Alert archive / Delaware / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 114, NWS Philadelphia/Mount Holly

July 22, 2017Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 22, 2017, 3:17 PM EDT for Sussex County, Delaware. It was in force for 43 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
Jul 22, 2017, 3:17 PM EDT (19:17 UTC)
Expired
Jul 22, 2017, 4:00 PM EDT
In force
43 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 40 km from the middle of the area, began a volume at 19:21 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, 7.3 hours before the alert went out and 69 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 2017-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 83 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 2017-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.1939Sfc1 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
83 J/kg
Mixed-layer CIN
-191 J/kg
Mixed-layer LCL
1397 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

525 
WUUS51 KPHI 221917
SVRPHI
DEC005-222000-
/O.NEW.KPHI.SV.W.0114.170722T1917Z-170722T2000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
317 PM EDT SAT JUL 22 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Sussex County in southern Delaware...

* Until 400 PM EDT

* At 317 PM EDT, a severe thunderstorm was located over Selbyville,
  or 11 miles northwest of Ocean City, moving southeast at 25 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Millsboro, Selbyville, Dagsboro, Millville, Long Neck, Ocean View,
  Frankford and South Bethany.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm...and
the storm will affect the beaches. For your safety...immediately move
off the beach and seek shelter indoors.

&&

LAT...LON 3864 7533 3861 7504 3845 7504 3846 7505
      3845 7505 3845 7537
TIME...MOT...LOC 1917Z 294DEG 20KT 3849 7521 

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

JRK
2 follow-up statements
414 
WWUS51 KPHI 221941
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
341 PM EDT SAT JUL 22 2017

DEC005-222000-
/O.CON.KPHI.SV.W.0114.000000T0000Z-170722T2000Z/
Sussex DE-
341 PM EDT SAT JUL 22 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM EDT
FOR SOUTHEASTERN SUSSEX COUNTY...

At 341 PM EDT, severe thunderstorms were located along a line
extending from near Millville to near Selbyville, moving east at 15
mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

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

Locations impacted include...
Selbyville, Millville, Long Neck, Ocean View, Frankford and South
Bethany.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm...and
the storm will affect the beaches. For your safety...immediately move
off the beach and seek shelter indoors.

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

&&

LAT...LON 3850 7529 3854 7519 3857 7519 3863 7523
      3861 7504 3845 7504 3846 7505 3845 7505
      3845 7527 3846 7527
TIME...MOT...LOC 1941Z 271DEG 13KT 3861 7515 3846 7518 

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

JRK
186 
WWUS51 KPHI 221958
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
358 PM EDT SAT JUL 22 2017

DEC005-222008-
/O.EXP.KPHI.SV.W.0114.000000T0000Z-170722T2000Z/
Sussex DE-
358 PM EDT SAT JUL 22 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SUSSEX COUNTY
WILL EXPIRE AT 400 PM EDT...
    
The storms which prompted the warning have weakened below severe 
limits and have exited the warned area. Therefore the warning will 
be allowed to expire.  However gusty winds and heavy rain are still 
possible with these thunderstorms.

LAT...LON 3850 7529 3854 7519 3857 7519 3863 7523
      3861 7504 3845 7504 3846 7505 3845 7505
      3845 7527 3846 7527
TIME...MOT...LOC 1958Z 294DEG 20KT 3857 7505 3842 7508 

$$

JRK

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 10:45 AM EDTCoastal Flood AdvisoryPHIKent, Sussex13 hr
Jul 22, 2:58 PM EDTSpecial Weather StatementPHISussex62 min
Jul 22, 3:34 PM EDTSpecial Weather StatementPHISussex41 min
Jul 22, 3:36 PM EDTAreal Flood AdvisoryPHISussex114 min
Jul 22, 3:38 PM EDTSevere Thunderstorm WarningPHISussex52 min
Jul 22, 3:57 PM EDTSpecial Weather StatementPHISussex33 min
Jul 22, 5:18 PM EDTSevere Thunderstorm WarningPHINew Castle42 min

Nearby

Severe Thunderstorm Warnings in Delaware, 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.