Alert archive / Maryland / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 125, NWS Philadelphia/Mount Holly

July 17, 2009Kent County, New Castle County, Delaware; Cecil County, Kent County, Queen Anne's County, Maryland; Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 2009, 6:10 PM EDT for Kent County, New Castle County, Delaware; Cecil County, Kent County, Queen Anne's County, Maryland; Chester County, Pennsylvania. It was in force for 80 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: Jul 17, 2009, 6:10 PM EDT (22:10 UTC)
Expired: Jul 17, 2009, 7:30 PM EDT
In force: 80 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, Chester County, PA

The radar

The Dover AFB radar (KDOX), 86 km from the middle of the area, began a volume at 22:10 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 12:00Z, 10.2 hours before the alert went out and 149 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 154 J/kg
Mixed-layer CIN: -209 J/kg
Mixed-layer LCL: 1593 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: -58 m²/s²
0-3 km storm-relative helicity: 131 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 172210
SVRPHI
DEC001-003-MDC015-029-035-PAC029-172330-
/O.NEW.KPHI.SV.W.0125.090717T2210Z-090717T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
610 PM EDT FRI JUL 17 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN KENT COUNTY IN CENTRAL DELAWARE...
  EASTERN CECIL COUNTY IN NORTHEAST MARYLAND...
  THIS INCLUDES THE CITY OF ELKTON...
  NORTHEASTERN KENT COUNTY IN NORTHEAST MARYLAND...
  NORTHEASTERN QUEEN ANNES COUNTY IN NORTHEAST MARYLAND...
  WESTERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITIES OF...NEWARK...MIDDLETOWN...
  SOUTH CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 730 PM EDT

* AT 608 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  MASSEY...OR 11 MILES SOUTHWEST OF MIDDLETOWN...AND MOVING NORTH AT
  25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  SASSAFRAS AND CECILTON AROUND 620 PM EDT...
  WARWICK AROUND 625 PM EDT...
  BOHEMIAS MILLS AND MIDDLETOWN AROUND 630 PM EDT...
  CAYOTS AND HOLLYWOOD BEACH AROUND 635 PM EDT...
  BRANTWOOD AROUND 645 PM EDT...
  ELKTON AROUND 650 PM EDT...

LAT...LON 3978 7560 3922 7571 3923 7595 3948 7596
      3949 7595 3950 7596 3981 7598
TIME...MOT...LOC 2209Z 181DEG 24KT 3932 7583

$$

KRUZDLO

3 follow-up statements

000 
WWUS51 KPHI 172227
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
627 PM EDT FRI JUL 17 2009

MDC035-172237-
/O.CAN.KPHI.SV.W.0125.000000T0000Z-090717T2330Z/
QUEEN ANNES MD-
627 PM EDT FRI JUL 17 2009

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN QUEEN ANNES
COUNTY IS CANCELLED...

LAT...LON 3978 7560 3922 7571 3935 7592 3948 7596
      3949 7595 3950 7596 3981 7598
TIME...MOT...LOC 2227Z 181DEG 24KT 3944 7583

$$

DEC001-003-MDC015-029-PAC029-172330-
/O.CON.KPHI.SV.W.0125.000000T0000Z-090717T2330Z/
KENT DE-CECIL MD-KENT MD-CHESTER PA-NEW CASTLE DE-
627 PM EDT FRI JUL 17 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR WESTERN NEW CASTLE...SOUTH CENTRAL CHESTER...NORTHEASTERN KENT...
EASTERN CECIL AND NORTHWESTERN KENT COUNTIES...

AT 626 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR WARWICK...OR 6 MILES WEST OF MIDDLETOWN...MOVING NORTH
AT 30 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  CAYOTS AND HOLLYWOOD BEACH BY 635 PM EDT...
  CHESAPEAKE CITY BY 640 PM EDT...
  BRANTWOOD BY 645 PM EDT...
  ELKTON AND GLASGOW BY 650 PM EDT...
  BARKSDALE...CHERRY HILL AND PLEASANT HILL BY 700 PM EDT...
  APPLETON BY 705 PM EDT...

LAT...LON 3978 7560 3922 7571 3935 7592 3948 7596
      3949 7595 3950 7596 3981 7598
TIME...MOT...LOC 2227Z 181DEG 24KT 3944 7583

$$

KRUZDLO

000 
WWUS51 KPHI 172249
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
649 PM EDT FRI JUL 17 2009

DEC001-MDC029-172258-
/O.CAN.KPHI.SV.W.0125.000000T0000Z-090717T2330Z/
KENT DE-KENT MD-
649 PM EDT FRI JUL 17 2009

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN KENT AND
NORTHWESTERN KENT COUNTIES IS CANCELLED...

LAT...LON 3978 7560 3939 7568 3947 7588 3948 7596
      3949 7595 3950 7596 3981 7598
TIME...MOT...LOC 2248Z 182DEG 25KT 3963 7581

$$

DEC003-MDC015-PAC029-172330-
/O.CON.KPHI.SV.W.0125.000000T0000Z-090717T2330Z/
CECIL MD-CHESTER PA-NEW CASTLE DE-
649 PM EDT FRI JUL 17 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR WESTERN NEW CASTLE...SOUTH CENTRAL CHESTER AND EASTERN CECIL
COUNTIES...

AT 647 PM EDT...A SEVERE THUNDERSTORM WAS REPORTED CAPABLE OF
PRODUCING PENNY SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. 
THIS STORM WAS LOCATED NEAR ELKTON...MOVING NORTH AT 30 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  BARKSDALE...CHERRY HILL...NEWARK AND ANDORA BY 655 PM EDT...
  APPLETON...GLEN WESTOVER AND FAIR HILL BY 700 PM EDT...
  KEMBLESVILLE AND PIKE CREEK BY 705 PM EDT...
  LADENBERG BY 710 PM EDT...

LAT...LON 3978 7560 3939 7568 3947 7588 3948 7596
      3949 7595 3950 7596 3981 7598
TIME...MOT...LOC 2248Z 182DEG 25KT 3963 7581

$$

KRUZDLO

000 
WWUS51 KPHI 172324
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
724 PM EDT FRI JUL 17 2009

DEC003-MDC015-PAC029-172334-
/O.EXP.KPHI.SV.W.0125.000000T0000Z-090717T2330Z/
CECIL MD-CHESTER PA-NEW CASTLE DE-
724 PM EDT FRI JUL 17 2009

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN NEW CASTLE...SOUTH
CENTRAL CHESTER AND EASTERN CECIL COUNTIES WILL EXPIRE AT 730 PM
EDT...

LAT...LON 3978 7560 3939 7568 3947 7588 3948 7596
      3949 7595 3950 7596 3981 7598
TIME...MOT...LOC 2324Z 182DEG 25KT 3988 7580

$$

KRUZDLO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 6:25 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	113 min
Jul 17, 7:33 PM EDT	Areal Flood Advisory	PHI	New Castle	86 min
Jul 17, 5:41 PM EDT	Severe Thunderstorm Warning	PHI	Northampton	52 min
Jul 17, 7:07 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Lehigh, Montgomery	53 min
Jul 17, 7:22 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	53 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2009 Severe Thunderstorm Warnings in Delaware, 2009 Severe Thunderstorm Warnings in Pennsylvania, 2009 Every severe thunderstorm warning in 2009

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.