Alert archive / Virginia / Frost Advisories in 2012

Frost Advisory 2, NWS Blacksburg, VA

April 2, 20125 counties in Virginia

NWS Blacksburg, VA issued this frost advisory at Apr 2, 2012, 3:36 PM EDT for 5 counties in Virginia. It took effect at Apr 3, 2012, 2:00 AM EDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Apr 2, 2012, 3:36 PM EDT (19:36 UTC)
In effect from
Apr 3, 2012, 2:00 AM EDT
Expired
Apr 3, 2012, 9:00 AM EDT
In force
7 hr
Issued by
NWS Blacksburg, VA

Counties Alleghany County, VA, City of Buena Vista, VA, City of Covington, VA, City of Lexington, VA, Rockbridge County, VA

The radar

The Roanoke radar (KFCX), 101 km from the middle of the area, began a volume at 19:38 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 7.6 hours before the alert went out and 66 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Roanoke, VA at 12:00Z on 2012-04-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 267 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Roanoke, VA at 12:00Z on 2012-04-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 97 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
267 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
666 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.2
Supercell composite
0.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

510 
WWUS71 KRNK 021936
NPWRNK

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE BLACKSBURG VA
336 PM EDT MON APR 2 2012

...FROST ADVISORY IN EFFECT FROM 2 AM TO 9 AM EDT TUESDAY...

.HIGH PRESSURE WILL SETTLE ACROSS THE AREA OVERNIGHT...BRINGING
WITH IT A SHOT OF POLAR AIR TO THE ALLEGHANY HIGHLANDS. THIS POLAR
AIR...WHEN COMBINED WITH CLEAR SKIES AND LIGHT WINDS...WILL ALLOW
TEMPERATURES TO FALL INTO THE LOW TO MID 30S...ESPECIALLY IN SOME
OF THE VALLEYS AND DRAINAGES WHERE COOL AIR MAY POOL AT THE
BOTTOM.

VAZ019-024-030345-
/O.NEW.KRNK.FR.Y.0002.120403T0600Z-120403T1300Z/
ALLEGHANY VA-ROCKBRIDGE-
INCLUDING THE CITIES OF...CLIFTON FORGE...COVINGTON...LEXINGTON...
BUENA VISTA
336 PM EDT MON APR 2 2012

...FROST ADVISORY IN EFFECT FROM 2 AM TO 9 AM EDT TUESDAY...

THE NATIONAL WEATHER SERVICE IN BLACKSBURG HAS ISSUED A FROST
ADVISORY...WHICH IS IN EFFECT FROM 2 AM TO 9 AM EDT TUESDAY.

* LOCATIONS...VALLEYS AND DRAINAGES IN ROCKBRIDGE AND ALLEGHANY
  COUNTIES IN VIRGINIA.

* TEMPERATURES...TEMPERATURES OVERNIGHT WILL FALL INTO THE LOW TO
  MID 30S.

* IMPACTS...VEGETATION SENSITIVE TO FROST MAY BE DAMAGED OR KILLED
  IF LEFT UNPROTECTED.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$
2 follow-up statements
168 
WWUS71 KRNK 030147
NPWRNK

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE BLACKSBURG VA
947 PM EDT MON APR 2 2012

...FROST ADVISORY IN EFFECT FROM 2 AM TO 9 AM EDT TUESDAY...

.HIGH PRESSURE WILL SETTLE ACROSS THE AREA OVERNIGHT...BRINGING
WITH IT A SHOT OF POLAR AIR TO THE ALLEGHANY HIGHLANDS. THIS
POLAR AIR...WHEN COMBINED WITH CLEAR SKIES AND LIGHT WINDS...WILL
ALLOW TEMPERATURES TO FALL INTO THE LOW TO MID 30S...ESPECIALLY
IN SOME OF THE VALLEYS AND DRAINAGES WHERE COOL AIR MAY POOL AT
LOWER ELEVATIONS.

VAZ019-024-031300-
/O.CON.KRNK.FR.Y.0002.120403T0600Z-120403T1300Z/
ALLEGHANY VA-ROCKBRIDGE-
INCLUDING THE CITIES OF...CLIFTON FORGE...COVINGTON...LEXINGTON...
BUENA VISTA
947 PM EDT MON APR 2 2012

...FROST ADVISORY REMAINS IN EFFECT FROM 2 AM TO 9 AM EDT
TUESDAY...

* LOCATIONS...VALLEYS AND DRAINAGES IN ROCKBRIDGE AND ALLEGHANY 
  COUNTIES IN VIRGINIA. 

* TEMPERATURES...OVERNIGHT LOWS WILL BE IN THE LOWER TO MID 30S.

* IMPACTS...VEGETATION SENSITIVE TO FROST MAY BE DAMAGED OR 
  KILLED IF LEFT UNPROTECTED. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$
991 
WWUS71 KRNK 031300
NPWRNK

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE BLACKSBURG VA
900 AM EDT TUE APR 3 2012


VAZ019-024-031400-
/O.CAN.KRNK.FR.Y.0002.000000T0000Z-120403T1300Z/
ALLEGHANY VA-ROCKBRIDGE-
INCLUDING THE CITIES OF...CLIFTON FORGE...COVINGTON...LEXINGTON...
BUENA VISTA
900 AM EDT TUE APR 3 2012

...FROST ADVISORY IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN BLACKSBURG HAS CANCELLED THE
FROST ADVISORY.

TEMPERATURES CONTINUE TO WARM THIS MORNING...AND THE THREAT OF
FROST HAS NOW PASSED.

$$

The office that day

Everything else NWS Blacksburg, VA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 2, 12:30 AM EDTSpecial Weather StatementRNKBland, Tazewell60 min
Apr 2, 1:34 AM EDTSpecial Weather StatementRNKWythe56 min

Nearby

Frost Advisories in Virginia, 2012Every frost advisory in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.