Alert archive / Delaware / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 20, NWS Philadelphia/Mount Holly

March 1, 2017Kent County, New Castle County, Sussex County, Delaware; Atlantic County, Cape May County, Cumberland County, New Jersey; Caroline County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Mar 1, 2017, 2:45 PM EST for Kent County, New Castle County, Sussex County, Delaware; Atlantic County, Cape May County, Cumberland County, New Jersey; Caroline County, Maryland. It was in force for 60 min. 16 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
Mar 1, 2017, 2:45 PM EST (19:45 UTC)
Expired
Mar 1, 2017, 3:45 PM EST
In force
60 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
70.0 mph

Counties Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Atlantic County, NJ, Cape May County, NJ, Cumberland County, NJ

The radar

The Dover AFB radar (KDOX), 27 km from the middle of the area, began a volume at 19:49 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
Mar 1, 2:53 PM ESTTSTM WND DMGDover, DETREES REPORTED DOWN ON SEVERAL ROADWAYS IN DOVER.
Mar 1, 2:55 PM ESTTSTM WND DMG1 W Melvins Crossroads, DETWO STEEL BUILDINGS AND A HOME WERE DAMAGED FROM THUNDERSTORM WIND GUSTS. SEVERAL IRRIGATION PIVOTS OVERTURNED AND NUMEROUS LARGE TREES DOWNED. TIME ESTIMATED FROM RADAR.
Mar 1, 2:55 PM ESTTSTM WND DMGFelton, DETREES DOWN ON A ROADWAY IN FELTON.
Mar 1, 2:57 PM ESTTSTM WND DMGHarrington, DETREES DOWN ON ROADWAYS IN HARRINGTON.
Mar 1, 2:58 PM ESTTSTM WND GST 76Dover Air Force Base, DE
Mar 1, 3:01 PM ESTTSTM WND DMGMilford, DETREES DOWN ON ROADWAYS IN MILFORD.
Mar 1, 3:05 PM ESTTSTM WND GST 52Milford, DE
Mar 1, 3:20 PM ESTMARINE TSTM WIND 54Lewes, DE
Mar 1, 3:20 PM ESTMARINE TSTM WIND 54Lewes Nos Buoy, DE
Mar 1, 3:25 PM ESTTSTM WND DMGCape May Court House, NJTREE DOWN ON GOSHEN RD.
Mar 1, 3:30 PM ESTTSTM WND GST 61Goshen, NJPROPERTY DAMAGE WAS REPORTED AT THE TIME OF THE PEAK WIND GUST.
Mar 1, 3:30 PM ESTMARINE TSTM WIND 41Cape May, NJ
Mar 1, 3:30 PM ESTMARINE TSTM WIND 51Lewes Nos Buoy, DE
Mar 1, 3:42 PM ESTMARINE TSTM WIND 49Dewey Beach, DE
Mar 1, 3:44 PM ESTTSTM WND GST 60Ocean City, NJ
Mar 1, 3:44 PM ESTMARINE TSTM WIND 60Ocean City, NJ

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

IssuedProductOfficeLasted
Mar 1, 1:13 PM ESTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.8 hours before the alert went out and 86 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, Phillips Aaf/Abe, MD at 12:00Z on 2017-03-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Phillips Aaf/Abe, MD at 12:00Z on 2017-03-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 212 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
624 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
212 m²/s²
0-3 km storm-relative helicity
284 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

282 
WUUS51 KPHI 011945
SVRPHI
DEC001-003-005-MDC011-NJC001-009-011-012045-
/O.NEW.KPHI.SV.W.0020.170301T1945Z-170301T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
245 PM EST WED MAR 1 2017

The National Weather Service in Mount Holly NJ  has issued a

* Severe Thunderstorm Warning for...
  Sussex County in southern Delaware...
  South central New Castle County in northern Delaware...
  Kent County in central Delaware...
  Southeastern Caroline County in eastern Maryland...
  Southwestern Atlantic County in southern New Jersey...
  Cumberland County in southern New Jersey...
  Cape May County in southern New Jersey...

* Until 345 PM EST

* At 244 PM EST, severe thunderstorms were located along a line
  extending from Clayton to near Sandtown to near Denton to
  Windyhill, moving east at 60 mph.

  HAZARD...70 mph wind gusts and penny size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings. 

* Locations impacted include...
  Vineland, Atlantic City, Dover, Millville, Bridgeton, Ocean City,
  Georgetown, Cape May, Cumberland, Pleasantville, Somers Point,
  Ventnor City, Smyrna, Milford, Northfield, Absecon, Seaford,
  Margate City, North Wildwood and Millsboro.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This is a DANGEROUS SITUATION. These storms are producing widespread 
wind damage. SEEK SHELTER NOW inside a sturdy structure and stay 
away from windows! This severe thunderstorm may contain little or no 
lightning. Do not wait until you hear thunder before taking cover.

&&

LAT...LON 3864 7568 3875 7587 3894 7574 3940 7564
      3938 7548 3924 7537 3928 7530 3941 7541
      3951 7447 3930 7447 3891 7486 3893 7497
      3915 7490 3927 7529 3925 7534 3893 7529
      3880 7506 3846 7504 3846 7566
TIME...MOT...LOC 1944Z 267DEG 65KT 3928 7563 3906 7569 3891 7578 3869
7597

HAIL...0.75IN
WIND...70MPH
 
$$

33
4 follow-up statements
309 
WWUS51 KPHI 012007
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
307 PM EST WED MAR 1 2017

DEC003-012015-
/O.CAN.KPHI.SV.W.0020.000000T0000Z-170301T2045Z/
New Castle DE-
307 PM EST WED MAR 1 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL NEW CASTLE
COUNTY IS CANCELLED...

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

A severe thunderstorm watch remains in effect until 700 PM EST for
central and southern Delaware...eastern Maryland...and southern New
Jersey.

LAT...LON 3864 7568 3872 7581 3894 7557 3923 7538
      3905 7537 3893 7529 3881 7514 3881 7507
      3894 7497 3915 7490 3926 7531 3941 7541
      3951 7447 3930 7447 3919 7462 3891 7486
      3893 7497 3846 7504 3846 7566
TIME...MOT...LOC 2005Z 270DEG 65KT 3930 7518 3908 7524 3893 7533 3871
7552

$$

DEC001-005-MDC011-NJC001-009-011-012045-
/O.CON.KPHI.SV.W.0020.000000T0000Z-170301T2045Z/
Sussex DE-Kent DE-Caroline MD-Atlantic NJ-Cumberland NJ-Cape May NJ-
307 PM EST WED MAR 1 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EST
FOR SUSSEX...SOUTHEASTERN KENT...SOUTHEASTERN CAROLINE...SOUTHWESTERN
ATLANTIC...CUMBERLAND AND CAPE MAY COUNTIES...

At 305 PM EST, severe thunderstorms were located along a line
extending from Newport to 8 miles east of Bowers to near Big Stone
Beach to near Bridgeville, moving east at 60 mph.

HAZARD...70 mph wind gusts and penny size hail. 

SOURCE...Radar indicated. 

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings. 

Locations impacted include...
Vineland, Atlantic City, Dover, Millville, Bridgeton, Ocean City,
Georgetown, Cape May, Cumberland, Pleasantville, Somers Point,
Ventnor City, Milford, Northfield, Absecon, Seaford, Margate City,
North Wildwood, Millsboro and Laurel Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This is a DANGEROUS SITUATION. These storms are producing widespread 
wind damage. SEEK SHELTER NOW inside a sturdy structure and stay 
away from windows.
 
This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3864 7568 3872 7581 3894 7557 3923 7538
      3905 7537 3893 7529 3881 7514 3881 7507
      3894 7497 3915 7490 3926 7531 3941 7541
      3951 7447 3930 7447 3919 7462 3891 7486
      3893 7497 3846 7504 3846 7566
TIME...MOT...LOC 2005Z 270DEG 65KT 3930 7518 3908 7524 3893 7533 3871
7552

HAIL...0.75IN
WIND...70MPH
 
$$

33
228 
WWUS51 KPHI 012019
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
319 PM EST WED MAR 1 2017

DEC001-MDC011-012028-
/O.CAN.KPHI.SV.W.0020.000000T0000Z-170301T2045Z/
Kent DE-Caroline MD-
319 PM EST WED MAR 1 2017

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

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

A severe thunderstorm watch remains in effect until 700 PM EST for
southern Delaware...and southern New Jersey.

LAT...LON 3862 7560 3871 7548 3893 7530 3881 7514
      3881 7507 3894 7497 3915 7490 3922 7516
      3944 7517 3951 7447 3930 7447 3919 7462
      3891 7486 3893 7497 3882 7506 3846 7504
      3846 7566
TIME...MOT...LOC 2018Z 267DEG 65KT 3931 7489 3909 7495 3894 7504 3872
7523

$$

DEC005-NJC001-009-011-012045-
/O.CON.KPHI.SV.W.0020.000000T0000Z-170301T2045Z/
Sussex DE-Atlantic NJ-Cumberland NJ-Cape May NJ-
319 PM EST WED MAR 1 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EST
FOR SUSSEX...SOUTHWESTERN ATLANTIC...SOUTHEASTERN CUMBERLAND AND CAPE
MAY COUNTIES...

At 318 PM EST, severe thunderstorms were located along a line
extending from near Belleplain Forest to near Green Creek to near
North Cape May to near Lewes, moving east at 60 mph.

HAZARD...70 mph wind gusts and penny size hail. 

SOURCE...Radar indicated. 

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings. 

Locations impacted include...
Vineland, Atlantic City, Millville, Ocean City, Georgetown, Cape May,
Cumberland, Pleasantville, Somers Point, Ventnor City, Northfield,
Absecon, Margate City, North Wildwood, Millsboro, Laurel Lake,
Laurel, Wildwood Crest, Lewes and Milton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This is a DANGEROUS SITUATION. These storms are producing widespread 
wind damage. SEEK SHELTER NOW inside a sturdy structure and stay 
away from windows.
 
This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3862 7560 3871 7548 3893 7530 3881 7514
      3881 7507 3894 7497 3915 7490 3922 7516
      3944 7517 3951 7447 3930 7447 3919 7462
      3891 7486 3893 7497 3882 7506 3846 7504
      3846 7566
TIME...MOT...LOC 2018Z 267DEG 65KT 3931 7489 3909 7495 3894 7504 3872
7523

HAIL...0.75IN
WIND...70MPH
 
$$

33
875 
WWUS51 KPHI 012036
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
336 PM EST WED MAR 1 2017

DEC005-NJC001-009-011-012045-
/O.CON.KPHI.SV.W.0020.000000T0000Z-170301T2045Z/
Sussex DE-Atlantic NJ-Cumberland NJ-Cape May NJ-
336 PM EST WED MAR 1 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EST
FOR SOUTHEASTERN SUSSEX...SOUTHWESTERN ATLANTIC...EAST CENTRAL
CUMBERLAND AND CAPE MAY COUNTIES...

At 335 PM EST, severe thunderstorms were located along a line
extending from Longport to 6 miles southeast of Sea Isle City to 7
miles southeast of North Wildwood to 11 miles east of Henlopen Acres,
moving east at 60 mph.

HAZARD...70 mph wind gusts and penny size hail. 

SOURCE...Radar indicated. 

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings. 

Locations impacted include...
Vineland, Atlantic City, Ocean City, Cape May, Cumberland,
Pleasantville, Somers Point, Ventnor City, Northfield, Absecon,
Margate City, North Wildwood, Millsboro, Wildwood Crest, Lewes,
Woodbine, Sea Isle City, Estell Manor, Avalon and Port Republic.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This is a DANGEROUS SITUATION. These storms are producing widespread 
wind damage. SEEK SHELTER NOW inside a sturdy structure and stay 
away from windows.

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3860 7538 3881 7514 3882 7506 3894 7497
      3915 7490 3946 7496 3951 7447 3930 7447
      3919 7462 3891 7486 3893 7497 3846 7504
      3846 7548
TIME...MOT...LOC 2035Z 267DEG 65KT 3932 7452 3910 7458 3895 7467 3873
7487

HAIL...0.75IN
WIND...70MPH
 
$$

33
070 
WWUS51 KPHI 012042
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
342 PM EST WED MAR 1 2017

DEC005-NJC001-009-011-012051-
/O.EXP.KPHI.SV.W.0020.000000T0000Z-170301T2045Z/
Sussex DE-Atlantic NJ-Cumberland NJ-Cape May NJ-
342 PM EST WED MAR 1 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SUSSEX...
SOUTHWESTERN ATLANTIC...EAST CENTRAL CUMBERLAND AND CAPE MAY COUNTIES
WILL EXPIRE AT 345 PM EST...
    
The storms which prompted the warning are moving out of the area.
Therefore the warning will be allowed to expire.  However gusty winds
are still possible with these thunderstorms.

A severe thunderstorm watch remains in effect until 700 PM EST for
southern Delaware...and southern New Jersey.

LAT...LON 3860 7538 3881 7514 3882 7506 3894 7497
      3915 7490 3946 7496 3951 7447 3930 7447
      3919 7462 3891 7486 3893 7497 3846 7504
      3846 7548
TIME...MOT...LOC 2041Z 267DEG 65KT 3932 7441 3910 7447 3895 7456 3873
7476

$$

33

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 1, 2:00 PM ESTSevere Thunderstorm WarningPHINew Castle45 min
Mar 1, 2:09 PM ESTSevere Thunderstorm WarningPHIKent, New Castle, Sussex51 min
Mar 1, 3:09 PM ESTWind AdvisoryPHIKent, New Castle, Sussex19 hr
Mar 1, 3:32 AM ESTGale WarningPHI36 hr
Mar 1, 2:21 PM ESTSpecial Marine WarningPHI54 min
Mar 1, 2:46 PM ESTSpecial Weather StatementPHICamden, Gloucester29 min
Mar 1, 2:55 PM ESTSpecial Weather StatementPHIHunterdon, Morris, Somerset, Sussex, Warren35 min
Mar 1, 2:57 PM ESTSpecial Marine WarningPHI63 min
Mar 1, 3:16 PM ESTSpecial Weather StatementPHIBurlington, Camden, Gloucester, Salem44 min
Mar 1, 3:43 PM ESTSpecial Weather StatementPHIAtlantic, Burlington, Camden, Ocean32 min
Mar 1, 3:52 PM ESTSpecial Marine WarningPHI83 min
Mar 1, 4:00 PM ESTSpecial Marine WarningPHI60 min
Mar 1, 4:00 PM ESTSevere Thunderstorm WarningPHIBurlington, Ocean31 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.