Alert archive / Pennsylvania / Flash Flood Watches in 2014

Flash Flood Watch 3, NWS Philadelphia/Mount Holly

June 12, 20144 states

NWS Philadelphia/Mount Holly issued this flash flood watch at Jun 12, 2014, 3:56 AM EDT for 4 states. It took effect at Jun 12, 2014, 12:00 PM EDT. It was in force for 12 hr.

The area

The counties it named.

The facts

Issued
Jun 12, 2014, 3:56 AM EDT (07:56 UTC)
In effect from
Jun 12, 2014, 12:00 PM EDT
Expired
Jun 12, 2014, 11:46 PM EDT
In force
12 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None

Counties New Castle County, DE, Cecil County, MD, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 82 km from the middle of the area, began a volume at 07:52 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 00:00Z, 7.9 hours before the alert went out and 207 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 00:00Z on 2014-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1187 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, Washington/Dulle, VA at 00:00Z on 2014-06-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 97 square meters per square second.193958Sfc1 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
1187 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
698 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
186 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.5

Open this sounding in Storm Lab

The text

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

561 
WGUS61 KPHI 120756
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
356 AM EDT THU JUN 12 2014


DEZ001-MDZ008-NJZ017>019-PAZ060-070-071-101>104-106-122000-
/O.NEW.KPHI.FF.A.0003.140612T1600Z-140613T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-CECIL-GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-BERKS-
DELAWARE-PHILADELPHIA-WESTERN CHESTER-EASTERN CHESTER-
WESTERN MONTGOMERY-EASTERN MONTGOMERY-LOWER BUCKS-
INCLUDING THE CITIES OF...WILMINGTON...ELKTON...GLASSBORO...
CAMDEN...CHERRY HILL...MOORESTOWN...MOUNT HOLLY...READING...
MEDIA...PHILADELPHIA...HONEY BROOK...OXFORD...WEST CHESTER...
KENNETT SQUARE...COLLEGEVILLE...POTTSTOWN...NORRISTOWN...
LANSDALE...MORRISVILLE...DOYLESTOWN
356 AM EDT THU JUN 12 2014

...FLASH FLOOD WATCH IN EFFECT FROM NOON EDT TODAY THROUGH LATE
TONIGHT...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF NORTHERN DELAWARE... 
  NORTHEAST MARYLAND...SOUTHERN NEW JERSEY AND PENNSYLVANIA... 
  INCLUDING THE FOLLOWING AREAS...IN NORTHERN DELAWARE...NEW 
  CASTLE. IN NORTHEAST MARYLAND...CECIL. IN SOUTHERN NEW 
  JERSEY...CAMDEN...GLOUCESTER AND NORTHWESTERN BURLINGTON. IN 
  PENNSYLVANIA...BERKS...DELAWARE...EASTERN CHESTER...EASTERN 
  MONTGOMERY...LOWER BUCKS...PHILADELPHIA...WESTERN CHESTER AND 
  WESTERN MONTGOMERY. 

* FROM NOON EDT TODAY THROUGH LATE TONIGHT

* HEAVY RAIN WILL BE POSSIBLE WITH ANY THUNDERSTORMS THAT DEVELOP
  TODAY AND TONIGHT. RAIN RATES OF 1 INCH PER HOUR WILL BE
  POSSIBLE IN THE STRONGER STORMS. THIS COULD LEAD TO FLASH
  FLOODING ESPECIALLY IN URBAN AND POOR DRAINAGE AREAS.

* THE AFTERNOON COMMUTE TODAY COULD BE IMPACTED BY HEAVY RAIN AND
  FLASH FLOODING IN SOME LOCATIONS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$

JOHNSON
2 follow-up statements
683 
WGUS61 KPHI 121904
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
304 PM EDT THU JUN 12 2014

DEZ001-MDZ008-NJZ017>019-PAZ060-070-071-101>104-106-130600-
/O.CON.KPHI.FF.A.0003.000000T0000Z-140613T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-CECIL-GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-BERKS-
DELAWARE-PHILADELPHIA-WESTERN CHESTER-EASTERN CHESTER-
WESTERN MONTGOMERY-EASTERN MONTGOMERY-LOWER BUCKS-
INCLUDING THE CITIES OF...WILMINGTON...ELKTON...GLASSBORO...
CAMDEN...CHERRY HILL...MOORESTOWN...MOUNT HOLLY...READING...
MEDIA...PHILADELPHIA...HONEY BROOK...OXFORD...WEST CHESTER...
KENNETT SQUARE...COLLEGEVILLE...POTTSTOWN...NORRISTOWN...
LANSDALE...MORRISVILLE...DOYLESTOWN
304 PM EDT THU JUN 12 2014

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 2 AM EDT FRIDAY...

THE FLASH FLOOD WATCH CONTINUES FOR

* PORTIONS OF NORTHERN DELAWARE...NORTHEAST MARYLAND...SOUTHERN 
  NEW JERSEY AND PENNSYLVANIA...INCLUDING THE FOLLOWING AREAS... 
  IN NORTHERN DELAWARE...NEW CASTLE. IN NORTHEAST MARYLAND... 
  CECIL. IN SOUTHERN NEW JERSEY...CAMDEN...GLOUCESTER AND 
  NORTHWESTERN BURLINGTON. IN PENNSYLVANIA...BERKS...DELAWARE... 
  EASTERN CHESTER...EASTERN MONTGOMERY...LOWER BUCKS... 
  PHILADELPHIA...WESTERN CHESTER AND WESTERN MONTGOMERY. 

* UNTIL 2 AM EDT FRIDAY

* BANDS OF HEAVY SHOWERS WITH ISOLATED EMBEDDED THUNDERSTORMS WILL
  BE MOVING VERY SLOWLY NORTHWARD THROUGH THE WATCH AREA THIS
  EVENING. HEAVY RAINS FROM EARLIER THIS WEEK HAVE LEFT PORTIONS
  OF THE DELAWARE VALLEY VULNERABLE TO FLOODING. RAINFALL OF 1.5
  INCHES IN AN HOUR WOULD PROBABLY RESULT IN POCKETS OF FLASH
  FLOODING.

* THERE IS CONSIDERABLE UNCERTAINTY WHETHER EXCESSIVE RAIN OCCURS
  TONIGHT AND WHERE. HOWEVER...IT DOES LOOK LIKE THE HEAVIEST RAIN WILL
  OCCUR AFTER DARK.

* BE ALERT FOR POCKETS OF POOR DRAINAGE FLOODING DURING THE EVENING
  COMMUTE. IF HEAVY RAIN DOES OCCUR...DO NOT DRIVE THROUGH FLOODED
  ROADS...ESPECIALLY AT NIGHT.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$


DRAG
744 
WGUS61 KPHI 130346
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1146 PM EDT THU JUN 12 2014


DEZ001-MDZ008-NJZ017>019-PAZ060-070-071-101>104-106-130500-
/O.CAN.KPHI.FF.A.0003.000000T0000Z-140613T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-CECIL-GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-BERKS-
DELAWARE-PHILADELPHIA-WESTERN CHESTER-EASTERN CHESTER-
WESTERN MONTGOMERY-EASTERN MONTGOMERY-LOWER BUCKS-
INCLUDING THE CITIES OF...WILMINGTON...ELKTON...GLASSBORO...
CAMDEN...CHERRY HILL...MOORESTOWN...MOUNT HOLLY...READING...
MEDIA...PHILADELPHIA...HONEY BROOK...OXFORD...WEST CHESTER...
KENNETT SQUARE...COLLEGEVILLE...POTTSTOWN...NORRISTOWN...
LANSDALE...MORRISVILLE...DOYLESTOWN
1146 PM EDT THU JUN 12 2014

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR PORTIONS OF NORTHERN DELAWARE...
NORTHEAST MARYLAND...SOUTHERN NEW JERSEY AND PENNSYLVANIA HAS
BEEN CANCELLED. WE ARE CURRENTLY EXPERIENCING A LULL IN THE
SHOWER ACTIVITY...THUS THE WATCH WAS CANCELLED. HOWEVER...MORE
SHOWERS AND THUNDERSTORMS ARE POSSIBLE FRIDAY.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 12, 5:30 PM EDTCoastal Flood AdvisoryPHICape May, Cumberland7 hr
Jun 12, 6:33 PM EDTAreal Flood AdvisoryPHIChester4 hr
Jun 12, 2:07 AM EDTSpecial Weather StatementPHIKent53 min
Jun 12, 12:54 AM EDTSpecial Weather StatementPHICaroline66 min
Jun 12, 1:44 AM EDTAreal Flood AdvisoryPHICaroline, Talbot4 hr
Jun 12, 12:31 PM EDTAreal Flood AdvisoryPHITalbot6 hr
Jun 12, 2:20 PM EDTAreal Flood AdvisoryPHIKent, Queen Anne's4 hr

Nearby

Flash Flood Watches in Pennsylvania, 2014Flash Flood Watches in New Jersey, 2014Flash Flood Watches in Delaware, 2014Every flash flood watch 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.