Alert archive / Maryland / Severe Thunderstorm Warnings in 2010

Severe Thunderstorm Warning 9, NWS Philadelphia/Mount Holly

April 16, 2010Cecil County, Kent County, Maryland; Chester County, Pennsylvania; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 16, 2010, 7:41 PM EDT for Cecil County, Kent County, Maryland; Chester County, Pennsylvania; New Castle County, Delaware. It was in force for 34 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
Apr 16, 2010, 7:41 PM EDT (23:41 UTC)
Expired
Apr 16, 2010, 8:15 PM EDT
In force
34 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Dover AFB radar (KDOX), 102 km from the middle of the area, began a volume at 23:41 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
Apr 16, 8:00 PM EDTTSTM WND DMGTownsend, DELARGE TREE DOWN IN TOWNSEND.

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 11.7 hours before the alert went out and 22 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, Phillips Aaf/Abe, MD at 12:00Z on 2010-04-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Phillips Aaf/Abe, MD at 12:00Z on 2010-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 172 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1605 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
172 m²/s²
0-3 km storm-relative helicity
135 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.

969 
WUUS51 KPHI 162341
SVRPHI
DEC003-MDC015-029-PAC029-170015-
/O.NEW.KPHI.SV.W.0009.100416T2341Z-100417T0015Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
741 PM EDT FRI APR 16 2010

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CECIL COUNTY IN NORTHEAST MARYLAND...
  THIS INCLUDES THE CITY OF ELKTON...
  NORTHERN KENT COUNTY IN NORTHEAST MARYLAND...
  WESTERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITIES OF...NEWARK...MIDDLETOWN...
  CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF WEST CHESTER...

* UNTIL 815 PM EDT

* AT 734 PM EDT...NATIONAL WEATHER SERVICE RADAR INDICATED A LINE OF
  SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS UP TO
  AROUND 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  FROM 18 MILES EAST OF READING TO 18 MILES EAST OF BALTIMORE...AND
  MOVING EAST AT 35 TO 40 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  LADENBERG...KEMBLESVILLE...NEWTOWN AND FAIR HILL AROUND 745 PM
  EDT...
  HOLLYWOOD BEACH...GLEN WESTOVER...BARKSDALE AND NORTH STAR AROUND
  750 PM EDT...
  KENNEDYVILLE AND CAYOTS AROUND 755 PM EDT...

LAT...LON 3934 7617 3938 7611 3938 7607 3942 7602
      3946 7602 3951 7599 3953 7600 3956 7610
      3967 7620 3970 7619 3978 7607 3987 7601
      3999 7599 4011 7590 4023 7568 4006 7546
      3985 7565 3936 7557 3927 7621
TIME...MOT...LOC 2339Z 284DEG 35KT 4024 7555 3930 7621

$$
1 follow-up statement
265 
WWUS51 KPHI 170010
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
810 PM EDT FRI APR 16 2010

DEC003-MDC015-029-PAC029-170018-
/O.EXP.KPHI.SV.W.0009.000000T0000Z-100417T0015Z/
CECIL MD-KENT MD-CHESTER PA-NEW CASTLE DE-
810 PM EDT FRI APR 16 2010

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN NEW CASTLE...
CHESTER...NORTHERN KENT AND CECIL COUNTIES WILL EXPIRE AT 815 PM
EDT...

ALTHOUGH SHOWERS AND A FEW THUNDERSTORMS WILL MOVE THROUGH THE AREA 
THIS EVENING...ADDITIONAL SEVERE WEATHER IS NOT EXPECTED. 

LAT...LON 3934 7617 3938 7611 3938 7607 3942 7602
      3946 7602 3951 7599 3953 7600 3956 7610
      3967 7620 3970 7619 3978 7607 3987 7601
      3999 7599 4011 7590 4023 7568 4006 7546
      3985 7565 3936 7557 3927 7621
TIME...MOT...LOC 0008Z 284DEG 35KT 4016 7519 3923 7586

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 16, 6:44 PM EDTSevere Thunderstorm WarningPHIBerks61 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2010Severe Thunderstorm Warnings in Pennsylvania, 2010Severe Thunderstorm Warnings in Delaware, 2010Every severe thunderstorm warning in 2010

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.