Alert archive / Maryland / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 111, NWS Philadelphia/Mount Holly

June 28, 2008Chester County, Pennsylvania; 5 counties in Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 28, 2008, 9:35 PM EDT for Chester County, Pennsylvania; 5 counties in Maryland. It was in force for 70 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: Jun 28, 2008, 9:35 PM EDT (01:35 UTC)
Expired: Jun 28, 2008, 10:45 PM EDT
In force: 70 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Caroline County, MD, Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, Chester County, PA

The radar

The Dover AFB radar (KDOX), 68 km from the middle of the area, began a volume at 01:38 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, 1.6 hours before the alert went out and 107 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: 2773 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 1327 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 290136
SVRPHI
MDC011-015-029-035-041-PAC029-290245-
/O.NEW.KPHI.SV.W.0111.080629T0135Z-080629T0245Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
935 PM EDT SAT JUN 28 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CAROLINE COUNTY IN EASTERN MARYLAND...
  TALBOT COUNTY IN EASTERN MARYLAND...
  CECIL COUNTY IN NORTHEAST MARYLAND...
  KENT COUNTY IN NORTHEAST MARYLAND...
  QUEEN ANNES COUNTY IN NORTHEAST MARYLAND...
  SOUTHWESTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 1045 PM EDT

* AT 933 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
  EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  FROM CONOWINGO TO 8 MILES NORTHWEST OF ROCK HALL TO 15 MILES WEST
  OF TILGHMAN ISLAND...AND MOVING EAST AT 40 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  CONOWINGO...ROCK SPRINGS AND OCTORARO BY 940 PM...
  WEST NOTTINGHAM...RICHARDSMERE...NEWTOWN AND WOODLAWN BY 945 PM...
  FARMINGTON...RISING SUN AND CHESTER BY 950 PM...

THIS STORM HAS A HISTORY OF PRODUCING WIND DAMAGE WEST OF THE
CHESAPEAKE BAY.  THIS IS A VERY DANGEROUS SITUATION. SEEK 
SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS

LAT...LON 3885 7620 3892 7621 3884 7638 3896 7637
      3909 7615 3910 7615 3901 7619 3916 7629
      3938 7611 3938 7600 3938 7603 3954 7598
      3972 7624 3980 7581 3866 7572 3863 7616
      3873 7625 3866 7635 3877 7640
TIME...MOT...LOC 0135Z 269DEG 37KT 3966 7623 3924 7629
          3879 7658

$$

SZATKOWSKI

Nearby

Severe Thunderstorm Warnings in Maryland, 2008 Severe Thunderstorm Warnings in Pennsylvania, 2008 Every severe thunderstorm warning in 2008

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.