Alert archive / New Jersey / Freeze Warnings in 2018

Freeze Warning 1, NWS Philadelphia/Mount Holly

April 17, 20187 counties in New Jersey; 4 counties in Pennsylvania; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this freeze warning at Apr 17, 2018, 2:36 PM EDT for 7 counties in New Jersey; 4 counties in Pennsylvania; Cecil County, Maryland. It took effect at Apr 18, 2018, 2:00 AM EDT. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 17, 2018, 2:36 PM EDT (18:36 UTC)
In effect from
Apr 18, 2018, 2:00 AM EDT
Expired
Apr 18, 2018, 8:00 AM EDT
In force
6 hr
Issued by
NWS Philadelphia/Mount Holly

Counties Cecil County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Ocean County, NJ, Salem County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 67 km from the middle of the area, began a volume at 18:39 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, 6.6 hours before the alert went out and 214 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 2018-04-17Temperature 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 2018-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -36 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
1077 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
-36 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

598 
WWUS71 KPHI 171836
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
236 PM EDT Tue Apr 17 2018

MDZ008-NJZ016>022-027-PAZ060-101>104-106-181200-
/O.NEW.KPHI.FZ.W.0001.180418T0600Z-180418T1200Z/
Cecil-Salem-Gloucester-Camden-Northwestern Burlington-Ocean-
Cumberland-Atlantic-Southeastern Burlington-Berks-Western Chester-
Eastern Chester-Western Montgomery-Eastern Montgomery-Lower Bucks-
Including the cities of Elkton, Pennsville, Glassboro, Camden, 
Cherry Hill, Moorestown, Mount Holly, Jackson, Millville, 
Hammonton, Wharton State Forest, Reading, Honey Brook, Oxford, 
West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Morrisville, and Doylestown
236 PM EDT Tue Apr 17 2018

...FREEZE WARNING IN EFFECT FROM 2 AM TO 8 AM EDT WEDNESDAY...

The National Weather Service in Mount Holly has issued a Freeze
Warning, which is in effect from 2 AM to 8 AM EDT Wednesday.

* TEMPERATURES...Overnight lows are expected to drop to near or
  below freezing.
 
* IMPACTS...Frost and freeze conditions may damage sensitive 
  vegetation. Take steps now to protect tender plants from the 
  cold.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Freeze Warning means sub-freezing temperatures are imminent or
highly likely. These conditions will kill crops and other
sensitive vegetation.

&&

$$
2 follow-up statements
229 
WWUS71 KPHI 180738
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
338 AM EDT Wed Apr 18 2018

NJZ016>022-027-180845-
/O.CAN.KPHI.FZ.W.0001.000000T0000Z-180418T1200Z/
Salem-Gloucester-Camden-Northwestern Burlington-Ocean-Cumberland-
Atlantic-Southeastern Burlington-
Including the cities of Pennsville, Glassboro, Camden, 
Cherry Hill, Moorestown, Mount Holly, Jackson, Millville, 
Hammonton, and Wharton State Forest
338 AM EDT Wed Apr 18 2018

...FREEZE WARNING IS CANCELLED...

The National Weather Service in Mount Holly has cancelled the 
Freeze Warning for southern New Jersey.

A west wind around 10 mph should keep temperatures from dropping 
to the freezing mark this morning. Lows in southern New Jersey 
should favor the middle and upper 30s.

$$

MDZ008-PAZ060-101>104-106-181200-
/O.CON.KPHI.FZ.W.0001.000000T0000Z-180418T1200Z/
Cecil-Berks-Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Lower Bucks-
Including the cities of Elkton, Reading, Honey Brook, Oxford, 
West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Morrisville, and Doylestown
338 AM EDT Wed Apr 18 2018

..FREEZE WARNING REMAINS IN EFFECT UNTIL 8 AM EDT THIS MORNING...

* TEMPERATURES...Lows early this morning should be around 32 
  degrees.

* IMPACTS...Freezing temperatures may damage sensitive 
  vegetation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This Freeze Warning means that freezing temperatures are likely 
in parts of the warned area. The expected conditions may damage 
sensitive vegetation.

&&

$$

Iovino
946 
WWUS71 KPHI 181156
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
756 AM EDT Wed Apr 18 2018

MDZ008-PAZ060-101>104-106-181300-
/O.EXP.KPHI.FZ.W.0001.000000T0000Z-180418T1200Z/
Cecil-Berks-Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Lower Bucks-
Including the cities of Elkton, Reading, Honey Brook, Oxford, 
West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Morrisville, and Doylestown
756 AM EDT Wed Apr 18 2018

...FREEZE WARNING WILL EXPIRE AT 8 AM EDT THIS MORNING...

Temperatures are at or above 32 degrees across the warned area 
and will continue to rise this morning. Therefore, the Freeze 
Warning will be allowed to expire at 8 AM.

$$

Meola

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 16, 9:35 PM EDTRiver Flood WarningPHIMorris19 hr
Apr 16, 9:37 PM EDTRiver Flood WarningPHIMiddlesex, Somerset6 hr
Apr 16, 9:37 PM EDTRiver Flood WarningPHIMiddlesex, Somerset11 hr
Apr 17, 10:37 AM EDTRiver Flood WarningPHIEssex, Morris, Passaic59 hr

Nearby

Freeze Warnings in New Jersey, 2018Freeze Warnings in Pennsylvania, 2018Freeze Warnings in Maryland, 2018Every freeze warning in 2018

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.