Alert archive / Pennsylvania / Special Weather Statements in 2011

Special Weather Statement, NWS Philadelphia/Mount Holly

October 14, 2011Chester County, Delaware County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Oct 14, 2011, 12:25 PM EDT for Chester County, Delaware County, Montgomery County, Pennsylvania. It was in force for 80 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 14, 2011, 12:25 PM EDT (16:25 UTC)
Expired: Oct 14, 2011, 1:45 PM EDT
In force: 80 min
Issued by: NWS Philadelphia/Mount Holly

Counties Chester County, PA, Delaware County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 113 km from the middle of the area, began a volume at 16:26 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 4.4 hours before the alert went out and 65 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: 262 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 748 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: 63 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.

830 
WWUS81 KPHI 141625
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1225 PM EDT FRI OCT 14 2011

DEZ001-PAZ067-068-070-141745-
CHESTER PA-DELAWARE PA-MONTGOMERY PA-NEW CASTLE DE-
1225 PM EDT FRI OCT 14 2011

...A STRONG THUNDERSTORM WILL AFFECT CHESTER...DELAWARE...MONTGOMERY
AND NEW CASTLE COUNTIES...

AT 1218 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 11 MILES NORTH OF NEWARK...MOVING NORTH AT 30 
MPH. THIS THUNDERSTORM WILL BE MOVING THROUGH CHESTER COUNTY AND 
WESTERN DELAWARE COUNTY DURING THE EARLY AFTERNOON HOURS. OTHER 
STORMS WERE LOCATED IN NORTHERN NEW CASTLE COUNTY...MOVING NORTH AT 
35 MPH.

HEAVY RAIN WILL FALL FROM THESE STORMS...AND WILL CAUSE WATER TO 
POND ON ROADS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.

WIND GUSTS TO 50 MPH ARE ALSO POSSIBLE WITH THESE STORMS. SMALL HAIL 
AND CLOUD TO GROUND LIGHTNING CAN ALSO BE EXPECTED.

LAT...LON 4003 7595 4011 7595 4024 7570 4044 7553
      4026 7529 3994 7528 3963 7571 3965 7579
      3973 7580 3973 7593 4001 7597

$$

FORECASTER:JJM

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 14, 12:15 AM EDT	Coastal Flood Advisory	PHI	Atlantic, Burlington, Cape May, Cumberland, Middlesex, Monmouth and 1 more	13 hr
Oct 14, 3:26 AM EDT	Coastal Flood Advisory	PHI	Burlington, Camden, Gloucester, Salem	19 hr
Oct 14, 4:01 AM EDT	Gale Watch	PHI		12 hr
Oct 14, 2:21 PM EDT	Special Weather Statement	PHI	Warren	54 min
Oct 14, 2:53 PM EDT	Special Weather Statement	PHI	Burlington, Camden, Hunterdon, Mercer, Somerset	67 min
Oct 14, 3:12 PM EDT	Special Weather Statement	PHI	Sussex, Warren	63 min
Oct 14, 3:59 PM EDT	Gale Watch	PHI		12 hr
Oct 14, 3:59 PM EDT	Gale Warning	PHI		27 hr
Oct 14, 3:59 PM EDT	Special Weather Statement	PHI	Middlesex, Monmouth, Morris	61 min
Oct 14, 10:45 AM EDT	Special Weather Statement	PHI	Berks, Lehigh	60 min
Oct 14, 11:38 AM EDT	Special Weather Statement	PHI	Berks, Carbon, Lehigh	52 min
Oct 14, 12:51 PM EDT	Special Weather Statement	PHI	Lehigh	54 min
Oct 14, 1:22 PM EDT	Special Weather Statement	PHI	Carbon, Monroe, Northampton	53 min
Oct 14, 1:43 PM EDT	Special Weather Statement	PHI	Bucks, Delaware, Montgomery, Philadelphia	62 min
Oct 14, 11:21 AM EDT	Special Weather Statement	PHI	Cecil	54 min

Nearby

Special Weather Statements in Pennsylvania, 2011 Every 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.