Alert archive / Maryland / Flash Flood Warnings in 2011

Flash Flood Warning 28, NWS Philadelphia/Mount Holly

August 14, 2011Cecil County, Kent County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 14, 2011, 8:41 AM EDT for Cecil County, Kent County, Queen Anne's County, Maryland. It was in force for 4 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 14, 2011, 8:41 AM EDT (12:41 UTC)
Expired
Aug 14, 2011, 12:30 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Cecil County, MD, Kent County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 67 km from the middle of the area, began a volume at 12:44 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.

What was reported inside it

TimeReportWhereRemark
Aug 14, 11:45 AM EDTFLASH FLOODMillington, MDROAD FLOODED AT THE INTERSECTION OF 290 N AND 291.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 0.7 hours before the alert went out and 110 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 12:00Z on 2011-08-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 618 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2011-08-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 square meters per square second.19395878Sfc1 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
618 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
493 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
156 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.5

Open this sounding in Storm Lab

The text

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

677 
WGUS51 KPHI 141241
FFWPHI
MDC015-029-035-141630-
/O.NEW.KPHI.FF.W.0028.110814T1241Z-110814T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
841 AM EDT SUN AUG 14 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CECIL COUNTY...
  KENT COUNTY...
  QUEEN ANNE'S COUNTY...

* UNTIL 1230 PM EDT...

* AT 831 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  AN AREA OF VERY HEAVY RAIN OVER KENT AND QUEEN ANNES COUNTY MOVING  
  VERY SLOWLY NORTHEAST. ANOTHER 2 TO 3 INCHES OF RAIN IS POSSIBLE   
  IN THE LOCATIONS WHERE THE HEAVIEST RAIN HAPPENS TO FALL.          
  ADDITIONAL FLOODING OF ROADWAYS...LOW LYING AREAS AND SMALL        
  STREAMS IS LIKELY WHERE THE HEAVIEST RAIN OCCURS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ELKTON AND
  CENTERVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE TO THE NATIONAL WEATHER
SERVICE BY CALLING TOLL FREE...1-877-633-6772.

&&

LAT...LON 3904 7632 3905 7629 3899 7624 3900 7618
      3903 7625 3914 7628 3935 7616 3944 7600
      3972 7597 3972 7579 3916 7575 3912 7584
      3893 7596 3895 7609 3889 7610 3886 7621
      3894 7624 3890 7624 3893 7628 3884 7638

$$

NIERENBERG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 14, 12:37 AM EDTAreal Flood AdvisoryPHICecil3 hr
Aug 14, 1:12 AM EDTFlash Flood WarningPHICecil4 hr
Aug 14, 1:51 AM EDTAreal Flood AdvisoryPHICaroline, Kent, Queen Anne's, Talbot6 hr
Aug 14, 2:27 AM EDTFlash Flood WarningPHICaroline, Kent, Queen Anne's4 hr
Aug 14, 3:42 AM EDTFlash Flood WatchPHICaroline, Cecil, Kent, Queen Anne's, Talbot25 hr
Aug 14, 5:03 AM EDTFlash Flood WarningPHICecil, Kent, Queen Anne's4 hr
Aug 14, 7:43 AM EDTFlash Flood WarningPHIKent, Queen Anne's4 hr
Aug 14, 12:16 PM EDTAreal Flood WarningPHICecil, Kent4 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.