Alert archive / Maryland / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 201, NWS Philadelphia/Mount Holly

August 17, 2012Caroline County, Queen Anne's County, Talbot County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 17, 2012, 9:55 PM EDT for Caroline County, Queen Anne's County, Talbot County, Maryland. It was in force for 65 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 17, 2012, 9:55 PM EDT (01:55 UTC)
Expired
Aug 17, 2012, 11:00 PM EDT
In force
65 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Caroline County, MD, Queen Anne's County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 61 km from the middle of the area, began a volume at 01:55 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.9 hours before the alert went out and 109 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-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 2012-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 288 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2012-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
288 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
1300 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
44 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

425 
WUUS51 KPHI 180155
SVRPHI
MDC011-035-041-180300-
/O.NEW.KPHI.SV.W.0201.120818T0155Z-120818T0300Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
955 PM EDT FRI AUG 17 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CAROLINE COUNTY IN EASTERN MARYLAND...
  TALBOT COUNTY IN EASTERN MARYLAND...
  SOUTHERN QUEEN ANNE'S COUNTY IN NORTHEAST MARYLAND...

* UNTIL 1100 PM EDT

* AT 951 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
  LOCATED ALONG A LINE EXTENDING FROM CENTREVILLE TO TILGHMAN
  ISLAND...OR ALONG A LINE EXTENDING FROM 32 MILES SOUTHEAST OF
  BALTIMORE TO 40 MILES SOUTHEAST OF BALTIMORE...AND MOVING EAST AT
  15 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  CENTREVILLE AROUND 1000 PM EDT...
  ST. MICHAELS AROUND 1005 PM EDT...
  STARKEY CORNER AROUND 1010 PM EDT...
  COPPERVILLE...WYE MILLS AND CARVILLE AROUND 1015 PM EDT...
  OXFORD AND HOPE AROUND 1020 PM EDT...
  STARR AND SKIPTON AROUND 1025 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! REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE
ENOUGH TO BE STRUCK BY LIGHTNING.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 3870 7584 3867 7595 3867 7622 3872 7626
      3872 7631 3867 7632 3868 7635 3875 7639
      3887 7625 3881 7621 3882 7620 3893 7622
      3890 7626 3894 7628 3899 7624 3900 7618
      3908 7618 3912 7611 3916 7576 3866 7572
TIME...MOT...LOC 0154Z 265DEG 14KT 3906 7609 3877 7630

$$

SZATKOWSKI

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 8:24 PM EDTSpecial Weather StatementPHICecil, Kent81 min
Aug 17, 9:08 PM EDTSevere Thunderstorm WarningPHICecil, Kent, Queen Anne's67 min
Aug 17, 9:31 PM EDTSpecial Weather StatementPHICaroline, Queen Anne's89 min
Aug 17, 10:55 PM EDTSpecial Weather StatementPHICaroline, Talbot65 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2012Every severe thunderstorm warning in 2012

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.