Alert archive / Maryland / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 107, NWS Philadelphia/Mount Holly

August 4, 2015Kent County, New Castle County, Delaware; Cecil County, Kent County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 4, 2015, 5:37 AM EDT for Kent County, New Castle County, Delaware; Cecil County, Kent County, Queen Anne's County, Maryland. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 4, 2015, 5:37 AM EDT (09:37 UTC)
Expired
Aug 4, 2015, 6:11 AM EDT
In force
34 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Kent County, DE, New Castle County, DE, Cecil County, MD, Kent County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 68 km from the middle of the area, began a volume at 09:39 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, 9.6 hours before the alert went out and 148 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 2015-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 627 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, Washington/Dulle, VA at 00:00Z on 2015-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 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
627 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
1863 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
156 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

810 
WUUS51 KPHI 040937
SVRPHI
DEC001-003-MDC015-029-035-041030-
/O.NEW.KPHI.SV.W.0107.150804T0937Z-150804T1030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
537 AM EDT TUE AUG 4 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  NORTHERN KENT COUNTY IN CENTRAL DELAWARE...
  NORTHEASTERN QUEEN ANNE'S COUNTY IN NORTHEASTERN MARYLAND...
  NORTHERN KENT COUNTY IN NORTHEASTERN MARYLAND...
  CECIL COUNTY IN NORTHEASTERN MARYLAND...

* UNTIL 630 AM EDT

* AT 536 AM EDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS
  OF 60 MPH. THIS STORM WAS LOCATED OVER MIDDLE RIVER...AND MOVING
  EAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  DOVER...MIDDLETOWN...SMYRNA...CHESTERTOWN...CLAYTON...DELAWARE
  CITY...CHESWOLD...CECILTON...MILLINGTON...SUDLERSVILLE...
  BETTERTON...HARTLY...CAYOTS...KENNEDYVILLE...BOHEMIAS MILLS...
  DELANEY CORNER...PORT PENN...WARWICK...HOLLYWOOD BEACH AND MASSEY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...LARGE HAIL...DEADLY
LIGHTNING AND VERY HEAVY RAIN. FOR YOUR PROTECTION...MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY
RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER
COVERS THE ROAD.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY. REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE
ENOUGH TO BE STRUCK BY LIGHTNING.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

LAT...LON 3926 7622 3929 7617 3932 7618 3942 7600
      3952 7598 3954 7599 3960 7564 3959 7557
      3959 7558 3951 7556 3946 7559 3935 7549
      3933 7550 3934 7549 3931 7543 3925 7540
      3917 7541 3917 7627
TIME...MOT...LOC 0936Z 261DEG 44KT 3928 7634 

$$

HEAVENER
1 follow-up statement
860 
WWUS51 KPHI 041011
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
611 AM EDT TUE AUG 4 2015

DEC001-003-MDC015-029-035-041019-
/O.CAN.KPHI.SV.W.0107.000000T0000Z-150804T1030Z/
NEW CASTLE DE-KENT DE-QUEEN ANNE'S MD-KENT MD-CECIL MD-
611 AM EDT TUE AUG 4 2015

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN NEW CASTLE...
NORTHERN KENT...NORTHEASTERN QUEEN ANNE'S...NORTHERN KENT AND CECIL
COUNTIES IS CANCELLED...
    
THE SEVERE THUNDERSTORM WHICH PROMPTED THE WARNING HAS 
WEAKENED. THEREFORE THE WARNING HAS BEEN CANCELLED.

LAT...LON 3926 7622 3929 7617 3932 7618 3942 7600
      3952 7598 3954 7599 3960 7564 3959 7557
      3959 7558 3951 7556 3946 7559 3935 7549
      3933 7550 3934 7549 3931 7543 3925 7540
      3917 7541 3917 7627
TIME...MOT...LOC 1008Z 261DEG 44KT 3934 7582 

$$

HEAVENER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 4:20 AM EDTSevere Thunderstorm WarningPHINew Castle33 min
Aug 4, 6:11 PM EDTSpecial Weather StatementPHISussex64 min
Aug 4, 6:20 PM EDTSevere Thunderstorm WarningPHISussex20 min
Aug 4, 5:18 AM EDTSpecial Weather StatementPHIKent, Queen Anne's57 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2015Severe Thunderstorm Warnings in Delaware, 2015Every severe thunderstorm warning in 2015

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.