Alert archive / Maryland / Special Weather Statements in 2011

Special Weather Statement, NWS Philadelphia/Mount Holly

July 31, 2011Caroline County, Maryland

NWS Philadelphia/Mount Holly issued this special weather statement at Jul 31, 2011, 12:30 PM EDT for Caroline County, Maryland. It was in force for 60 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
Jul 31, 2011, 12:30 PM EDT (16:30 UTC)
Expired
Jul 31, 2011, 1:30 PM EDT
In force
60 min
Issued by
NWS Philadelphia/Mount Holly

County Caroline County, MD

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 4.5 hours before the alert went out and 95 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 12:00Z on 2011-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2011-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -22 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2108 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
-22 m²/s²
0-3 km storm-relative helicity
22 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.

744 
WWUS81 KPHI 311630
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1230 PM EDT SUN JUL 31 2011

DEZ002-003-MDZ019-020-311730-
CAROLINE MD-INLAND SUSSEX DE-KENT DE-TALBOT MD-
1230 PM EDT SUN JUL 31 2011

...A STRONG THUNDERSTORM WILL AFFECT CAROLINE...KENT...SUSSEX AND
TALBOT COUNTIES...

AT 1227 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 7 MILES EAST OF EASTON...MOVING EAST AT 10 MPH.
THE THUNDERSTORM WILL BE NEAR HARMONY...PRESTON AROUND 1245 PM...
DENTON...GREENSBORO AROUND 100 PM...AGNER...FEDERALSBURG AROUND 115
PM...SMITHVILLE AND BRIDGEVILLE AROUND 130 PM.

VERY HEAVY RAIN WILL FALL FROM THIS STORM...AND WILL CAUSE WATER TO
POND ON ROADS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THIS STORM.

EXPECT INTENSE LIGHTNING FROM THIS STORM. DO NOT SEEK SHELTER UNDER
TREES WHEN LIGHTNING THREATENS...MOVE INDOORS WHEN A THUNDERSTORM
APPROACHES.

LAT...LON 3857 7572 3865 7572 3867 7576 3867 7580
      3869 7582 3869 7586 3867 7593 3872 7601
      3876 7600 3881 7595 3889 7598 3904 7586
      3892 7545 3853 7562

$$

HEAVENER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 6:40 PM EDTSpecial Weather StatementPHISussex, Warren95 min
Jul 31, 7:39 PM EDTSpecial Weather StatementPHICamden66 min
Jul 31, 7:59 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden31 min
Jul 31, 5:39 PM EDTSpecial Weather StatementPHIMonroe96 min
Jul 31, 7:29 PM EDTSpecial Weather StatementPHIBerks91 min
Jul 31, 1:23 PM EDTSpecial Weather StatementPHICaroline82 min
Jul 31, 2:39 PM EDTSpecial Weather StatementPHITalbot96 min
Jul 31, 3:58 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's36 min
Jul 31, 2:09 PM EDTSpecial Weather StatementPHIKent66 min
Jul 31, 2:35 PM EDTAreal Flood AdvisoryPHIKent115 min
Jul 31, 2:45 PM EDTSpecial Weather StatementPHIKent90 min
Jul 31, 3:33 PM EDTFlash Flood WarningPHIKent, New Castle2 hr
Jul 31, 4:36 PM EDTSpecial Weather StatementPHIKent84 min
Jul 31, 4:56 PM EDTSpecial Weather StatementPHISussex64 min

Nearby

Special Weather Statements in Maryland, 2011Every special weather statement in 2011

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.