Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 222354 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 754 PM EDT Thu Jun 22 2017 .SYNOPSIS... Bermuda high pressure begins to shift back towards the Eastern Seaboard through tonight. The high becomes centered off the Southeast Coast Friday and a surface cold front approaches the region from the northwest. Tropical moisture from the remnants of TD Cindy will push across the region ahead of the front for Friday night through early Saturday...before the front shifts offshore late in the weekend. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Latest weather analysis features Tropical Depression Cindy moving N-NE over the Arklatex region of the lower Mississippi River Valley. Out ahead of the system, a broad plume of mid to upper level clouds has pushed across the Mid-South into the Carolinas. To the north, a quasi-stationary boundary remains in place along and just north of the Mason-Dixon line, extending NW into the western Great Lakes. Meanwhile, the Bermuda High is settling in off the Southeast Coast and will remain there through at least Saturday. 12z soundings indicate SSW flow has allowed for quick moistening out ahead of the system, with PW values already ~1.50"...running just a bit faster than model timing. Slight to low end chance (20-30%) POP continues for isolated to widely sct convection over the southern 1/3 of the area (mainly US-460 south) this aftn. A couple of lobes of shortwave energy out ahead of TD Cindy lift ENE from the TN Valley/SE States this afternoon. Given that shear is still on the low side, expect activity over the local area to drop off quickly with loss of heating, with most pcpn remaining to our w-sw through midnight. Overall, increasing clouds, very warm/muggy for the balance of this aftn with highs reaching into the lower 90s most areas and dewpoints around 70F. More widespread area of showers pushes in late tonight as theta-e ridge pushes across the piedmont toward the Eastern Shore late tonight into Friday morning. Expect a period of moderate to locally heavy rainfall during this time frame, and have therefore continued likely pop mainly NW of a FVX-RIC-SBY line. Farther south, have gone with a low chance pop for some isolated showers over south central VA and NE NC. Warm and muggy overnight with lows in the 70s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... The core remnants of TD Cindy will merge with the approaching cold front on Friday, and lift NE from the Mid-South toward the central and southern Appalachians Friday afternoon and night before crossing the local area late Friday night through Saturday morning. Out ahead of the system, rain showers associated with lead shortwave/Theta-e ridge will push across the northern tier of counties Friday morning. Expect a brief period of partial clearing behind this initial wave, which should allow for strong surface-based instability. PW values will creep to and above 2" by Friday morning. Additionally, expect 0-6km deep layer shear will be on the order of 35-45 kt, with Hi-Res models showing a pronounced low level jet streak of ~50 kt just to the north by mid to late afternoon. The caveat to all this thunderstorm potential is that regional soundings continue to indicate a fairly substantial capping inversion that will need to be overcome to realize the strong convective threat. Given strong amount of lift to the north, expect that best chance for T-Storms tomorrow afternoon will be across our northern tier of counties, and have oriented a high end pop for Scattered T-Storms Friday afternoon. Farther south, removed from the better dynamics, have tapered back to a 20-30 pop tomorrow afternoon. Very warm and humid tomorrow with highs again u80s to low 90s inland. Warm and muggy Friday night with lows in the 70s. After another brief lull tomorrow night, the actual remnants of Cindy track across the approaching cold front Early Saturday morning. Given favorable dynamics and PW values AOA 2", expect a period of moderate to locally heavy rainfall across the northern half of the region. Despite short-lived heavy rain rates in the tropical airmass Sat morning, progressive nature of system should preclude too many flooding issues. However, important to note that flash flood values are lower than they typically would be for this time of year, especially along the I-64 corridor. Therefore, we will have to watch this time frame closely. Front will push to the coast and then offshore by Saturday evening, with POPs gradually diminishing Saturday afternoon and early evening. Locally heavy rainfall possible along the coast and southern zones into the early evening hours on Saturday. Remaining warm and moderately humid Saturday. Highs mainly in the mid to upper 80s to around 90 SE zones. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Cold front pushes offshore Saturday night, stalling along the coast Sunday. Height falls ahead of a deepening upper level trough over the Great Lakes/Ohio Valley Sunday and remnant moisture along the boundary will result in isolated to scattered showers and thunderstorms across northeast North Carolina Sunday afternoon. Drying inland. Highs Sunday in the low to mid 80`s. A secondary front pushes into the region Sunday night and Monday. Have only kept slight chance POPs inland Monday given limited moisture. Highs in the low to mid 80`s. Potent shortwave digs into the Ohio Valley and central Appalachians Monday night into Tuesday with a stronger cold front pushing through the region Tuesday. Moisture return along the coast will result in isolated to scattered showers and thunderstorms across eastern Virginia. Cooler Tuesday with highs in the mid to upper 70`s. Dewpoints mix into the 50`s, resulting in pleasant afternoon conditions. Dry and comfortable conditions forecast again Wednesday as the trough pushes offshore and heights build over the Ohio Valley. Surface high pressure settles over the Mid-Atlantic. Highs Wednesday generally in the low 80`s. Cool Thursday morning, with lows in the upper 50`s inland to mid 60`s near the coast. High pressure slides offshore Thursday with return flow resulting in moderating temperatures. Highs in the mid 80`s. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/...
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The Bermuda High pressure ridge extended from the east into the Carolinas. Tropical depression Cindy was over western Louisiana. A warm front reached from low pressure over the northern Great Lakes to Connecticut. As of 23z...High clouds covered the Mid Atlantic States. Isolated showers were staying away from the TAF sites and will end shortly. A moist flow from the Gulf of Mexico ahead of a cold front will produce scattered showers and isolated thunderstorms Fri8day. Most of these will be north of the TAF sites and went no more than showers in vicinity in the TAFs. Winds will continue from the southwest through the period. OUTLOOK...The remnants of Cindy will cross the northern portion of the Mid Atlantic States Saturday morning and will be located along a cold front. That front will cross the TAF sites during the day Saturday. Showers and thunderstorms will be likely Saturday afternoon. These will come to an end Saturday evening. Far southeast portions will have a slight chance for showers and thunderstorms Sunday. There will be a chance for showers and thunderstorms Monday through Tuesday across the area. Patchy MVFR or IFR ceilings and visibilities will be possible each morning within a few hours of sunrise.
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&& .MARINE... Latest surface analysis centers high pressure off the Southeast coast with a weak frontal boundary over the Northeast. Southwest wind of 10-15 knots prevails over the waters this afternoon with waves 1-2 feet and seas 2 feet. High pressure prevails off the Southeast coast through Saturday as the remnant low of Cindy tracks along a cold front through the Tennessee Valley Friday and Friday night and into the Mid-Atlantic Saturday morning. Southwest winds increase over the waters Friday afternoon, with speeds increasing to 15-20 knots in the northern waters Friday afternoon. Have raised SCA headlines for the upper Bay Friday afternoon for gusts of 20-25 knots. Pressure gradient strengthens Friday night ahead of the remnant low as winds aloft increase. Southwest winds increase to 15-25 knots with gusts up to 30 knots in the Bay and coastal waters Saturday morning. Seas increase to 4-6 feet out 20 nm north of Parramore Island. 3-4 feet elsewhere. Waves increase to 2-4 feet. SCA headlines have been raised for the Bay beginning late Friday evening, but have held off on additional headlines due to the time frame being late 4th period. The remnant low lifts north of the region Saturday afternoon as pressure rises return over the waters mid to late afternoon. Expect improving conditions late Saturday as winds become west to southwest at 10-20 knots. Seas subside to 2-4 feet Saturday evening. Winds become northwest Saturday night as the front pushes across the region, but a lack of cold advection and weak gradient winds expected to keep conditions sub-SCA. Another cold front pushes across the waters Monday night with high pressure building over the region through the middle of next week. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 10 PM Friday to 6 AM EDT Saturday for ANZ632-634. Small Craft Advisory from 1 PM Friday to 6 AM EDT Saturday for ANZ630-631. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MAM LONG TERM...SAM AVIATION...LSA MARINE...AJZ/SAM is the U.S. government's official web portal to all federal, state and local government web resources and services.