Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 310537 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 137 AM EDT TUE MAY 31 2016 .SYNOPSIS... The remnants of Bonnie will linger along the South Carolina coast tonight, before slowly working northeast to the North Carolina coast Tuesday. A cold front arriving from the west Thursday into Friday will finally boot Bonnie out to sea by the end of the week. && .NEAR TERM /THROUGH TODAY/...
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As of 114 am EDT Tuesday... Updated forecast reflects radar trends which closely resemble a mix of the 04z HRRR and the 00z Local WRF. Still seeing some instability gradient per mesoanalysis along/east of the Blue Ridge. Will see showers mainly isolated linger here for most of the early morning. Added more fog to the grids, but will be contingent on clearing. Best bet over the New River Valley and near the Blue Ridge. Previous valid discussion... Expecting another mild overnight given moist dewpoints with lows mainly 60 to 65 except for a few cooler 50s mountains. Faint boundary should shift east of the mountains Tuesday as the remnant tropical low remains stuck near ILM/MYR through the afternoon. Models again attempt to swing a band or two of deeper moisture into far eastern sections while keeping a low level convergence zone out west. This would again support more scattered nature deeper convection mountains as forecast CAPE values climb to above 1k J/KG despite only weak forcing aloft. However pwats remain quite moist so expecting more heavy rain potential as the continued low level north/ne trajectory under sw flow aloft will likely keep showers from moving too much. This more in line with the latest drier 12z ECMWF, so running again with mainly chance pops, although spots along and just east of the Blue Ridge may stay dry per lingering subsidence once fog/low clouds burn off. Kept highs closer to the warmer mos after a mild start with most in the 80-85 range.
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&& .SHORT TERM /TONIGHT THROUGH THURSDAY/... As of 230 PM EDT Monday... Continued sluggish pattern will result in a repeat performance Tuesday night of that seen tonight with early convection likely giving way to fog and only isolated pops per latest drier Nam. Flow over the west should finally start to turn more southerly later Wednesday afternoon as the Bonnie remnant slides toward the Outer Banks by Wednesday night and a weak backdoor front slips toward the region from the north. Guidance also suggests that weak shortwave energy may eject across the mountains from the west later in the day with tropical moisture and instability still in place. This may allow for a bit more widespread scattering of convection Wednesday afternoon but still not overly impressed. Therefore bumped up pops a little but still moreso on the side of the drier Nam/Euro solutions at this point with still some weak subsidence in place. Again expect any evening convection to fade by midnight Wednesday night with added fog around overnight. Upper heights should start to decrease on Thursday with developing upper troffiness heading southeast toward the region preceded by a weak surface cold front in the afternoon. This will allow for a very congested scenario with the Bonnie remnant near HSE, weak subsidence over the Piedmont, and a pre-frontal convergence zone working into deep pwats over the west where aided by orographics and decent instability. However just how far east lift across the west gets remains uncertain given latest slower trends, but perhaps enough to include afternoon likely pops far western sections and higher chances out to the Blue Ridge. Temps again of the warm/humid flavor with lows mostly 60s and highs in the low/mid 80s. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 1245 PM EDT Monday... Gradual lowering of heights will continue into next weekend as the upper zonal flow starts to break down and eventually gives way to a more pronounced trough across the region into early next week. This should be preceded by passing surface cold fronts with the initial boundary approaching Thursday night and crossing the area Friday pending timing of a few differing model solutions. This looks to put the best coverage of convection over the mountains Thursday evening and then perhaps southern/eastern sections Friday. However appears decent chances to likely pops in order across the CWA per a typical slower scenario than guidance suggests given the lagging mean upper trough well to the northwest. Initial boundary should be to the south Saturday with a brief lull in showers possible before the true secondary front arrives Sunday. This boundary ahead of a rather potent chilly upper cold pool for early June that will pivot east across the region by Day7 and likely knock temps back to below normal levels for early next week. Ahead of the front looks like added bands of shra/tsra Sunday followed by more post frontal upslope nature western showers Monday. Otherwise warm and humid temps with highs at or above normal to prevail into Saturday despite some drying early in the weekend. This before seeing somewhat cooler and even drier air especially mountains by Monday as deeper cool advection arrives with highs mostly in the 70s west to around 80 east. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/...
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As of 130 AM EDT Tuesday... Fog will be good bet across LWB/BCB with clearing, but not sure how low it will go elsewhere. Dealing with more clouds east of Roanoke and Bluefield seems to have a larger dewpoint spread. Still could see some tempo periods of IFR fog at all sites, with LWB/BCB falling to LIFR after 09z. Confidence on having even VCTS in the tafs is low. Axis seems to setup across the Blue Ridge or just east Tuesday afternoon. At the moment took out VCTS or VCSH from the forecast except BCB. This can be amended later today once we see where convection forms. Otherwise look fog/low clouds to start to lift out to VFR conditions after 12-14z. Mainly VFR with scattered to broken cu field with some AC/CS aloft, with less cloud cover as you head toward BLF. Any convection should still hang on into the evening, but again lack of coverage is such that not needed in the terminals at this time. EXTENDED DISCUSSION... Similar setup again Tuesday night with more fog around after any evening convection ends. Appears convection may be more isolated Wednesday as the area slides in between the next upstream cold front and the remnants of Bonnie near the coast. Thus more potential to see more widespread VFR Wednesday with exceptions over the east and with any pop up storms across the mountains. Finally an stronger upper trough will kick what is left of Bonnie out to sea Thursday-Friday. Expect more widespread showers Thursday afternoon into Friday ahead of a cold front, making for periods of sub-VFR ceilings and visibilities. Saturday may be VFR behind this front and before moisture and lowering conditions return by Saturday night.
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&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH/WP NEAR TERM...DS/JH/WP SHORT TERM...JH LONG TERM...JH AVIATION...AMS/JH/WP is the U.S. government's official web portal to all federal, state and local government web resources and services.