Alert archive / Maryland / Flash Flood Warnings in 2014

Flash Flood Warning 51, NWS Philadelphia/Mount Holly

August 12, 2014Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 12, 2014, 9:37 PM EDT for Cecil County, Maryland. It was in force for 4 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: Aug 12, 2014, 9:37 PM EDT (01:37 UTC)
Expired: Aug 13, 2014, 1:30 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Cecil County, MD

The radar

The Dover AFB radar (KDOX), 84 km from the middle of the area, began a volume at 01:39 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, 1.6 hours before the alert went out and 137 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: 571 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 726 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 134 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

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

674 
WGUS51 KPHI 130137
FFWPHI
MDC015-130530-
/O.NEW.KPHI.FF.W.0051.140813T0137Z-140813T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
937 PM EDT TUE AUG 12 2014

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CECIL COUNTY IN NORTHEAST MARYLAND...
  THIS INCLUDES THE CITY OF NORTHEAST...

* UNTIL 130 AM EDT

* AT 930 PM EDT...DOPPLER RADAR INDICATED AREAS OF MODERATE TO HEAVY 
RAIN CONTINUED ACROSS CECIL COUNTY.  RADAR ESTIMATES 3 TO 4 INCHES 
OF RAIN HAS FALLEN ACROSS PORTIONS OF CECIL COUNTY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO BOHEMIAS
  MILLS...ZION...PLEASANT HILL...NORTH EAST...LOMBARD...HOLLYWOOD
  BEACH...GLEN WESTOVER...FAIR HILL...ELKTON...CHERRY HILL...
  CHARLESTOWN...CAYOTS...BRANTWOOD...BLAKE...BAY VIEW...BARKSDALE...
  APPLETON AND ANDORA

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 1/2 TO 1 INCH ARE POSSIBLE IN THE WARNED 
AREA.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF 
ROADWAYS, STREAMS, CREEKS AND POOR DRAINAGE AREAS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

&&

LAT...LON 3938 7605 3944 7600 3946 7602 3947 7600
      3952 7599 3954 7601 3972 7597 3972 7579
      3938 7577 3938 7582 3936 7589 3938 7597
      3937 7598

$$

NIERENBERG

1 follow-up statement

645 
WGUS71 KPHI 130329
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1129 PM EDT TUE AUG 12 2014

MDC015-130339-
/O.CAN.KPHI.FF.W.0051.000000T0000Z-140813T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CECIL MD-
1129 PM EDT TUE AUG 12 2014

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CECIL COUNTY...

THE HEAVY RAINFALL HAS EXITED THE AREA. FLOODING IS NO LONGER 
EXPECTED.

LAT...LON 3938 7605 3944 7600 3946 7602 3947 7600
      3952 7599 3954 7601 3972 7597 3972 7579
      3938 7577 3938 7582 3936 7589 3938 7597
      3937 7598

$$

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 13, 12:40 AM EDT	Areal Flood Warning	PHI	Kent, Queen Anne's	6 hr

Nearby

Flash Flood Warnings in Maryland, 2014 Every flash flood warning 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.