Area Forecast Discussion
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FXUS61 KRNK 291657
Area Forecast Discussion
National Weather Service Blacksburg VA
1257 PM EDT Fri Jul 29 2016
A persistent stationary front extended from eastern Virginia, into
the Ohio Valley and through the mid Mississippi Valley and Central
Plains. Little change in this weather pattern is expected through
Monday. The front may move south into the Carolinas on Tuesday and
.NEAR TERM /THROUGH TONIGHT/...
As of 1250 PM EDT Friday...
Daytime surface heating has allowed for cumulus cloud street
development across the region. None have increased enough for
showers to form. That is expected to change as we head into the
middle afternoon with continual heating and the approach of a
shortwave trough eastward through Kentucky. Our forecast will
still reflect scattered coverage of showers and storms across the
mountains and isolated coverage over the Piedmont by the late
Have made minor tweaks by a degree or two to forecast high
temperatures based upon the latest values and expected trends
through the late afternoon.
As of 1025 AM EDT Friday...
Across the region, there were more clouds than sun across the
mountains and more sun than clouds across the Piedmont. This will
continue to be the pattern through the early afternoon. Some
sprinkles have been showing up on radar from time to time this
morning, and some of these past over the airport at Bluefield,
WV. These too will continue into the early afternoon across the
mountains, although the vast majority of the area will remain dry.
This afternoon, we are still expecting a disturbance currently
moving through eastern Kentucky to be across the western portion
of the forecast region. This feature paired with heating of the
afternoon will help spark shower and thunderstorm development.
Coverage is expected to be isolated across the Piedmont with
scattered coverage across the mountains. Current temperature
forecast is on track so little or no changes expected at this
As of 400AM EDT Friday...
Weak short wave from the Maryland panhandle into central Tennessee
will generate isolated showers over the forecast area this morning.
Low level winds will become northwest as the axis of this short wave
move east and the associated surface low tracks toward New York.
NAM, local WRF and HRRR bring the showers and thunderstorms that
were along the Kentucky/Tennessee border into the western part of
the county warning area this afternoon,then east by 00Z/8pm. With
the overall northwest winds, the best probability of precipitation
will remain in the western county warning area.
Starting out with widespread low clouds and some fog this morning in
the west. Bufkit forecast soundings suggest that southeast West
Virginia counties may not clear out until late morning. This will
limit available instability when the precipitation arrives in the
500MB heights today will be slightly lower than past few days.
Models should have a decent handle on the temperature trends of this
air mass. Stayed close to MAV guidance for both highs today and the
minimum temperature tonight.
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 230 AM EDT Friday...
An upper level trough will remain centered over the Great lakes this
weekend. Waves rounding this trough will bring a good chance for
showers and thunderstorms to the region each afternoon and evening.
Models are keeping the stronger dynamics north of the area, but with
ample moisture and instabilities, strong to severe storms are
possible with damaging winds being the primary threat. Torrential
downpours are also possible each afternoon with pwats remaining
well above normal.
Temperatures stay elevated at night thanks to high pwats with lows
from the mid to upper 60s west to lower 70s east. This weekend
should be at or just above typical late July values of lower to mid
80s west to around 90 east.
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 245 AM EDT Friday...
Belt of westerlies will be laying across the area Monday, with front
situated across the mid-Atlantic. Afterward the upper flow takes on
a more NW to SE orientation across our area as ridge builds over the
Central Plains. The front weakens but convergence along it to remain
through midweek. In addition, the upper pattern favors potential
ridge runners, where convective clusters form over the upper midwest
and shift southeast over our area.
Overall, will keep threat of showers and storms in the forecast all
periods but looks like Monday will have the better chance for
May see slight nudge downward in temps early but overall humidity
levels should stay the same, so no appreciable dry air expected thru
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
As of 725 AM EDT Friday...
Satellite pictures and surface observations indicated eastern edge
of LIFR to IFR clouds from just west of KLWB to just west of KTNB.
Expect a slow improvement in ceilings this morning, with high
confidence that KBLF will be up to VFR by 16Z/noon.
HRRR and NAM are bringing the cluster of showers and thunderstorms
along the Kentucky/Tennessee border into southern West Virginia
and western Virginia around 18Z.The showers and thunderstorms
with MVFR ceilings and visibilities continue east across the
region during the afternoon and early evening. High confidence
that the precipitation will be east of KLYH and KDAN by 03Z/11PM.
Locations that get rain this afternoon may have MVFR fog overnight
as well as the typically valleys in the west. No fog in the TAF
for KLWB yet.
Extended aviation discussion...
The area will remain in a relatively active period for showers and
storms through Tuesday thanks to a persistent, nearly stationary
frontal boundary across or near our region. Outside of the
precipitation and during the daylight hours, VFR conditions are
expected. Within the heavier showers and storms, and during the
overnight hours sub-VFR conditions are more likely.