Alert archive / Pennsylvania / Areal Flood Advisories in 2014

Areal Flood Advisory 370, NWS Philadelphia/Mount Holly

September 6, 2014Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood advisory at Sep 6, 2014, 2:43 PM EDT for Chester County, Pennsylvania. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Sep 6, 2014, 2:43 PM EDT (18:43 UTC)
Expired
Sep 6, 2014, 6:45 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

County Chester County, PA

The radar

The Philadelphia radar (KDIX), 114 km from the middle of the area, began a volume at 18:43 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 182 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 2014-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1444 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 2014-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 square meters per square second.1939Sfc1 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
1444 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
867 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 Sep 6, 2:28 PM EDT, 15 minutes earlier.

Area forecast discussion, Sep 6, 2:28 PM EDT, 15 minutes before
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Hazardous weather outlook, Sep 6, 2:22 PM EDT, 21 minutes before
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In the hours before

Special weather statement, Sep 6, 1:37 PM EDT, 1 hour 6 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
137 PM EDT SAT SEP 6 2014

NJZ007-PAZ055-062-061830-
MONROE PA-NORTHAMPTON PA-WARREN NJ-
137 PM EDT SAT SEP 6 2014

...A SHOWER WITH STRONG WIND GUSTS WILL AFFECT NORTHAMPTON...SOUTH
CENTRAL MONROE AND SOUTHWESTERN WARREN COUNTIES...

AT 136 PM EDT...A SHOWER WITH STRONG WIND GUSTS WAS NEAR
BEERSVILLE...MOVING EAST AT 20 MPH.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THIS SHOWER.

VERY HEAVY RAIN WILL FALL FROM THIS SHOWER...AND WILL CAUSE WATER TO
POND ON ROADS AND FILL POOR DRAINAGE AREAS. THE RAIN CAN CAUSE RAPID
RISES ON SMALL STREAMS AND CREEKS.

THIS SHOWER WILL BE NEAR CHAPMAN AROUND 150 PM...NAZARETH AROUND 200
PM...STOCKERTOWN AROUND 210 PM...FORKS AROUND 220 PM AND HARMONY
AROUND 230 PM.

LAT...LON 4089 7495 4061 7517 4071 7552 4074 7553
      4072 7555 4072 7556 4079 7559 4081 7548
      4087 7550 4088 7548

FORECASTER:SFJ
Special weather statement, Sep 6, 1:46 PM EDT, 57 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
146 PM EDT SAT SEP 6 2014

NJZ001-061845-
SUSSEX NJ-
146 PM EDT SAT SEP 6 2014

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN SUSSEX COUNTY...

AT 145 PM EDT...A STRONG THUNDERSTORM WAS NEAR HAINESVILLE...MOVING
EAST AT 5 MPH.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THIS STORM.

VERY HEAVY RAIN WILL FALL FROM THIS STORM...AND WILL CAUSE WATER TO
POND ON ROADS AND FILL POOR DRAINAGE AREAS. THE RAIN CAN CAUSE RAPID
RISES ON SMALL STREAMS AND CREEKS.

THIS STORM WILL BE NEAR BRANCHVILLE AROUND 200 PM...PELLETTOWN AROUND
240 PM AND SUSSEX AROUND 250 PM.

LAT...LON 4135 7467 4121 7437 4118 7438 4114 7443
      4110 7488 4117 7490 4121 7487 4123 7487
      4129 7484 4135 7474 4136 7471

FORECASTER:SFJ
Special weather statement, Sep 6, 2:13 PM EDT, 30 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
213 PM EDT SAT SEP 6 2014

DEZ001-PAZ101-102-061915-
EASTERN CHESTER PA-NEW CASTLE DE-WESTERN CHESTER PA-
213 PM EDT SAT SEP 6 2014

...A STRONG THUNDERSTORM WILL AFFECT CHESTER AND NORTHWESTERN NEW
CASTLE COUNTIES...

AT 211 PM EDT...A STRONG THUNDERSTORM WAS NEAR ATGLEN...MOVING EAST
AT 10 MPH.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THIS STORM.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM. DO
NOT STAY IN THE OPEN NOR SEEK SHELTER UNDER TREES WHEN LIGHTNING
THREATENS...MOVE INDOORS WHEN A THUNDERSTORM APPROACHES.

THIS STORM WILL BE NEAR PARKESBURG AROUND 230 PM...ELVERSON AROUND
250 PM...MODENA AROUND 300 PM...THORNDALE AROUND 310 PM AND
MARSHALLTON AROUND 320 PM.

LAT...LON 3988 7599 3997 7600 4004 7594 4011 7595
      4017 7583 4021 7558 4019 7557 4020 7555
      4014 7552 3988 7558 3988 7560 3985 7559
      3966 7563 3985 7602

FORECASTER: SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 6, 1:37 PM EDTSpecial Weather StatementPHIWarren53 min
Sep 6, 1:46 PM EDTSpecial Weather StatementPHISussex59 min
Sep 6, 2:58 PM EDTAreal Flood AdvisoryPHIHunterdon, Mercer, Middlesex, Somerset4 hr
Sep 6, 3:19 PM EDTSpecial Weather StatementPHIMiddlesex26 min
Sep 6, 3:25 PM EDTSpecial Weather StatementPHIMercer65 min
Sep 6, 3:32 PM EDTSpecial Weather StatementPHIHunterdon58 min
Sep 6, 3:45 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer60 min
Sep 6, 4:03 PM EDTSevere Thunderstorm WarningPHIMercer, Middlesex, Monmouth57 min
Sep 6, 4:19 PM EDTSpecial Marine WarningPHI56 min
Sep 6, 4:45 PM EDTSpecial Weather StatementPHIHunterdon, Mercer, Middlesex, Morris, Somerset60 min
Sep 6, 4:47 PM EDTSpecial Weather StatementPHIBurlington58 min
Sep 6, 4:52 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester, Salem36 min
Sep 6, 4:54 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean43 min
Sep 6, 4:58 PM EDTSpecial Marine WarningPHI62 min
Sep 6, 5:09 PM EDTSpecial Marine WarningPHI66 min
Sep 6, 5:26 PM EDTSpecial Marine WarningPHI64 min
Sep 6, 5:31 PM EDTSpecial Weather StatementPHIBurlington59 min
Sep 6, 5:44 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean35 min
Sep 6, 6:41 PM EDTSpecial Weather StatementPHISalem64 min
Sep 6, 7:41 PM EDTSpecial Marine WarningPHI64 min
Sep 6, 7:45 PM EDTSpecial Weather StatementPHICape May60 min
Sep 6, 2:13 PM EDTSpecial Weather StatementPHIChester62 min
Sep 6, 2:19 PM EDTSevere Thunderstorm WarningPHIChester43 min
Sep 6, 3:21 PM EDTSpecial Weather StatementPHIBerks, Bucks, Lehigh, Montgomery54 min
Sep 6, 3:51 PM EDTFlash Flood WarningPHIChester4 hr
Sep 6, 7:36 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton54 min
Sep 6, 4:56 PM EDTSpecial Weather StatementPHICecil64 min
Sep 6, 7:43 PM EDTSpecial Weather StatementPHICaroline62 min

Nearby

Areal Flood Advisories in Pennsylvania, 2014Every areal flood advisory in 2014

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.