Alert archive / Pennsylvania / Freeze Warnings in 2018

Freeze Warning 2, NWS Philadelphia/Mount Holly

April 19, 2018Berks County, Chester County, Montgomery County, Pennsylvania; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this freeze warning at Apr 19, 2018, 3:04 PM EDT for Berks County, Chester County, Montgomery County, Pennsylvania; Cecil County, Maryland. It took effect at Apr 20, 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 19, 2018, 3:04 PM EDT (19:04 UTC)
In effect from
Apr 20, 2018, 2:00 AM EDT
Expired
Apr 20, 2018, 8:00 AM EDT
In force
6 hr
Issued by
NWS Philadelphia/Mount Holly

Counties Cecil County, MD, Berks County, PA, Chester County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 114 km from the middle of the area, began a volume at 19:05 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.1 hours before the alert went out and 187 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, Washington/Dulle, VA at 12:00Z on 2018-04-19Temperature 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, Washington/Dulle, VA at 12:00Z on 2018-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -187 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
1338 m above ground
0-6 km bulk shear
84 kt
0-1 km storm-relative helicity
-187 m²/s²
0-3 km storm-relative helicity
-250 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

585 
WWUS71 KPHI 191904
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
304 PM EDT Thu Apr 19 2018


MDZ008-PAZ060-101>103-201200-
/O.NEW.KPHI.FZ.W.0002.180420T0600Z-180420T1200Z/
Cecil-Berks-Western Chester-Eastern Chester-Western Montgomery-
Including the cities of Elkton, Reading, Honey Brook, Oxford, 
West Chester, Kennett Square, Collegeville, and Pottstown
304 PM EDT Thu Apr 19 2018

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

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

* TEMPERATURES...Lows early Saturday morning should be in the low
  30s.

* 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
842 
WWUS71 KPHI 191907 CCA
NPWPHI

URGENT - WEATHER MESSAGE...CORRECTED
National Weather Service Mount Holly NJ
307 PM EDT Thu Apr 19 2018


MDZ008-PAZ060-101>103-201200-
/O.COR.KPHI.FZ.W.0002.180420T0600Z-180420T1200Z/
Cecil-Berks-Western Chester-Eastern Chester-Western Montgomery-
Including the cities of Elkton, Reading, Honey Brook, Oxford, 
West Chester, Kennett Square, Collegeville, and Pottstown
307 PM EDT Thu Apr 19 2018

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

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

* TEMPERATURES...Lows early Friday morning should be in the low 
  30s.

* 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.

&&

$$
552 
WWUS71 KPHI 200930
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
530 AM EDT Fri Apr 20 2018

MDZ008-PAZ060-101>103-201200-
/O.CON.KPHI.FZ.W.0002.000000T0000Z-180420T1200Z/
Cecil-Berks-Western Chester-Eastern Chester-Western Montgomery-
Including the cities of Elkton, Reading, Honey Brook, Oxford, 
West Chester, Kennett Square, Collegeville, and Pottstown
530 AM EDT Fri Apr 20 2018

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

* TEMPERATURES...In the lower 30s early this morning.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This Freeze Warning means that freezing temperatures are imminent
in parts of the warned area. Sensitive vegetation may be damaged 
by the cold.

&&

$$

Iovino

Nearby

Freeze 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.