Alert archive / Maryland / Freeze Watches in 2021

Freeze Watch 1, NWS Philadelphia/Mount Holly

March 31, 20214 counties in Maryland; Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this freeze watch at Mar 31, 2021, 3:46 PM EDT for 4 counties in Maryland; Kent County, Sussex County, Delaware. It took effect at Apr 2, 2021, 2:00 AM EDT. It was in force for .

The area

The counties it named.

The facts

Issued
Mar 31, 2021, 3:46 PM EDT (19:46 UTC)
In effect from
Apr 2, 2021, 2:00 AM EDT
Expired
Apr 1, 2021, 3:14 AM EDT
In force
Issued by
NWS Philadelphia/Mount Holly

Counties Kent County, DE, Sussex County, DE, Caroline County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 37 km from the middle of the area, began a volume at 19:50 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, 7.8 hours before the alert went out and 119 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 2021-03-31Temperature 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 2021-03-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 105 square meters per square second.19395878Sfc1 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
940 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
105 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

533 
WWUS71 KPHI 311946
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
346 PM EDT Wed Mar 31 2021

DEZ002>004-MDZ012-015-019-020-010900-
/O.NEW.KPHI.FZ.A.0001.210402T0600Z-210402T1400Z/
Kent-Inland Sussex-Delaware Beaches-Kent MD-Queen Annes-Talbot-
Caroline-
Including the cities of Dover, Georgetown, Rehoboth Beach, 
Chestertown, Centreville, Easton, and Denton
346 PM EDT Wed Mar 31 2021

...FREEZE WATCH IN EFFECT FROM LATE THURSDAY NIGHT THROUGH FRIDAY
MORNING...

* WHAT...Sub-freezing temperatures as low as 29 possible.

* WHERE...In Maryland, Kent MD, Queen Annes, Talbot and 
  Caroline. In Delaware, Kent, Inland Sussex and Delaware 
  Beaches.

* WHEN...From late Thursday night through Friday morning.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$
1 follow-up statement
584 
WWUS71 KPHI 010714
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
314 AM EDT Thu Apr 1 2021

DEZ002>004-MDZ012-015-019-020-012015-
/O.UPG.KPHI.FZ.A.0001.210402T0600Z-210402T1400Z/
/O.NEW.KPHI.FZ.W.0001.210402T0600Z-210402T1400Z/
Kent-Inland Sussex-Delaware Beaches-Kent MD-Queen Annes-Talbot-
Caroline-
Including the cities of Dover, Georgetown, Rehoboth Beach, 
Chestertown, Centreville, Easton, and Denton
314 AM EDT Thu Apr 1 2021

...FREEZE WARNING IN EFFECT FROM 2 AM TO 10 AM EDT FRIDAY...

* WHAT...Sub-freezing temperatures as low as 29 expected.

* WHERE...In Maryland, Kent MD, Queen Annes, Talbot and 
  Caroline. In Delaware, Kent, Inland Sussex and Delaware 
  Beaches.

* WHEN...From 2 AM to 10 AM EDT Friday.

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

* ADDITIONAL DETAILS...Another widespread freeze is possible
  Friday night into Saturday morning.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

Johnson

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 31, 3:50 PM EDTAreal Flood AdvisoryPHINew Castle3 hr

Nearby

Freeze Watches in Maryland, 2021Freeze Watches in Delaware, 2021Every freeze watch in 2021

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.