Alert archive / New Jersey / Frost Advisories in 2011

Frost Advisory 2, NWS Philadelphia/Mount Holly

April 21, 201111 counties in New Jersey; New Castle County, Delaware; Berks County, Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this frost advisory at Apr 21, 2011, 3:15 PM EDT for 11 counties in New Jersey; New Castle County, Delaware; Berks County, Delaware County, Pennsylvania. It took effect at Apr 22, 2011, 3:00 AM EDT. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Apr 21, 2011, 3:15 PM EDT (19:15 UTC)
In effect from
Apr 22, 2011, 3:00 AM EDT
Expired
Apr 22, 2011, 8:00 AM EDT
In force
5 hr
Issued by
NWS Philadelphia/Mount Holly

Counties New Castle County, DE, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Salem County, NJ, Berks County, PA, Delaware County, PA

The radar

The Philadelphia radar (KDIX), 47 km from the middle of the area, began a volume at 19:18 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, 7.3 hours before the alert went out and 107 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 2011-04-21Temperature 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 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 2011-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -119 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
1302 m above ground
0-6 km bulk shear
71 kt
0-1 km storm-relative helicity
-119 m²/s²
0-3 km storm-relative helicity
-344 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.

699 
WWUS71 KPHI 211915
NPWPHI

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
315 PM EDT THU APR 21 2011

...AREAS OF FROST POSSIBLE LATE TONIGHT AND EARLY FRIDAY MORNING...

.HIGH PRESSURE WILL BUILD ACROSS THE AREA THROUGH TONIGHT,
ALLOWING THE WINDS TO DIMINISH. THE COMBINATION OF LIGHTER WINDS,
A DRY AIR MASS AND A CLEAR TO PARTLY CLOUDY SKY WILL ALLOW
TEMPERATURES TO DROP INTO THE 30S. THIS MAY RESULT IN THE
FORMATION OF AREAS OF FROST.

DEZ001-NJZ012-013-015>023-027-PAZ060-067>070-220900-
/O.NEW.KPHI.FR.Y.0002.110422T0700Z-110422T1200Z/
NEW CASTLE-MIDDLESEX-WESTERN MONMOUTH-MERCER-SALEM-GLOUCESTER-
CAMDEN-NORTHWESTERN BURLINGTON-OCEAN-CUMBERLAND-ATLANTIC-CAPE MAY-
SOUTHEASTERN BURLINGTON-BERKS-CHESTER-MONTGOMERY-BUCKS-DELAWARE-
INCLUDING THE CITIES OF...WILMINGTON...NEW BRUNSWICK...FREEHOLD...
TRENTON...PENNSVILLE...GLASSBORO...CAMDEN...CHERRY HILL...
MOORESTOWN...MOUNT HOLLY...JACKSON...MILLVILLE...HAMMONTON...
CAPE MAY COURT HOUSE...WHARTON STATE FOREST...READING...
WEST CHESTER...NORRISTOWN...DOYLESTOWN...MEDIA
315 PM EDT THU APR 21 2011

...FROST ADVISORY IN EFFECT FROM 3 AM TO 8 AM EDT FRIDAY...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A FROST
ADVISORY, WHICH IS IN EFFECT FROM 3 AM TO 8 AM EDT FRIDAY.

* LOCATIONS...SOUTHEASTERN PENNSYLVANIA, CENTRAL AND SOUTHERN NEW
  JERSEY AND NORTHERN DELAWARE. THIS DOES NOT INCLUDE PHILADELPHIA
  COUNTY AND THE IMMEDIATE COAST OF NEW JERSEY.

* TEMPERATURES...DROPPING INTO THE LOWER TO MID 30S LATE TONIGHT
  AND EARLY FRIDAY MORNING.

* WINDS...NORTHWEST TO NORTH AND DIMINISHING TO AROUND 5 MPH.

* IMPACTS...THE FORMATION OF SOME FROST COULD DAMAGE BLOSSOMS AND
  TENDER VEGETATION.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED. POTTED PLANTS NORMALLY
LEFT OUTDOORS SHOULD BE COVERED OR BROUGHT INSIDE.

&&

$$

GORSE
2 follow-up statements
492 
WWUS71 KPHI 220841
NPWPHI

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
441 AM EDT FRI APR 22 2011

DEZ001-NJZ012-013-015>023-027-PAZ060-067>070-221200-
/O.CON.KPHI.FR.Y.0002.000000T0000Z-110422T1200Z/
NEW CASTLE-MIDDLESEX-WESTERN MONMOUTH-MERCER-SALEM-GLOUCESTER-
CAMDEN-NORTHWESTERN BURLINGTON-OCEAN-CUMBERLAND-ATLANTIC-CAPE MAY-
SOUTHEASTERN BURLINGTON-BERKS-CHESTER-MONTGOMERY-BUCKS-DELAWARE-
INCLUDING THE CITIES OF...WILMINGTON...NEW BRUNSWICK...FREEHOLD...
TRENTON...PENNSVILLE...GLASSBORO...CAMDEN...CHERRY HILL...
MOORESTOWN...MOUNT HOLLY...JACKSON...MILLVILLE...HAMMONTON...
CAPE MAY COURT HOUSE...WHARTON STATE FOREST...READING...
WEST CHESTER...NORRISTOWN...DOYLESTOWN...MEDIA
441 AM EDT FRI APR 22 2011

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM EDT THIS MORNING...


* LOCATIONS...SOUTHEASTERN PENNSYLVANIA... CENTRAL AND SOUTHERN 
  NEW JERSEY AND NORTHERN DELAWARE. THIS DOES NOT INCLUDE 
  PHILADELPHIA COUNTY AND THE IMMEDIATE COAST OF NEW JERSEY. 

* TEMPERATURES...IN THE LOWER TO MID 30S.

* WINDS...NORTHEAST UP TO 5 TO 10 MPH.

* IMPACTS...THE FORMATION OF SOME FROST COULD DAMAGE BLOSSOMS 
  AND TENDER VEGETATION. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED. POTTED PLANTS NORMALLY
LEFT OUTDOORS SHOULD BE COVERED OR BROUGHT INSIDE.

&&

$$
653 
WWUS71 KPHI 221155
NPWPHI

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
755 AM EDT FRI APR 22 2011

DEZ001-NJZ012-013-015>023-027-PAZ060-067>070-221300-
/O.EXP.KPHI.FR.Y.0002.000000T0000Z-110422T1200Z/
NEW CASTLE-MIDDLESEX-WESTERN MONMOUTH-MERCER-SALEM-GLOUCESTER-
CAMDEN-NORTHWESTERN BURLINGTON-OCEAN-CUMBERLAND-ATLANTIC-CAPE MAY-
SOUTHEASTERN BURLINGTON-BERKS-CHESTER-MONTGOMERY-BUCKS-DELAWARE-
INCLUDING THE CITIES OF...WILMINGTON...NEW BRUNSWICK...FREEHOLD...
TRENTON...PENNSVILLE...GLASSBORO...CAMDEN...CHERRY HILL...
MOORESTOWN...MOUNT HOLLY...JACKSON...MILLVILLE...HAMMONTON...
CAPE MAY COURT HOUSE...WHARTON STATE FOREST...READING...
WEST CHESTER...NORRISTOWN...DOYLESTOWN...MEDIA
755 AM EDT FRI APR 22 2011

...FROST ADVISORY WILL EXPIRE AT 8 AM EDT THIS MORNING...

THE FROST ADVISORY WILL EXPIRE AT 8 AM EDT THIS MORNING. 

TEMPERATURES DROPPED INTO THE 30S EARLY THIS MORNING...IN SOME
CASES INTO THE LOWER 30S...BUT WERE RECOVERING AFTER MORNING LOWS.

$$

Nearby

Frost Advisories in New Jersey, 2011Frost Advisories in Pennsylvania, 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.