Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 03/17/20


Area Forecast Discussion
National Weather Service Blacksburg VA
1015 PM EDT Mon Mar 16 2020 .SYNOPSIS... High pressure over northern New England will maintain a damp and cool northeast flow until early Tuesday before the first in a series of upper-level disturbances tracks into the Ohio and Tennessee valleys, keeping the weather unsettled through much of the week ahead. Temperatures will be moderating to well above normal by late week. && .NEAR TERM /THROUGH TUESDAY/... As of 1015 PM EDT Monday... No change to previous thinking as the wedge will persist through tonight. Have sculpted POPs a bit to match current and expected radar trends, but the flavor of the forecast remains the same with the best chance of showers for locations west of the Blue Ridge. Previous discussion... Cold air damming from the New England surface high will persist until around mid-day Tuesday with low clouds and fairly cool temps, although not much diurnal fluctuation. Lows tonight upper 30s NW to mid-40s SE. Wedge starts to weaken Tuesday with some breaks in overcast, mainly across the piedmont and temperatures rebounding sharply where the sun does appear. Fairly wide spread in guidance for highs tomorrow but went toward higher end with mid-60s in the piedmont and mid/upper 50s in the mountains. Just as the wedge weakens tomorrow, cloudiness from an approaching weak short- wave over the Tennessee Valley will bring more low clouds and increased chances for rain with the highest pops across our southwest counties. Like many recent systems, this one looks `prepped` to deliver the best QPF to the far western counties with up to around 0.25 inches by evening, but with considerably less across the central mountains and piedmont where very little is expected in this time frame. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 230 PM EDT Monday... With high pressure starting to wedge back into the area Tuesday night into Wednesday, looking for temperatures on Wednesday to struggle to warm. Meanwhile, we will be tracking a low pressure system that will track across the Great Lakes/Ohio Valley that will bring in the chances for showers mainly for Wednesday evening/night. Moisture with this system will be limited, with most of the rainfall occuring north of I-64. Looking ahead to Thursday and Friday, the most notable part of the forecast will be the warming trend. Guidance remains on track for areas east like Danville to warm to 80 degrees, along with most in the west warming into the 70s. We can thank some stout SW flow for that. As to be expected, nighttime lows will also be above average with the warm. A weak wave and then a front will provide the opportunity for rainfall both days. With both days also comes some instability with CAPE values 100-300j/kg, don`t be surprised to see at least a few isolated storms. I think Thursday will have the greatest chance for them with the most abundant spread in instability, as well as some shear to work with. && .LONG TERM /FRIDAY THROUGH MONDAY/... As of 230 PM EDT Monday... After Friday`s system pushes to our south early Saturday, the weekend trends toward mostly dry, though cloud coverage comes into question thanks to that front not making it very far to our south. High pressure builds in, but doesn`t remain settled as it quickly pushes off the coast by Sunday. This makes way for our next system that will start to move in late Sunday into Monday. Thanks to the front that does pass through for the start of the weekend, temperatures make a sudden downward trend and turn back to a more average range, though Saturday night will be chilly with areas in the west dropping to the mid 20s. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... As of 815 PM EDT Monday... Expect some variability in flight conditions all sites as the lingering wedge gets challenged by a weak wave approaching from the west. Believe locations east of the Blue Ridge will maintain VFR for most of the night with MVFR conditions most likely for a period early Tuesday morning. Locations west of the Ridge will see early VFR conditions trend down after Midnight with MVFR/IFR conditions becoming established late tonight. As the wave pulls away and high pressure starts to build in Tuesday afternoon expect some improvement west of the Ridge toward the end of the valid period, but KBLF looks to remain in cloud with persistent IFR through the end of the valid period. Winds will generally be light with litte impact to aircraft operations. .Extended Aviation Discussion... The pattern of quick moving arriving and exiting systems continues this week with a strong zonal flow aloft across the U.S. Several chances for rain and poor flying conditions will occur this week but the main effect will be intermittent cloudiness. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...PC NEAR TERM...MBS/PC SHORT TERM...RR LONG TERM...RR AVIATION...MBS/PC