Alert archive / Delaware / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 24, NWS Philadelphia/Mount Holly

May 15, 2018New Castle County, Delaware; Salem County, New Jersey; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 15, 2018, 7:18 PM EDT for New Castle County, Delaware; Salem County, New Jersey; Cecil County, Maryland. It was in force for 57 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 15, 2018, 7:18 PM EDT (23:18 UTC)
Expired
May 15, 2018, 8:15 PM EDT
In force
57 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

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

The radar

The Dover AFB radar (KDOX), 72 km from the middle of the area, began a volume at 23:18 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 15, 1:46 PM EDTSevere Thunderstorm WatchSPC9 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.3 hours before the alert went out and 157 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 2018-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 47 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 2018-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 117 square meters per square second.193958Sfc1 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
47 J/kg
Mixed-layer CIN
-484 J/kg
Mixed-layer LCL
1259 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
117 m²/s²
0-3 km storm-relative helicity
79 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

918 
WUUS51 KPHI 152318
SVRPHI
DEC003-MDC015-NJC033-160015-
/O.NEW.KPHI.SV.W.0024.180515T2318Z-180516T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
718 PM EDT TUE MAY 15 2018

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  New Castle County in northern Delaware...
  Cecil County in northeastern Maryland...
  Western Salem County in southern New Jersey...

* Until 815 PM EDT.

* At 718 PM EDT, a severe thunderstorm was located over Charlestown,
  or near Havre De Grace, moving southeast at 40 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Wilmington, Newark, Middletown, Elkton, Havre De Grace, Pennsville,
  Carneys Point, New Castle, Salem, North East, Quinton, Delaware
  City, Charlestown, Cecilton, Warwick, Zion, Barksdale, Woodland
  Beach, Glasgow and Bear.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3971 7539 3946 7540 3943 7541 3939 7549
      3934 7544 3933 7540 3933 7550 3936 7551
      3933 7556 3934 7576 3938 7578 3936 7590
      3938 7605 3943 7600 3946 7601 3952 7598
      3955 7609 3967 7616
TIME...MOT...LOC 2318Z 295DEG 36KT 3957 7598 

HAIL...0.88IN
WIND...60MPH
 
$$

po
1 follow-up statement
294 
WWUS51 KPHI 160001
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
801 PM EDT TUE MAY 15 2018

DEC003-MDC015-NJC033-160015-
/O.CON.KPHI.SV.W.0024.000000T0000Z-180516T0015Z/
New Castle DE-Cecil MD-Salem NJ-
801 PM EDT TUE MAY 15 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM EDT
FOR SOUTHWESTERN NEW CASTLE...SOUTHEASTERN CECIL AND SOUTHWESTERN
SALEM COUNTIES...

At 800 PM EDT, severe thunderstorms were located across Cecil 
and northern New castle counties, near Middletown, moving southeast 
at 20 mph.

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

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Middletown, Salem, Quinton, Delaware City, Charlestown, Cecilton,
Warwick, Saint Georges, Mount Pleasant, Woodland Beach, Bohemias
Mills, Hancocks Bridge, Port Penn, Brantwood, Hope Creek, Cayots,
Hollywood Beach, Glasgow, Townsend and Chesapeake City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3961 7540 3943 7541 3939 7549 3933 7544
      3933 7550 3935 7549 3936 7551 3935 7555
      3933 7556 3934 7576 3938 7578 3936 7590
      3938 7605 3943 7600 3946 7601 3952 7598
      3956 7609 3957 7601
TIME...MOT...LOC 0000Z 295DEG 36KT 3939 7548 

HAIL...0.88IN
WIND...60MPH
 
$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 14, 8:45 PM EDTSpecial Weather StatementPHISussex30 min
May 15, 3:40 AM EDTFlash Flood WatchPHIKent, New Castle, Sussex21 hr
May 15, 5:35 PM EDTAreal Flood AdvisoryPHINew Castle4 hr
May 15, 5:38 PM EDTSevere Thunderstorm WarningPHINew Castle67 min
May 15, 6:10 PM EDTAreal Flood AdvisoryPHINew Castle4 hr
May 15, 6:35 PM EDTSevere Thunderstorm WarningPHIKent, New Castle40 min
May 15, 6:58 PM EDTAreal Flood AdvisoryPHINew Castle4 hr
May 15, 2:49 PM EDTSpecial Weather StatementPHISussex, Warren56 min
May 15, 3:46 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Sussex, Warren74 min
May 15, 4:24 PM EDTSpecial Weather StatementPHIHunterdon, Somerset51 min
May 15, 4:41 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset, Warren64 min
May 15, 4:49 PM EDTSpecial Marine WarningPHI86 min
May 15, 5:22 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean38 min
May 15, 5:31 PM EDTAreal Flood AdvisoryPHIHunterdon, Mercer, Middlesex, Morris, Somerset3 hr
May 15, 5:53 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean52 min
May 15, 6:02 PM EDTSpecial Marine WarningPHI88 min
May 15, 6:12 PM EDTSpecial Marine WarningPHI63 min
May 15, 6:17 PM EDTSpecial Weather StatementPHIBurlington, Camden, Cumberland, Gloucester, Ocean43 min
May 15, 6:46 PM EDTSpecial Weather StatementPHIAtlantic, Cumberland, Ocean, Salem74 min
May 15, 7:14 PM EDTSpecial Marine WarningPHI91 min
May 15, 7:30 PM EDTSpecial Marine WarningPHI90 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2018Severe Thunderstorm Warnings in New Jersey, 2018Severe Thunderstorm Warnings in Maryland, 2018Every severe thunderstorm warning in 2018

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.