Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 17, NWS Philadelphia/Mount Holly

March 1, 20174 states

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Mar 1, 2017, 2:00 PM EST for 4 states. It was in force for 45 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: Mar 1, 2017, 2:00 PM EST (19:00 UTC)
Expired: Mar 1, 2017, 2:45 PM EST
In force: 45 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties New Castle County, DE, Cecil County, MD, Kent County, MD, Salem County, NJ, Chester County, PA, Delaware County, PA

The radar

The Dover AFB radar (KDOX), 96 km from the middle of the area, began a volume at 19:02 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Mar 1, 1:13 PM EST	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.0 hours before the alert went out and 15 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 624 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 212 m²/s²
0-3 km storm-relative helicity: 284 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

635 
WUUS51 KPHI 011900
SVRPHI
DEC003-MDC015-029-NJC033-PAC029-045-011945-
/O.NEW.KPHI.SV.W.0017.170301T1900Z-170301T1945Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
200 PM EST WED MAR 1 2017

The National Weather Service in Mount Holly NJ  has issued a

* Severe Thunderstorm Warning for...
  New Castle County in northern Delaware...
  Northeastern Kent County in northeastern Maryland...
  Cecil County in northeastern Maryland...
  Northwestern Salem County in southern New Jersey...
  Southwestern Chester County in southeastern Pennsylvania...
  Southwestern Delaware County in southeastern Pennsylvania...

* Until 245 PM EST

* At 159 PM EST, severe thunderstorms were located along a line
  extending from Delta to Fallston to Towson, moving east at 60 mph.

  HAZARD...60 mph wind gusts and penny size hail. 

  SOURCE...Trained weather spotters. 

  IMPACT...Expect damage to roofs, siding, and trees. 

* Severe thunderstorms will be near,
  Rock Springs, Richardsmere, Conowingo, West Nottingham and 
  Octoraro around 210 PM EST. 
  Calvert, Rising Sun, Glen Roy and Farmington around 215 PM EST. 
  Havre De Grace, Oxford, Lombard, Blake, Woodlawn, Zion and 
  Pleasant Hill around 220 PM EST. 
  North East, Charlestown, Betterton, Kemblesville, Glen Westover, 
  Fair Hill, Bay View, Appleton and Andora around 225 PM EST. 
  Newark, North Star, Ladenberg, Pike Creek and Cherry Hill around 
  230 PM EST. 
  Elkton, Elsmere, Newport, Cecilton, Ashland, Greenville, 
  Brantwood, Hockessin, Hollywood Beach and Stanton around 235 PM 
  EST. 
  Wilmington, Penns Grove, Arden, Talleyville, Bohemias Mills, Saint 
  Georges, Cayots, Glasgow, Warwick and Bear around 240 PM EST. 
  Middletown, Pennsville, Carneys Point, New Castle, Salem, Delaware 
  City, Mount Pleasant, Port Penn, Wilmington Manor and Delaware 
  Memorial Bridge around 245 PM EST. 

Other locations impacted by these severe thunderstorms include
Townsend, Brookside, Perryville, Chesapeake City, Ardencroft, Port
Deposit, Edgemoor, Claymont, Bellefonte and Ardentown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3972 7614 3974 7612 3973 7610 3977 7606
      3986 7545 3961 7543 3936 7569 3934 7613
      3937 7611 3937 7606 3942 7600 3946 7601
      3952 7598 3955 7603 3955 7609 3972 7623
TIME...MOT...LOC 1859Z 262DEG 55KT 3973 7633 3951 7647 3937 7661 

HAIL...0.75IN
WIND...60MPH
 
$$

33

2 follow-up statements

016 
WWUS51 KPHI 011929
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
229 PM EST WED MAR 1 2017

DEC003-MDC015-029-NJC033-PAC029-045-011945-
/O.CON.KPHI.SV.W.0017.000000T0000Z-170301T1945Z/
New Castle DE-Kent MD-Cecil MD-Salem NJ-Chester PA-Delaware PA-
229 PM EST WED MAR 1 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM EST
FOR NEW CASTLE...NORTHEASTERN KENT...CECIL...NORTHWESTERN SALEM...
SOUTHWESTERN CHESTER AND SOUTHWESTERN DELAWARE COUNTIES...

At 228 PM EST, severe thunderstorms were located along a line
extending from Ladenberg to near North East to near Betterton, moving
east at 60 mph.

HAZARD...60 mph wind gusts and penny size hail. 

SOURCE...Trained weather spotters. 

IMPACT...Expect damage to roofs, siding, and trees. 

These severe storms will be near...
  Newark, Elsmere, Newport, Ashland, Greenville, Pike Creek, 
  Hockessin, North Star and Stanton around 235 PM EST. 
  Wilmington, New Castle, Arden, Saint Georges, Talleyville, 
  Glasgow, Mount Pleasant, Bear, Wilmington Manor and Delaware 
  Memorial Bridge around 240 PM EST. 
  Middletown, Pennsville, Carneys Point, Penns Grove, Salem, 
  Delaware City and Port Penn around 245 PM EST. 

Other locations impacted by these severe thunderstorms include
Townsend, Brookside, Perryville, Chesapeake City, Ardencroft, Port
Deposit, Edgemoor, Claymont, Bellefonte and Ardentown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3972 7614 3974 7612 3973 7610 3977 7606
      3986 7545 3961 7543 3936 7569 3934 7613
      3937 7611 3937 7606 3942 7600 3946 7601
      3952 7598 3955 7603 3955 7609 3972 7623
TIME...MOT...LOC 1928Z 270DEG 55KT 3978 7577 3957 7591 3943 7605 

HAIL...0.75IN
WIND...60MPH
 
$$

33

443 
WWUS51 KPHI 011947
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
247 PM EST WED MAR 1 2017

DEC003-MDC015-029-NJC033-PAC029-045-011956-
/O.EXP.KPHI.SV.W.0017.000000T0000Z-170301T1945Z/
New Castle DE-Kent MD-Cecil MD-Salem NJ-Chester PA-Delaware PA-
247 PM EST WED MAR 1 2017

...THE SEVERE THUNDERSTORM WARNING FOR NEW CASTLE...NORTHEASTERN
KENT...CECIL...NORTHWESTERN SALEM...SOUTHWESTERN CHESTER AND
SOUTHWESTERN DELAWARE COUNTIES HAS EXPIRED...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning has been allowed to expire.  However gusty
winds to 45 mph are still possible with these showers.

A severe thunderstorm watch remains in effect until 700 PM EST for
northern Delaware...northeastern Maryland...southern New Jersey...and
southeastern Pennsylvania.

LAT...LON 3972 7614 3974 7612 3973 7610 3977 7606
      3986 7545 3961 7543 3936 7569 3934 7613
      3937 7611 3937 7606 3942 7600 3946 7601
      3952 7598 3955 7603 3955 7609 3972 7623
TIME...MOT...LOC 1946Z 262DEG 55KT 3982 7542 3961 7557 3947 7571 

$$

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 1, 2:09 PM EST	Severe Thunderstorm Warning	PHI	Kent, New Castle, Sussex	51 min
Mar 1, 2:45 PM EST	Severe Thunderstorm Warning	PHI	Kent, New Castle, Sussex	60 min
Mar 1, 3:09 PM EST	Wind Advisory	PHI	Kent, New Castle, Sussex	19 hr
Mar 1, 2:02 PM EST	Special Weather Statement	PHI	Berks, Chester, Lehigh	43 min
Mar 1, 2:09 PM EST	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	51 min
Mar 1, 2:31 PM EST	Special Weather Statement	PHI	Northampton	29 min
Mar 1, 2:46 PM EST	Special Weather Statement	PHI	Delaware, Philadelphia	29 min
Mar 1, 2:55 PM EST	Special Weather Statement	PHI	Bucks, Montgomery, Northampton	35 min
Mar 1, 3:32 AM EST	Gale Warning	PHI		36 hr
Mar 1, 2:21 PM EST	Special Marine Warning	PHI		54 min
Mar 1, 2:57 PM EST	Special Marine Warning	PHI		63 min
Mar 1, 3:16 PM EST	Special Weather Statement	PHI	Burlington, Camden, Gloucester, Salem	44 min
Mar 1, 3:43 PM EST	Special Weather Statement	PHI	Atlantic, Burlington, Camden, Ocean	32 min
Mar 1, 3:52 PM EST	Special Marine Warning	PHI		83 min
Mar 1, 4:00 PM EST	Special Marine Warning	PHI		60 min
Mar 1, 4:00 PM EST	Severe Thunderstorm Warning	PHI	Burlington, Ocean	31 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2017 Severe Thunderstorm Warnings in Maryland, 2017 Severe Thunderstorm Warnings in Delaware, 2017 Every 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.