Alert archive / Maryland / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 60, NWS Philadelphia/Mount Holly

June 9, 2009Cecil County, Maryland; Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 9, 2009, 3:29 PM EDT for Cecil County, Maryland; Chester County, Pennsylvania. It was in force for 61 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 9, 2009, 3:29 PM EDT (19:29 UTC)
Expired: Jun 9, 2009, 4:30 PM EDT
In force: 61 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Cecil County, MD, Chester County, PA

The radar

The Dover AFB radar (KDOX), 123 km from the middle of the area, began a volume at 19:31 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.

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.5 hours before the alert went out and 42 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: 1272 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 804 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 091929
SVRPHI
MDC015-PAC029-092030-
/O.NEW.KPHI.SV.W.0060.090609T1929Z-090609T2030Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
329 PM EDT TUE JUN 9 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN CECIL COUNTY IN NORTHEAST MARYLAND...
  SOUTHWESTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 430 PM EDT

* AT 327 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM.  THIS STORM WAS LOCATED NEAR HOMEVILLE...OR 18
  MILES NORTHWEST OF NEWARK...AND MOVING EAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  COCHRANVILLE AND PARKESBURG AROUND 335 PM EDT...
  WEST GROVE AROUND 345 PM EDT...
  8 MILES NORTH OF LADENBERG AROUND 355 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT
TUESDAY EVENING FOR NORTHEASTERN PENNSYLVANIA.

&&

LAT...LON 3975 7611 3978 7607 3985 7603 3987 7601
      3992 7601 3993 7600 3996 7600 4001 7598
      4003 7595 3982 7572 3959 7591 3967 7612
TIME...MOT...LOC 1929Z 267DEG 20KT 3989 7595

$$

NIERENBERG

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 9, 1:49 PM EDT	Flash Flood Watch	PHI	Cecil	5 hr
Jun 9, 3:14 PM EDT	Tornado Warning	PHI	Cecil	46 min
Jun 9, 4:19 PM EDT	Severe Thunderstorm Warning	PHI	Cecil, Kent, Queen Anne's	56 min
Jun 9, 5:13 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Cecil, Kent, Queen Anne's, Talbot	92 min
Jun 9, 5:19 PM EDT	Areal Flood Warning	PHI	Cecil	71 min
Jun 9, 4:17 AM EDT	Dense Fog Advisory	PHI		5 hr
Jun 9, 5:38 AM EDT	Severe Thunderstorm Warning	PHI	Berks	67 min
Jun 9, 7:20 AM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	55 min
Jun 9, 8:00 AM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	60 min
Jun 9, 8:06 AM EDT	Severe Thunderstorm Warning	PHI	Philadelphia	54 min
Jun 9, 8:20 AM EDT	Areal Flood Advisory	PHI	Delaware, Montgomery, Philadelphia	3 hr
Jun 9, 8:42 AM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Jun 9, 9:56 AM EDT	Flash Flood Warning	PHI	Chester	105 min
Jun 9, 2:20 PM EDT	Flash Flood Warning	PHI	Berks, Chester	3 hr
Jun 9, 2:24 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	66 min
Jun 9, 2:59 PM EDT	Tornado Warning	PHI	Chester	32 min
Jun 9, 3:08 PM EDT	Tornado Warning	PHI	Chester	28 min

Nearby

Severe Thunderstorm Warnings in Maryland, 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.