Alert archive / Delaware / Severe Thunderstorm Warnings in 2016

Severe Thunderstorm Warning 122, NWS Philadelphia/Mount Holly

July 23, 2016New Castle County, Delaware; Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 23, 2016, 4:28 PM EDT for New Castle County, Delaware; Chester County, Pennsylvania. It was in force for 47 min. 2 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: Jul 23, 2016, 4:28 PM EDT (20:28 UTC)
Expired: Jul 23, 2016, 5:15 PM EDT
In force: 47 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties New Castle County, DE, Chester County, PA

The radar

The Dover AFB radar (KDOX), 114 km from the middle of the area, began a volume at 20:28 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

Time	Report	Where	Remark
Jul 23, 4:30 PM EDT	TSTM WND DMG	West Grove, PA	LARGE TREE LIMBS DOWN. TIME ESTIMATED FROM RADAR.
Jul 23, 5:15 PM EDT	TSTM WND DMG	Wilmington, DE	TREES AND WIRES DOWN ON CENTERVILLE ROAD

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.5 hours before the alert went out and 166 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: 444 J/kg
Mixed-layer CIN: -145 J/kg
Mixed-layer LCL: 1393 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 100 m²/s²
0-3 km storm-relative helicity: 93 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

As transmitted.

449 
WUUS51 KPHI 232028
SVRPHI
DEC003-PAC029-232115-
/O.NEW.KPHI.SV.W.0122.160723T2028Z-160723T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
428 PM EDT SAT JUL 23 2016

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  SOUTHWESTERN CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 515 PM EDT

* AT 427 PM EDT...A SEVERE THUNDERSTORM WAS LOCATED OVER WEST
  GROVE... OR 12 MILES NORTH OF NEWARK...MOVING SOUTHEAST AT 35 MPH.

  HAZARD...60 MPH WIND GUSTS AND QUARTER SIZE HAIL. 

  SOURCE...RADAR INDICATED. 

  IMPACT...HAIL DAMAGE TO VEHICLES IS EXPECTED. EXPECT WIND DAMAGE 
           TO ROOFS...SIDING...AND TREES. 

* LOCATIONS IMPACTED INCLUDE...
  WILMINGTON...NEWARK...ELSMERE...KENNETT SQUARE...NEW CASTLE...
  OXFORD...PARKESBURG...WEST GROVE...NEWPORT...ARDEN...
  WILMINGTON MANOR...HOMEVILLE...MOUNT VERNON...COCHRANVILLE...
  HOCKESSIN...LADENBERG...NORTH STAR...TALLEYVILLE...
  GREENVILLE AND KEMBLESVILLE.

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.

&&

LAT...LON 3981 7603 3983 7604 3987 7599 3990 7599
      3997 7594 3987 7559 3984 7559 3984 7550
      3980 7542 3962 7560 3969 7579 3972 7579
      3972 7588 3978 7605
TIME...MOT...LOC 2027Z 293DEG 30KT 3985 7582 

HAIL...1.00IN
WIND...60MPH
 
$$

GORSE

1 follow-up statement

939 
WWUS51 KPHI 232040
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
440 PM EDT SAT JUL 23 2016

DEC003-PAC029-232115-
/O.CON.KPHI.SV.W.0122.000000T0000Z-160723T2115Z/
NEW CASTLE DE-CHESTER PA-
440 PM EDT SAT JUL 23 2016

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM EDT
FOR NORTHERN NEW CASTLE AND SOUTHWESTERN CHESTER COUNTIES...

AT 440 PM EDT...A SEVERE THUNDERSTORM WAS LOCATED OVER ASHLAND...OR 9
MILES NORTHWEST OF WILMINGTON...MOVING SOUTHEAST AT 30 MPH.

HAZARD...60 MPH WIND GUSTS AND QUARTER SIZE HAIL. 

SOURCE...RADAR INDICATED. 

IMPACT...HAIL DAMAGE TO VEHICLES IS EXPECTED. EXPECT WIND DAMAGE TO 
         ROOFS...SIDING...AND TREES. 

LOCATIONS IMPACTED INCLUDE...
WILMINGTON...NEWARK...ELSMERE...KENNETT SQUARE...NEW CASTLE...
OXFORD...WEST GROVE...NEWPORT...ARDEN...WILMINGTON MANOR...
HOCKESSIN...LADENBERG...NORTH STAR...TALLEYVILLE...GREENVILLE...
KEMBLESVILLE...PIKE CREEK...ASHLAND...STANTON AND AVONDALE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE IMMEDIATELY FOR LARGE HAIL AND DAMAGING WINDS. PEOPLE OUTSIDE
SHOULD MOVE TO A SHELTER...INSIDE A STRONG BUILDING AND AWAY FROM
WINDOWS.

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.

&&

LAT...LON 3993 7581 3987 7559 3986 7560 3984 7559
      3983 7548 3980 7542 3962 7560 3969 7579
      3972 7579 3972 7588 3978 7605
TIME...MOT...LOC 2040Z 300DEG 24KT 3981 7568 

HAIL...1.00IN
WIND...60MPH
 
$$

GORSE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 4:12 PM EDT	Heat Advisory	PHI	Kent, Sussex	50 hr
Jul 23, 5:03 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	28 min
Jul 23, 5:55 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	65 min
Jul 23, 6:46 PM EDT	Severe Thunderstorm Warning	PHI	Kent	44 min
Jul 23, 7:31 PM EDT	Special Weather Statement	PHI	Kent	29 min
Jul 23, 3:58 PM EDT	Special Weather Statement	PHI	Chester	47 min
Jul 23, 4:10 PM EDT	Special Weather Statement	PHI	Philadelphia	50 min
Jul 23, 4:55 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Montgomery, Philadelphia	35 min
Jul 23, 5:24 PM EDT	Severe Thunderstorm Warning	PHI	Philadelphia	51 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2016 Severe Thunderstorm Warnings in Pennsylvania, 2016 Every severe thunderstorm warning in 2016

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.