Alert archive / Maryland / Frost Advisories in 2011

Frost Advisory 1, NWS Philadelphia/Mount Holly

April 5, 2011Caroline County, Queen Anne's County, Talbot County, Maryland; Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this frost advisory at Apr 5, 2011, 3:05 PM EDT for Caroline County, Queen Anne's County, Talbot County, Maryland; Kent County, Sussex County, Delaware. It took effect at Apr 6, 2011, 3:00 AM EDT. It was in force for 65 min.

The area

The counties it named.

The facts

Issued
Apr 5, 2011, 3:05 PM EDT (19:05 UTC)
In effect from
Apr 6, 2011, 3:00 AM EDT
Expired
Apr 6, 2011, 4:05 AM EDT
In force
65 min
Issued by
NWS Philadelphia/Mount Holly

Counties Kent County, DE, Sussex County, DE, Caroline County, MD, Queen Anne's County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 31 km from the middle of the area, began a volume at 19:04 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.1 hours before the alert went out and 70 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, Phillips Aaf/Abe, MD at 12:00Z on 2011-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Phillips Aaf/Abe, MD at 12:00Z on 2011-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 106 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1186 m above ground
0-6 km bulk shear
79 kt
0-1 km storm-relative helicity
106 m²/s²
0-3 km storm-relative helicity
133 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

744 
WWUS71 KPHI 051905
NPWPHI

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
305 PM EDT TUE APR 5 2011

...THE GROWING SEASON HAS STARTED FOR PORTIONS OF SOUTHERN
DELAWARE AND THE ADJACENT EASTERN SHORE OF MARYLAND...

.TEMPERATURES HAVE CHILLED CONSIDERABLY FROM THIS MORNINGS VERY WINDY
WARM CONDITIONS. READINGS AT 3 PM WERE IN THE 30S FROM WESTERN
PENNSYLVANIA INTO WEST VIRGINIA. THIS COLD POOL OF AIR IS HEADING
TOWARD THE MID ATLANTIC COAST. THE COMBINATION OF THE VERY CHILLY
INCOMING AIR MASS AND THE START OF THE GROWING SEASON HAS PROMPTED
THE ISSUANCE OF A FROST ADVISORY.

DEZ002-003-MDZ015-019-020-060830-
/O.NEW.KPHI.FR.Y.0001.110406T0700Z-110406T1000Z/
KENT-INLAND SUSSEX-QUEEN ANNES-TALBOT-CAROLINE-
INCLUDING THE CITIES OF...DOVER...GEORGETOWN...CENTREVILLE...
EASTON...DENTON
305 PM EDT TUE APR 5 2011

...FROST ADVISORY IN EFFECT FROM 3 AM TO 6 AM EDT WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A FROST
ADVISORY...WHICH IS IN EFFECT FROM 3 AM TO 6 AM EDT WEDNESDAY. 

* LOCATIONS...THE SOUTHERN TWO THIRDS OF DELAWARE AND ADJACENT
  PORTIONS OF EASTERN MARYLAND BUT NOT ALONG THE COASTAL WATERS.

* HAZARDS...FROST.

* TEMPERATURES...WILL DROP INTO THE 30S LATE TONIGHT WITH DIMINISHING
  WIND.

* TIMING...THE BEST CHANCE FOR FROST FORMATION IS BETWEEN 3 AM AND
  6 AM WHEN THE MERCURY BOTTOMS OUT BETWEEN 31 AND 36 DEGREES IN
  THE ADVISORY AREA.

* IMPACTS...COULD DAMAGE EARLY SEASON BLOSSOMS AND TENDER VEGETATION.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

DRAG
1 follow-up statement
124 
WWUS71 KPHI 060805
NPWPHI

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
405 AM EDT WED APR 6 2011

DEZ002-003-MDZ015-019-020-060915-
/O.CAN.KPHI.FR.Y.0001.000000T0000Z-110406T1000Z/
KENT-INLAND SUSSEX-QUEEN ANNES-TALBOT-CAROLINE-
INCLUDING THE CITIES OF...DOVER...GEORGETOWN...CENTREVILLE...
EASTON...DENTON
405 AM EDT WED APR 6 2011

...FROST ADVISORY IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS CANCELLED THE
FROST ADVISORY. 

A LITTLE WIND HANGING ON IN MANY SPOTS AND SOME HIGH CLOUDS MOVING
ACROSS THE AREA EARLY THIS MORNING SHOULD LIMIT ANY FROST.

$$

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 5, 5:01 AM EDTSevere Thunderstorm WarningPHICaroline, Cecil, Kent, Queen Anne's, Talbot74 min
Apr 5, 5:28 AM EDTSevere Thunderstorm WarningPHICaroline, Queen Anne's, Talbot62 min
Apr 5, 8:55 AM EDTSpecial Weather StatementPHICaroline, Cecil, Kent, Queen Anne's, Talbot65 min
Apr 5, 9:37 AM EDTSpecial Weather StatementPHICaroline, Cecil, Kent, Queen Anne's53 min
Apr 5, 10:20 AM EDTSevere Thunderstorm WarningPHICaroline, Talbot40 min
Apr 5, 10:16 AM EDTSevere Thunderstorm WarningPHINew Castle44 min

Nearby

Frost Advisories in Maryland, 2011Frost Advisories in Delaware, 2011Every frost advisory in 2011

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.