Area Forecast Discussion
Issued by NWS Blacksburg, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KRNK 190609
Area Forecast Discussion
National Weather Service Blacksburg VA
209 AM EDT Wed Oct 19 2016
High pressure was off the southeast coast this afternoon. A cold
front extended from Michigan to Missouri and will stall across the
Mid Atlantic region on Wednesday. Low pressure will move along
this boundary on Thursday, then push a strong cold front through
the eastern United States on Thursday night and Friday.
.NEAR TERM /THROUGH TODAY/...
As of 800 PM EDT Tuesday...
Updated T/Td readings to better reflect current conditions. Added
some cloud cover to match areas of patchy dense fog later tonight.
Otherwise, no changes of significance needed at this time.
As of 335 PM EDT Tuesday...
High pressure was off the southeast coast this afternoon. Expect
winds to diminish, especially in the valleys after sunset as a
surface based inversion forms. Similar to past few nights, there
will be a spread in temperatures between the cooler valleys and
the higher elevations. Enough time with a clear sky and light/calm
wind for fog development in the typical mountain and river
As a front over the Great Lakes approaches from the northwest late
tonight, mid and high clouds will increase over southeast West
Virginia on Wednesday. This will hold back heating, but maximum
temperatures will remain 10 to 20 degrees above normal. Records
for Oct 19 may be found in the climate section of this forecast
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
As of 100 PM EDT Tuesday...
The region will remain within the mild air regime Wednesday night
into Thursday in advance of an approaching cold front. Temperatures
will average fifteen to twenty degrees above normal. Low
temperatures will range from the upper 50s to around 60 degrees
across the region. Highs will again will range from the upper 70s to
near 80 expected across the mountains with low to mid 80s across the
Piedmont. Isolated to scattered showers, and a few thunderstorms,
will be possible across the mountains by Thursday afternoon in
advance of the cold front.
Thursday night into Friday, the cold front is expected to move
through the region along with its associated light to moderate
showers. Isolated thunderstorms will be possible during the evening
hours across western portions of the region. The operational models
are now in fairly good agreement of precipitation associated with
the front exiting the area by Friday afternoon. The closed low the
GFS was promising is no more and is a more progressive wave like its
national and foreign counterparts. However, so as not to not flip
flop too much on our official forecast, we will continue to offer
the potential for lingering showers in the east throughout the
afternoon, just in less coverage than previously offered. In the
western sections, we will continue to offer lingering upslope
showers given the expected northwest 850 mb flow of at least 30 to
40 kts continuing into Friday night. Surface wind gusts across the
mountains during this time period will commonly be between 25 and 35
mph with the higher peaks near 40 mph. Across the Piedmont, gusts of
20 to 25 mph will be more likely. Late Friday night into early
Saturday morning, enough colder air is expected to move into the
region to allow the s-word to be used in the forecast at elevations
around or above 4000 feet agl. A brief period of snow or rain/snow
mix will be possible during this time period at these elevations.
Given how mild the conditions will have been leading up to this
period, little or no accumulations are expected.
Low temperatures Thursday night will be about five degrees cooler
than Wednesday night. Highs on Friday will be lower in the wake of
the front with readings back to values near normal for this time of
.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 130 PM EDT Tuesday...
During the Saturday through Monday this portion of the forecast the
general synoptic pattern over the region will be one of a zonal to
northwest flow aloft as an upper ridge builds over the Rockies and
then translates eastward into the Mississippi River Valley. Closer
to home, high pressure will again take up residency over the
southeast United States. The impact of our area will be one of
little or no precipitation and temperatures trending milder each
day, with Saturday being the coolest day of the next seven days with
readings at, or slightly below normal. By Monday, temperatures
around five degrees above normal are forecast. What precipitation
that does exist will be lingering, and dissipating, upslope showers
across the western portion of the area that will conclude Saturday
Monday night into Tuesday, a shortwave trough is expected to
progress through the northwest flow and cross New England. An
associated backdoor cold front is currently forecast to drop south
into and through the area. While precipitation is not expected at
this time, a drop to temperatures around normal for this time of
year is anticipated.
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
As of 200 AM EDT Wednesday...
High pressure aloft will remain anchored over the southeast states
through Wednesday. A cold front will approach from the north late
Wednesday, but stall before moving into the area, then retreat to
the north Wednesday night as a stronger cold front approaches from
the west by Thursday evening.
Generally VFR conditions will prevail through the TAF valid
period. The only exception will be late night/early morning fog in
the usual more sheltered/decoupled areas, including KLWB and KBCB.
Confidence in fog this morning compared to the last several
mornings is less given very warm temperatures yesterday, but
given long nights and decoupling, feel that it remains a distinct
possibility for IFR-LIFR vsbys/cigs in patchy dense fog mainly at
KLWB and KBCB. Little to none expected at the remaining TAF sites,
possibly MVFR at KLYH briefly.
Low/Mid clouds will begin to increase from the west/northwest
late Wed in association with the front to our north, but cigs are
expected to remain VFR. No precipitation is expected within this
time period...shower threat remaining confined to the Ohio
Winds will be primarily out of the southwest, less than 5 kts
before 14z, then increasing to 5-9kts after 14Z Wed, with a few
gusts near 15kts possible during the peak heating part of the day.
Medium to high confidence in cigs and vsbys through the TAF valid
period. Medium to high confidence in wind speed/direction through
the TAF valid period.
Extended aviation discussion...
A cold front is expected to move through the region Thursday
night into early Friday. Expect the initial onset of scattered
showers across the mountains late Thursday afternoon. A southwest
to northwest wind shift is expected to occur Thursday night across
the region with gusty winds behind the front continuing into
Friday night and possibly Saturday. Areas of sub-VFR conditions
will likely accompany the front and precipitation.
A return to VFR conditions is expected for most areas Friday
night into Saturday. The exception will be western parts of the
region where a healthy northwest upslope flow, and lingering low
level moisture, will prolong an IFR/MVFR ceiling during this time
period. Even the mountain areas will become VFR again on Sunday.
As of 800 PM EDT Tuesday...
No records max temperatures were set today, Tuesday, 18 October.
Very warm temperatures are forecast again Wednesday. Currently,
a record max temperature is forecast for Danville Wednesday and
the record max temp is forecast to be tied in Blacksburg on
Record maximum temperatures through Thursday, Oct 20.
Location Record Max
Bluefield.....81 in 1984
Danville......85 in 1953
Lynchburg.....88 in 1938
Roanoke.......91 in 1938
Blacksburg....80 in 1991
Location Record Max
Bluefield.....79 in 1993
Danville......88 in 1984
Lynchburg.....85 in 1993
Roanoke.......84 in 2005
Blacksburg....82 in 1985