Alert archive / Maryland / Flash Flood Warnings in 2011
Flash Flood Warning 37, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 21, 2011, 4:45 PM EDT for Kent County, Maryland. It was in force for 3 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 21, 2011, 4:45 PM EDT (20:45 UTC)
- Expired
- Aug 21, 2011, 7:45 PM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
County Kent County, MD
The radar
The Dover AFB radar (KDOX), 77 km from the middle of the area, began a volume at 20:46 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 12:00Z, 8.8 hours before the alert went out and 105 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.
- Mixed-layer CAPE
- 1589 J/kg
- Mixed-layer CIN
- -99 J/kg
- Mixed-layer LCL
- 969 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 131 m²/s²
- 0-3 km storm-relative helicity
- 125 m²/s²
- Significant tornado parameter
- 0.6
- Supercell composite
- 4.9
The text
As transmitted, in the capitals the NWS used until 2016.
396
WGUS51 KPHI 212045
FFWPHI
MDC029-212345-
/O.NEW.KPHI.FF.W.0037.110821T2045Z-110821T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
445 PM EDT SUN AUG 21 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* FLASH FLOOD WARNING FOR...
SOUTHWESTERN KENT COUNTY...
* UNTIL 745 PM EDT...
* AT 441 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
FLASH FLOODING FROM PERSISTENT THUNDERSTORMS OVER SOUTHWESTERN
KENT COUNTY. STATE POLICE REPORTED FLOODING ON SOME ROADS AND ROAD
CLOSURES.
* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ROCK
HALL...AS WELL AS RURAL AREAS OF SOUTHWESTERN KENT COUNTY.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE TO THE NATIONAL WEATHER
SERVICE BY CALLING TOLL FREE...1-877-633-6772.
FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS
OCCUR IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED
BRIDGES...DIPS...OR LOW WATER CROSSINGS. TURN AROUND...DON'T DROWN!
NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO
ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.
&&
LAT...LON 3922 7624 3925 7616 3920 7610 3908 7617
3909 7624 3914 7626 3915 7628 3916 7628
$$The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 3:28 AM EDT | Flash Flood Watch | PHI | Cecil, Kent | 17 hr |
| Aug 21, 8:01 AM EDT | Special Weather Statement | PHI | Cecil, Kent | 59 min |
| Aug 21, 9:08 AM EDT | Special Weather Statement | PHI | Cecil, Kent | 52 min |
| Aug 21, 9:36 AM EDT | Areal Flood Advisory | PHI | Cecil, Kent, Queen Anne's | 2 hr |
| Aug 21, 2:01 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 59 min |
| Aug 21, 2:43 PM EDT | Areal Flood Advisory | PHI | Cecil, Kent, Queen Anne's | 3 hr |
| Aug 21, 2:55 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's, Talbot | 65 min |
| Aug 21, 3:11 PM EDT | Areal Flood Advisory | PHI | Kent, Queen Anne's | 2 hr |
| Aug 21, 4:03 PM EDT | Special Weather Statement | PHI | Caroline, Kent, Queen Anne's, Talbot | 57 min |
| Aug 21, 5:09 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 37 min |
| Aug 21, 5:20 PM EDT | Areal Flood Advisory | PHI | Caroline, Queen Anne's, Talbot | 115 min |
| Aug 21, 7:17 PM EDT | Areal Flood Advisory | PHI | Caroline | 118 min |
Nearby
Flash Flood Warnings in Maryland, 2011Every flash flood warning in 2011
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.