Alert archive / Maryland / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 85, NWS Philadelphia/Mount Holly

July 1, 2015Cecil County, Maryland; Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 1, 2015, 1:42 AM EDT for Cecil County, Maryland; Chester County, Pennsylvania. It was in force for 48 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
Jul 1, 2015, 1:42 AM EDT (05:42 UTC)
Expired
Jul 1, 2015, 2:30 AM EDT
In force
48 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Cecil County, MD, Chester County, PA

The radar

The Dover AFB radar (KDOX), 104 km from the middle of the area, began a volume at 05:45 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
Jul 1, 1:53 AM EDTTSTM WND DMGNortheast Heights, MDDOCK WAS DESTROYED AT THE NORTHEAST MARINA

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 00:00Z, 5.7 hours before the alert went out and 145 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, Washington/Dulle, VA at 00:00Z on 2015-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 665 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, Washington/Dulle, VA at 00:00Z on 2015-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 100 square meters per square second.19395878Sfc1 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
665 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
1402 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
100 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.8

Open this sounding in Storm Lab

The text

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

890 
WUUS51 KPHI 010542
SVRPHI
MDC015-PAC029-010630-
/O.NEW.KPHI.SV.W.0085.150701T0542Z-150701T0630Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
142 AM EDT WED JUL 1 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CECIL COUNTY IN NORTHEASTERN MARYLAND...
  SOUTHWESTERN CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 230 AM EDT

* AT 141 AM 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 ABERDEEN...AND MOVING
  NORTHEAST AT 40 MPH.

* LOCATIONS IMPACTED INCLUDE...
  ELKTON...CALVERT...KENNETT SQUARE...OXFORD...PARKESBURG...NORTH
  EAST...WEST GROVE...RISING SUN...CHARLESTOWN...CECILTON...CAYOTS...
  ROCK SPRINGS...BOHEMIAS MILLS...BLAKE...PLEASANT HILL...ANDORA...
  HOMEVILLE...MOUNT VERNON...GLEN ROY AND RICHARDSMERE.

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.

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.

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

&&

LAT...LON 3973 7610 3976 7606 3983 7604 3987 7599
      3995 7599 4000 7596 3988 7565 3971 7579
      3938 7577 3936 7589 3938 7605 3943 7600
      3946 7601 3952 7598 3955 7603 3955 7608
      3972 7623
TIME...MOT...LOC 0541Z 208DEG 35KT 3949 7614 

$$
1 follow-up statement
627 
WWUS51 KPHI 010624
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
224 AM EDT WED JUL 1 2015

MDC015-PAC029-010633-
/O.EXP.KPHI.SV.W.0085.000000T0000Z-150701T0630Z/
CECIL MD-CHESTER PA-
224 AM EDT WED JUL 1 2015

...THE SEVERE THUNDERSTORM WARNING FOR CECIL AND SOUTHWESTERN CHESTER
COUNTIES WILL EXPIRE AT 230 AM EDT...
    
THE STRONGEST PART OF THE SEVERE THUNDERSTORM WHICH PROMPTED THE 
WARNING HAS MOVED INTO NEW CASTLE COUNTY. THEREFORE THE WARNING WILL
BE ALLOWED TO EXPIRE.

LAT...LON 3973 7610 3976 7606 3983 7604 3987 7599
      3995 7599 4000 7596 3988 7565 3971 7579
      3938 7577 3936 7589 3938 7605 3943 7600
      3946 7601 3952 7598 3955 7603 3955 7608
      3972 7623
TIME...MOT...LOC 0615Z 208DEG 35KT 3949 7614 

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 1, 12:56 AM EDTSpecial Weather StatementPHICaroline, Cecil, Kent, Queen Anne's94 min
Jul 1, 1:13 AM EDTSevere Thunderstorm WarningPHICaroline, Cecil, Kent, Queen Anne's62 min
Jul 1, 2:14 AM EDTAreal Flood AdvisoryPHICecil4 hr
Jun 30, 8:03 PM EDTSpecial Weather StatementPHIPhiladelphia27 min
Jun 30, 8:15 PM EDTSevere Thunderstorm WarningPHIBucks, Delaware, Montgomery, Philadelphia28 min
Jun 30, 8:23 PM EDTAreal Flood AdvisoryPHIBucks, Delaware, Montgomery, Philadelphia4 hr
Jun 30, 8:26 PM EDTAreal Flood AdvisoryPHIMonroe4 hr
Jul 1, 2:17 AM EDTSevere Thunderstorm WarningPHIDelaware43 min
Jul 1, 2:47 AM EDTAreal Flood AdvisoryPHIBucks3 hr
Jul 1, 2:50 AM EDTSpecial Weather StatementPHIDelaware, Philadelphia55 min
Jul 1, 4:48 AM EDTAreal Flood WarningPHIMonroe10 hr

Nearby

Severe Thunderstorm Warnings in Maryland, 2015Severe Thunderstorm Warnings in Pennsylvania, 2015Every 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.