Alert archive / Pennsylvania / Special Weather Statements in 2011

Special Weather Statement, NWS Philadelphia/Mount Holly

September 7, 2011Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Sep 7, 2011, 2:39 PM EDT for Chester County, Pennsylvania. It was in force for 66 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
Sep 7, 2011, 2:39 PM EDT (18:39 UTC)
Expired
Sep 7, 2011, 3:45 PM EDT
In force
66 min
Issued by
NWS Philadelphia/Mount Holly

County Chester County, PA

The radar

The Philadelphia radar (KDIX), 134 km from the middle of the area, began a volume at 18:39 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 12:00Z, 6.7 hours before the alert went out and 177 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 12:00Z on 2011-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 12:00Z on 2011-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 154 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
1 J/kg
Mixed-layer CIN
-270 J/kg
Mixed-layer LCL
448 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
154 m²/s²
0-3 km storm-relative helicity
184 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.

067 
WWUS81 KPHI 071839
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
239 PM EDT WED SEP 7 2011

PAZ060-067-071945-
BERKS PA-CHESTER PA-
239 PM EDT WED SEP 7 2011

...A STRONG THUNDERSTORM WILL AFFECT BERKS AND CHESTER COUNTIES...

AT 235 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 17 MILES WEST OF WEST CHESTER...MOVING NORTH AT
30 MPH. THE THUNDERSTORM WILL BE NEAR HONEY BROOK...NEW MORGAN AROUND
300 PM...KENHORST...SHILLINGTON AROUND 315 PM...WEST WYOMISSING AND
MOUNT PENN AROUND 330 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.

LAT...LON 4032 7607 4034 7577 3991 7581 3990 7601
      3992 7601 3993 7600 3996 7600 4003 7595
      4011 7595 4014 7590 4025 7606

$$

HAYES

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 6, 8:28 PM EDTRiver Flood WarningPHIMorris, Somerset14 hr
Sep 6, 8:28 PM EDTRiver Flood WarningPHIMorris, Somerset4 days
Sep 6, 8:28 PM EDTRiver Flood WarningPHISomerset3 days
Sep 6, 8:28 PM EDTRiver Flood WarningPHIHunterdon, Somerset56 hr
Sep 6, 8:28 PM EDTRiver Flood WarningPHISomerset14 hr
Sep 6, 8:28 PM EDTRiver Flood WarningPHIMiddlesex, Somerset25 hr
Sep 6, 8:28 PM EDTRiver Flood WarningPHIMiddlesex, Somerset3 days
Sep 6, 8:28 PM EDTRiver Flood WarningPHIMorris20 hr
Sep 7, 4:15 AM EDTRiver Flood WarningPHIMorris, Passaic3 days
Sep 7, 4:34 AM EDTRiver Flood WarningPHIBergen, Morris, Passaic17 hr
Sep 7, 5:42 AM EDTAreal Flood WarningPHIMorris28 hr
Sep 7, 6:12 AM EDTRip Current StatementPHIAtlantic, Cape May, Monmouth, Ocean65 hr
Sep 7, 10:05 AM EDTRiver Flood WarningPHISussex, Warren60 hr
Sep 7, 10:05 AM EDTRiver Flood WarningPHIHunterdon, Warren67 hr
Sep 7, 10:05 AM EDTRiver Flood WarningPHIHunterdon, Mercer68 hr
Sep 7, 10:05 AM EDTRiver Flood WarningPHIHunterdon67 hr
Sep 7, 10:05 AM EDTRiver Flood WarningPHIHunterdon67 hr
Sep 7, 10:05 AM EDTRiver Flood WarningPHIHunterdon, Mercer64 hr
Sep 7, 10:05 AM EDTRiver Flood WarningPHIHunterdon, Mercer67 hr
Sep 7, 10:05 AM EDTRiver Flood WarningPHIMercer68 hr
Sep 7, 11:48 AM EDTCoastal Flood AdvisoryPHIBurlington, Camden, Cumberland, Gloucester, Salem18 hr
Sep 7, 7:39 PM EDTCoastal Flood WarningPHIBurlington, Camden, Gloucester6 hr
Sep 6, 10:31 PM EDTAreal Flood WarningPHIBerks, Lehigh15 hr
Sep 6, 11:13 PM EDTRiver Flood WarningPHIChester, Montgomery, Philadelphia3 days
Sep 6, 11:19 PM EDTRiver Flood WarningPHIMontgomery17 hr
Sep 7, 12:59 AM EDTRiver Flood WarningPHIChester, Delaware41 hr
Sep 7, 3:40 AM EDTRiver Flood WarningPHIMontgomery, Philadelphia54 hr
Sep 7, 3:47 AM EDTRiver Flood WarningPHIDelaware4 hr
Sep 7, 4:26 AM EDTRiver Flood WarningPHIBerks, Montgomery6 hr
Sep 7, 4:26 AM EDTRiver Flood WarningPHIMontgomery3 days
Sep 7, 9:48 AM EDTRiver Flood WarningPHILehigh, Northampton5 hr
Sep 7, 1:32 PM EDTSpecial Weather StatementPHIBerks58 min
Sep 7, 1:38 PM EDTSpecial Weather StatementPHILebanon52 min
Sep 7, 1:50 PM EDTAreal Flood AdvisoryPHIBerks17 min
Sep 7, 2:05 PM EDTFlash Flood WarningPHIBerks4 hr
Sep 7, 2:36 PM EDTSpecial Weather StatementPHIBerks54 min
Sep 7, 3:06 PM EDTFlash Flood WarningPHIChester4 hr
Sep 7, 3:33 PM EDTFlash Flood WarningPHIBerks, Chester4 hr
Sep 7, 3:49 PM EDTSpecial Weather StatementPHIBerks, Chester56 min
Sep 7, 4:06 PM EDTRiver Flood WarningPHIBerks, Montgomery41 hr
Sep 7, 4:06 PM EDTRiver Flood WarningPHIBerks45 hr
Sep 7, 4:09 PM EDTSpecial Weather StatementPHIBucks, Delaware, Lehigh, Montgomery, Northampton, Philadelphia66 min
Sep 7, 5:10 PM EDTAreal Flood AdvisoryPHIBerks, Bucks, Carbon, Lehigh, Monroe, Montgomery and 1 more3 hr
Sep 7, 6:07 PM EDTRiver Flood WarningPHIChester10 hr
Sep 7, 7:14 PM EDTAreal Flood AdvisoryPHIBerks65 min
Sep 7, 7:21 PM EDTAreal Flood WarningPHIBerks, Chester14 hr
Sep 7, 7:32 PM EDTSpecial Weather StatementPHIBerks58 min
Sep 6, 10:21 PM EDTFlash Flood WarningPHICaroline, Cecil, Kent, Queen Anne's, Talbot3 hr
Sep 7, 1:34 PM EDTSpecial Weather StatementPHICecil56 min
Sep 7, 4:40 PM EDTRiver Flood WarningPHICecil, Harford4 days
Sep 7, 6:34 PM EDTSpecial Weather StatementPHICecil, Kent, Queen Anne's56 min
Sep 7, 7:52 PM EDTSpecial Weather StatementPHIHarford53 min
Sep 7, 7:32 AM EDTRiver Flood WarningPHINew Castle3 hr

Nearby

Special Weather Statements in Pennsylvania, 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; radar from the NEXRAD Level II archive.