.