Alert archive / Delaware / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 14, NWS Philadelphia/Mount Holly

May 18, 2015Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 18, 2015, 2:30 PM EDT for Sussex County, Delaware. It was in force for 45 min. 1 report 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: May 18, 2015, 2:30 PM EDT (18:30 UTC)
Expired: May 18, 2015, 3:15 PM EDT
In force: 45 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Sussex County, DE

What was reported inside it

Time	Report	Where	Remark
May 18, 2:45 PM EDT	TSTM WND DMG	Laurel, DE	TREE DOWN AT ROAD 72 AND TRUSSUM POND ROAD

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

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 6.5 hours before the alert went out and 70 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: 476 J/kg
Mixed-layer CIN: -81 J/kg
Mixed-layer LCL: 1270 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 47 m²/s²
0-3 km storm-relative helicity: 38 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

847 
WUUS51 KPHI 181830
SVRPHI
DEC005-181915-
/O.NEW.KPHI.SV.W.0014.150518T1830Z-150518T1915Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
230 PM EDT MON MAY 18 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN SUSSEX COUNTY IN CENTRAL DELAWARE...

* UNTIL 315 PM EDT

* AT 229 PM EDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS
  OF 60 MPH. THIS STORM WAS LOCATED OVER SYCAMORE...OR 10 MILES
  SOUTHWEST OF GEORGETOWN. THIS STORM WAS NEARLY STATIONARY.

* LOCATIONS IMPACTED INCLUDE...
  MILLSBORO...LAUREL...GUMBORO...SYCAMORE AND BETHEL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...LARGE HAIL...DEADLY
LIGHTNING AND VERY HEAVY RAIN. FOR YOUR PROTECTION...MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY
RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER
COVERS THE ROAD.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

LAT...LON 3853 7569 3865 7557 3868 7553 3857 7528
      3845 7539 3845 7553
TIME...MOT...LOC 1829Z 038DEG 2KT 3856 7550 

$$

1 follow-up statement

309 
WWUS51 KPHI 181909
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
309 PM EDT MON MAY 18 2015

DEC005-181918-
/O.EXP.KPHI.SV.W.0014.000000T0000Z-150518T1915Z/
SUSSEX DE-
309 PM EDT MON MAY 18 2015

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SUSSEX COUNTY
WILL EXPIRE AT 315 PM EDT...
    
THE SEVERE THUNDERSTORM WHICH PROMPTED THE WARNING HAS WEAKENED AND 
WAS MOVING OUT OF THE AREA.

LAT...LON 3853 7569 3865 7557 3868 7553 3857 7528
      3845 7539 3845 7553
TIME...MOT...LOC 1907Z 038DEG 2KT 3856 7550 

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
May 18, 2:25 PM EDT	Special Weather Statement	PHI	Sussex	35 min
May 18, 2:36 PM EDT	Areal Flood Advisory	PHI	New Castle	3 hr
May 18, 2:51 PM EDT	Areal Flood Advisory	PHI	New Castle	3 hr
May 18, 3:28 PM EDT	Special Weather Statement	PHI	Kent	62 min
May 18, 3:41 PM EDT	Areal Flood Advisory	PHI	Kent	3 hr
May 18, 4:57 PM EDT	Areal Flood Advisory	PHI	New Castle	3 hr

Nearby

Severe Thunderstorm Warnings in Delaware, 2015 Every severe thunderstorm warning in 2015

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.