Special Weather Statement, NWS Blacksburg, VA

Area Forecast Discussion
National Weather Service Blacksburg VA
1119 PM EDT Thu Jul 5 2018

.SYNOPSIS...
A cold front arrives in the northwest early Friday with
increased chances for rainfall through the day. Noticeably
cooler and drier conditions expected this weekend as high
pressure builds in. Warmer and more humid conditions return by
mid-week.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 1115 PM EDT Thursday...

Hi Res and HRRR guidance showing persistent convergence in
southeast West Virginia overnight, otherwise isolated showers
and thunderstorms for southwest Virginia and northwest North
Carolina. Little change needed to forecast for minimum
temperatures overnight.

Front should be on our doorstep around 12Z/8AM with chances for
showers and thunderstorms beginning to increase and continuing
to likely POPs for most areas during the day. The front is
fairly progressive and will be about to exit the southeast CWA
around 00z Saturday/8PM Friday but with lingering showers
possible especially in the southern sections. QPF is generally
in the 0.50 to 0.75 inch range most of which will fall in a
roughly 12-hour period between 12z/8AM Fri and 00z Sat/8PM Fri.
Expect considerable variation as is typical in convective
regimes, with localized amounts up to 1 to 2 inches. WPC Day 1
Excessive Rainfall Outlook, just issued, highlights a slight
risk in the far NW CWA, mainly Greenbrier County for rainfall
exceeding flash flood guidance even before 12z. The Day 2
outlook was pointed toward mainly the southern sections of the
CWA where the front could be slow- moving enough to produce some
higher rainfall amounts and some local runoff issues. Portions
of the CWA have become very dry in recent weeks and could
benefit greatly from a decent slug of moisture, especially in
part of the New River valley and parts of southside VA.

Temperatures will be held down somewhat tomorrow by the
increased cloud cover especially in the northwest where clouds
arrive earlier.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 140 PM EDT Thursday...

Friday night a cold front will head south of the region. Good
coverage of showers and storms associated with it will still be
across at least the southern half of the region around sunset. By
daybreak Saturday, isolated to scattered showers will be across
the far southern sections of the region. These showers will
linger during the course of the day Saturday across the far
southwest part of the area as winds become easterly and pool
moisture along the northern mountains of North Carolina.

High pressure will start to make its way into the area on
Saturday with lower dew points and temperatures. By Saturday
night, low temperatures across the mountains will range from the
low to mid 50s with upper 50s to readings around 60 across the
Piedmont. High temperatures on Sunday will average the mid to
upper 70s across the mountains with some the higher peaks and
ridges only reaching the upper 60s to around 70 degrees. Across
the Piedmont, highs around 80 to the lower 80s are forecast.

Cloud cover will decrease from north to south during the course of
the day Saturday, with sunny skies for the entire area on Sunday.

Winds will be steady from the north to northeast around 10 to 15 mph
late Friday night into Saturday behind the front. Saturday night
into Sunday they will become weaker and trend more easterly.

Confidence in the above portion of the forecast is high.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 1230 PM EDT Thursday...

Cooler and drier high pressure will settle over the region this
weekend. Look for a trend of decreasing cloud cover with
temperatures averaging five to ten degrees below normal. The dry
weather is expected to continue into early next week. Monday
into Tuesday, the center of the high retrogrades west as a
trough starts to develop across New England. Precipitation
chances will start to increase, but still be on the low side.
Temperatures will rebound to values closer to normal for this
time of year. By Wednesday into Thursday, temperatures will
continue their trend upward with readings slightly above normal.
Guidance differs as to the degree which a shortwave trough
approaches the area by Thursday. Will continue with a status quo
forecast that keeps precipitation chances on the low side with
the shortwave trough north of the area. Temperatures will
continue to creep higher through Thursday with values slightly
above normal.

Forecast confidence on the above portion of the forecast is low to
moderate with precipitation chances being the biggest question
mark.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
As of 750 PM EDT Thursday...

Area radars indicated isolated thunderstorms over southwest
Virginia, northwest North Carolina, and southeast West Virginia.
These thunderstorms will diminish throughout the evening.

Above average confidence that patchy fog will develop in
locations that had rain this afternoon. Expect MVFR fog across
much of the New River and Greenbrier River Valleys late
tonight, including at KLWB and KBCB.

A cold front will move into the region on Friday with widespread
showers and thunderstorms along with MVFR ceilings and
visibilities. The wind will be to the west to southwest ahead of
the front and will turn to the northwest then north behind the
front. Timing of the front in the models has been consistent for
the past few runs. Have narrowed down the time of the worst
conditions and highest probability of precipitation in the TAFs
but this could easily occur for more than just a couple of
hours. It is possible that the storms will be ongoing and the
wind shift will just be approaching KDAN at the end of the TAF
forecast period.

Confidence is above average on the ocarinas of thunderstorms
and the timing of the front on Friday.

Extended Aviation...

Over the weekend and into Tuesday, high pressure and drier air
work its way into the area. VFR conditions will prevail for most
of the region, most of this time. Late night/early morning will
be a daily issue.

Confidence in the extended forecast is above average.

&&

.EQUIPMENT...
As of 750 PM EDT Thursday...

The NOAA weather radio transmitter in Hinton, West Virginia,
WXM72 broadcasting on a frequency of 162.425 MHz, remains off
the air. It will remain offline until sometime next week. Parts
are on order to repair the transmitter, and are expected early
next week. Therefore, the system may again be operation on/by
July 11th. We apologize for any inconvenience.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.

&&

SYNOPSIS...JR
NEAR TERM...AMS/PC
SHORT TERM...DS
LONG TERM...DS
AVIATION...AMS/PC
EQUIPMENT...AMS/WERT

Hazardous Weather Outlook
National Weather Service Blacksburg VA
410 PM EDT Thu Jul 5 2018

NCZ001>006-018>020-VAZ007-009>020-022>024-032>035-043>047-058-059-
WVZ042>044-507-508-062015-
Ashe-Alleghany NC-Surry-Stokes-Rockingham-Caswell-Watauga-Wilkes-
Yadkin-Tazewell-Smyth-Bland-Giles-Wythe-Pulaski-Montgomery-Grayson-
Carroll-Floyd-Craig-Alleghany VA-Bath-Roanoke-Botetourt-Rockbridge-
Patrick-Franklin-Bedford-Amherst-Henry-Pittsylvania-Campbell-
Appomattox-Buckingham-Halifax-Charlotte-Mercer-Summers-Monroe-
Eastern Greenbrier-Western Greenbrier-
410 PM EDT Thu Jul 5 2018

This Hazardous Weather Outlook is for north central North Carolina,
northwest North Carolina, central Virginia, south central Virginia,
southwest Virginia, west central Virginia and southeast West
Virginia.

.DAY ONE...Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service BLACKSBURG VA
113 AM EDT FRI JUL 6 2018

VAZ014-017-018-022-023-060615-
Botetourt-Floyd-Montgomery-Craig-Roanoke-
113 AM EDT FRI JUL 6 2018

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT
ROANOKE...CRAIG...FLOYD...SOUTHWESTERN BOTETOURT AND MONTGOMERY
COUNTIES...THE CITY OF RADFORD...THE CITY OF SALEM AND THE CITY OF
ROANOKE...

Until 215 AM EDT

At 111 AM EDT, radar indicated strong thunderstorms were located
along a line extending from near New Castle to near Christiansburg
to near Childress. Movement was southeast at 10 mph.

Locations impacted include...
Roanoke...
Blacksburg...
Salem...
Christiansburg...
Radford...
Interstate 81 between mile markers 103 and 145.

This includes The following Locations The Salem Fairgrounds and
the Roanoke-Blacksburg Airport.

Very heavy rainfall is occurring with these storms, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 3766 8003 3733 7982 3722 7985 3714 7996
      3717 8001 3715 8011 3696 8014 3672 8046
      3693 8064 3699 8054 3710 8059 3735 8033
      3736 8033 3732 8043 3742 8048 3751 8030
      3753 8028 3756 8033 3763 8022 3760 8015
TIME...MOT...LOC 0511Z 328DEG 11KT 3748 8007 3703 8052

RAB