Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 139, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 26, 2009, 7:05 PM EDT for Chester County, Pennsylvania; New Castle County, Delaware; Cecil County, Maryland. It was in force for 70 min. 3 reports 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 26, 2009, 7:05 PM EDT (23:05 UTC)
- Expired
- Jul 26, 2009, 8:15 PM EDT
- In force
- 70 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 Dover AFB radar (KDOX), 114 km from the middle of the area, began a volume at 23:06 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 26, 7:24 PM EDT | TSTM WND DMG | 4 Nnw Havre De Grace, MD | TREES TOPPED AND NUMEROUS BRANCHES SNAPPED. 2 TO 3 FOOT DIAMETER TREES BLOWN DOWN WITH POWER OUTAGES REPORTED. |
| Jul 26, 7:30 PM EDT | TSTM WND DMG | Port Deposit, MD | TREES DOWN. |
| Jul 26, 8:15 PM EDT | TSTM WND DMG | 3 Ne Kennett Square, PA | MULTIPLE TREES DOWN IN CHADDS FORD. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jul 26, 3:51 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 26, 2:07 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 11.1 hours before the alert went out and 147 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.
- Mixed-layer CAPE
- 398 J/kg
- Mixed-layer CIN
- -44 J/kg
- Mixed-layer LCL
- 919 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 10 m²/s²
- 0-3 km storm-relative helicity
- 96 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.6
The text
As transmitted, in the capitals the NWS used until 2016.
000
WUUS51 KPHI 262305
SVRPHI
DEC003-MDC015-PAC029-270015-
/O.NEW.KPHI.SV.W.0139.090726T2305Z-090727T0015Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
705 PM EDT SUN JUL 26 2009
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
NORTHERN CECIL COUNTY IN NORTHEAST MARYLAND...
NORTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
THIS INCLUDES THE CITIES OF...WILMINGTON...NEWARK...
SOUTHERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 815 PM EDT
* AT 703 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED 12
MILES SOUTHWEST OF OCTORARO...OR 23 MILES NORTHEAST OF BALTIMORE...
AND MOVING NORTHEAST AT 30 MPH.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
OCTORARO AROUND 725 PM EDT...
RICHARDSMERE...CONOWINGO AND ROCK SPRINGS AROUND 730 PM EDT...
WEST NOTTINGHAM AND WOODLAWN AROUND 735 PM EDT...
FARMINGTON AND RISING SUN AROUND 740 PM EDT...
CALVERT AND ZION AROUND 745 PM EDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY LIGHTNING IS ONE OF NATURES GREATEST KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT SUNDAY
EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN NEW
JERSEY.
&&
LAT...LON 3973 7623 3973 7615 3975 7610 3978 7607
3985 7603 3997 7584 3988 7563 3973 7548
3954 7607 3962 7616 3965 7617 3970 7624
TIME...MOT...LOC 2305Z 240DEG 26KT 3956 7632
$$
NIERENBERGThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 26, 3:07 AM EDT | Flash Flood Watch | PHI | Berks, Carbon, Delaware, Lehigh, Monroe, Northampton and 1 more | 20 hr |
| Jul 26, 4:06 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Lehigh, Northampton | 54 min |
| Jul 25, 10:29 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 61 min |
| Jul 26, 4:19 PM EDT | Severe Thunderstorm Warning | PHI | Kent | 44 min |
| Jul 25, 9:41 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 64 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2009Severe Thunderstorm Warnings in Delaware, 2009Severe Thunderstorm Warnings in Maryland, 2009Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.