Marine Weather and Tide Forecast for Clarksville, VA

NEAR TERM /UNTIL 6 AM THIS MORNING/
As of 915 PM EST Monday...

Key Messages:

- Very cold tonight with wind chills ranging from 0-10 degrees across much of the area.

- Cold Weather Advisories remain in effect for much of eastern Virginia (including Hampton Roads) as well as all of northeast North Carolina.

Dry conditions are expected through tonight as very dry air (single digit to below zero dewpoints) continues to filter in from the northwest. Temperatures quickly dropped after sunset with northwestern portions of the area already in the teens as of latest obs. Very cold overnight, with low temperatures ranging from the upper single digits across the northwest, to the low to mid 10s elsewhere. The cold air temperatures, combined with a light breeze (highest closer to the coast) will allow for wind chills in the 0-10 degree range, with the coldest values likely occuring on the MD Eastern Shore. Cold Weather Advisories are in effect for the Eastern Shore and the Northern Neck where wind chills of 0-5 degrees are forecast. Cold Weather Advisories are also in effect for Hampton Roads and northeast North Carolina where wind chills of 5-10 degrees are forecast (wind chills of 10 degrees or lower constitutes an advisory for these locations). For the remainder of the area, while not under a Cold Weather Advisory, it will still be very cold with wind chills hovering in the upper single digits or lower 10s.

SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/
As of 345 PM EST Monday...

Key Messages:

- Increasing confidence for snow accumulations across far southeast Virginia and northeast North Carolina Tuesday night into Wednesday morning. Snow totals have increased.

- A Winter Storm Watch is now in effect for the Albemarle Sound counties in NC, over to the northern Outer Banks.

- Very cold Tuesday through Wednesday night, with additional Cold Weather Advisories likely being needed.

Confidence continues to increase that southeastern portions of the area will see snow accumulations Tuesday night into early Wednesday morning. There was a small, but notable, shift in respect to the 12z model suite, bringing slightly higher QPF (and thus more snow) a bit further to the NW. Diving into the model ensemble probabilities, the 12z GEFS trended upward from overnight, now showing a stripe of ~30- 50% chances for > 1" of snow accumulation across northeast North Carolina and up into southeast Virginia, with ~10-20% chances for > 3". The 12z EPS made a bit more of a significant jump, with ~50-70+% chances for > 1" of snow and ~10-40% for > 3" over the same areas. T he operational GFS and ECMWF both paint a stripe of 3+" along the Albemarle Sound. In addition, the NAM is starting to come into range and is painting even higher snow totals over northeast North Carolina and into potentially far southeast Virginia. Knowing all of this, and also knowing that air temperatures will only be in the low to (perhaps) mid 20s, snow to liquid ratios will be better than 10:1 which will lead to efficient accumulations. As a result, have decided to issue a Winter Storm Watch for northeast North Carolina counties along the Albemarle Sound, over to the northern Outer Banks. These locations have the best potential for seeing 3" or greater of accumulations at this time. There is some possibility that additional counties/cities may need to be added to the watch depending on the model trends this evening, with Virginia Beach and Chesapeake being possible additions if the snow trends further NW. Little to no snow is expected outside of southeast Virginia and northeast North Carolina where very dry air will remain in place. There will likely be a very sharp gradient in snow accumulations, likely setting up somewhere over Hampton Roads and interior northeast North Carolina.

Otherwise, very cold on Tuesday with highs struggling to get out of the mid 20s across northern portions of the area ranging to just around or slightly above freezing across the south. There will also be much more cloud cover tomorrow compared to today, adding to the winter feel. Temperatures Tuesday night tank into the single digits or teens once again. There will also be a bit more wind compared to tonight, which will lead to widespread wind chills of 0-10. Cold Weather Advisories are looking increasingly likely for much, if not all of the forecast area, Tuesday night into Wednesday morning.

Any snow across the southeast will quickly come to an end by or shortly before sunrise Wednesday. Wednesday will likely be the coldest day of the stretch, with highs in the 20s for a majority of the area (lower 20s north). This will set the stage for another cold night with low temperatures again in the single digits or teens for most of the area. One "positive" is that there will be less wind Wednesday night, so the wind chill may close to or equal to air temperatures.

LONG TERM /THURSDAY THROUGH MONDAY/
As of 355 PM EST Monday...

Key Messages:

- Generally dry conditions late this week into the weekend.

- Temperatures gradually moderate to end the week and into next weekend.

A weak low pressure system still looks poised to develop along a coastal trough Thursday to our S. Models have trended down in regards to the precipitation with this system and are generally dry across the local area. Still, given the cold air in place, there is a low chance for some additional wintry precipitation across far southern portions of the area ~20-30% chance. Thursday's highs remain chilly and in the 30s, while most areas should reach the lower 40s Friday. A more noticeable moderating trend is expected by the weekend with highs possibly in the lower 50s by Sunday.

AVIATION /06Z TUESDAY THROUGH SATURDAY/
As of 100 AM EST Tuesday...

1045mb high pressure is centered over the Central Plains as of 06z and extends eastward into the Mid-Atlantic region. VFR under a mostly clear sky with some bands of cirrus developing over the region, and also some patchy SC across SE VA/NE NC. The wind is very light out of the N inland, and NNE 8-12kt along the coast. VFR conditions continue today with mid and high clouds increasing and thickening as low pressure develops in vicinity of the northern Gulf coast. This area of low pressure tracks off the Southeast coast tonight bringing a period of snow to NE NC and far SE VA, mainly affecting ECG and potentially ORF as well with occasional IFR vsby in snow. Very light snow or flurries are possible at the remaining sites, but this is not expected to result in reduced vsby. Additionally, occasional MVFR cigs are possible at ORF and ECG tonight. The wind will primarily be NNE 5-10kt inland and 8-12kt along the coast today into tonight.

Dry and VFR conditions return Wednesday into Wednesday night as high pressure builds in from the NW. The only exception is the potential for a streamer off the Ches. Bay early Wednesday. Weak low pressure tracks off the coast Thursday, bringing clouds and a minimal chc of mixed precip at ORF and ECG. High pressure and VFR conditions prevail Thursday night through Saturday.

MARINE
As of 1240 AM EST Tuesday...

Key Messages

- Periods of freezing spray will be possible tonight through Wednesday due to very cold temperatures in combination with elevated winds.

- Low pressure tracks off the Southeast coast Tuesday night into Wednesday.

Strong high pressure of Arctic origin is centered over the lower Ohio Valley, building toward the area tonight. Meanwhile, developing low pressure is beginning to take shape in the western Gulf of Mexico. Compressed pressure gradient between high pressure to the west and developing coastal trough along the SE coast has allowed for NW winds to increase to 15 to 20 kt in the middle and upper bay over the past couple of hours.
Winds continue to hold at SCA conditions across the bay this evening.
Winds should slightly weaken overnight, as very cold high pressure builds into the region and gradient slackens a bit.
Have accordingly continued SCA for the Bay through 4 am.

High pressure builds west of the waters through Tuesday morning, as a broad surface trough continues to sharpen off the SE coast.
The gradient between these features sharpens further Tuesday night into Wednesday, as low pressure lifts NE from the gulf coast. Latest guidance has winds increasing to ~15-20 kt for the Ches Bay, Currituck Sound, and lower James River with 20-25 kt for the southern coastal waters S of Cape Charles Light. SCA headlines will likely be needed for this period. Seas build to 4-6 ft for the southern coastal waters but are forecast to stay in the 3-4 ft range N of Parramore Island. Low pressure lifts out quickly on Wednesday with improving conditions. Additional areas of low pressure may develop along the strong baroclinic zone offshore later in the week but confidence in the specifics and local impacts remains very low.

Very cold temperatures will result in a continued potential for periods of light to locally moderate freezing spray. The current advisory is in effect until mid morning Tuesday. An extension or expansion of the Freezing Spray Advisory into Tuesday night and early Wednesday seems likely as winds increase overnight and cold temps linger. Thereafter, winds decrease and temperatures slowly moderate so further freezing spray headlines are not anticipated.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...Cold Weather Advisory until 10 AM EST this morning for MDZ021>025.
NC...Cold Weather Advisory until 10 AM EST this morning for NCZ012>017-030>032-102.
Winter Storm Watch from this afternoon through Wednesday morning for NCZ015>017-031-032-102.
VA...Cold Weather Advisory until 10 AM EST this morning for VAZ075>078-084>086-089-090-092-093-095>100-523>525.
MARINE...Small Craft Advisory until 4 AM EST early this morning for ANZ630>632-634.
Freezing Spray Advisory until 10 AM EST this morning for ANZ630>632-634>638-650-652-654-656.