Alert archive / Maryland / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 89, NWS Philadelphia/Mount Holly

July 9, 2015Cecil County, Maryland; New Castle County, Delaware; Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 9, 2015, 6:50 PM EDT for Cecil County, Maryland; New Castle County, Delaware; Chester County, Pennsylvania. It was in force for 40 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 9, 2015, 6:50 PM EDT (22:50 UTC)
Expired: Jul 9, 2015, 7:30 PM EDT
In force: 40 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties New Castle County, DE, Cecil County, MD, Chester County, PA

The radar

The Dover AFB radar (KDOX), 96 km from the middle of the area, began a volume at 22:52 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 9, 7:10 PM EDT	TSTM WND DMG	Port Deposit, MD	TREES DOWN IN THE PORT DEPOSIT AND COLORA AREA.
Jul 9, 7:12 PM EDT	FUNNEL CLOUD	Rising Sun, MD	FUNNEL CLOUD REPORTED IN RISING SUN.

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.

Issued	Product	Office	Lasted
Jul 9, 4:57 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.8 hours before the alert went out and 161 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: 1 J/kg
Mixed-layer CIN: -194 J/kg
Mixed-layer LCL: 1091 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: -2 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.

346 
WUUS51 KPHI 092250
SVRPHI
DEC003-MDC015-PAC029-092330-
/O.NEW.KPHI.SV.W.0089.150709T2250Z-150709T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
650 PM EDT THU JUL 9 2015

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...
  SOUTHWESTERN CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 730 PM EDT

* AT 648 PM EDT...DOPPLER RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS
  CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS
  WERE LOCATED NEAR DELTA...OR 7 MILES NORTH OF BEL AIR...AND MOVING
  EAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WILMINGTON...NEWARK...MIDDLETOWN...ELKTON...CALVERT...ELSMERE...
  KENNETT SQUARE...NEW CASTLE...OXFORD...NORTH EAST...WEST GROVE...
  RISING SUN...DELAWARE CITY...CHARLESTOWN...NEWPORT...BOHEMIAS
  MILLS...PLEASANT HILL...WOODLAWN...LADENBERG AND NORTH STAR.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...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.

THESE STORMS HAVE A HISTORY OF PRODUCING WIND DAMAGE. THIS IS A VERY
DANGEROUS SITUATION. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND
STAY AWAY FROM WINDOWS.

&&

LAT...LON 3973 7610 3979 7605 3987 7560 3984 7559
      3984 7554 3970 7552 3964 7559 3961 7556
      3964 7560 3962 7561 3959 7560 3958 7556
      3958 7557 3944 7557 3942 7599 3952 7598
      3955 7608 3972 7623
TIME...MOT...LOC 2248Z 259DEG 48KT 3964 7635 

$$

GORSE/FRANCK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 8, 9:15 PM EDT	Special Weather Statement	PHI	Cecil	30 min
Jul 8, 9:43 PM EDT	Special Weather Statement	PHI	Cecil	32 min
Jul 9, 7:29 PM EDT	Severe Thunderstorm Warning	PHI	Cecil, Kent	46 min
Jul 9, 7:38 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's, Talbot	52 min
Jul 9, 7:55 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	40 min
Jul 9, 6:15 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	45 min
Jul 9, 6:35 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	40 min
Jul 9, 6:46 PM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	4 hr
Jul 9, 6:57 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery	48 min
Jul 9, 7:12 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Lehigh, Northampton	48 min
Jul 9, 7:21 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	4 hr
Jul 9, 7:39 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	66 min
Jul 9, 7:56 PM EDT	Areal Flood Advisory	PHI	Bucks, Delaware, Montgomery, Philadelphia	4 hr

Nearby

Severe Thunderstorm Warnings in Maryland, 2015 Severe Thunderstorm Warnings in Delaware, 2015 Severe Thunderstorm Warnings in Pennsylvania, 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; radar from the NEXRAD Level II archive.