textproduct: Wakefield

SYNOPSIS

Low pressure and a passing disturbance aloft brings the chance for snow to much of the area today, with the heaviest snow looking to occur along and just south of I-64. Drying out and becoming much colder tonight and Tuesday. Milder Wednesday and Thursday, with shower chances increasing with the next strong cold front next weekend.

NEAR TERM /THROUGH TONIGHT/

As of 530 AM EST Monday...

Key Messages:

- Winter Storm Warnings now in effect for much of central VA over to portions of eastern VA.

- Winter Weather Advisories expanded to include the remainder of VA and northeast NC. Early morning IR/WV imagery reveals broad upper level troughing over the east coast, with a pair of embedded H5 troughs pushing toward the area in W-SW flow aloft. At the surface, low pressure over the eastern TN Valley and its associated strong surface cold front have pushed into northern portions of the local area, bringing markedly colder air and another round of wintry precip to the region later today.

Of course, the biggest weather challenge of the day is the impending wintry weather. Strong (~1030 mb) sfc high pressure to the north will remain favorably located across NY state to supply a good feed of cold/dry air into the region today. Meanwhile the previously referenced mid-level shortwave and its associated sfc low, swing east across the Carolinas today, pushing offshore tonight, providing ample forcing for ascent. This will promote a swath of precip crossing at least the southern half to two thirds of the area. The 00z model suite continued to hone in on a narrow band of higher QPF embedded within this regime of broad WAA/overrunning moisture. Overall, taking strong CAA and the arriving moisture into account, it is easy to see why models are becoming increasingly aggressive with snow totals for much of the region on Monday. QPF has tightened up a bit with this model suite, and is now varying from around 0.10" across the far northern tier of the local area, with a bulls-eye of 0.20-0.40" overall encompassing mainly the US-60 and US-460 corridors in central and south central VA.

Given the strong CAA that will come quickly on the heels of the frontal passage, continued to undercut NBM by a few degrees, closer to a time-lagged HRRR/NAM 3km look, with yields a thermal profile that holds temps more or less steady this morning, then falling as best slug of overrunning moisture arrives this afternoon. Precipitation begins as snow across the piedmont, and a light rain- snow mix along the I-95 corridor and points eastward. Dynamical cooling will take over from there, facilitating a very quick progression to primarily snow from NW to SE in the 8-10 am period inland, reaching the coast by early afternoon and southside Hampton Roads and NE NC by the start of the evening commute time.

In terms of headlines: Winter Storm Warnings have been expanded slightly to the E-SE into the peninsula and western portions of Southside Hampton Roads. Given the aforementioned QPF, and cold temperatures aloft that should outrun standard 10:1 ratios, especially late morning and afternoon as CAA strengthens, have trended snow totals a bit higher into the 3-5" range for the narrow corridor that swings from US-60/I-64 south/southeast to US-460. As is often the case, there remains some uncertainty on the periphery of the warning. It is possible that some locally higher totals occur from Hanover to King William/Gloucester County, with the same also true for Mecklenburg County farther to the south. However, on an areal/county average basis, expect these counties remain more or less in the 1-3" range, and will keep the Winter Wx Advisory in place there and for all counties locally that are not in the Winter Storm Warning, with the exception of the MD Lower Eastern Shore and coastal Currituck County (NC).

Very cold air moves into the region tonight with low temps in the low to mid teens west of I-95 with upper teens to the low/mid 20s to the east. Inland winds drop off by Tue AM, so not anticipating wind chills to be much below actual air temperatures.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/

As of 250 AM EST Monday...

Key Messages:

- Dry and cold Tuesday, followed by short-lived milder temperatures on Wednesday.

Continued cold Tuesday with most inland areas likely not warming out of the 30s, with low 40s in the SE. Not as cold Tue night, and turning milder Wed as a deep upper trough amplifies across central Canada, with low pressure tracking through the Great Lakes. This allows for an increasing SW low level flow Wed, with highs into the 50s for most.

LONG TERM /THURSDAY THROUGH SUNDAY/

As of 250 AM EST Monday...

- Trending cooler Thursday, with low-end precip chances Friday, possibly ending as some wintry precip. - Dry, but again turning sharply colder next weekend.

Medium range models and ensembles remain in decent agreement that the later week timeframe trends colder with increasing rain chances Thursday night/Friday as the next system impacts the region. Precip potentially changes over to a rain/snow mix before ending Friday night. Next weekend looks dry and cold as another Arctic cold front crosses Sat, once again ushering in cold high pressure from the NW.

AVIATION /12Z MONDAY THROUGH FRIDAY/

As of 615 AM EST MONDAY...

A cold front is crossing the area this morning and will cause northerly winds to increase over the next few hours. Any lingering fog will diminish as well. During the day today, NNE winds increase and become rather strong along the coast (gusting to 25-30 kt at ORF), with winds 10-15 kt with gusts to 20-25 kt elsewhere. Precipitation is expected to impact the area by mid morning, bringing IFR to LIFR flight restrictions that will last through the early evening. RIC and PHF should see mainly snow from this event, but ORF/ECG are likely to see a period with -RA before changing over to snow later in the aftn, with snow as the main p-type this evening for any remaining precip that will linger along the coast. SBY will likely also see a period of snow this afternoon, though still have lower confidence due to northern edge of precipitation being nearby for most of the day. VIS will be greatly reduced in the SN today. Rain/snow chances gradually come to an end west to east after 03-06Z. NNE winds will remain breezy at the coast through Tues morning.

Outlook: VFR, with diminishing winds Tue afternoon, then winds become SW and breezy on Wednesday.

MARINE

As of 250 AM EST Monday...

Key Messages:

- A Gale Warning is in effect today for the coastal waters south of Parramore Island, including the Currituck Sound and Mouth of the Chesapeake Bay, with Small Craft Advisories in effect in the remaining waters.

- Another system will bring degraded marine conditions to the area Wednesday and Wednesday night, followed by additional elevated winds by the end of the week into the weekend.

Early morning surface analysis indicates high pressure and light winds persisting across the waters, but that will change very shortly as a cold front crosses the area. Winds will turn N/NE after 4am and increase in speed as daybreak approaches as the gradient tightens between high pressure building in from the north and an area of low pressure moving northeast off the Carolina coast. That gradient combined with CAA behind the front will allow winds to increase to 20-25kt for most of the waters, with gusts to 30 kt by late morning/mid-day. Rivers will see winds of 15-20kt with gusts to 25 kt. Thus, Small Craft Advisories are in effect through Tuesday morning. For coastal waters south of Parramore Island, the mouth of the Bay, and Currituck Sound, guidance continues to show higher speeds as the low passes nearby. NE winds of 25-30kt with gusts to 35-40kt are expected, warranting a Gale Warning for these waters. This is in effect from 9am through midnight tonight. A few gale- force gusts can't be ruled out outside of the Warning, especially for the coastal zone from Chincoteague to Parramore Island, but it will be a short enough duration to use SMWs to cover if necessary. Waves in the Bay today will increase to 3-4ft, with 4-5ft in the mouth of the Bay. Seas will build to 6-7ft north and 7-9ft across the south.

High pressure will build in across the waters later Monday night into Tuesday allowing the winds to quickly diminish. Gales and wind- driven SCAs will be allowed to expire by daybreak Tuesday. Southern waters may need a lingering SCA into part of Tuesday for 5ft seas. SW winds will remain light through the day before they increase once again as a warm front lifts across the area and a strong low pressure system advances northeastward across the Great Lakes. Winds will continue to strengthen into the day on Wednesday. Local wind probabilities have a 60-95% chance for wind gusts >=34kt for the coastal waters north of Parramore Island (highest farther offshore between 15-20nm). With 40-60% from Parramore Island to Cape Charles. Strongest winds look to be mid/late morning Wednesday through the afternoon/early evening. Solid SCAs are expected for most of the waters, with gales possible in the aforementioned zones. Expect waves in the Bay to become 3-4ft again with seas building to 5-7ft (highest north). As the low pressure lifts well north of the area on Thursday afternoon, winds will diminish to 10-15 kts through Friday morning. Yet another system is progged to approach the region by late week, bringing possibly another round of strong to near-gale conditions to the area.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...Winter Weather Advisory from 10 AM this morning to 10 PM EST this evening for NCZ012>014-030. Winter Weather Advisory from 2 PM this afternoon to midnight EST tonight for NCZ015>017-031-032. VA...Winter Weather Advisory from 10 AM this morning to 10 PM EST this evening for VAZ084-086-096-099-525. Winter Weather Advisory from 2 PM this afternoon to midnight EST tonight for VAZ095-097-098-100. Winter Weather Advisory until 6 PM EST this evening for VAZ048- 062-064-065-075>078-085-509>512-517>522. Winter Storm Warning until 6 PM EST this evening for VAZ060- 061-066>069-079>083-513>516. Winter Storm Warning from 10 AM this morning to 6 PM EST this evening for VAZ087>090-092-093-523-524. MARINE...Small Craft Advisory until 6 AM EST Tuesday for ANZ630>632-650- 652. Gale Warning until midnight EST tonight for ANZ633-634-654-656- 658. Small Craft Advisory until midnight EST tonight for ANZ635>638.