Alert archive / Maryland / Areal Flood Advisories in 2014

Areal Flood Advisory 374, NWS Philadelphia/Mount Holly

October 15, 2014Chester County, Pennsylvania; 4 counties in Maryland

NWS Philadelphia/Mount Holly issued this areal flood advisory at Oct 15, 2014, 5:01 PM EDT for Chester County, Pennsylvania; 4 counties in Maryland. It was in force for 119 min.

The area

The counties it named.

The facts

Issued: Oct 15, 2014, 5:01 PM EDT (21:01 UTC)
Expired: Oct 15, 2014, 7:00 PM EDT
In force: 119 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, Chester County, PA

The radar

The Dover AFB radar (KDOX), 73 km from the middle of the area, began a volume at 21:03 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, 9.0 hours before the alert went out and 19 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: 8 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 636 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 265 m²/s²
0-3 km storm-relative helicity: 274 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 Oct 15, 4:04 PM EDT, 57 minutes earlier.

Area forecast discussion, Oct 15, 4:04 PM EDT, 57 minutes before

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Hazardous weather outlook, Oct 15, 4:02 PM EDT, 59 minutes before

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In the hours before

Special weather statement, Oct 15, 2:45 PM EDT, 2 hours 16 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
245 PM EDT WED OCT 15 2014

PAZ060-151915-
BERKS PA-
245 PM EDT WED OCT 15 2014

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT CENTRAL BERKS COUNTY...

AT 243 PM EDT...A LINE OF STRONG THUNDERSTORMS WAS LOCATED FROM PORT
CLINTON TO WYOMISSING TO TERRE HILL...MOVING NORTHEAST AT 35 MPH.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THESE STORMS.

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

VERY HEAVY RAIN WILL FALL FROM THESE STORMS...AND WILL CAUSE WATER TO
POND ON ROADS AND FILL POOR DRAINAGE AREAS. THE RAIN CAN CAUSE RAPID
RISES ON SMALL STREAMS AND CREEKS. THERE COULD BE AN INCH OF RAIN IN
30 MINUTES.

THESE STORMS WILL BE NEAR LEESPORT AROUND 250 PM...HAMBURG AROUND 255
PM...KENHORST AROUND 300 PM...LENHARTSVILLE AROUND 305 PM AND
KUTZTOWN AROUND 315 PM.

LAT...LON 4059 7605 4058 7603 4063 7600 4065 7599
      4068 7589 4059 7576 4057 7574 4021 7599
      4023 7602 4025 7601 4055 7614

FORECASTER:  DRAG

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 15, 2:45 PM EDT	Special Weather Statement	PHI	Berks	30 min
Oct 15, 4:06 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	15 hr

Nearby

Areal Flood Advisories in Maryland, 2014 Areal Flood Advisories in Pennsylvania, 2014 Every 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.