Alert archive / Maryland / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 198, NWS Philadelphia/Mount Holly

August 11, 2009Talbot County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 11, 2009, 9:04 PM EDT for Talbot County, Maryland. It was in force for 26 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 11, 2009, 9:04 PM EDT (01:04 UTC)
Expired: Aug 11, 2009, 9:30 PM EDT
In force: 26 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Talbot County, MD

The radar

The Dover AFB radar (KDOX), 57 km from the middle of the area, began a volume at 01:05 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 1.1 hours before the alert went out and 92 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: 1107 J/kg
Mixed-layer CIN: -26 J/kg
Mixed-layer LCL: 1250 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: 29 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 120104
SVRPHI
MDC041-120130-
/O.NEW.KPHI.SV.W.0198.090812T0104Z-090812T0130Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
904 PM EDT TUE AUG 11 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN TALBOT COUNTY IN EASTERN MARYLAND...

* UNTIL 930 PM EDT

* AT 902 PM EDT...NATIONAL WEATHER SERVICE RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED OVER
  SOUTH CENTRAL TALBOT COUNTY...OR 10 MILES SOUTH OF EASTON...AND
  MOVING SOUTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  RURAL SOUTHEASTERN TALBOT COUNTY THROUGH 930 PM EDT

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT 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.

&&

LAT...LON 3857 7607 3866 7605 3864 7596 3858 7600
      3856 7604
TIME...MOT...LOC 0103Z 291DEG 17KT 3862 7606

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 11, 8:09 PM EDT	Severe Thunderstorm Warning	PHI	Queen Anne's, Talbot	66 min
Aug 12, 4:16 PM EDT	Areal Flood Advisory	PHI	Caroline, Queen Anne's, Talbot	3 hr
Aug 12, 5:55 PM EDT	Flash Flood Warning	PHI	Cecil	100 min

Nearby

Severe Thunderstorm Warnings in Maryland, 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.