textproduct: Wakefield

SYNOPSIS

Low pressure offshore and a passing disturbance aloft brings the chance for snow to mainly the southwestern half of the area on Monday. Mainly dry for Tuesday through Thursday, with shower chances increasing with the next cold front late in the week.

NEAR TERM /THROUGH MONDAY/

As of 330 PM EST Sunday...

Key Messages:

- Headlines have been issued for Winter Weather that is expected for much of the area Monday. Weak high pressure is currently centered across the VA coastal plain this aftn, with low pressure along the Gulf coast. A WSW flow prevails aloft. Low clouds and fog finally dissipated over most of the area early this aftn, allowing temperatures to rise into the low-mid 40s, though it remains overcast and in the 30s across the northern piedmont. For tonight, light wind and a variably cloudy sky this evening will tend to promote some quick cooling after sunset with the potential for patchy fog later in the evening, mainly inland. It will not be nearly as widespread and of the duration which occurred late last night and this morning since northerly winds begin to increase after midnight in the wake of a dry cold front. Low temps dip into the upper 20s to low 30s for most spots with mid and upper 30s near the coast in the far SE.

The latest 12Z/07 model suite continues to trend stronger with the potential for a significant winter weather event for much of the region on Monday. Low pressure deepens off the Carolina coast early Monday. Aloft, a short wave trough traverses the local area Monday morning into the afternoon which will provide enough lift for precip across at least the southern half to two thirds of the area. 12z guidance continues to trend wetter vs previous runs with forecast QPF now varying from 0.20-0.40" overall. 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, so went a little colder than the blended guidance and show temps holding roughly steady in the morning and then falling through the afternoon. There are some notable model differences with respect to the highest snowfall and QPF amounts, which yields uncertainty in the forecast- the RAP/HRRR are a little north of the consensus with respect to heavier snow and higher QPF which would suggest 3-4" snowfall amounts along and even to the N of I-64. In contrast, the ENS/GEFS/GEPS and deterministic ECMWF, GFS, CMC are farther south, with the highest probs for seeing 3-4" or more of snowfall across south central and interior SE VA. Confidence is rather high for 1-2"+ across most of the CWA so went primarily with Winter WX Advisories, with a small watch area along and S of route 460 and W of I-95 in south central VA where probs for >3" are well over 50%. Very cold temps aloft also argue for snow to liquid ratios to be higher than 10:1, especially in the afternoon as cold advection strengthens. Forecast soundings show saturation or supersaturation with respect to ice in the DGZ so expect most of the precip to fall as snow or perhaps a brief rain/snow mix at the onset. The far SE portion of the area remains problematic with colder air taking longer to arrive. Given the upward trends, included most of metro Norfolk in an Advisory, but left out VA Beach and Currituck NC where the warmer air hangs on the longest.

SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/

As of 330 PM EST Sunday...

Key Messages:

- Snow ending Mon night, then dry and cold Tuesday, followed by milder temperatures Wednesday.

Very cold air moves into the region Monday night with low temps in the 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. 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 /WEDNESDAY NIGHT THROUGH SUNDAY/

As of 345 PM EST Sunday...

- Trending cooler Thursday, with low-end precip chances Friday - Dry, but cold 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 high pressure builds in from the NW.

AVIATION /00Z MONDAY THROUGH FRIDAY/

As of 645 PM EST Sunday...

VFR conditions at all of the TAF sites to start off the forecast period. Most of the guidances suggests flight restrictions return with low stratus and fog after ~03Z, especially across interior portions of the forecast area. IFR CIGs (and/or fog) may try to work into RIC ~06z. As the cold front crosses the area, and northerly winds increase after midnight, and especially approaching daybreak Monday, it is expected that fog will dissipate (prior to 12Z), though MVFR to IFR CIGs probably continue. On Monday, 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 later morning, bringing IFR to LIFR flight restrictions that will then last through the late aftn/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 Monday evening for any remaining precip that will linger along the coast. SBY may also see a period of snow Monday afternoon, but lower confidence compared to the remainder of the sites.

Outlook: Drying out, but NNE winds remain breezy at the coast through Tuesday morning. VFR, with diminishing winds Tue aftn, then winds become SW on Wednesday.

MARINE

As of 300 PM EST Sunday...

- A Gale Warning is in effect for Monday 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 may 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.

High pressure has settled across the local waters this afternoon, which has resulted in light and variable winds. Marine observation sites are measuring winds of around 5 kts and waves of less than 1 ft in the Bay and seas ranging between 2-3 ft in the Ocean. Marine conditions will rapidly deteriorate late tonight into early Monday morning as a cold front drops through the area. Winds will quickly increase as the gradient tightens between high pressure to the north that will be building southward across the region and an area of low pressure that will be skirting northeast off the Carolina coast. With the tightened gradient in place, combined with exceptional CAA expected in the wake of this front, strong to near-gale force winds are forecast for all coastal waters. Guidance has kept the strongest winds in the coastal waters south of Parramore Island, so have upgraded the Gale Watch to a Gale Warning for these coastal waters, as well as the Currituck and the mouth of the Bay. All other waters will see high-end SCA conditions for the event. There will likely be a brief period of gale-force gusts accompanying at least the initial push of this drier, colder air in waters outside of the Gale Warning, though these short duration gusts will likely be able to be covered by Special Marine Warnings.

High pressure is forecast to build across the area late Monday night through Tuesday, and winds will quickly diminish in response. This reprieve from winds will be fleeting as another system approaches the region on Wednesday. Winds will begin to increase Wednesday morning as a warm front lifts across the region and strong low pressure system advances northeastward across the Great Lakes. The gradient tightens significantly and the in-house probs for the coastal waters for wind gusts >=34 kts range between 50% to near 100% (highest farther offshore between 15-20 nm). Probs for sustained winds of 34 kts or greater remain relatively low, maxing out around 20% in the northern waters. As the aforementioned low 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.

As winds increase on Monday, waves will rapidly build to 3-5 ft in the Bay (highest at the mouth of the Bay) and seas will build to 6-9 ft in the Ocean (highest in the southern coastal waters). With the northeasterly wind direction during the day tomorrow, the southern waters wave heights may actually be slightly under done. Despite an expected downtrend in winds late Monday night through Tuesday, seas will be slower to subside and will likely remain near or just briefly drop below SCA criteria before building again with the second wind surge forecast for Wednesday. With southwesterly winds and shifting to a WSW direction by Wednesday afternoon, forecast wave heights generally range between 4-7 ft in the coastal waters (may briefly reach 8ft in the northern coastal waters) and 3-4 ft in the Bay. Seas will drop briefly below SCA criteria by Thursday afternoon before trending upwards again by late week into the weekend.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...Winter Weather Advisory from 10 AM to 10 PM EST Monday for NCZ012>014-030. Winter Weather Advisory from 2 PM Monday to midnight EST Monday night for NCZ015-016-031-032. VA...Winter Weather Advisory from 10 AM to 10 PM EST Monday for VAZ084-086-088>090-092-093-096-523>525. Winter Weather Advisory from 2 PM Monday to midnight EST Monday night for VAZ095-097-100. Winter Weather Advisory from 6 AM to 6 PM EST Monday for VAZ048-062-083-085-509>512-517-518-520. Winter Storm Watch from 6 AM EST Monday through Monday afternoon for VAZ060-065>067-079-080-087. Winter Weather Advisory from 6 AM to 10 PM EST Monday for VAZ061-068-069-081-082-513>516. MARINE...Small Craft Advisory from 4 AM Monday to 6 AM EST Tuesday for ANZ630>632-650-652. Gale Warning from 9 AM Monday to midnight EST Monday night for ANZ633-634-654-656-658. Small Craft Advisory from 4 AM Monday to midnight EST Monday night for ANZ635>638.