Alert archive / Maryland / Flash Flood Warnings in 2009

Flash Flood Warning 61, NWS Philadelphia/Mount Holly

August 28, 2009Caroline County, Talbot County, Maryland; Kent County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 28, 2009, 3:21 PM EDT for Caroline County, Talbot County, Maryland; Kent County, Delaware. 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
Aug 28, 2009, 3:21 PM EDT (19:21 UTC)
Expired
Aug 28, 2009, 9:45 PM EDT
In force
6 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Kent County, DE, Caroline County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 40 km from the middle of the area, began a volume at 19:23 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, 7.4 hours before the alert went out and 118 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 2009-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2064 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 2009-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 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
2064 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
762 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
38 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPHI 281921
FFWPHI
DEC001-MDC011-041-282145-
/O.NEW.KPHI.FF.W.0061.090828T1921Z-090828T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN KENT COUNTY IN CENTRAL DELAWARE...
  CENTRAL CAROLINE COUNTY IN EASTERN MARYLAND...
  NORTHEASTERN TALBOT COUNTY IN EASTERN MARYLAND...
  THIS INCLUDES THE CITY OF EASTON...

* UNTIL 545 PM EDT

* AT 318 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SKIPTON...
  CORDOVA...SANDTOWN...RIDGELY...GREENSBORO AND DENTON

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. 

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 

&&

LAT...LON 3872 7605 3888 7612 3893 7599 3892 7595
      3894 7596 3900 7575 3904 7576 3913 7565
      3888 7564

$$

KRUZDLO
2 follow-up statements
000 
WGUS51 KPHI 282142
FFWPHI
DEC001-MDC011-041-290015-
/O.EXT.KPHI.FF.W.0061.000000T0000Z-090829T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN KENT COUNTY IN CENTRAL DELAWARE...
  CENTRAL CAROLINE COUNTY IN EASTERN MARYLAND...
  NORTHEASTERN TALBOT COUNTY IN EASTERN MARYLAND...

* UNTIL 815 PM EDT

* AT 530 PM EDT...MORE HEAVY RAIN WAS MOVING NORTH NORTHEAST THROUGH 
  DORCHESTER COUNTY. THE RAIN WILL MAKE IT INTO THE WARNED AREA      
  SHORTLY AFTER 600 PM. ANOTHER ONE TO TWO INCHES IS LIKELY IN       
  SPOTS. THE FLASH FLOOD WARNING HAS BEEN EXTENDED.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SANDTOWN...
  RIDGELY AND GREENSBORO

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. 

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 

&&

LAT...LON 3872 7605 3888 7612 3893 7599 3892 7595
      3894 7596 3900 7575 3904 7576 3913 7565
      3888 7564

$$

KRUZDLO
000 
WGUS51 KPHI 290008
FFWPHI
DEC001-MDC011-041-290145-
/O.EXT.KPHI.FF.W.0061.000000T0000Z-090829T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN KENT COUNTY IN CENTRAL DELAWARE...
  CENTRAL CAROLINE COUNTY IN EASTERN MARYLAND...
  NORTHEASTERN TALBOT COUNTY IN EASTERN MARYLAND...

* UNTIL 945 PM EDT

* AT 805 PM EDT...MORE MODERATE TO HEAVY RAIN WAS APPROACHING THE    
  WARNED AREA. THE FLASH FLOOD WARNING HAS BEEN EXTENDED.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SANDTOWN...
  RIDGELY AND GREENSBORO

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. 

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 

&&

LAT...LON 3872 7605 3888 7612 3893 7599 3892 7595
      3894 7596 3900 7575 3904 7576 3913 7565
      3888 7564

$$

KRUZDLO

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 28, 1:40 AM EDTFlash Flood WarningPHICecil5 hr
Aug 28, 2:13 PM EDTFlash Flood WarningPHICecil2 hr
Aug 28, 2:52 PM EDTFlash Flood WatchPHICecil14 hr
Aug 28, 2:53 PM EDTFlash Flood WarningPHICaroline, Kent, Queen Anne's, Talbot6 hr
Aug 28, 6:49 PM EDTAreal Flood AdvisoryPHICaroline, Talbot5 hr
Aug 28, 3:13 PM EDTAreal Flood AdvisoryPHIKent, New Castle4 hr

Nearby

Flash Flood Warnings in Maryland, 2009Flash Flood Warnings in Delaware, 2009Every 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.