Alert archive / Delaware / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 34, NWS Philadelphia/Mount Holly

May 25, 2017Kent County, New Castle County, Delaware; Cumberland County, Salem County, New Jersey; Cecil County, Kent County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 25, 2017, 7:56 PM EDT for Kent County, New Castle County, Delaware; Cumberland County, Salem County, New Jersey; Cecil County, Kent County, Maryland. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 25, 2017, 7:56 PM EDT (23:56 UTC)
Expired
May 25, 2017, 8:45 PM EDT
In force
49 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Kent County, DE, New Castle County, DE, Cecil County, MD, Kent County, MD, Cumberland County, NJ, Salem County, NJ

The radar

The Dover AFB radar (KDOX), 62 km from the middle of the area, began a volume at 23:55 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 11.9 hours before the alert went out and 162 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, Wallops Is Stn, VA at 12:00Z on 2017-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 492 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, Wallops Is Stn, VA at 12:00Z on 2017-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 206 square meters per square second.1939587897117Sfc1 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
492 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
478 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
206 m²/s²
0-3 km storm-relative helicity
170 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

As transmitted.

957 
WUUS51 KPHI 252356
SVRPHI
DEC001-003-MDC015-029-NJC011-033-260045-
/O.NEW.KPHI.SV.W.0034.170525T2356Z-170526T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
756 PM EDT THU MAY 25 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  New Castle County in northern Delaware...
  Northern Kent County in central Delaware...
  Northeastern Kent County in northeastern Maryland...
  Southeastern Cecil County in northeastern Maryland...
  Northwestern Cumberland County in southern New Jersey...
  Salem County in southern New Jersey...

* Until 845 PM EDT

* At 756 PM EDT, severe thunderstorms were located along a line
  extending from Sassafras to Smyrna to near Dover Speedway, moving
  northeast at 25 mph.

  HAZARD...60 mph wind gusts and penny size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to trees and power lines. 

* Locations impacted include...
  Wilmington, Vineland, Dover, Newark, Millville, Bridgeton,
  Middletown, Pennsville, Smyrna, Carneys Point, Elsmere, New Castle,
  Salem, Woodstown, Alloway, Clayton, Quinton, Delaware City,
  Cheswold and Newport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

In addition to large hail and damaging winds...frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember...if you can hear thunder...you are close
enough to be struck by lightning.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3947 7582 3976 7569 3962 7526 3947 7500
      3925 7529 3937 7545 3939 7549 3927 7537
      3919 7537 3915 7542 3923 7565 3934 7586
TIME...MOT...LOC 2356Z 217DEG 23KT 3937 7580 3928 7560 3920 7545 

HAIL...0.75IN
WIND...60MPH
 
$$

JRK
3 follow-up statements
351 
WWUS51 KPHI 260011
SVSPHI

(

        WWUS51 KPHI 000000 
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
811 PM EDT THU MAY 25 2017

MDC029-260020-
/O.CAN.KPHI.SV.W.0034.000000T0000Z-170526T0045Z/
Kent MD-
811 PM EDT THU MAY 25 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN KENT COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

LAT...LON 3976 7569 3962 7526 3947 7500 3925 7529
      3939 7549 3927 7537 3922 7537 3929 7558
      3941 7584
TIME...MOT...LOC 0010Z 217DEG 23KT 3943 7575 3934 7555 3926 7540 

$$

DEC001-003-MDC015-NJC011-033-260045-
/O.CON.KPHI.SV.W.0034.000000T0000Z-170526T0045Z/
New Castle DE-Kent DE-Cecil MD-Cumberland NJ-Salem NJ-
811 PM EDT THU MAY 25 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR NEW CASTLE...NORTHEASTERN KENT...SOUTHEASTERN CECIL...
NORTHWESTERN CUMBERLAND AND SALEM COUNTIES...

At 810 PM EDT, severe thunderstorms were located along a line
extending from Warwick to near Woodland Beach to 8 miles northeast of
Dover Speedway, moving northeast at 25 mph.

HAZARD...60 mph wind gusts and penny size hail. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to trees and power lines. 

Locations impacted include...
Wilmington, Vineland, Millville, Bridgeton, Middletown, Pennsville,
Smyrna, Carneys Point, Elsmere, New Castle, Salem, Woodstown,
Alloway, Quinton, Delaware City, Newport, Greenwich, Shiloh, Warwick
and Stanton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

In addition to damaging winds...frequent cloud to ground lightning 
is occurring with this storm. Move indoors immediately. Remember... 
if you can hear thunder...you are close enough to be struck by 
lightning.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3976 7569 3962 7526 3947 7500 3925 7529
      3939 7549 3927 7537 3922 7537 3929 7558
      3941 7584
TIME...MOT...LOC 0010Z 217DEG 23KT 3943 7575 3934 7555 3926 7540 

HAIL...0.75IN
WIND...60MPH
 
$$

JRK
458 
WWUS51 KPHI 260028
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
828 PM EDT THU MAY 25 2017

DEC001-MDC015-260037-
/O.CAN.KPHI.SV.W.0034.000000T0000Z-170526T0045Z/
Kent DE-Cecil MD-
828 PM EDT THU MAY 25 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN KENT AND
SOUTHEASTERN CECIL COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3976 7569 3964 7531 3956 7515 3947 7501
      3925 7529 3939 7548 3934 7545 3945 7563
      3956 7578
TIME...MOT...LOC 0027Z 214DEG 21KT 3958 7572 3940 7550 3935 7536 

$$

DEC003-NJC011-033-260045-
/O.CON.KPHI.SV.W.0034.000000T0000Z-170526T0045Z/
New Castle DE-Cumberland NJ-Salem NJ-
828 PM EDT THU MAY 25 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR WESTERN NEW CASTLE...NORTHWESTERN CUMBERLAND AND SALEM
COUNTIES...

At 827 PM EDT, severe thunderstorms were located along a line
extending from Glasgow to near Woodland Beach to near Greenwich,
moving northeast at 25 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to trees and power lines. 

Locations impacted include...
Wilmington, Vineland, Newark, Millville, Bridgeton, Pennsville,
Carneys Point, Elsmere, New Castle, Salem, Woodstown, Alloway,
Quinton, Delaware City, Newport, Greenwich, Shiloh, Stanton, Glasgow
and Bear.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

In addition to damaging winds...frequent cloud to ground lightning 
is occurring with this storm. Move indoors immediately. Remember... 
if you can hear thunder...you are close enough to be struck by 
lightning.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3976 7569 3964 7531 3956 7515 3947 7501
      3925 7529 3939 7548 3934 7545 3945 7563
      3956 7578
TIME...MOT...LOC 0027Z 214DEG 21KT 3958 7572 3940 7550 3935 7536 

HAIL...<.75IN
WIND...60MPH
 
$$

JRK
678 
WWUS51 KPHI 260040
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
840 PM EDT THU MAY 25 2017

DEC003-NJC011-033-260049-
/O.EXP.KPHI.SV.W.0034.000000T0000Z-170526T0045Z/
New Castle DE-Cumberland NJ-Salem NJ-
840 PM EDT THU MAY 25 2017

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN NEW CASTLE...
NORTHWESTERN CUMBERLAND AND SALEM COUNTIES WILL EXPIRE AT 845 PM
EDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning will be allowed to expire. However gusty winds 
and heavy rain are still possible with these thunderstorms.

LAT...LON 3976 7569 3964 7531 3956 7515 3947 7501
      3925 7529 3939 7548 3934 7545 3945 7563
      3956 7578
TIME...MOT...LOC 0039Z 217DEG 23KT 3964 7566 3946 7544 3941 7530 

$$

JRK

The office that day

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

IssuedProductOfficeCountiesLasted
May 25, 5:29 PM EDTAreal Flood AdvisoryPHIKent, New Castle2 hr
May 25, 6:26 PM EDTSevere Thunderstorm WarningPHIKent, Sussex49 min
May 25, 6:48 PM EDTSpecial Weather StatementPHISussex27 min
May 25, 7:13 PM EDTSpecial Weather StatementPHIKent32 min
May 25, 7:49 PM EDTSpecial Weather StatementPHINew Castle26 min
May 25, 5:12 PM EDTSpecial Marine WarningPHI63 min
May 25, 5:15 PM EDTSpecial Weather StatementPHICumberland30 min
May 25, 5:51 PM EDTSpecial Weather StatementPHISalem24 min
May 25, 6:16 PM EDTSpecial Weather StatementPHIGloucester29 min
May 25, 7:37 PM EDTSpecial Marine WarningPHI38 min
May 25, 7:50 PM EDTSpecial Marine WarningPHI55 min
May 25, 5:48 PM EDTSevere Thunderstorm WarningPHIQueen Anne's, Talbot42 min
May 25, 7:09 PM EDTSevere Thunderstorm WarningPHICecil, Kent, Queen Anne's51 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2017Severe Thunderstorm Warnings in New Jersey, 2017Severe Thunderstorm Warnings in Maryland, 2017Every severe thunderstorm 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.