Alert archive / Pennsylvania / Areal Flood Warnings in 2015

Areal Flood Warning 13, NWS Philadelphia/Mount Holly

March 14, 2015Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood warning at Mar 14, 2015, 12:39 PM EDT for Montgomery County, Pennsylvania. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Mar 14, 2015, 12:39 PM EDT (16:39 UTC)
Expired
Mar 14, 2015, 6:30 PM EDT
In force
6 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 106 km from the middle of the area, began a volume at 16:42 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, 4.7 hours before the alert went out and 227 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 2015-03-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2015-03-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 454 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
524 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
454 m²/s²
0-3 km storm-relative helicity
563 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.

853 
WGUS41 KPHI 141639
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1239 PM EDT SAT MAR 14 2015

PAC091-142230-
/O.NEW.KPHI.FA.W.0013.150314T1639Z-150314T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY PA-
1239 PM EDT SAT MAR 14 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* FLOOD WARNING FOR...
  NORTHWESTERN MONTGOMERY COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 630 PM EDT

* AT 1233 PM EDT...HEAVY RAIN IS CAUSING RISES IN THE PERKIOMEN 
  CREEK IN MONTGOMERY COUNTY. THE PERKIOMEN CREEK AT EAST GREENVILLE 
  IS WITHIN HALF A FOOT OF FLOOD STAGE AND STILL RISING. IT SHOULD 
  REACH FLOOD STAGE BY MID AFTERNOON. 

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...MOLASSES CREEK...
WEST BRANCH PERKIOMEN CREEK...SCHLEGEL RUN...UNAMI CREEK...MACOBY
CREEK...PERKIOMEN CREEK...HOSENSACK CREEK AND STONY RUN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL 
CREEKS AND STREAMS...AS WELL AS FARM AND SOME ROADS. DO NOT ATTEMPT 
TO TRAVEL ACROSS FLOODED ROADS. FIND ALTERNATE ROUTES.

&&

LAT...LON 4044 7553 4038 7543 4032 7549 4037 7559

$$

KLINE
1 follow-up statement
768 
WGUS81 KPHI 142141
FLSPHI

FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
541 PM EDT SAT MAR 14 2015

PAC091-142148-
/O.CAN.KPHI.FA.W.0013.000000T0000Z-150314T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY PA-
541 PM EDT SAT MAR 14 2015

...THE FLOOD WARNING FOR NORTHWESTERN MONTGOMERY COUNTY IS 
CANCELLED...

THE HEAVY RAIN HAS ENDED...PERKIOMEN CREEK HAS CRESTED AND IS 
EXPECTED TO CONTINUE TO FALL. THEREFORE...FLOODING IS NO LONGER 
EXPECTED TO POSE A THREAT.

LAT...LON 4044 7553 4038 7543 4032 7549 4037 7559

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 14, 10:44 AM EDTAreal Flood WarningPHIChester6 hr
Mar 14, 11:12 AM EDTRiver Flood WarningPHIChester18 hr

Nearby

Areal Flood Warnings in Pennsylvania, 2015Every areal flood warning in 2015

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.