Alert archive / Pennsylvania / Special Weather Statements in 2012

Special Weather Statement, NWS Philadelphia/Mount Holly

January 27, 20124 states

NWS Philadelphia/Mount Holly issued this special weather statement at Jan 27, 2012, 8:27 AM EST for 4 states. It was in force for 93 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
Jan 27, 2012, 8:27 AM EST (13:27 UTC)
Expired
Jan 27, 2012, 10:00 AM EST
In force
93 min
Issued by
NWS Philadelphia/Mount Holly

Counties New Castle County, DE, Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Gloucester County, NJ, Salem County, NJ, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Dover AFB radar (KDOX), 79 km from the middle of the area, began a volume at 13:28 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, 1.5 hours before the alert went out and 151 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 2012-01-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 85 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, Washington/Dulle, VA at 12:00Z on 2012-01-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 306 square meters per square second.1939587897117136Sfc1 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
85 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
738 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
306 m²/s²
0-3 km storm-relative helicity
329 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

743 
WWUS81 KPHI 271327
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
827 AM EST FRI JAN 27 2012

DEZ001-002-MDZ008-012-015-020-NJZ015>019-021-PAZ067>071-271500-
BUCKS PA-CAMDEN NJ-CAROLINE MD-CECIL MD-CHESTER PA-CUMBERLAND NJ-
DELAWARE PA-GLOUCESTER NJ-KENT DE-KENT MD-MERCER NJ-MONTGOMERY PA-
NEW CASTLE DE-NORTHWESTERN BURLINGTON NJ-PHILADELPHIA PA-
QUEEN ANNE'S MD-SALEM NJ-
827 AM EST FRI JAN 27 2012

...SHOWERS WITH STRONG WIND GUSTS AND HEAVY RAIN WILL AFFECT 
CAMDEN...MERCER...BUCKS...MONTGOMERY...PHILADELPHIA...DELAWARE...
GLOUCESTER...NEW CASTLE...CECIL...KENT...CHESTER...CAROLINE...
BURLINGTON...QUEEN ANNE'S...SALEM AND CUMBERLAND COUNTIES...

AT 820 AM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
SHOWERS WITH STRONG WIND GUSTS ALONG A LINE EXTENDING FROM 13 MILES
SOUTHEAST OF READING TO 19 MILES SOUTHWEST OF ELKTON TO 25 MILES WEST
OF EASTON...MOVING EAST AT 45 MPH. THE SHOWERS WILL BE NEAR
CEDARVILLE...SOUTH POTTSTOWN...STOWE...PUGHTOWN AROUND 830 AM...
KENILWORTH...SANATOGA...POTTSTOWN...POTTSGROVE AROUND 835 AM...
CHESTER SPRINGS AND OLD TOWN AROUND 840 AM.
 
VERY HEAVY RAIN WILL FALL FROM THESE SHOWERS...AND WILL CAUSE WATER
TO POND ON ROADWAYS AND LOW LYING AREAS, AROUND A QUARTER OF AN INCH 
OF RAIN IN ABOUT 30 MINUTES IS LIKELY AS THIS LINE MOVES THROUGH.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THESE SHOWERS. THIS WILL KNOCK 
DOWN WEAK TREE BRANCHES.

PLEASE BE ALERT FOR CHANGING WEATHER CONDITIONS IF OUTDOORS THIS 
MORNING.

LAT...LON 3904 7632 3900 7618 3914 7629 3932 7619
      3943 7600 3952 7599 3959 7610 4014 7588
      4028 7567 4042 7506 4034 7486 4042 7478
      3967 7508 3933 7537 3948 7558 3926 7540
      3903 7557 3888 7621 3894 7624 3884 7638

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 27, 4:54 AM ESTGale WarningPHI20 hr
Jan 27, 9:38 AM ESTSpecial Marine WarningPHI82 min
Jan 27, 10:27 AM ESTSpecial Marine WarningPHI63 min
Jan 27, 10:31 AM ESTSpecial Weather StatementPHIGloucester, Salem29 min
Jan 27, 11:06 AM ESTSpecial Weather StatementPHIAtlantic, Burlington, Camden, Ocean54 min
Jan 27, 2:15 PM ESTWind AdvisoryPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 10 more6 hr
Jan 27, 9:34 AM ESTSpecial Weather StatementPHIKent, New Castle56 min

Nearby

Special Weather Statements in Pennsylvania, 2012Special Weather Statements in Maryland, 2012Special Weather Statements in New Jersey, 2012Every special weather statement 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.