Alert archive / Maryland / Severe Thunderstorm Warnings in 2010

Severe Thunderstorm Warning 170, NWS Philadelphia/Mount Holly

October 27, 2010Caroline County, Talbot County, Maryland; Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Oct 27, 2010, 9:06 PM EDT for Caroline County, Talbot County, Maryland; Sussex County, Delaware. It was in force for 54 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
Oct 27, 2010, 9:06 PM EDT (01:06 UTC)
Expired
Oct 27, 2010, 10:00 PM EDT
In force
54 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Sussex County, DE, Caroline County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 43 km from the middle of the area, began a volume at 01:07 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 88 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, Wallops Is Stn, VA at 00:00Z on 2010-10-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 660 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Wallops Is Stn, VA at 00:00Z on 2010-10-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 144 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
660 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
983 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
144 m²/s²
0-3 km storm-relative helicity
157 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

707 
WUUS51 KPHI 280106
SVRPHI
DEC005-MDC011-041-280200-
/O.NEW.KPHI.SV.W.0170.101028T0106Z-101028T0200Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
906 PM EDT WED OCT 27 2010

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN CAROLINE COUNTY IN EASTERN MARYLAND...
  SOUTHEASTERN TALBOT COUNTY IN EASTERN MARYLAND...
  WESTERN SUSSEX COUNTY IN SOUTHERN DELAWARE...
  THIS INCLUDES THE CITY OF GEORGETOWN...

* UNTIL 1000 PM EDT

* AT 901 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 TRAPPE...OR 
15   MILES SOUTH OF EASTON...AND MOVING EAST NORTHEAST AT 35 TO
40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  6 MILES SOUTH OF WINDYHILL AROUND 915 PM EDT...
  6 MILES SOUTH OF CHOPTANK AROUND 920 PM EDT...
  FEDERALSBURG AROUND 935 PM EDT...
  SEAFORD AROUND 945 PM EDT...
  BRIDGEVILLE AROUND 950 PM EDT...
  GEORGETOWN AROUND 1000 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

&&

LAT...LON 3865 7572 3869 7583 3867 7595 3860 7598
      3856 7604 3857 7607 3860 7607 3861 7609
      3861 7611 3866 7617 3887 7541 3860 7530
      3852 7571
TIME...MOT...LOC 0105Z 253DEG 31KT 3857 7606

$$

RPW
1 follow-up statement
339 
WWUS51 KPHI 280135
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
935 PM EDT WED OCT 27 2010

MDC041-280144-
/O.CAN.KPHI.SV.W.0170.000000T0000Z-101028T0200Z/
TALBOT MD-
935 PM EDT WED OCT 27 2010

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN TALBOT COUNTY IS
CANCELLED...

LAT...LON 3865 7572 3868 7579 3875 7580 3887 7541
      3860 7530 3852 7571
TIME...MOT...LOC 0134Z 253DEG 31KT 3869 7572

$$

DEC005-MDC011-280200-
/O.CON.KPHI.SV.W.0170.000000T0000Z-101028T0200Z/
CAROLINE MD-SUSSEX DE-
935 PM EDT WED OCT 27 2010

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM EDT
FOR WESTERN SUSSEX AND SOUTHEASTERN CAROLINE COUNTIES...

AT 932 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR FEDERALSBURG...OR 19 
MILES WEST OF GEORGETOWN...MOVING EAST NORTHEAST AT 35 TO 40 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  SEAFORD AND BLADES BY 940 PM EDT...
  BRIDGEVILLE BY 945 PM EDT...
  6 MILES SOUTH OF GREENWOOD BY 950 PM EDT...
  ELLENDALE AND GEORGETOWN BY 1000 PM EDT...

LAT...LON 3865 7572 3868 7579 3875 7580 3887 7541
      3860 7530 3852 7571
TIME...MOT...LOC 0134Z 253DEG 31KT 3869 7572

$$

RPW

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 27, 8:37 PM EDTSpecial Weather StatementPHITalbot53 min
Oct 27, 10:48 PM EDTSpecial Weather StatementPHISussex27 min
Oct 27, 11:10 PM EDTSpecial Weather StatementPHISussex50 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2010Severe Thunderstorm Warnings in Delaware, 2010Every severe thunderstorm warning in 2010

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.