Alert archive / Pennsylvania / Frost Advisories in 2020

Frost Advisory 9, NWS Philadelphia/Mount Holly

September 19, 20204 counties in Pennsylvania; Sussex County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this frost advisory at Sep 19, 2020, 2:46 PM EDT for 4 counties in Pennsylvania; Sussex County, Warren County, New Jersey. It took effect at Sep 20, 2020, 1:00 AM EDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Sep 19, 2020, 2:46 PM EDT (18:46 UTC)
In effect from
Sep 20, 2020, 1:00 AM EDT
Expired
Sep 20, 2020, 8:00 AM EDT
In force
7 hr
Issued by
NWS Philadelphia/Mount Holly

Counties Sussex County, NJ, Warren County, NJ, Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 128 km from the middle of the area, began a volume at 18:45 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

Brookhaven, NY (KOKX), launched 12:00Z, 6.8 hours before the alert went out and 202 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, Brookhaven, NY at 12:00Z on 2020-09-19Temperature 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, Brookhaven, NY at 12:00Z on 2020-09-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -100 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
1449 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
-100 m²/s²
0-3 km storm-relative helicity
-52 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

278 
WWUS71 KPHI 191846
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
246 PM EDT Sat Sep 19 2020

NJZ001-PAZ054-055-201200-
/O.NEW.KPHI.FR.Y.0009.200920T0500Z-200920T1200Z/
Sussex-Carbon-Monroe-
Including the cities of Newton, Jim Thorpe, and Stroudsburg
246 PM EDT Sat Sep 19 2020

...FROST ADVISORY IN EFFECT FROM 1 AM TO 8 AM EDT SUNDAY...

* WHAT...Temperatures between 32 and 36 degrees will result in 
  frost formation.

* WHERE...In New Jersey, Sussex County. In Pennsylvania, Carbon
  and Monroe Counties. 

* WHEN...From 1 AM to 8 AM EDT Sunday.

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


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$
3 follow-up statements
595 
WWUS71 KPHI 192212
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
612 PM EDT Sat Sep 19 2020

NJZ007-PAZ061-062-201115-
/O.EXA.KPHI.FR.Y.0009.200920T0500Z-200920T1200Z/
Warren-Lehigh-Northampton-
Including the cities of Washington, Allentown, Bethlehem, 
and Easton
612 PM EDT Sat Sep 19 2020

...FROST ADVISORY IN EFFECT FROM 1 AM TO 8 AM EDT SUNDAY...

* WHAT...Temperatures as low as 35 will result in frost 
  formation.

* WHERE...In New Jersey, Warren. In Pennsylvania, Lehigh and 
  Northampton.

* WHEN...From 1 AM to 8 AM EDT Sunday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

NJZ001-PAZ054-055-201115-
/O.CON.KPHI.FR.Y.0009.200920T0500Z-200920T1200Z/
Sussex-Carbon-Monroe-
Including the cities of Newton, Jim Thorpe, and Stroudsburg
612 PM EDT Sat Sep 19 2020

...FROST ADVISORY REMAINS IN EFFECT FROM 1 AM TO 8 AM EDT
SUNDAY...

* WHAT...Temperatures as low as 32 will result in frost 
  formation.

* WHERE...In New Jersey, Sussex. In Pennsylvania, Carbon and 
  Monroe.

* WHEN...From 1 AM to 8 AM EDT Sunday.

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

* ADDITIONAL DETAILS...Sheltered valleys in the southern Poconos
  may get down to right around freezing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

Johnson
800 
WWUS71 KPHI 201026
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
626 AM EDT Sun Sep 20 2020

NJZ001-007-PAZ054-055-061-062-201200-
/O.CON.KPHI.FR.Y.0009.000000T0000Z-200920T1200Z/
Sussex-Warren-Carbon-Monroe-Lehigh-Northampton-
Including the cities of Newton, Washington, Jim Thorpe, 
Stroudsburg, Allentown, Bethlehem, and Easton
626 AM EDT Sun Sep 20 2020

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

* WHAT...Temperatures near freezing will result in frost 
  formation.

* WHERE...In New Jersey, Sussex and Warren Counties. In 
  Pennsylvania, Carbon, Northampton, Lehigh, and Monroe Counties.

* WHEN...Until 8 AM EDT this morning.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

CMS
374 
WWUS71 KPHI 201154
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
754 AM EDT Sun Sep 20 2020

NJZ001-007-PAZ054-055-061-062-201300-
/O.EXP.KPHI.FR.Y.0009.000000T0000Z-200920T1200Z/
Sussex-Warren-Carbon-Monroe-Lehigh-Northampton-
Including the cities of Newton, Washington, Jim Thorpe, 
Stroudsburg, Allentown, Bethlehem, and Easton
754 AM EDT Sun Sep 20 2020

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

Temperatures continue to warm up this morning, and any frost will
melt off.

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 19, 4:21 AM EDTRip Current StatementPHIAtlantic, Cape May, Monmouth, Ocean5 days
Sep 19, 3:36 PM EDTCoastal Flood AdvisoryPHIAtlantic, Cape May23 hr
Sep 19, 6:19 PM EDTHigh Surf AdvisoryPHIAtlantic, Cape May, Monmouth, Ocean3 days

Nearby

Frost Advisories in Pennsylvania, 2020Frost Advisories in New Jersey, 2020Every frost advisory in 2020

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.