Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 130118 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 918 PM EDT Mon Mar 12 2018 .SYNOPSIS... Low pressure will rapidly intensify into this evening while moving northeast off the North Carolina and southern Virginia coast The low will continue moving northeast well off the Delmarva later tonight. High pressure builds south of the region Tuesday and Wednesday as low pressure lingers to our north. && .NEAR TERM /THROUGH TUESDAY/... Rapidly developing low pressure off the coast combined with a powerful upper level system has resulted in continued areas of heavy snow as the main pcpn band has shifted ewd. Have issued Winter Weather Advisories for the Tidewater and NE NC for an average of 2-3" of snow. Surface temperatures will be 32-34F during the snow. Previous Discussion... Main concern/challenge through this evening will be further development of deformation axis/banding now pushing through the I-95 corridor and affecting metro Richmond. Have hoisted a short term winter wx adsy to cover the next few hrs/evening commute as cams showing roads have become at least partially slush/snow covered in some spots, particularly secondary roads. The adsvy will go through 10pm into interior NE NC and portions of interior SE VA. This region lines up w/ NAM/GFS modeled low level thicknesses of ~1295m. 12Z NAM/GFS depict strong lift through the dGZ late this aftn shifting across far southern VA and reaching the coast by 00Z. The limiting factor the farther to the SE at the coast including Hampton Roads will be the warmer antecedent airmass (1000-850mb thicknesses currently at or above 1310 mb and sfc temps still in the 40s). Thus, it will take several hrs of moderate/heavy precip to cool/wet bulb down to yield potential for accumulating snow/sleet. Also, the band is becoming oriented almost due N-S and expect the eastward progression of the band to slow down. Likewise, for late this evening/tonight, if accumulating snow/sleet does persist, will need to consider an adsy almost to the coast. Otherwise, expect drying conditions fairly rapidly over the NW 1/2 of the CWA later this evening. Temperatures will tend to be steady this evening as precip winds down and are not likely to drop below freezing overnight until after about 4 am most areas. Thus, this does not look like a significant black ice type of commute for early Tue at this time even though much of the region will likely fall a little below freezing for actual mins (lows upper 20s west/lower 30s east). No major change in forecast rationale for the midweek period. Becoming partly/mostly sunny Tue behind the departing system. Gusty NW flow will keep highs well below normal, mainly in the mid- upper 40s (around 50 F far S). && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... Cold/partly cloudy and dry Tue night with lows in the mid 20s to lower 30s. Upper low progged to be slowly shifting ENE into New England on Wed, with a significant shortwave trough rotating around the base of this feature and traversing through the mid Atlc and Carolinas. At this time, it still appears downslope flow at lower/mid levels will inhibit measurable precip across the AKQ CWA. However, cannot rule out a few isolated/scattered rain/snow showers during the late morning through the aftn (mainly north). Highs Wed mainly staying in the mid-upper 40s. Partly cloudy Wed night with lows in the mid 20s to lower 30s again. Partly cloudy, turning a little warmer on Thu with highs around 50 F NE to the mid/upper 50s SW. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Overall pattern will be rather progressive during the extended period, with temps expected to be near or just above normal. Expect generally dry weather Thu night thru Sat, except for a slgt chc of showers near the VA/NC border Fri into Fri night. The best chc for showers looks like it will be late Sun thru Mon, as a warm front lifts into and acrs the area. Highs will range fm the upper 40s to upper 50s Fri, in the upper 40s to mid 50s Sat, and mainly in the mid 50s to lower 60s Sun and Mon. Lows will range thru the 30s Thu night, in the upper 20s to mid 30s Fri night, in the mid 30s to lower 40s Sat night, and in the lower to mid 40s Sun night. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... IFR/LIFR in snow at ORF/PHF/ECG and IFR cigs at SBY where pcpn could change to snow later this evening. KRIC is improving. Other terminals improve after 06z. A strong N to NE wind is expected gusting to 20-25kt and ~30 to 40 kt at ORF/ECG. Outlook: Improving conditions are expected later tonight and Tuesday as high pressure returns. An upper trough rotating through the area Wednesday and Thursday could bring brief periods of MVFR cigs, especially at KSBY. High pressure returns Friday. && .MARINE... Low pressure off of Cape Hatteras continues to strengthen this afternoon as the strong upper level low to the west pushes through South Carolina and Georgia. The low will continue to strengthen tonight and the winds will continue to increase to Gale force along the coast and for the Mouth of the Bay and Currituck Sound beginning around 00z and continuing through the overnight hours. While the duration of the gale force winds is not long, there will be a quick build up of the seas with wave heights increasing to 6 to 12 ft in the coastal waters. The low will pull away from the coast on Tuesday and head for New England and the Canadian Maritimes. In its wake, the winds will continue to blow from the NW and SCA conditions should continue through Tuesday. There will be a short respite in conditions on Tuesday night before another reinforcing cold front slides across the area on Wednesday morning. Behind the front, another shot of cold nw flow will arrive with potentially more SCA conditions of nw wind 20 to 25 kt. The NW flow will continue through the remainder of the week into the weekend as another weak and dissipating disturbance slides through the area on Thursday before Canadian high pressure finally moves over the area later Friday into the weekend. && .TIDES/COASTAL FLOODING... Increasing NE winds today will result in a slow rise in tidal anomalies. Period of tide anomalies avgg close to 1 ft above normal expected this eve/tonight (potential to 1.5 ft above normal invof mouth of the Ches Bay and srn ocean waters). Kept forecasts below minor flooding thresholds for now. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...Winter Weather Advisory until 10 PM EDT this evening for NCZ012>014-030>032. Winter Weather Advisory until 1 AM EDT Tuesday for NCZ015>017. VA...Winter Weather Advisory until 10 PM EDT this evening for VAZ088>090-092-093-096. Winter Weather Advisory until 1 AM EDT Tuesday for VAZ095-097- 098-100. MARINE...Gale Warning until 7 AM EDT Tuesday for ANZ630>634-650-652-654- 656-658. Small Craft Advisory until 7 AM EDT Tuesday for ANZ635>637. Small Craft Advisory until 2 PM EDT Tuesday for ANZ638. && $$ SYNOPSIS...LKB NEAR TERM...AJZ/LKB SHORT TERM...LKB/MAM LONG TERM...TMG AVIATION...AJZ/LKB MARINE...ESS TIDES/COASTAL FLOODING... is the U.S. government's official web portal to all federal, state and local government web resources and services.