Alert archive / New Jersey / Frost Advisories in 2020

Frost Advisory 11, NWS Philadelphia/Mount Holly

October 17, 20204 states

NWS Philadelphia/Mount Holly issued this frost advisory at Oct 17, 2020, 3:46 AM EDT for 4 states. It took effect at Oct 18, 2020, 1:00 AM EDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Oct 17, 2020, 3:46 AM EDT (07:46 UTC)
In effect from
Oct 18, 2020, 1:00 AM EDT
Expired
Oct 18, 2020, 8:00 AM EDT
In force
7 hr
Issued by
NWS Philadelphia/Mount Holly
All 29 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Salem County, NJ, Somerset County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 69 km from the middle of the area, began a volume at 07:45 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 7.8 hours before the alert went out and 213 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 00:00Z on 2020-10-17Temperature 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, Washington/Dulle, VA at 00:00Z on 2020-10-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -160 square meters per square second.1939587897117136Sfc1 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
1374 m above ground
0-6 km bulk shear
81 kt
0-1 km storm-relative helicity
-160 m²/s²
0-3 km storm-relative helicity
-28 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

397 
WWUS71 KPHI 170746
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
346 AM EDT Sat Oct 17 2020

NJZ007>010-PAZ060>062-103-105-172115-
/O.NEW.KPHI.FR.Y.0011.201018T0500Z-201018T1200Z/
Warren-Morris-Hunterdon-Somerset-Berks-Lehigh-Northampton-
Western Montgomery-Upper Bucks-
Including the cities of Washington, Morristown, Flemington, 
Somerville, Reading, Allentown, Bethlehem, Easton, Collegeville, 
Pottstown, Chalfont, and Perkasie
346 AM EDT Sat Oct 17 2020

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

* WHAT...Temperatures as low as 34 will result in frost 
  formation.

* WHERE...In New Jersey, Warren, Morris, Hunterdon and Somerset. 
  In Pennsylvania, Berks, Lehigh, Northampton, Western 
  Montgomery and Upper Bucks.

* 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.

&&

$$

NJZ020>022-027-172115-
/O.NEW.KPHI.FR.Y.0011.201018T0500Z-201018T1200Z/
Ocean-Cumberland-Atlantic-Southeastern Burlington-
Including the cities of Jackson, Millville, Hammonton, 
and Wharton State Forest
346 AM EDT Sat Oct 17 2020

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

* WHAT...Temperatures as low as 34 will result in frost 
  formation.

* WHERE...Ocean, Cumberland, Atlantic and Southeastern 
  Burlington.

* 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.

&&

$$

Meola
3 follow-up statements
118 
WWUS71 KPHI 171826
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
226 PM EDT Sat Oct 17 2020

PAZ101-180730-
/O.EXA.KPHI.FR.Y.0011.201018T0500Z-201018T1200Z/
Western Chester-
Including the cities of Honey Brook and Oxford
226 PM EDT Sat Oct 17 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...Western Chester.

* 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.

&&

$$

NJZ007>010-PAZ060>062-103-105-180730-
/O.CON.KPHI.FR.Y.0011.201018T0500Z-201018T1200Z/
Warren-Morris-Hunterdon-Somerset-Berks-Lehigh-Northampton-
Western Montgomery-Upper Bucks-
Including the cities of Washington, Morristown, Flemington, 
Somerville, Reading, Allentown, Bethlehem, Easton, Collegeville, 
Pottstown, Chalfont, and Perkasie
226 PM EDT Sat Oct 17 2020

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

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

* WHERE...In New Jersey, Morris, Hunterdon, Somerset and Warren. 
  In Pennsylvania, Northampton, Lehigh, Berks, Upper Bucks and 
  Western Montgomery.

* 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.

&&

$$

NJZ020>022-027-180730-
/O.CON.KPHI.FR.Y.0011.201018T0500Z-201018T1200Z/
Ocean-Cumberland-Atlantic-Southeastern Burlington-
Including the cities of Jackson, Millville, Hammonton, 
and Wharton State Forest
226 PM EDT Sat Oct 17 2020

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

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

* WHERE...Southeastern Burlington, Atlantic, Ocean and 
  Cumberland.

* 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.

&&

$$

Davis
240 
WWUS71 KPHI 172217
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
617 PM EDT Sat Oct 17 2020

NJZ012-015-PAZ102-104-106-181200-
/O.EXA.KPHI.FR.Y.0011.201018T0500Z-201018T1200Z/
Middlesex-Mercer-Eastern Chester-Eastern Montgomery-Lower Bucks-
Including the cities of New Brunswick, Trenton, West Chester, 
Kennett Square, Norristown, Lansdale, Morrisville, and Doylestown
617 PM EDT Sat Oct 17 2020

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

* WHAT...Temperatures as low as 34 will result in frost 
  formation.

* WHERE...In New Jersey, Middlesex and Mercer. In Pennsylvania, 
  Eastern Chester, Eastern Montgomery and Lower Bucks.

* 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.

&&

$$

DEZ001>003-MDZ008-012-015-019-020-NJZ013-016>019-023-181200-
/O.EXA.KPHI.FR.Y.0011.201018T0500Z-201018T1200Z/
New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot-
Caroline-Western Monmouth-Salem-Gloucester-Camden-
Northwestern Burlington-Cape May-
Including the cities of Wilmington, Dover, Georgetown, Elkton, 
Chestertown, Centreville, Easton, Denton, Freehold, Pennsville, 
Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly, 
and Cape May Court House
617 PM EDT Sat Oct 17 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...Portions of central and southern New Jersey, northeast 
  Maryland and central, northern and southern Delaware.

* 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.

&&

$$

NJZ007>010-PAZ060>062-101-103-105-181200-
/O.CON.KPHI.FR.Y.0011.201018T0500Z-201018T1200Z/
Warren-Morris-Hunterdon-Somerset-Berks-Lehigh-Northampton-
Western Chester-Western Montgomery-Upper Bucks-
Including the cities of Washington, Morristown, Flemington, 
Somerville, Reading, Allentown, Bethlehem, Easton, Honey Brook, 
Oxford, Collegeville, Pottstown, Chalfont, and Perkasie
617 PM EDT Sat Oct 17 2020

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

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

* WHERE...In New Jersey, Morris, Hunterdon, Somerset and Warren. 
  In Pennsylvania, Northampton, Lehigh, Berks, Upper Bucks and 
  Western Montgomery.

* 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.

&&

$$

NJZ020>022-027-181200-
/O.CON.KPHI.FR.Y.0011.201018T0500Z-201018T1200Z/
Ocean-Cumberland-Atlantic-Southeastern Burlington-
Including the cities of Jackson, Millville, Hammonton, 
and Wharton State Forest
617 PM EDT Sat Oct 17 2020

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

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

* WHERE...Southeastern Burlington, Atlantic, Ocean and 
  Cumberland.

* 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.

&&

$$
092 
WWUS71 KPHI 181152
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
752 AM EDT Sun Oct 18 2020

NJZ007>010-012-015-PAZ060>062-101>106-181300-
/O.EXP.KPHI.FR.Y.0011.000000T0000Z-201018T1200Z/
Warren-Morris-Hunterdon-Somerset-Middlesex-Mercer-Berks-Lehigh-
Northampton-Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Washington, Morristown, Flemington, 
Somerville, New Brunswick, Trenton, Reading, Allentown, 
Bethlehem, Easton, Honey Brook, Oxford, West Chester, 
Kennett Square, Collegeville, Pottstown, Norristown, Lansdale, 
Chalfont, Perkasie, Morrisville, and Doylestown
752 AM EDT Sun Oct 18 2020

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

Temperatures are beginning to rise above freezing and will
continue to quickly climb this morning, so the Frost Advisory is
no longer needed.

$$

DEZ001>003-MDZ008-012-015-019-020-NJZ013-016>023-027-181300-
/O.EXP.KPHI.FR.Y.0011.000000T0000Z-201018T1200Z/
New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot-
Caroline-Western Monmouth-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Cumberland-Atlantic-Cape May-
Southeastern Burlington-
Including the cities of Wilmington, Dover, Georgetown, Elkton, 
Chestertown, Centreville, Easton, Denton, Freehold, Pennsville, 
Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly, Jackson,
Millville, Hammonton, Cape May Court House, 
and Wharton State Forest
752 AM EDT Sun Oct 18 2020

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

Temperatures are beginning to rise above freezing and will
continue to quickly climb this morning, so the Frost Advisory is
no longer needed.

$$

Davis

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 17, 3:19 AM EDTCoastal Flood AdvisoryPHIAtlantic, Burlington, Cape May, Monmouth, Ocean10 hr

Nearby

Frost Advisories in New Jersey, 2020Frost Advisories in Pennsylvania, 2020Frost Advisories in Maryland, 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.