Alert archive / Maryland / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 93, NWS Philadelphia/Mount Holly

July 15, 2012Cecil County, Maryland; New Castle County, Delaware; Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 15, 2012, 8:30 PM EDT for Cecil County, Maryland; New Castle County, Delaware; Chester County, Pennsylvania. It was in force for 45 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
Jul 15, 2012, 8:30 PM EDT (00:30 UTC)
Expired
Jul 15, 2012, 9:15 PM EDT
In force
45 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties New Castle County, DE, Cecil County, MD, Chester County, PA

The radar

The Philadelphia radar (KDIX), 111 km from the middle of the area, began a volume at 00:31 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
Jul 15, 8:33 PM EDTTSTM WND DMGNew London Twp, PAWIRES DOWN REPORTED IN THE SOUTHERN PART OF CHESTER COUNTY.

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 0.5 hours before the alert went out and 176 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 2012-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 652 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2012-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 square meters per square second.1939Sfc1 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
652 J/kg
Mixed-layer CIN
-91 J/kg
Mixed-layer LCL
1264 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

144 
WUUS51 KPHI 160030
SVRPHI
DEC003-MDC015-PAC029-160115-
/O.NEW.KPHI.SV.W.0093.120716T0030Z-120716T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
830 PM EDT SUN JUL 15 2012

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...
  SOUTHERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 915 PM EDT

* AT 826 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED NEAR CALVERT...OR 12 MILES
  NORTHWEST OF ELKTON...AND MOVING EAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  FAIR HILL AROUND 835 PM EDT...
  KEMBLESVILLE...GLEN WESTOVER AND APPLETON AROUND 840 PM EDT...
  LADENBERG AND WEST GROVE AROUND 845 PM EDT...
  NORTH STAR AND PIKE CREEK AROUND 850 PM EDT...
  HOCKESSIN AND ASHLAND AROUND 855 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 3997 7566 3987 7559 3986 7560 3985 7558
      3974 7551 3966 7600 3976 7607
TIME...MOT...LOC 0030Z 256DEG 31KT 3973 7594

$$

AMC
2 follow-up statements
787 
WWUS51 KPHI 160044
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
844 PM EDT SUN JUL 15 2012

MDC015-160054-
/O.CAN.KPHI.SV.W.0093.000000T0000Z-120716T0115Z/
CECIL MD-
844 PM EDT SUN JUL 15 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CECIL COUNTY IS
CANCELLED...

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

LAT...LON 3997 7566 3988 7559 3986 7560 3985 7558
      3984 7558 3984 7557 3974 7551 3972 7582
      3972 7595 3982 7596
TIME...MOT...LOC 0044Z 256DEG 31KT 3976 7579

$$

DEC003-PAC029-160115-
/O.CON.KPHI.SV.W.0093.000000T0000Z-120716T0115Z/
NEW CASTLE DE-CHESTER PA-
844 PM EDT SUN JUL 15 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM EDT
FOR SOUTHERN CHESTER AND NORTHERN NEW CASTLE COUNTIES...

AT 839 PM 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 KEMBLESVILLE...OR 6
MILES NORTHWEST OF NEWARK...MOVING EAST AT 35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  NORTH STAR...PIKE CREEK AND TOUGHKENAMON BY 850 PM EDT...
  HOCKESSIN...ASHLAND AND KENNETT SQUARE BY 855 PM EDT...
  ELSMERE BY 900 PM EDT...
  TALLEYVILLE BY 905 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 3997 7566 3988 7559 3986 7560 3985 7558
      3984 7558 3984 7557 3974 7551 3972 7582
      3972 7595 3982 7596
TIME...MOT...LOC 0044Z 256DEG 31KT 3976 7579

$$

AMC
348 
WWUS51 KPHI 160110
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
910 PM EDT SUN JUL 15 2012

DEC003-PAC029-160119-
/O.EXP.KPHI.SV.W.0093.000000T0000Z-120716T0115Z/
NEW CASTLE DE-CHESTER PA-
910 PM EDT SUN JUL 15 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN CHESTER AND NORTHERN
NEW CASTLE COUNTIES WILL EXPIRE AT 915 PM EDT...

THE STORMS THAT PROMPTED THE WARNING HAVE NOW MOVED EAST OF THE 
WARNED AREA.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

LAT...LON 3997 7566 3988 7559 3986 7560 3985 7558
      3984 7558 3984 7557 3974 7551 3972 7582
      3972 7595 3982 7596
TIME...MOT...LOC 0109Z 256DEG 31KT 3981 7552

$$

AMC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 15, 8:08 PM EDTSpecial Weather StatementPHICecil67 min
Jul 15, 10:51 PM EDTSpecial Weather StatementPHINew Castle54 min
Jul 16, 4:32 PM EDTSpecial Weather StatementPHISussex88 min
Jul 15, 8:27 PM EDTSpecial Weather StatementPHIChester, Montgomery, Philadelphia63 min
Jul 15, 8:35 PM EDTSpecial Weather StatementPHIBucks55 min
Jul 15, 8:58 PM EDTSpecial Weather StatementPHIDelaware, Philadelphia62 min
Jul 15, 9:16 PM EDTSpecial Weather StatementPHIChester59 min
Jul 15, 9:21 PM EDTSpecial Weather StatementPHIBucks54 min
Jul 15, 9:55 PM EDTSevere Thunderstorm WarningPHIBucks80 min
Jul 16, 3:35 AM EDTHeat AdvisoryPHIBerks, Lehigh, Northampton62 hr

Nearby

Severe Thunderstorm Warnings in Maryland, 2012Severe Thunderstorm Warnings in Delaware, 2012Severe Thunderstorm Warnings in Pennsylvania, 2012Every severe thunderstorm warning in 2012

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.