Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 8, NWS Philadelphia/Mount Holly

May 16, 2007Chester County, Pennsylvania; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 16, 2007, 4:16 PM EDT for Chester County, Pennsylvania; Cecil County, Maryland. It was in force for 44 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: May 16, 2007, 4:16 PM EDT (20:16 UTC)
Expired: May 16, 2007, 5:00 PM EDT
In force: 44 min
Issued by: NWS Philadelphia/Mount Holly
Area: Counties, with a storm outline in the text

Counties Cecil County, MD, Chester County, PA

The radar

The Dover AFB radar (KDOX), 110 km from the middle of the area, began a volume at 20:17 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 16, 1:26 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.3 hours before the alert went out and 37 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: 18 J/kg
Mixed-layer CIN: -160 J/kg
Mixed-layer LCL: 1421 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 107 m²/s²
0-3 km storm-relative helicity: 138 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 162016
SVRPHI
MDC015-PAC029-162100-
/O.NEW.KPHI.SV.W.0008.070516T2016Z-070516T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
416 PM EDT WED MAY 16 2007

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 500 PM EDT

* AT 413 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 8 MILES SOUTH OF OXFORD...OR
  ABOUT 12 MILES WEST OF NEWARK...AND MOVING EAST AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  7 MILES SOUTH OF WEST GROVE BY 430 PM EDT...
  7 MILES SOUTH OF KENNETT SQUARE BY 435 PM EDT...

LAT...LON 3983 7602 3958 7608 3962 7580 3977 7577
      3989 7560

$$

MPD

The office that day

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

Issued	Product	Office	Counties	Lasted
May 16, 2:48 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Montgomery	42 min
May 16, 3:26 PM EDT	Severe Thunderstorm Warning	PHI	Delaware	49 min
May 16, 3:30 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Montgomery, Philadelphia	45 min
May 16, 4:35 PM EDT	Severe Thunderstorm Warning	PHI	Delaware	40 min
May 16, 4:53 PM EDT	Severe Thunderstorm Warning	PHI	Philadelphia	52 min
May 16, 5:12 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Queen Anne's	48 min
May 16, 5:41 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Talbot	79 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2007 Severe Thunderstorm Warnings in Maryland, 2007 Every severe thunderstorm warning in 2007

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.