Alert archive / Maryland / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 143, NWS Philadelphia/Mount Holly

July 23, 2008Cecil County, Maryland; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 23, 2008, 1:11 AM EDT for Cecil County, Maryland; New Castle County, Delaware. It was in force for 64 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 23, 2008, 1:11 AM EDT (05:11 UTC)
Expired: Jul 23, 2008, 2:15 AM EDT
In force: 64 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties New Castle County, DE, Cecil County, MD

The radar

The Dover AFB radar (KDOX), 96 km from the middle of the area, began a volume at 05:11 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, 5.2 hours before the alert went out and 175 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: 934 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 1560 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 81 m²/s²
0-3 km storm-relative helicity: 224 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 5.6

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 230511
SVRPHI
DEC003-MDC015-230615-
/O.NEW.KPHI.SV.W.0143.080723T0511Z-080723T0615Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
111 AM EDT WED JUL 23 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN CECIL COUNTY IN NORTHEAST MARYLAND...
  NORTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...

* UNTIL 215 AM EDT

* AT 106 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  ELKTON...AND MOVING NORTHEAST AT 31 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  GLASGOW AND NEWARK BY 120 AM...
  BEAR BY 125 AM...
  PIKE CREEK BY 130 AM...
  NEWPORT...WILMINGTON MANOR...STANTON AND NEW CASTLE BY 135 AM...
  ELSMERE BY 140 AM...
  WILMINGTON BY 145 AM...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

THUNDERSTORMS ARE CAPABLE OF PRODUCING HEAVY RAINFALL WHICH MAY
RESULT IN LOCALIZED AREAS OF FLOODING. DO NOT DRIVE IN AREAS WHERE
WATER IS CROSSING THE ROAD.

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

LAT...LON 3983 7554 3979 7543 3976 7547 3973 7547
      3970 7550 3969 7553 3965 7556 3965 7559
      3959 7560 3954 7565 3948 7588 3963 7599
TIME...MOT...LOC 0511Z 241DEG 27KT 3961 7582

$$

RNS

1 follow-up statement

000 
WWUS51 KPHI 230547
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
146 AM EDT WED JUL 23 2008

DEC003-MDC015-230615-
/O.CON.KPHI.SV.W.0143.000000T0000Z-080723T0615Z/
CECIL MD-NEW CASTLE DE-
146 AM EDT WED JUL 23 2008

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 AM EDT
FOR NORTHERN NEW CASTLE AND EXTREME EAST CENTRAL CECIL COUNTIES...

AT 142 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR WILMINGTON...MOVING
NORTHEAST AT 31 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  ARDENCROFT AND ARDEN BY 155 AM EDT...

IN ADDITION TO DAMAGING WINDS...FREQUENT CLOUD TO GROUND LIGHTNING 
IS OCCURRING WITH THIS STORM. MOVE INDOORS IMMEDIATELY LIGHTNING IS 
ONE OF NATURES NUMBER ONE KILLERS. REMEMBER...IF YOU CAN HEAR 
THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING.

THUNDERSTORMS ARE CAPABLE OF PRODUCING HEAVY RAINFALL WHICH MAY
RESULT IN LOCALIZED AREAS OF FLOODING. DO NOT DRIVE IN AREAS WHERE
WATER IS COVERING THE ROAD.

LAT...LON 3983 7554 3979 7543 3975 7547 3972 7548
      3971 7551 3965 7556 3965 7559 3959 7560
      3954 7565 3951 7578 3971 7579
TIME...MOT...LOC 0546Z 241DEG 27KT 3974 7552

$$

RNS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 12:30 AM EDT	Severe Thunderstorm Warning	PHI	Cecil	45 min
Jul 23, 3:51 AM EDT	Flash Flood Watch	PHI	Caroline, Cecil, Kent, Queen Anne's, Talbot	25 hr
Jul 23, 6:11 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	64 min
Jul 23, 7:14 PM EDT	Severe Thunderstorm Warning	PHI	Cecil, Kent, Queen Anne's	61 min
Jul 23, 3:30 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	60 min
Jul 23, 4:27 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	38 min
Jul 23, 7:00 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	60 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2008 Severe Thunderstorm Warnings in Delaware, 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.