Alert archive / Maryland / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 28, NWS Philadelphia/Mount Holly

May 5, 2017Kent County, New Castle County, Sussex County, Delaware; 4 counties in Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 5, 2017, 10:00 AM EDT for Kent County, New Castle County, Sussex County, Delaware; 4 counties in Maryland. 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 5, 2017, 10:00 AM EDT (14:00 UTC)
Expired: May 5, 2017, 10:45 AM EDT
In force: 45 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Cecil County, MD, Kent County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 52 km from the middle of the area, began a volume at 14:00 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
May 5, 10:10 AM EDT	TSTM WND DMG	Perryville, MD	TREE DOWN ON A CAR AT JACKSON STATION ROAD AND OLD HAWLEY 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, 2.0 hours before the alert went out and 148 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: 8 J/kg
Mixed-layer CIN: -15 J/kg
Mixed-layer LCL: 473 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 407 m²/s²
0-3 km storm-relative helicity: 508 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

700 
WUUS51 KPHI 051400
SVRPHI
DEC001-003-005-MDC011-015-029-035-051445-
/O.NEW.KPHI.SV.W.0028.170505T1400Z-170505T1445Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service MOUNT HOLLY NJ
1000 AM EDT FRI MAY 5 2017

The National Weather Service in MOUNT HOLLY NJ  has issued a

* Severe Thunderstorm Warning for...
  Western Sussex County in southern Delaware...
  New Castle County in northern Delaware...
  Kent County in central Delaware...
  Northeastern Queen Anne's County in northeastern Maryland...
  Caroline County in eastern Maryland...
  Northeastern Kent County in northeastern Maryland...
  Cecil County in northeastern Maryland...

* Until 1045 AM EDT

* At 958 AM EDT, severe thunderstorms were located along a line
  extending from near Betterton to Oakland to near Vienna, moving
  northeast at 55 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Dover, Newark, Middletown, Elkton, Georgetown, Calvert, Pennsville,
  Smyrna, Milford, Seaford, New Castle, Chestertown, Denton, Laurel,
  North East, Harrington, Camden, Clayton, Federalsburg and Milton.

These storms have a history of producing wind damage in eastern 
Maryland. They could also prodce a brief tornado with enhanced wind 
damage.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3865 7571 3869 7591 3894 7590 3935 7613
      3943 7600 3952 7598 3957 7609 3972 7601
      3966 7552 3962 7556 3957 7550 3950 7553
      3951 7548 3946 7554 3943 7546 3864 7529
      3847 7569
TIME...MOT...LOC 1358Z 217DEG 46KT 3939 7610 3899 7587 3849 7590 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

amc

1 follow-up statement

234 
WWUS51 KPHI 051426
SVSPHI

Severe Weather Statement
National Weather Service MOUNT HOLLY NJ
1026 AM EDT FRI MAY 5 2017

MDC011-015-029-035-051434-
/O.CAN.KPHI.SV.W.0028.000000T0000Z-170505T1445Z/
Queen Anne's MD-Caroline MD-Kent MD-Cecil MD-
1026 AM EDT FRI MAY 5 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN QUEEN ANNE'S...
CAROLINE...NORTHEASTERN KENT AND CECIL COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

LAT...LON 3865 7569 3969 7579 3966 7552 3963 7556
      3960 7556 3957 7550 3954 7554 3950 7553
      3946 7554 3943 7546 3937 7546 3939 7549
      3934 7544 3864 7529 3847 7569
TIME...MOT...LOC 1424Z 231DEG 32KT 3961 7568 3909 7565 3848 7566 

$$

DEC001-003-005-051445-
/O.CON.KPHI.SV.W.0028.000000T0000Z-170505T1445Z/
Sussex DE-New Castle DE-Kent DE-
1026 AM EDT FRI MAY 5 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1045 AM EDT
FOR WESTERN SUSSEX...NEW CASTLE AND KENT COUNTIES...

At 1024 AM EDT, severe thunderstorms were located along a line
extending from Bear to Hazlettville to near Hebron, moving northeast
at 35 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Expect minor damage to roofs, siding, and some trees 
         downed. 

Locations impacted include...
Dover, Newark, Middletown, Georgetown, Smyrna, Milford, Seaford, New
Castle, Laurel, Harrington, Camden, Clayton, Milton, Bridgeville,
Delaware City, Cheswold, Ellendale, Bowers, Woodside and Viola.

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 3865 7569 3969 7579 3966 7552 3963 7556
      3960 7556 3957 7550 3954 7554 3950 7553
      3946 7554 3943 7546 3937 7546 3939 7549
      3934 7544 3864 7529 3847 7569
TIME...MOT...LOC 1424Z 231DEG 32KT 3961 7568 3909 7565 3848 7566 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

amc

The office that day

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

Issued	Product	Office	Counties	Lasted
May 5, 9:12 AM EDT	Special Weather Statement	PHI	New Castle	33 min
May 5, 11:00 AM EDT	Special Weather Statement	PHI	Sussex	60 min
May 5, 11:14 AM EDT	Areal Flood Advisory	PHI	New Castle	4 hr
May 5, 11:33 AM EDT	Areal Flood Advisory	PHI	Kent, Sussex	4 hr
May 5, 9:00 AM EDT	Severe Thunderstorm Warning	PHI	Caroline, Cecil, Kent, Queen Anne's, Talbot	60 min

Nearby

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.