Alert archive / New Jersey / Frost Advisories in 2023

Frost Advisory 2, NWS Philadelphia/Mount Holly

April 2, 20234 states

NWS Philadelphia/Mount Holly issued this frost advisory at Apr 2, 2023, 11:40 AM EDT for 4 states. It took effect at Apr 3, 2023, 12:00 AM EDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Apr 2, 2023, 11:40 AM EDT (15:40 UTC)
In effect from
Apr 3, 2023, 12:00 AM EDT
Expired
Apr 3, 2023, 9:00 AM EDT
In force
9 hr
Issued by
NWS Philadelphia/Mount Holly

Counties Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, Atlantic County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Dover AFB radar (KDOX), 82 km from the middle of the area, began a volume at 15:44 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 3.7 hours before the alert went out and 180 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, Wallops Is Stn, VA at 12:00Z on 2023-04-02Temperature 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, Wallops Is Stn, VA at 12:00Z on 2023-04-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -16 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1284 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
-16 m²/s²
0-3 km storm-relative helicity
141 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

328 
WWUS71 KPHI 021540
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
1140 AM EDT Sun Apr 2 2023

NJZ015-019-027-PAZ060-103-106-031300-
/O.NEW.KPHI.FZ.W.0001.230403T0400Z-230403T1300Z/
Mercer-Northwestern Burlington-Southeastern Burlington-Berks-
Western Montgomery-Lower Bucks-
Including the cities of Trenton, Moorestown, Mount Holly, 
Wharton State Forest, Reading, Collegeville, Pottstown, 
Morrisville, and Doylestown
1140 AM EDT Sun Apr 2 2023

...FREEZE WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM EDT
MONDAY...

* WHAT...Sub-freezing temperatures as low as 30 expected.

* WHERE...In New Jersey, Mercer, Northwestern Burlington and 
  Southeastern Burlington. In Pennsylvania, Berks, Western 
  Montgomery and Lower Bucks.

* WHEN...From midnight tonight to 9 AM EDT Monday.

* IMPACTS...Frost and freeze conditions will kill crops and 
  other sensitive vegetation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

DEZ001>003-MDZ012-015-019-020-NJZ012-013-016>018-020>023-PAZ070-
071-101-102-104-031300-
/O.NEW.KPHI.FR.Y.0002.230403T0400Z-230403T1300Z/
New Castle-Kent-Inland Sussex-Kent MD-Queen Annes-Talbot-Caroline-
Middlesex-Western Monmouth-Salem-Gloucester-Camden-Ocean-
Cumberland-Atlantic-Cape May-Delaware-Philadelphia-
Western Chester-Eastern Chester-Eastern Montgomery-
Including the cities of Wilmington, Dover, Georgetown, 
Chestertown, Centreville, Easton, Denton, New Brunswick, 
Freehold, Pennsville, Glassboro, Camden, Cherry Hill, Jackson, 
Millville, Hammonton, Cape May Court House, Media, Philadelphia, 
Honey Brook, Oxford, West Chester, Kennett Square, Norristown, 
and Lansdale
1140 AM EDT Sun Apr 2 2023

...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM EDT
MONDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

* WHERE...Portions of central, northern and southern Delaware, 
  northeast Maryland, central, northern and southern New Jersey 
  and southeast Pennsylvania.

* WHEN...From midnight tonight to 9 AM EDT Monday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$
1 follow-up statement
405 
WWUS71 KPHI 031241
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
841 AM EDT Mon Apr 3 2023

NJZ015-019-027-PAZ060-103-106-031345-
/O.EXP.KPHI.FZ.W.0001.000000T0000Z-230403T1300Z/
Mercer-Northwestern Burlington-Southeastern Burlington-Berks-
Western Montgomery-Lower Bucks-
Including the cities of Trenton, Moorestown, Mount Holly, 
Wharton State Forest, Reading, Collegeville, Pottstown, 
Morrisville, and Doylestown
841 AM EDT Mon Apr 3 2023

...FREEZE WARNING WILL EXPIRE AT 9 AM EDT THIS MORNING...

Temperatures are warming up.

$$

DEZ001>003-MDZ012-015-019-020-NJZ012-013-016>018-020>023-PAZ070-
071-101-102-104-031345-
/O.EXP.KPHI.FR.Y.0002.000000T0000Z-230403T1300Z/
New Castle-Kent-Inland Sussex-Kent MD-Queen Annes-Talbot-Caroline-
Middlesex-Western Monmouth-Salem-Gloucester-Camden-Ocean-
Cumberland-Atlantic-Cape May-Delaware-Philadelphia-
Western Chester-Eastern Chester-Eastern Montgomery-
Including the cities of Wilmington, Dover, Georgetown, 
Chestertown, Centreville, Easton, Denton, New Brunswick, 
Freehold, Pennsville, Glassboro, Camden, Cherry Hill, Jackson, 
Millville, Hammonton, Cape May Court House, Media, Philadelphia, 
Honey Brook, Oxford, West Chester, Kennett Square, Norristown, 
and Lansdale
841 AM EDT Mon Apr 3 2023

...FROST ADVISORY WILL EXPIRE AT 9 AM EDT THIS MORNING...

Temperatures are warming up.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 1, 8:10 PM EDTSpecial Marine WarningPHI65 min
Apr 2, 11:03 AM EDTSmall Craft AdvisoryPHI7 hr
Apr 2, 11:40 AM EDTFreeze WarningPHIBurlington, Mercer21 hr
Apr 2, 6:01 PM EDTSmall Craft AdvisoryPHI28 hr
Apr 1, 8:28 PM EDTSevere Thunderstorm WarningPHISussex47 min

Nearby

Frost Advisories in New Jersey, 2023Frost Advisories in Pennsylvania, 2023Frost Advisories in Maryland, 2023Every frost advisory in 2023

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.