Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 232034 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 434 PM EDT Sat Sep 23 2017 .SYNOPSIS... High pressure will continue to influence the weather pattern through Sunday night. Hurricane Maria is forecast to move northward between the offshore Atlantic waters and Bermuda through most of the upcoming week. A cold front is expected to cross the area by mid week and push Maria east of the region. && .NEAR TERM /THROUGH SUNDAY/... Not much of a pattern change anticipated for tonight with stacked high pressure to the north and a weak upper low over the Gulf Coast states west of FL. Kept low temperatures similar to those experienced this morning and added patchy fog mainly for inland VA/NE NC areas late this evening to just after sunrise. Expect mostly clear skies and lows in the upper 50s to lower 60s. The stacked high slowly slides eastward on Sun...preventing Hurricane Maria from moving too far northward. Skies remain mostly sunny with temperatures warming nicely to highs in the mid-upper 80s inland (low-mid 80s beaches due to breezy NE winds). Afternoon dewpoints falling into the upper 50s to mid 60s will create ambient conditions that should feel comfortable rather than humid. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... Southern end of the stacked high begins to break down Sun night as Hurricane Maria drifts northward but remaining well off the Southeast Coast. Biggest change will be slightly warmer overnight lows in the mid 60s (upper 60s to around 70F beaches) as onshore/NE winds remain breezy in response to the pressure gradient tightening between the sfc high to the north and Maria to the south. Maria continues to move northward on Monday with gradient winds remaining persistently breezy from the NE. Gusts around 20-25 mph should be anticipated along coastal areas of SE VA/NE NC...where farther inland, gusts should range from 15-20 mph. Clouds from the outer bands of Maria will start to rotate into areas along the coast from NE NC to MD...especially as the afternoon progresses. This should impact temperatures near SE coastal areas with highs in the upper 70s to lower 80s. Farther inland, less clouds present should allow temps to warm into the mid- upper 80s. Isolated thunderstorms may be possible Mon afternoon if the outer bands can make it far enough north to rotate into far SE VA/NE NC coastal areas. Per 12Z data, models in fair agreement in showing Maria`s center located an average of 320 miles SE of Cape Hatteras by Monday evening with variations in precip coverage, thus the reason why precip is limited to isolated for Mon. From Mon night into Tue, model consensus begins to fall apart. The general trend among all models is for Maria to continue pushing northward. However, the GFS is more progressive in shifting its track NNW and closer to Cape Hatteras (around 160 miles ESE), whereas the ECMWF shows a slower northward track and keeping the center around 225 miles SE of Cape Hatteras. Despite model differences, the overall trend is for Maria to approach the Mid Atlantic Region Mon night and Tue with precip chances increasing during this time. Have broad-brushed POPs into 6 hour segments in an effort to show the upward trend while not putting too much detail into the forecast until models get a better handle on how close Maria can get to the coast before being pushed out to sea by a cold front and incoming upper trough with stronger westerly steering winds aloft. Given model differences, temperatures will be tricky...however dewpoints will be on the rise into the upper 60s to lower 70s. Expect increasing low temperatures Mon night (upper 60s to lower 70s), and lower high temperatures on Tue due to more clouds/precip across the area. Highs in the mid-upper 70s near the coast to around 80F generally along/west of Interstate 95. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... First part of the extended, Tuesday night through Thursday, will be predicated on future track of Hurricane Maria. Latest NHC track is a bit further west than 24 hours ago, which increases the potential for some rainfall near the Bay/Ocean, somewhat stronger winds, higher seas, and some coastal flooding. Have utilized Superblend for tangible weather during this period, given potential uncertainty in the track. Models quite consistent after the daytime hours Thursday in taking Maria fairly quickly northeastward away from the area. in advance of upper trof dropping southeastward from Canada. This trof and associated cold front move into the region next Saturday /Day 7/. Above normal temperatures continue through Thursday, with highs from the upper 70s to mid 80s. Temperatures cool into the 70s Friday/Saturday in the wake of Hurricane Maria. Lows Tuesday night through Wednesday night range from the mid 60s to around 70F, then mid 50s NW to mid 60s SE Thursday night, and in the 50s Friday night. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... VFR conditions prevail for the most part through the 18z TAF period, as high pressure remains in control over the area. Have maintained some MVFR overnight at KRIC/KSBY per 12Z TAF issuance. This seems reasonable given little overall pattern change, and dew points are about the same as Friday. Have kept KORF VFR through the period, as that terminal is generally not prone to nocturnal fog development. However, have opted to forecast similar conditions to Friday night at KPHF/KECG. Both these locations had at least intermittent IFR/LIFR Friday night. Since the overall pattern is unchanged from the last 24 hours, both of these sites should again see intermittent IFR/LIFR conditions after 02Z. Outlook: Generally VFR/dry conditions, with the exception of patchy morning fog, are anticipated through the Monday due to the influence of high pressure over the region. Sub-VFR conditions will be possible Tuesday through mid next week, primarily at eastern TAF sites, as moist northerly flow from Tropical Cyclone Maria overspreads the region. && .MARINE... Long period swell continues to propagate toward the coast with seas generally 4-6 ft and the current Small Craft for Hazardous Seas will continue in effect through Sun night (after that winds will increase and the headlines will likely be converted to the more usual Small Craft Advsy). Overall, expect seas of 4-6 ft to persist Sunday/Sunday night, then build more significantly Mon- Wed as ESE swell and some increasing winds arrive from slow moving Maria. The bulk of the forecast guidance (as well as the official NHC forecast) still keeps Maria offshore of the Carolinas Tue into Thu, before it gets kicked quickly ENE out to sea Thu night into Fri night. Based on the latest guidance, have increased winds and seas fcst for Tue-Thu, with at least SCA conditions expected all areas and the potential for Gales over the lower Bay/coastal waters (or tropical headlines). Either way, seas over the coastal waters should easily reach 10 ft or greater from Tue-Thu. Monitor the NHC forecast for the official forecast track of Maria. && .TIDES/COASTAL FLOODING... Tidal departures this aftn avg 1.0 to 1.5 ft across the entire area. Minor flooding continues mainly across the upper Bay from Lewisetta to Bishops Head through this evening. The following high tide overnight/early Sunday will tend to be slightly lower than the one this evening but will be close enough to just extend the coastal flood advisory through Sun morning. Elsewhere over the mid/lower Bay, the water levels peaked a few tenths below minor flood thresholds earlier today, with the overnight tide expected to be slightly lower so did not issue any headlines for these areas. Water levels will tend to remain elevated Sun-Mon, but overall most places should remain below any minor flood thresholds. Will need to watch for additional flooding next week, especially by Later Tue and Wed (and perhaps Thu). This will depend on the exact track of Maria, but the potential for significant tidal flooding exists (especially over locations adjacent to the lower Bay and southern VA/NE NC waters. High Surf advisories likely will be needed by late Mon or Tue as well. High risk for rip currents for all beaches adjacent to coastal waters continues through Sunday, as 3-5 ft nearshore waves and 13-15 second swell persists. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...Coastal Flood Advisory until 9 AM EDT Sunday for MDZ021>023. NC...None. VA...Coastal Flood Advisory until 7 AM EDT Sunday for VAZ075-077. MARINE...Small Craft Advisory for hazardous seas until 6 AM EDT Monday for ANZ650-652-654-656-658. && $$ SYNOPSIS...BMD NEAR TERM...BMD SHORT TERM...BMD LONG TERM...AJZ/ALB/WRS AVIATION...AJZ/WRS MARINE...LKB/TMG TIDES/COASTAL FLOODING...AKQ

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