Alert archive / Maryland / Flash Flood Warnings in 2016

Flash Flood Warning 34, NWS Philadelphia/Mount Holly

August 21, 2016Cecil County, Kent County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 21, 2016, 4:20 PM EDT for Cecil County, Kent County, Queen Anne's County, Maryland. It was in force for 4 hr. 11 reports 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 21, 2016, 4:20 PM EDT (20:20 UTC)
Expired
Aug 21, 2016, 8:15 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 20:22 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 21, 4:30 PM EDTFLOOD1 Ssw Melitota, MDSIX INCHES OF FLOWING WATER AT ROUTE 298 AND NICHOLSON ROAD
Aug 21, 4:41 PM EDTHEAVY RAIN 2.071 Se Betterton, MD
Aug 21, 4:54 PM EDTHEAVY RAIN 1.85Little Neck Farms, MD
Aug 21, 5:15 PM EDTHEAVY RAIN 2.31Prospect Bay, MD
Aug 21, 5:15 PM EDTHEAVY RAIN 3.02The Grove, MD
Aug 21, 5:15 PM EDTHEAVY RAIN 3.1Amberly Trailer Park, MD
Aug 21, 5:15 PM EDTHEAVY RAIN 3.341 Wsw Church Hill, MD
Aug 21, 5:20 PM EDTHEAVY RAIN 2.561 Ene Pleasant Cove, MD
Aug 21, 5:20 PM EDTHEAVY RAIN 2.651 Ene Betterton, MD
Aug 21, 5:30 PM EDTHEAVY RAIN 2.1Centreville, MDONE-HOUR RAINFALL
Aug 21, 7:09 PM EDTHEAVY RAIN 3.01Galena, MD

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, 8.3 hours before the alert went out and 112 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 2016-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 310 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, Washington/Dulle, VA at 12:00Z on 2016-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 square meters per square second.1939Sfc1 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
310 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
719 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
78 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

485 
WGUS51 KPHI 212020
FFWPHI
MDC015-029-035-220015-
/O.NEW.KPHI.FF.W.0034.160821T2020Z-160822T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
420 PM EDT SUN AUG 21 2016

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  KENT COUNTY IN NORTHEASTERN MARYLAND...
  SOUTHEASTERN CECIL COUNTY IN NORTHEASTERN MARYLAND...
  QUEEN ANNE'S COUNTY IN NORTHEASTERN MARYLAND...

* UNTIL 815 PM EDT
    
* AT 418 PM EDT...DOPPLER RADAR AND AUTOMATED RAIN GAUGES INDICATED
  A THUNDERSTORM PRODUCING HEAVY RAIN ACROSS THE WARNED AREA. TWO TO
  THREE INCHES OF RAIN HAVE ALREADY FALLEN. FLASH FLOODING IS
  EXPECTED TO BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CENTERVILLE...CHESTERTOWN...CENTREVILLE...ROCK HALL...
  CHURCH HILL...CECILTON...MILLINGTON...SUDLERSVILLE...BETTERTON...
  OLD TOWN...KENNEDYVILLE...STARR...WARWICK...HOPE...MASSEY...
  GRASONVILLE...MORGNEC...SASSAFRAS...WYE MILLS AND NEWTOWN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

AN ADDITIONAL ONE TO TWO INCHES OF RAINFALL IS POSSIBLE IN THE
WARNED AREA...ESPECIALLY OVER KENT AND QUEEN ANNES COUNTIES...
WHERE A LINE OF STORMS ARE MOVING OVER THE SAME AREAS.

TURN AROUND...DON'T DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

PLEASE REPORT FLOODING TO YOUR LOCAL LAW ENFORCEMENT AGENCY WHEN YOU
CAN DO SO SAFELY.

&&

LAT...LON 3929 7617 3932 7618 3942 7600 3947 7599
      3948 7578 3914 7575 3911 7584 3904 7588
      3888 7620 3891 7625 3891 7621 3895 7621
      3892 7626 3896 7624 3898 7627 3897 7622
      3900 7617 3902 7624 3909 7623 3915 7628

$$

JRK
1 follow-up statement
469 
WGUS71 KPHI 212143
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
543 PM EDT SUN AUG 21 2016

MDC015-029-035-220015-
/O.CON.KPHI.FF.W.0034.000000T0000Z-160822T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KENT MD-CECIL MD-QUEEN ANNE'S MD-
543 PM EDT SUN AUG 21 2016

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM EDT FOR
KENT...SOUTHEASTERN CECIL AND QUEEN ANNE'S COUNTIES...

AT 531 PM EDT...EMERGENCY MANAGEMENT REPORTED HIGH WATER ACROSS
NUMEROUS ROADS IN KENT AND QUEENE ANNE'S COUNTIES DUE TO HEAVY
RAINFALL FROM THUNDERSTORMS. DOPPLER RADAR AND AUTOMATED RAIN GAUGES
INDICATED OVER THREE INCHES OF RAIN HAS FALLEN NEAR THE KENT AND
QUEENE ANNE'S COUNTY BORDER. AN AUTOMATED RAIN GAUGE IN ROCK HALL
RECORDED FIVE AND HALF INCHES OF RAIN. 

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
CENTERVILLE...CHESTERTOWN...CENTREVILLE...ROCK HALL...CHURCH HILL...
CECILTON...MILLINGTON...SUDLERSVILLE...BETTERTON...OLD TOWN...
KENNEDYVILLE...STARR...WARWICK...HOPE...MASSEY...GRASONVILLE...
MORGNEC...SASSAFRAS...WYE MILLS AND NEWTOWN.

LIGHT TO MODERATE RAIN WILL CONTINUE EARLY THIS EVENING BUT THE
HEAVY THUNDERSTORMS HAVE EXITED THE AREA. ADDITIONAL RAINFALL
AMOUNTS OF LESS THAN ONE-HALF INCH ARE POSSIBLE IN THE WARNED AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TURN AROUND...DON'T DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

PLEASE REPORT FLOODING TO YOUR LOCAL LAW ENFORCEMENT AGENCY WHEN YOU
CAN DO SO SAFELY.

WE WILL UPDATE THIS STATEMENT AS WE GET ADDITIONAL REPORTS OF
HIGH WATER AND CONFIRMATION OF FLASH FLOODING.

&&

LAT...LON 3929 7617 3932 7618 3942 7600 3947 7599
      3948 7578 3914 7575 3911 7584 3904 7588
      3888 7620 3891 7625 3891 7621 3895 7621
      3892 7626 3896 7624 3898 7627 3897 7622
      3900 7617 3902 7624 3909 7623 3915 7628

$$

JRK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 2:38 PM EDTSpecial Weather StatementPHICecil22 min
Aug 21, 2:51 PM EDTAreal Flood AdvisoryPHICecil114 min
Aug 21, 2:57 PM EDTSpecial Weather StatementPHIKent, Queen Anne's33 min
Aug 21, 3:30 PM EDTAreal Flood AdvisoryPHICaroline, Cecil, Kent, Queen Anne's2 hr
Aug 21, 3:40 PM EDTSpecial Weather StatementPHITalbot50 min
Aug 21, 3:50 PM EDTSpecial Weather StatementPHIKent25 min
Aug 21, 4:06 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's39 min
Aug 21, 4:19 PM EDTSpecial Weather StatementPHITalbot26 min
Aug 21, 4:29 PM EDTSpecial Weather StatementPHICaroline31 min
Aug 21, 4:50 PM EDTAreal Flood AdvisoryPHICaroline, Queen Anne's, Talbot3 hr
Aug 21, 4:54 PM EDTSpecial Weather StatementPHICaroline36 min
Aug 21, 5:06 PM EDTSevere Thunderstorm WarningPHICaroline39 min
Aug 21, 5:09 PM EDTFlash Flood WarningPHICaroline, Queen Anne's, Talbot4 hr
Aug 21, 6:35 PM EDTAreal Flood AdvisoryPHICaroline, Queen Anne's, Talbot3 hr

Nearby

Flash Flood Warnings in Maryland, 2016Every flash flood warning in 2016

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.