Area Forecast Discussion
Issued by NWS Wakefield, VA

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403 FXUS61 KAKQ 221943 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 243 PM EST Mon Jan 22 2018 .SYNOPSIS... High pressure remains centered off the Mid Atlantic coast today. A trough crosses the region Tuesday morning, with the cold front lagging behind and pushing through the region by late afternoon. es well off the coast by Tuesday night. High pressure becomes centered over the south central states Wednesday and builds east into the local area by Thursday. && .NEAR TERM /THROUGH TONIGHT/... Latest analysis places a potent sfc low ~992mb over Iowa with cutoff upper low lagging back a bit to the SW acrs eastern Kansas and NW Missouri. Meanwhile, sfc high pressure remains off the mid- Atlantic coast with dry/warm conditions over the local area. Temperatures are now mainly ranging through the 50s as of 10 am with a fairly thick cirrus shield in place (and some mid clouds with cigs around 10k ft over the eastern shore). Bufkit soundings suggest a continuation of high clouds all day and will call it partly cloudy overall for the aftn. Well above avg for highs today, mainly in the mid-upper 60s except locally cooler coastal eastern shore/Va Beach/NC Outer Banks. Do not anticipate setting any record highs today but for reference these are included in Climate section below. Dry/very mild tonight with temperatures staying in the 50s just about everywhere. Partly/mostly cloudy in the evening, then becoming cloudy overnight with increasing rain chances after 06Z mainly over the Piedmont. Have likely PoPs to the I-95 corridor after 09Z. Enough mid level instability will move in late to include mention of isolated tstms late across the far west. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... High rain chances (60-80%) prevail Tue morning as main sfc low pressure becomes occluded over Michigan and significant pressure falls and a meso-low develop along the central Appalachians by around 12Z. The strength of this feature will likely have a significant affect on QPF and the potential for some embedded convection in the morning in a high shear/minimal CAPE environment. At this time, SPC does not even place the CWA in a marginal risk and current pattern with convection across the deep south and Gulf of Mexico could be a hint that a split in the precip shield is likely (and thus most areas should expect 0.25" or less of total QPF except for locally higher amounts in tstms). Models remain in good general agreement wrt timing and should see PoPs taper off W-E quickly by aftn...w/ pcpn moving out of the entire area by 21Z/Tue to 00Z/Wed. With aftn sunshine, deep mixing, and a downslope flow highs Tue will be breezy and unseasonably warm, possibly close to record highs. Current forecast is for highs 70-75 F across much of central/SE VA and NE NC, with 65-70 F on the eastern shore and over the far N/NW sections of the CWA. Dry cooler Tue night/Wed w/ lows mainly in the 30s and highs Wed upper 40s N and on the ern shore to 50-55 F elsewhere. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
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Overall pattern continues to show the long term period beginning with a shortwave ridge building eastward from the Mississippi Valley into the Southeastern US and Mid-Atlantic states on Friday into Saturday. This is followed by a full latitude trough that moves in on Sunday into Monday. But today, the timing between the models and strength of the cold front crossing the area is different with the 12z GFS slower and weaker while the 12z ECMWF is slower, stronger and would provide more rain for the region. The ECMWF right now has better run to run continuity than the GFS as the 6z GFS was slower and wetter than the 12z run. So for now have leaned a little more toward the slower ECMWF for that part of the forecast. On Thursday night through Friday, high pressure will be in control of the regions weather with the high overhead expect to see a very cool night with good radiational cooling, lows in the m20s-l30s. Temperatures will begin to warm again on Friday as warm advection begins with sw flow, expect highs in the u40s to mid 50s. Mex guidance is a bit warmer and began to trend that direction raising highs a few degrees above the other guidance. The SW flow continues on Fri night with more dry weather and maybe a few more clouds. Temperatures in the mid to upper 30s are expected. For Saturday through Sunday night, this is where the most interesting portion of the extended lies as the quicker GFS has the moisture and front approaching the area by late Sat afternoon, which is about 6 to 12 hours faster than the 6z GFS or ECMWF. At this range, did raise pops a touch, but kept the forecast dry on Sat with temperatures getting back into the U50s to l60s. But beginning Sat night did start to raise pops up to high chance values. Some guidance suggest pops in the likely range are possible now, but with timing issues and also the questionable forcing have capped pops at 50% from Late Sat night through Sunday with a slow clearing of the pops in Sunday evening. Sunday looks like the most probably period for rain and the ECMWF would indicate a beneficial rain, which would be good for the drought areas, but at this range models have been showing these types of events for the last few weeks, but the plentiful rain has been materializing. Have kept temps mild on Sat night and Sunday with lows in the 40s and highs still in the 60s. The front should clear the area Sunday night with NW and high pressure building in on Monday. The strength of the developing upper trough will determine how strong the low over New England gets Sunday night and this will impact temps on Monday. The ECMWF would suggest temperatures cooler than the currently forecast in the upper 40s to mid 50s on Monday. But for now will not bit completely on the ECMWF.
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&& .AVIATION /19Z MONDAY THROUGH SATURDAY/... VFR conditions expected to continue through the bulk of the 12Z TAF period. BKN-OVC mid level cloudiness (CIGS mainly 7-9 kft) moving across the local area attm...expected to continue into the morning hours...w/ most CIGS lifting to above 12 kft for late this morning-this eve. Generally light S winds early today...increasing to 10-15 kt through the rest of day. Sfc high pres remains off the SE coast w/ dry conditions continuing. The next chance for widespread precipitation and flight restrictions comes after 06-09Z/23 through (early) Tue aftn with a passing cold front. Gusty SSW winds (to 20-30 kt) early Tue shift to the WNW late in the day along w/ potential for widespread IFR CIGs (and SHRAS). ISOLD tstms possible with the front mainly Tue morning. Dry and VFR conditions then prevail late Tue-Fri. && .MARINE... High pressure over the waters today will keep S winds below 15 kt Waves/seas 1-2 ft. Winds will begin to increase tonight as a deepening low over the Great Lakes pushes its associated cold front toward the region by Tues morning. Winds will increase to 15 to 25 kt from the S-SW prior to daybreak Tues, continuing thru midday/early aftn, with seas on the coastal waters building to 4-6 FT; waves 3-4 ft on the Bay. SCAs remain in effect for all waters. Hard to get Gales with warm S-SW winds over cold water this time of year, but did keep mention of a few gusts to 35 kt for our northern coastal waters. Once the front clears the area Tues afternoon, winds will shift to the west 10-15 kt Tues night/Wed and then northwest on Thursday. Waves/seas subside to 1-3 ft. && .CLIMATE... Record high temperatures today and Tuesday. Today Tuesday RIC 75/1906 76/1974 ORF 77/1937 76/1999 SBY 72/1927 73/1999 ECG 79/1937 76/1937 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 4 AM to 6 PM EST Tuesday for ANZ630>632-634>638. Small Craft Advisory from 6 AM to 6 PM EST Tuesday for ANZ633. Small Craft Advisory from 4 AM Tuesday to midnight EST Tuesday night for ANZ650-652-654. Small Craft Advisory from 6 AM to 10 PM EST Tuesday for ANZ656- 658. && $$ SYNOPSIS...LKB NEAR TERM...LKB SHORT TERM...ALB/LKB LONG TERM...ESS AVIATION...ALB MARINE...JDM/MAM CLIMATE...

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