Alert archive / Maryland / Flash Flood Warnings in 2017

Flash Flood Warning 23, NWS Philadelphia/Mount Holly

July 23, 2017Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 23, 2017, 6:26 PM EDT for Cecil 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: Jul 23, 2017, 6:26 PM EDT (22:26 UTC)
Expired: Jul 23, 2017, 10:30 PM EDT
In force: 4 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), 102 km from the middle of the area, began a volume at 22:29 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

Time	Report	Where	Remark
Jul 23, 7:30 PM EDT	FLOOD	Concord, MD	BROAD ST NEAR MARC TRAIN STATION IMPASSABLE DUE TO HIGH WATERS

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, 10.4 hours before the alert went out and 137 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: 186 J/kg
Mixed-layer CIN: -43 J/kg
Mixed-layer LCL: 983 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 31 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

870 
WGUS51 KPHI 232226
FFWPHI
MDC015-240230-
/O.NEW.KPHI.FF.W.0023.170723T2226Z-170724T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
626 PM EDT SUN JUL 23 2017

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Cecil County in northeastern Maryland...

* Until 1030 PM EDT

* At 623 PM EDT...Doppler radar indicated thunderstorms producing 
  heavy rain moving into Cecil County from the west. Up to two 
  inches of rain have already fallen around Perryville. Flash 
  flooding is expected to begin shortly in the areas of heaviest 
  rain.

* Some locations that could experience flooding include...
  Elkton, Calvert, North East, Rising Sun, Charlestown, Zion, Blake,
  Barksdale, West Nottingham, Octoraro, Brantwood, Fair Hill, Glen
  Westover, Bay View, Lombard, Richardsmere, Woodlawn, Andora,
  Pleasant Hill and Cherry Hill.

Additional rainfall amounts of 2 to 4 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flood waters. The water may be deeper than you 
think it is. A vehicle can easily become trapped in flood waters 
endangering its occupants and those who come to their rescue.

If you live in a flood prone location be prepared to move to higher 
ground.

&&

LAT...LON 3972 7623 3972 7579 3948 7578 3948 7600
      3952 7598 3955 7603 3955 7608 3965 7616
      3968 7621

$$

Iovino

2 follow-up statements

581 
WGUS71 KPHI 232313
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
713 PM EDT SUN JUL 23 2017

MDC015-240230-
/O.CON.KPHI.FF.W.0023.000000T0000Z-170724T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cecil MD-
713 PM EDT SUN JUL 23 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT FOR
CECIL COUNTY...

At 709 PM EDT...Doppler radar indicated thunderstorms producing 
heavy rain in Cecil County, especially in the northwestern part of 
the county. Rainfall totals of 2 to 3 inches have already fallen 
around Perryville. Flash flooding is expected in the areas of 
heaviest rainfall. 

Some locations that could experience flooding include...
Elkton, Calvert, North East, Rising Sun, Charlestown, Zion, Blake,
Barksdale, West Nottingham, Octoraro, Brantwood, Fair Hill, Glen
Westover, Bay View, Lombard, Richardsmere, Woodlawn, Andora, Pleasant
Hill and Cherry Hill.

Additional rainfall amounts of 1 to 2 inches in a short amount of 
time are possible in the warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flood waters. The water may be deeper than you 
think it is. A vehicle can easily become trapped in flood waters 
endangering its occupants and those who come to their rescue.

If you live in a flood prone location be prepared to move to higher 
ground.

&&

LAT...LON 3972 7623 3972 7579 3948 7578 3948 7600
      3952 7598 3955 7603 3955 7608 3965 7616
      3968 7621

$$

Iovino

822 
WGUS71 KPHI 240130
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
930 PM EDT SUN JUL 23 2017

MDC015-240138-
/O.CAN.KPHI.FF.W.0023.000000T0000Z-170724T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cecil MD-
930 PM EDT SUN JUL 23 2017

...THE FLASH FLOOD WARNING FOR CECIL COUNTY IS CANCELLED...

The heavy rain and rapid rises in area creeks and streams have 
subsided. 

A Flood Warning is in effect for western portions of Cecil County as 
flood waters have yet to recede. Please continue to heed any 
remaining road closures.

LAT...LON 3972 7623 3972 7579 3948 7578 3948 7600
      3952 7598 3955 7603 3955 7608 3965 7616
      3968 7621

$$

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 10:18 PM EDT	Special Weather Statement	PHI	Caroline, Talbot	72 min
Jul 22, 11:26 PM EDT	Areal Flood Advisory	PHI	Caroline, Queen Anne's, Talbot	4 hr
Jul 23, 2:38 PM EDT	Special Weather Statement	PHI	Caroline, Kent, Queen Anne's, Talbot	67 min
Jul 23, 2:47 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	43 min
Jul 23, 2:53 PM EDT	Special Weather Statement	PHI	Cecil	52 min
Jul 23, 3:16 PM EDT	Flash Flood Watch	PHI	Cecil	15 hr
Jul 23, 3:27 PM EDT	Special Weather Statement	PHI	Cecil	33 min
Jul 23, 3:31 PM EDT	Special Weather Statement	PHI	Dorchester	44 min
Jul 23, 3:53 PM EDT	Areal Flood Advisory	PHI	Cecil, Kent	4 hr
Jul 23, 4:26 PM EDT	Areal Flood Advisory	PHI	Cecil	3 hr
Jul 23, 5:40 PM EDT	Areal Flood Advisory	PHI	Cecil	4 hr
Jul 23, 5:47 PM EDT	Special Weather Statement	PHI	Cecil	28 min
Jul 23, 6:22 PM EDT	Special Weather Statement	PHI	Cecil	38 min

Nearby

Flash Flood Warnings in Maryland, 2017 Every flash flood warning in 2017

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.