textproduct: Wakefield

SYNOPSIS

A strong cold front crosses the the Mid Atlantic this morning, with accumulating snow possible, especially on the Eastern Shore. Arctic air moves in behind the cold front this evening into tonight, and provides a cold start to the week. The very cold temperatures do quickly give way to relatively milder temperatures for the middle to end of next week.

NEAR TERM /THROUGH TONIGHT/

As of 230 AM EST Sunday...

- Snow totals have trended upward to 1-2" for the RIC metro and N and 2-3" for the MD Eastern Shore. The Winter Weather Advisory has been expanded to include the northern counties W of the bay, including the RIC metro. Moderate to heavy rates will reduce visbilities.

- Cold Weather Advisories have been issued for the entire area for bitterly cold temps tonight/Monday morning with wind chills in the single digits. Early morning sfc analysis indicates a warm front draped across the local forecast area and a cold front just to the NW. A strong UL trough is dipping down into the eastern CONUS, supporting the front from aloft. Latest obs show temps in the upper 30s to low 40s in the southeast and low to mid 30s elsewhere. An area of snow with a heavier band embedded can be observed on latest radar over the Baltimore and DC metro areas. The strong cold front and the precip associated with it will pass through the area as the morning progresses.

The 00z suite of CAMs, along with the HRRR runs since then, are in fair agreement with regard to timing of precip. Should start to see precip enter the N/NW portions of the area (Louisa over to Dorchester) around 4am, then progress SE from there, reaching central portions of the area (along a Mecklenburg-RIC-SBY line) around 5-7am. During this time, there could also be some light precip in the SE ahead of the main line. Precip continues to push SE and looks to exit off the coast around mid-morning. Given above freezing temps areas will see rain to start, then transitioning to snow as the cold air rushes in behind the front. Could also see some sleet briefly mixing in during the transition period, especially in the SE later this morning. With regard to snowfall amounts- there has been an upward trend in expected accumulations. The last several runs of the HRRR and the HREF probabilities both support extending the 1-2" area down through the Northern Neck and into the Richmond metro. There was also a slight bump up for the MD Eastern Shore to 2- 3" with highest amounts right along that northern edge of Dorchester County. This increase is further supported by the likely presence of an FGEN band as depicted in the latest NAM12. Snow would likely fall rather quickly in a burst, reducing visibilities drastically and putting down quick accumulation. With all of this in mind, the Winter Weather Advisory was expanded to include the northern counties west of the bay including the Richmond Metro.

Temperatures drop quickly behind the front and NW winds pick up to 30-35mph for most of the area and up to 40mph at the coast. Temperatures are forecast to be as low at the mid 20s across the NW up to the low 30s in the SE by mid afternoon. Wind chills this afternoon will be in the teens and low 20s. Temps continue to drop quickly after sunset as CAA ensues. Breezy/windy conditions continue overnight, especially in the east. Lows tonight will be in the mid teens for inland portions of the area and upper teens/around 20F at the coast. Wind Chills will be in the single digits across the entire FA. The Cold Weather Advisory issued for the area is unchanged since the initial issuance yesterday.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/

As of 230 AM EST Sunday...

Key Messages:

- Chilly and dry Monday and Monday night with a slow moderating trend beginning on Tuesday.

Strong Arctic high pressure behind the cold front builds into the area Monday as the UL trough pivots offshore. It will be pretty chilly on Monday with highs only in the mid 30s. The good news is that it will be mostly sunny and much less windy with that high pressure overhead. The high is suppressed to the S/SE Monday evening into Tuesday and sfc flow shifts back to the SW. Lows Monday night will be in the low to mid 20s for most, but some of the colder rural spots could see the upper teens. Temperatures start to moderate on Tuesday under mostly sunny skies. Forecast highs are in the upper 30s in the far NE and low to mid 40s elsewhere. Lows Tuesday night will be in the mid to upper 20s.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

As of 230 AM EST Sunday...

Key Messages:

- Much warmer temperatures (compared to the first half of December) are on the way for the middle and end of the week.

- Another (weaker) cold front brings another chance for light rain Thursday night.

The warming trend continues Wed as the sfc high moves further to the SE and the flow aloft turns to the WSW. Forecast highs are in the low to mid 50s. Lows Wed night will generally be around 30F. Another relatively mild day for Thursday ahead of an approaching cold front. Highs could even reach the low 60s in the SE. Could see some rain associated with the late-week front by Thursday afternoon, but timing has trended a little later across the global models and now brings the bulk of the precip in Thurs night into early Fri. So far it does not look like CAA behind this front will be terribly strong with the high behind it coming from the W rather than the NW. Forecast highs from Fri are in the 50s still, then cooling off slightly for Saturday.

AVIATION /07Z SUNDAY THROUGH THURSDAY/

As of 1235 AM EST Sunday...

High clouds and light 5 kt SW winds are expected for for the next few hours ahead of an Arctic front. The front will cross the terminals late tonight/early morning around 10-16z. A few hours of precipitation will likely accompany the front. A period of -RASN is likely at RIC/SBY changing to all snow with a couple hours worth of IFR VSBYs (best chc at SBY but an hour or so of IFR VSBYs is possible in -SN at RIC). Will note that LIFR VIS is possible at SBY and RIC with a brief band of heavier snowfall. A rain/snow mix is expected at PHF/ORF, with mainly rain at ECG. Could also see some sleet mixing in at these terminals. In addition to the precip, CIGs will drop behind the front to IFR at all terminals before returning to dry and VFR conditions this afternoon with terminals further west seeing clearing conditions first. Behind the front, NW winds will increase to 15-20 kt with gusts to 30-35 kt.

VFR conditions will prevail Sunday night through Wednesday. Gusty winds Sunday night into Monday morning near the coast will diminish on Monday.

MARINE

As of 230 AM EST Sunday...

Key Messages:

- A strong, Arctic cold front crosses the waters this morning, with Gale conditions then expected into tonight over all of the waters.

- Light freezing spray is possible later today through tonight.

- Another round of SCAs are possible Monday night into early Tuesday.

Early this morning, a strong, Arctic cold front is rapidly approaching from the NW. Meanwhile a weak warm front is located over the waters. Winds are light this morning (~5 to 10 knots) and mainly out of the S to SW across the southern half of the waters and N to NE across the northern half. Seas are running around 1 foot, and waves in the Bay 1 foot or less. The strong front will continue to quickly move SE, crossing the waters around or shortly after 09z (4 AM EST).

In the wake of the strong cold front, very cold and dry air advects into the region. Extremely cold temperatures aloft (850 mb temps as low as -20 C) mix down to the surface across (relatively) warmer waters, creating very windy conditions. Winds rapidly increase and become NW between 09 and 12z (4 to 7 AM EST), with sustained winds of 25 to 30 knots and gusts of 35+ knots expected by late morning- early afternoon over a majority of the waters. Winds increase further during the afternoon-evening hours, peaking between roughly ~00z to 06z Monday (7 PM to 1 AM EST Mon); sustained winds of 30 to 35 knots and gusts up to 45 knots are expected during this timeframe. Given the extreme airmass change, would not be surprised if brief storm-force wind gusts were realized, especially at the elevated observation sites. Gale Warnings are in effect for all zones. Winds should fall below Gale thresholds everywhere by sunrise Monday morning, and then below SCA thresholds by Monday afternoon, as high pressure builds back into the area.

In addition to the wind, seas build to 6 to 10 feet by Sunday night, though the slight offshore component of the wind should help to keep seas from building further. Waves in the Chesapeake Bay will build to 4 to 6 feet (locally up to 7 feet). Finally, some freezing spray is possible later today through tonight due to the strong winds and cold air temperatures. However, marginal water temperatures (low to mid 40s) should keep any freezing spray light. Thus, am not expecting the need for a Freezing Spray Advisory.

Calmer conditions are anticipated later Monday, though a brief surge of S-SW wind may lead to additional SCA headlines (mainly over the Chesapeake Bay) late Monday night into early Tuesday morning. Sub- SCA conditions then return Tuesday into Wednesday. Another cold front may bring increasing winds Thursday into Friday.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...Winter Weather Advisory until 1 PM EST this afternoon for MDZ021>025. Cold Weather Advisory from 7 PM this evening to 9 AM EST Monday for MDZ021>025. NC...Cold Weather Advisory from 7 PM this evening to 9 AM EST Monday for NCZ012>017-030>032-102. Wind Advisory from 1 PM this afternoon to 7 AM EST Monday for NCZ102. VA...Cold Weather Advisory from 7 PM this evening to 9 AM EST Monday for VAZ048-060>062-064>069-075>090-092-093-095>100- 509>525. Wind Advisory from 1 PM this afternoon to 7 AM EST Monday for VAZ098>100. Winter Weather Advisory until 11 AM EST this morning for VAZ062-064-069-075>078-083-085-509>522. MARINE...Gale Warning until 7 AM EST Monday for ANZ630-631. Gale Warning from 7 AM this morning to 7 AM EST Monday for ANZ632-634-650-652-654. Gale Warning from 10 AM this morning to 7 AM EST Monday for ANZ633-635>638-656-658.