Alert archive / Maryland / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 218, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 21, 2009, 3:28 PM EDT for Cecil County, Kent County, Queen Anne's County, Maryland. It was in force for 62 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
- Aug 21, 2009, 3:28 PM EDT (19:28 UTC)
- Expired
- Aug 21, 2009, 4:30 PM EDT
- In force
- 62 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Cecil County, MD, Kent County, MD, Queen Anne's County, MD
The radar
The Dover AFB radar (KDOX), 75 km from the middle of the area, began a volume at 19:29 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 |
|---|---|---|---|
| Aug 21, 12:36 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.5 hours before the alert went out and 38 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
- 96 J/kg
- Mixed-layer CIN
- -66 J/kg
- Mixed-layer LCL
- 930 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 43 m²/s²
- 0-3 km storm-relative helicity
- 108 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.6
The text
As transmitted, in the capitals the NWS used until 2016.
000
WUUS51 KPHI 211928
SVRPHI
MDC015-029-035-212030-
/O.NEW.KPHI.SV.W.0218.090821T1928Z-090821T2030Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
328 PM EDT FRI AUG 21 2009
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
SOUTH CENTRAL CECIL COUNTY IN NORTHEAST MARYLAND...
KENT COUNTY IN NORTHEAST MARYLAND...
NORTHERN QUEEN ANNES COUNTY IN NORTHEAST MARYLAND...
* UNTIL 430 PM EDT
* AT 326 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED 9 MILES
NORTHWEST OF STEVENSVILLE...OR 19 MILES SOUTHEAST OF BALTIMORE...
AND MOVING NORTHEAST AT 30 MPH.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
ROCK HALL AROUND 355 PM EDT...
LANGFORD AND OLD TOWN AROUND 405 PM EDT...
CHESTERTOWN AND 6 MILES SOUTHEAST OF NEWTOWN AROUND 415 PM EDT...
MORGNEC AROUND 425 PM EDT...
KENNEDYVILLE AND CRUMPTON AROUND 430 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 800 PM EDT FRIDAY
EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA. A SEVERE
THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 900 PM EDT FRIDAY
EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN NEW
JERSEY.
&&
LAT...LON 3902 7634 3905 7631 3903 7625 3906 7623
3914 7626 3916 7628 3932 7619 3938 7611
3938 7606 3944 7600 3915 7578 3901 7623
3904 7629 3900 7628 3898 7634
TIME...MOT...LOC 1928Z 239DEG 25KT 3906 7645
$$
POThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 2:47 PM EDT | Flash Flood Watch | PHI | Caroline, Cecil, Kent, Queen Anne's, Talbot | 35 hr |
| Aug 21, 3:48 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 57 min |
| Aug 21, 4:13 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 77 min |
Nearby
Severe 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.