Alert archive / Maryland / Flash Flood Warnings in 2017

Flash Flood Warning 9, NWS Philadelphia/Mount Holly

July 6, 2017Cecil County, Maryland; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 6, 2017, 3:35 PM EDT for Cecil County, Maryland; New Castle County, Delaware. It was in force for 4 hr. 12 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: Jul 6, 2017, 3:35 PM EDT (19:35 UTC)
Expired: Jul 6, 2017, 7:30 PM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties New Castle County, DE, Cecil County, MD

The radar

The Dover AFB radar (KDOX), 74 km from the middle of the area, began a volume at 19:37 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 6, 3:40 PM EDT	FLASH FLOOD	Townsend, DE	A DAYCARE WAS FLOODED DUE TO HIGH WATER. SEVERAL VECHICLES STUCK IN HIGH WATER.
Jul 6, 3:40 PM EDT	FLASH FLOOD	Townsend, DE	A DAYCARE WAS FLOODED DUE TO HIGH WATER. SEVERAL VECHILCES STUCK IN HIGH WATER.
Jul 6, 3:40 PM EDT	FLASH FLOOD	Townsend, DE	A DAYCARE WAS FLOODED DUE TO HIGH WATER. SEVERAL VEHICLES STUCK IN HIGH WATER.
Jul 6, 5:00 PM EDT	FLOOD	Middletown, DE	PATRIOT DRIVE FLOODED
Jul 6, 5:00 PM EDT	FLASH FLOOD	Townsend, DE	FLASH FLOODING ON WIGGINS MILL RD NEAR WIGGINS MILL POND
Jul 6, 5:03 PM EDT	HEAVY RAIN 5.78	Warwick, MD	RAINFALL RATES OF 4 INCHES PER HOUR.
Jul 6, 5:04 PM EDT	HEAVY RAIN 5.2	Middletown, DE
Jul 6, 5:32 PM EDT	FLOOD	1 Se Middletown, DE	FLOODING AT INTERSECTION OF 299 AND 301 AT HOOBERS INC.
Jul 6, 5:35 PM EDT	FLOOD	Townsend, DE	SEVERAL FIELDS IN LOW-LYING AREAS FLOODED.
Jul 6, 6:00 PM EDT	FLOOD	1 Sw Townsend, DE	DEXTER CORNER ROAD... AND LEVELS ROAD FLOODED.
Jul 6, 6:40 PM EDT	FLOOD	2 E Sassafras, DE	CALDWELL CORNER ROAD FLOODED.
Jul 6, 7:00 PM EDT	FLOOD	2 Nw Vandyke, DE	TOP ROAD OF GREEN GIANT ROAD AT THE MARYLAND LINE ROAD WASHED OUT. TIME ESTIMATED

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, 7.6 hours before the alert went out and 153 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: 227 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 468 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 33 m²/s²
0-3 km storm-relative helicity: 37 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

286 
WGUS51 KPHI 061935
FFWPHI
DEC003-MDC015-062330-
/O.NEW.KPHI.FF.W.0009.170706T1935Z-170706T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
335 PM EDT THU JUL 6 2017

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Southwestern New Castle County in northern Delaware...
  East central Cecil County in northeastern Maryland...

* Until 730 PM EDT

* At 333 PM EDT...Doppler radar indicated heavy rain across the 
  warned area. Rainfall is falling at the rate of up to two inches 
  per hour across the area. The excessive rains are moving 
  northward very slowly. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Middletown, Warwick, Mount Pleasant, Bohemias Mills, Townsend,
  Chesapeake City and Odessa.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 3954 7582 3954 7568 3934 7561 3935 7576
      3938 7578

$$

PO

1 follow-up statement

456 
WGUS71 KPHI 062052
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
452 PM EDT THU JUL 6 2017

DEC003-MDC015-062330-
/O.CON.KPHI.FF.W.0009.000000T0000Z-170706T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Cecil MD-
452 PM EDT THU JUL 6 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM EDT FOR
SOUTHWESTERN NEW CASTLE AND EAST CENTRAL CECIL COUNTIES...

At 448 PM EDT...Doppler radar indicated rainfall rates were on the 
decrease in southwestern New Castle County and southeastern Cecil 
County. However, over 5 inches of rain has already been reported in 
Middletown, Delaware and in Warwick, Maryland. Widespread flooding 
is occurring in the area, especially around Townsend, Delaware.

Some locations that will continue to experience flooding include... 
Middletown, Warwick, Mount Pleasant, Bohemias Mills, Townsend, 
Chesapeake City and Odessa.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

&&

LAT...LON 3954 7582 3954 7568 3934 7561 3935 7576
      3938 7578

$$

Iovino

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 6, 4:04 PM EDT	Areal Flood Advisory	PHI	Cecil	4 hr
Jul 6, 4:08 PM EDT	Special Weather Statement	PHI	Kent	67 min
Jul 6, 4:16 PM EDT	Flash Flood Watch	PHI	Cecil, Kent	3 hr
Jul 6, 4:17 PM EDT	Areal Flood Advisory	PHI	Kent	3 hr
Jul 6, 5:39 PM EDT	Special Weather Statement	PHI	Kent	66 min
Jul 6, 6:15 PM EDT	Areal Flood Advisory	PHI	Kent, Queen Anne's	3 hr
Jul 6, 7:36 PM EDT	Areal Flood Warning	PHI	Cecil, Kent	10 hr
Jul 6, 2:41 PM EDT	Special Weather Statement	PHI	New Castle	64 min
Jul 6, 3:01 PM EDT	Areal Flood Advisory	PHI	New Castle	119 min

Nearby

Flash Flood Warnings in Maryland, 2017 Flash Flood Warnings in Delaware, 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.