Alert archive / Pennsylvania / Areal Flood Advisories in 2009

Areal Flood Advisory 25, NWS Philadelphia/Mount Holly

July 1, 2009Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 1, 2009, 10:51 PM EDT for Berks County, Pennsylvania. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Jul 1, 2009, 10:51 PM EDT (02:51 UTC)
Expired: Jul 2, 2009, 1:45 AM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 139 km from the middle of the area, began a volume at 02:51 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

Brookhaven, NY (KOKX), launched 00:00Z, 2.9 hours before the alert went out and 263 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: 108 J/kg
Mixed-layer CIN: -156 J/kg
Mixed-layer LCL: 752 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 128 m²/s²
0-3 km storm-relative helicity: 195 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood advisory 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 areal flood advisory went out at Jul 1, 9:22 PM EDT, 1 hour 29 minutes earlier.

Area forecast discussion, Jul 1, 9:22 PM EDT, 1 hour 29 minutes before

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Hazardous weather outlook, Jul 1, 9:05 PM EDT, 1 hour 46 minutes before

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In the hours before

Special weather statement, Jul 1, 6:36 PM EDT, 4 hours 15 minutes before

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Local storm report, Jul 1, 8:17 PM EDT, 2 hours 34 minutes before

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Special weather statement, Jul 1, 8:51 PM EDT, 2 hours before

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Special weather statement, Jul 1, 9:01 PM EDT, 1 hour 50 minutes before

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Special weather statement, Jul 1, 10:17 PM EDT, 34 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1017 PM EDT WED JUL 1 2009

NJZ007-009-PAZ054-055-060>062-068-069-020415-
BERKS PA-BUCKS PA-CARBON PA-HUNTERDON NJ-LEHIGH PA-MONROE PA-
MONTGOMERY PA-NORTHAMPTON PA-WARREN NJ-
1017 PM EDT WED JUL 1 2009

...STRONG THUNDERSTORMS WILL AFFECT BERKS...BUCKS...CARBON...
HUNTERDON...LEHIGH...MONROE...MONTGOMERY...NORTHAMPTON AND WARREN
COUNTIES...

AT 1015 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS DEVELOPING ALONG A LINE EXTENDING FROM 20 MILES
NORTHWEST OF TRENTON TO 14 MILES EAST OF READING...MOVING NORTH AT
10 TO 15 MPH. THE THUNDERSTORMS WILL BE NEAR LUMBERVILLE...RED HILL
AROUND 1030 PM...BYRAM...STOCKTON AROUND 1045
PM...TINICUM...OTTSVILLE AROUND 1100 PM...ERWINNA...RICHLANDTOWN
AROUND 1115 PM...FRENCHTOWN AND ZIONSVILLE AROUND 1130 PM.
THESE STORMS IF THEY MAINTAIN THEMSELVES WOULD REACH THE POCONOS
AND WARREN COUNTY ABOUT MIDNIGHT.

VERY HEAVY RAIN WILL FALL FROM THESE STORMS...AND WILL CAUSE WATER TO
POND ON ROADS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.
EXPECT SMALL HAIL AND FREQUENT...DANGEROUS CLOUD TO GROUND LIGHTNING
FROM THESE STORMS.

TFG

Special weather statement, Jul 1, 10:30 PM EDT, 21 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1030 PM EDT WED JUL 1 2009

DEZ001>004-MDZ008-012-015-020-NJZ016>018-021>025-PAZ067-070-071-
020430-
ATLANTIC NJ-ATLANTIC COASTAL CAPE MAY NJ-CAMDEN NJ-CAPE MAY NJ-
CAROLINE MD-CECIL MD-CHESTER PA-COASTAL ATLANTIC NJ-CUMBERLAND NJ-
DELAWARE PA-DELAWARE BEACHES DE-GLOUCESTER NJ-INLAND SUSSEX DE-
KENT MD-KENT DE-NEW CASTLE DE-PHILADELPHIA PA-QUEEN ANNES MD-
SALEM NJ-
1030 PM EDT WED JUL 1 2009

...STRONG THUNDERSTORMS WILL AFFECT ATLANTIC...CAMDEN...CAPE MAY...
CAROLINE...CECIL...CHESTER...CUMBERLAND...DELAWARE...GLOUCESTER...
KENT...NEW CASTLE...PHILADELPHIA...QUEEN ANNES...SALEM AND SUSSEX
COUNTIES...

AT 1029 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED AN
AREA OF SHOWERS AND SCATTERED STRONG THUNDERSTORMS ALONG A LINE
EXTENDING FROM 17 MILES SOUTHEAST OF LANCASTER TO 22 MILES WEST OF
MIDDLETOWN TO 20 MILES NORTHEAST OF EASTON TO 23 MILES SOUTH OF
SALISBURY...MOVING EAST AT 25 MPH. THE THUNDERSTORMS WILL BE NEAR
ATGLEN...PARKESBURG AROUND 1045 PM...MODENA...SOUTH COATESVILLE
AROUND 1100 PM...MARSHALLTON...DOWNINGTOWN AROUND 1115 PM...WEST
CHESTER...WEST GOSHEN AROUND 1130 PM...NEWTOWN SQUARE AND
DEVON-BERWYN AROUND 1145 PM.

VERY HEAVY RAIN WILL FALL WITH THE STRONGEST STORMS...AND WILL CAUSE
WATER TO POND ON ROADS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL
STREAMS. WIND GUSTS TO AROUND 35 MPH ARE POSSIBLE WITH THE STRONGEST
STORMS IN THIS AREA. EXPECT SMALL HAIL AND DANGEROUS CLOUD TO GROUND
LIGHTNING FROM THESE STORMS.

TFG

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 2, 3:38 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Morris	3 hr
Jul 2, 4:50 AM EDT	Areal Flood Advisory	PHI	Morris	3 hr
Jul 2, 7:01 AM EDT	Areal Flood Warning	PHI	Hunterdon, Somerset	3 hr
Jul 2, 10:47 AM EDT	River Flood Warning	PHI	Hunterdon, Somerset	2 hr
Jul 1, 11:55 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Lehigh, Montgomery	3 hr
Jul 2, 1:34 AM EDT	Areal Flood Advisory	PHI	Carbon	3 hr

Nearby

Areal Flood Advisories in Pennsylvania, 2009 Every areal flood advisory in 2009

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.