Alert archive / Pennsylvania / Areal Flood Advisories in 2014

Areal Flood Advisory 252, NWS Philadelphia/Mount Holly

March 30, 20144 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood advisory at Mar 30, 2014, 5:10 PM EDT for 4 counties in Pennsylvania. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Mar 30, 2014, 5:10 PM EDT (21:10 UTC)
Expired
Mar 30, 2014, 9:00 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 115 km from the middle of the area, began a volume at 21:09 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 9.2 hours before the alert went out and 223 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, Wallops Is Stn, VA at 12:00Z on 2014-03-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 100 joules per kilogram.LCLLFCEL10008507005003002001001 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, Wallops Is Stn, VA at 12:00Z on 2014-03-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -34 square meters per square second.1939587897117Sfc1 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
100 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
489 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
-34 m²/s²
0-3 km storm-relative helicity
-31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

612 
WGUS81 KPHI 302110
FLSPHI

FLOOD ADVISORY
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
510 PM EDT SUN MAR 30 2014

PAC029-045-091-101-310100-
/O.NEW.KPHI.FA.Y.0252.140330T2110Z-140331T0100Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY PA-PHILADELPHIA PA-DELAWARE PA-CHESTER PA-
510 PM EDT SUN MAR 30 2014

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED AN

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR...
  MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  WEST CENTRAL PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 900 PM EDT

* AT 507 PM EDT METEOROLOGISTS WERE MONITORING AN AREA OF MODERATE   
  TO HEAVY RAIN IN SOUTHEASTERN PENNSYLVANIA. THIS RAIN WAS          
  SPREADING WEST. WITH THE HEAVY RAIN YESTERDAY AND LAST             
  NIGHT...THE GROUND IS NEARLY SATURATED AND ANY ADDITIONAL RAINFALL 
  WILL QUICKLY BECOME RUNOFF AND COULD LEAD TO PONDING IN POOR       
  DRAINAGE AREAS INCLUDING URBAN LOCATIONS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLOOD ADVISORY MEANS RIVER OR STREAM FLOWS ARE ELEVATED OR PONDING
OF WATER IN URBAN OR OTHER AREAS IS OCCURRING OR IS IMMINENT.

&&

LAT...LON 3987 7601 3988 7599 3990 7600 4014 7588
      4035 7541 4007 7505 3984 7549 3984 7564
      3978 7573 3973 7577 3973 7608

$$

SFJ
2 follow-up statements
893 
WGUS81 KPHI 302336
FLSPHI

FLOOD ADVISORY
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
736 PM EDT SUN MAR 30 2014

PAC029-045-091-101-310100-
/O.CON.KPHI.FA.Y.0252.000000T0000Z-140331T0100Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY PA-PHILADELPHIA PA-DELAWARE PA-CHESTER PA-
736 PM EDT SUN MAR 30 2014

...THE URBAN AND SMALL STREAM FLOOD ADVISORY REMAINS IN EFFECT UNTIL
900 PM EDT FOR CHESTER...DELAWARE...CENTRAL PHILADELPHIA AND
MONTGOMERY COUNTIES...

AT 734 PM EDT LIGHT TO MODERATE RAIN WAS CONTINUING TO MOVE INTO THE 
ADVISORY AREA. WITH THE HEAVY RAIN YESTERDAY AND LAST               
NIGHT...THE GROUND IS NEARLY SATURATED AND ANY ADDITIONAL RAINFALL   
WILL QUICKLY BECOME RUNOFF AND COULD LEAD TO PONDING IN POOR         
DRAINAGE AREAS INCLUDING URBAN LOCATIONS. IN ADDITION...SMALL 
STREAMS AND CREEKS COULD BE VERY NEAR BANKFULL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLOOD ADVISORY MEANS RIVER OR STREAM FLOWS ARE ELEVATED OR PONDING
OF WATER IN URBAN OR OTHER AREAS IS OCCURRING OR IS IMMINENT.

&&

LAT...LON 3987 7601 3988 7599 3990 7600 4014 7588
      4035 7541 4007 7505 3984 7549 3984 7564
      3978 7573 3973 7577 3973 7608

$$

SFJ
902 
WGUS81 KPHI 310052
FLSPHI

FLOOD ADVISORY
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
852 PM EDT SUN MAR 30 2014

PAC029-045-091-101-310102-
/O.EXP.KPHI.FA.Y.0252.000000T0000Z-140331T0100Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY PA-PHILADELPHIA PA-DELAWARE PA-CHESTER PA-
852 PM EDT SUN MAR 30 2014

...THE URBAN AND SMALL STREAM FLOOD ADVISORY WILL EXPIRE AT 900 PM
EDT FOR CHESTER...DELAWARE...CENTRAL PHILADELPHIA AND MONTGOMERY
COUNTIES...

RAIN HAS MOSTLY MOVED OUT OF THE ADVISORY AREA...SO THE ADVISORY 
WILL BE ALLOWED TO EXPIRE AT 9 PM EDT.

LAT...LON 3987 7601 3988 7599 3990 7600 4014 7588
      4035 7541 4007 7505 3984 7549 3984 7564
      3978 7573 3973 7577 3973 7608

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 29, 10:07 PM EDTAreal Flood AdvisoryPHIBucks, Montgomery, Philadelphia4 hr
Mar 29, 10:12 PM EDTAreal Flood AdvisoryPHIMonroe, Northampton4 hr
Mar 30, 3:50 AM EDTWinter Weather AdvisoryPHIBerks, Bucks, Carbon, Chester, Lehigh, Monroe and 2 more24 hr
Mar 30, 3:29 PM EDTAreal Flood AdvisoryPHIDelaware, Philadelphia4 hr

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.