Alert archive / Maryland / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 306, NWS Philadelphia/Mount Holly

September 23, 20214 counties in Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 23, 2021, 9:46 AM EDT for 4 counties in Maryland. It was in force for 44 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Sep 23, 2021, 9:46 AM EDT (13:46 UTC)
Expired
Sep 23, 2021, 10:30 AM EDT
In force
44 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
60.0 mph

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

The radar

The Dover AFB radar (KDOX), 45 km from the middle of the area, began a volume at 13:45 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.

What was reported inside it

TimeReportWhereRemark
Sep 23, 10:12 AM EDTTSTM WND DMG2 Nnw Morgnec, MDDOWNED TREE LIMBS AND WIRES NEAR WALLIS ROAD. TIME ESTIMATED FROM RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 1.8 hours before the alert went out and 111 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 2021-09-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 579 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-09-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 152 square meters per square second.193958Sfc1 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
579 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
743 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
152 m²/s²
0-3 km storm-relative helicity
200 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.0

Open this sounding in Storm Lab

The text

As transmitted.

061 
WUUS51 KPHI 231346
SVRPHI
MDC011-029-035-041-231430-
/O.NEW.KPHI.SV.W.0306.210923T1346Z-210923T1430Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
946 AM EDT Thu Sep 23 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Talbot County in eastern Maryland...
  Queen Anne's County in northeastern Maryland...
  Caroline County in eastern Maryland...
  Kent County in northeastern Maryland...

* Until 1030 AM EDT.

* At 945 AM EDT, severe thunderstorms were located along a line
  extending from near Aberdeen Proving Ground to 6 miles southwest of
  Cambridge, moving northeast at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Easton, Centerville, Chestertown, Denton, Centreville,
  Federalsburg, Greensboro, Oakland, Ridgely, Trappe, Church Hill,
  Preston, Millington, Sudlersville, Betterton, Goldsboro, Queen
  Anne, Smithville, Old Town and Starr.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3859 7606 3863 7608 3862 7611 3865 7615
      3933 7614 3937 7611 3938 7606 3936 7589
      3937 7577 3866 7571 3864 7571 3869 7577
      3868 7580 3871 7584 3870 7590 3866 7596
      3860 7599 3857 7603
TIME...MOT...LOC 1345Z 209DEG 36KT 3950 7611 3848 7612 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Iovino
1 follow-up statement
033 
WWUS51 KPHI 231412
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1012 AM EDT Thu Sep 23 2021

MDC011-029-035-041-231430-
/O.CON.KPHI.SV.W.0306.000000T0000Z-210923T1430Z/
Talbot MD-Queen Anne's MD-Caroline MD-Kent MD-
1012 AM EDT Thu Sep 23 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 AM EDT
FOR TALBOT...QUEEN ANNE'S...CAROLINE AND KENT COUNTIES...

At 1012 AM EDT, severe thunderstorms were located along a line
extending from Calvert to near Hambleton, moving north at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Easton, Centerville, Chestertown, Denton, Centreville, Federalsburg,
Greensboro, Oakland, Ridgely, Trappe, Church Hill, Preston,
Millington, Sudlersville, Betterton, Goldsboro, Queen Anne,
Smithville, Old Town and Starr.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3859 7606 3863 7608 3862 7611 3865 7615
      3933 7614 3937 7611 3938 7606 3936 7589
      3937 7577 3866 7571 3864 7571 3869 7577
      3868 7580 3871 7584 3870 7590 3866 7596
      3860 7599 3857 7603
TIME...MOT...LOC 1412Z 201DEG 34KT 3972 7601 3870 7602 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Iovino

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 23, 8:08 AM EDTSpecial Weather StatementPHIKent, Queen Anne's, Talbot52 min
Sep 23, 9:03 AM EDTAreal Flood AdvisoryPHIKent, Queen Anne's, Talbot3 hr
Sep 23, 9:31 AM EDTSpecial Weather StatementPHIKent, Queen Anne's, Talbot59 min
Sep 23, 9:49 AM EDTFlash Flood WarningPHIKent, Queen Anne's, Talbot4 hr
Sep 23, 10:35 AM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's40 min
Sep 23, 10:55 AM EDTAreal Flood AdvisoryPHICaroline, Kent, Queen Anne's, Talbot3 hr

Nearby

Severe Thunderstorm Warnings in Maryland, 2021Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.