Alert archive / Maryland / Flash Flood Warnings in 2009

Flash Flood Warning 57, NWS Philadelphia/Mount Holly

August 28, 2009Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 28, 2009, 1:40 AM EDT for Cecil County, Maryland. It was in force for 5 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 28, 2009, 1:40 AM EDT (05:40 UTC)
Expired: Aug 28, 2009, 6:30 AM EDT
In force: 5 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), 97 km from the middle of the area, began a volume at 05:39 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, 5.7 hours before the alert went out and 135 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: 454 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 1571 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 35 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.

000 
WGUS51 KPHI 280540
FFWPHI
MDC015-280800-
/O.NEW.KPHI.FF.W.0057.090828T0540Z-090828T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
140 AM EDT FRI AUG 28 2009

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 ELKTON...

* UNTIL 400 AM EDT

* AT 135 AM EDT...VERY HEAVY RAIN WAS MOVING INTO SOUTHWEST CECIL
  COUNTY. RADAR INDICATES AS MUCH AS 3 INCHES HAS FALLEN IN AN
  HOUR JUST TO THE WEST OF THE CECIL COUNTY. THE AREA HAS EXPANCDED
  AND IS MOVING TO THE NORTHEAT AT 10 MPH. 

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  OCTORARO...CONOWINGO...WOODLAWN...ROCK SPRINGS...RICHARDSMERE...
  HOLLYWOOD BEACH...WEST NOTTINGHAM...CAYOTS...RISING SUN...
  FARMINGTON...NORTH EAST...ZION...PLEASANT HILL...FAIR HILL...CHERRY
  HILL...CALVERT...BRANTWOOD...BAY VIEW...BARKSDALE...APPLETON AND
  ANDORA

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 3972 7617 3972 7580 3944 7578 3939 7604
      3941 7605 3944 7600 3946 7602 3953 7599
      3955 7603 3954 7607 3962 7616 3965 7617
      3967 7620

$$

EBERWINE

2 follow-up statements

000 
WGUS51 KPHI 280730
FFWPHI
MDC015-281030-
/O.EXT.KPHI.FF.W.0057.000000T0000Z-090828T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
330 AM EDT FRI AUG 28 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS EXTENDED THE

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

* UNTIL 630 AM EDT

* AT 324 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
OVER TWO INCHES OF RAIN HAS FALLEN MAINLY OVER THE LOWER HALF OF THE 
COUNTY IN THE VICINITY OF THE BIG ELK CREEK AND THE BOHEMIA RIVER.
MORE HEAVY RAIN IS GOING TO MOVE INTO THE CECIL COUNTY FROM HARFORD 
COUNTY BEFORE 4 AM AND IT TOO CAN BRING ANOTHER TWO INCHES. THE AREA 
OF HEAVY RAIN MAY ALSO AFFECT THE NORTHERN HALF OF THE COUNTY AS 
WELL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 3972 7617 3972 7580 3944 7578 3939 7604
      3941 7605 3944 7600 3946 7602 3953 7599
      3955 7603 3954 7607 3962 7616 3965 7617
      3967 7620

$$

EBERWINE

000 
WGUS71 KPHI 280914
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
514 AM EDT FRI AUG 28 2009

MDC015-281030-
/O.CON.KPHI.FF.W.0057.000000T0000Z-090828T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CECIL MD-
514 AM EDT FRI AUG 28 2009

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 AM EDT FOR
SOUTHERN CECIL COUNTY...

AT 505 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE THUNDERSTORMS PRODUCING HEAVY RAINS ACROSS THE LOWER HALF 
OF THE COUNTY. AS MUCH AS FOUR INCHES MAY HAVE FALLEN THIS MORNING. 
THE RAIN WILL GRADUALLY TAPER OFF OVER THE NEXT HALF HOUR BUT THERE 
IS STILL A POSSIBILITY OF MORE RAIN BEFORE 7 AM. 

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.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 3956 7608 3957 7600 3957 7595 3957 7591
      3958 7579 3944 7578 3939 7604 3941 7605
      3944 7600 3946 7602 3953 7599 3955 7603
      3954 7607

$$

EBERWINE

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 28, 2:13 PM EDT	Flash Flood Warning	PHI	Cecil	2 hr
Aug 28, 2:52 PM EDT	Flash Flood Watch	PHI	Cecil	14 hr
Aug 28, 2:53 PM EDT	Flash Flood Warning	PHI	Caroline, Kent, Queen Anne's, Talbot	6 hr
Aug 28, 3:21 PM EDT	Flash Flood Warning	PHI	Caroline, Talbot	6 hr
Aug 28, 6:49 PM EDT	Areal Flood Advisory	PHI	Caroline, Talbot	5 hr

Nearby

Flash Flood Warnings in Maryland, 2009 Every flash flood warning in 2009

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.