Alert archive / Pennsylvania / Special Weather Statements in 2010

Special Weather Statement, NWS Philadelphia/Mount Holly

May 31, 2010Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at May 31, 2010, 3:02 PM EDT for Chester County, Pennsylvania. It was in force for 43 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: May 31, 2010, 3:02 PM EDT (19:02 UTC)
Expired: May 31, 2010, 3:45 PM EDT
In force: 43 min
Issued by: NWS Philadelphia/Mount Holly

County Chester County, PA

The radar

The Philadelphia radar (KDIX), 126 km from the middle of the area, began a volume at 19:04 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, 7.0 hours before the alert went out and 185 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: 1509 J/kg
Mixed-layer CIN: -111 J/kg
Mixed-layer LCL: 1007 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 46 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.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this special weather statement went out at May 31, 10:46 AM EDT, 4 hours 16 minutes earlier.

Area forecast discussion, May 31, 10:46 AM EDT, 4 hours 16 minutes before

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Hazardous weather outlook, May 31, 4:25 AM EDT, 10 hours 37 minutes before

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In the hours before

Special weather statement, May 31, 3:02 PM EDT, 0 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
302 PM EDT MON MAY 31 2010

PAZ060-067-311945-
BERKS PA-CHESTER PA-
302 PM EDT MON MAY 31 2010

...A STRONG THUNDERSTORM WILL AFFECT FAR SOUTHERN BERKS AND
NORTHWESTERN CHESTER COUNTIES...

AT 300 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 15 MILES SOUTH OF READING...MOVING EAST AT 15
MPH. THE THUNDERSTORM WILL BE NEAR NEW MORGAN AROUND 310 PM...
ELVERSON AROUND 315 PM...GLENMOORE AROUND 320 PM AND PUGHTOWN AROUND
345 PM.

VERY HEAVY RAIN WILL FALL FROM THIS STORM...AND WILL CAUSE WATER TO
POND ON ROADS. WIND GUSTS TO 40 MPH AND SMALL HAIL ARE POSSIBLE WITH
THIS STORM.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM. DO
NOT SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS, MOVE INDOORS
WHEN A THUNDERSTORM APPROACHES.

LAT...LON 4007 7595 4011 7595 4014 7590 4017 7594
      4018 7594 4025 7571 4008 7547 4005 7595
      4006 7595

FORECASTER: GORSE

The office that day

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

Issued	Product	Office	Counties	Lasted
May 31, 4:30 PM EDT	Special Weather Statement	PHI	Monmouth	45 min
May 31, 4:37 PM EDT	Special Weather Statement	PHI	Mercer	38 min
May 31, 4:56 PM EDT	Special Weather Statement	PHI	Mercer, Middlesex	49 min
May 31, 5:03 PM EDT	Special Weather Statement	PHI	Mercer	57 min
May 31, 5:18 PM EDT	Special Weather Statement	PHI	Mercer, Middlesex, Monmouth	42 min
May 31, 5:40 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex	110 min
May 31, 6:01 PM EDT	Special Weather Statement	PHI	Monmouth	44 min
May 31, 6:44 PM EDT	Special Weather Statement	PHI	Monmouth	61 min
May 31, 6:49 PM EDT	River Flood Warning	PHI	Mercer	86 min
May 31, 3:30 PM EDT	Special Weather Statement	PHI	Montgomery	45 min

Nearby

Special Weather Statements in Pennsylvania, 2010 Every special weather statement 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.