Alert archive / Maryland / Severe Thunderstorm Warnings in 2017
Severe Thunderstorm Warning 173, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 18, 2017, 7:07 PM EDT for Kent County, New Castle County, Sussex County, Delaware; 4 counties in Maryland. It was in force for 53 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
- Aug 18, 2017, 7:07 PM EDT (23:07 UTC)
- Expired
- Aug 18, 2017, 8:00 PM EDT
- In force
- 53 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD
The radar
The Dover AFB radar (KDOX), 50 km from the middle of the area, began a volume at 23:10 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 |
|---|---|---|---|
| Aug 18, 2:27 PM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
The nearest sounding before it
Wallops Is Stn, VA (KWAL), launched 12:00Z, 11.1 hours before the alert went out and 115 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.
- Mixed-layer CAPE
- 582 J/kg
- Mixed-layer CIN
- -57 J/kg
- Mixed-layer LCL
- 808 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 105 m²/s²
- 0-3 km storm-relative helicity
- 112 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
346
WUUS51 KPHI 182307
SVRPHI
DEC001-003-005-MDC011-029-035-041-190000-
/O.NEW.KPHI.SV.W.0173.170818T2307Z-170819T0000Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
707 PM EDT FRI AUG 18 2017
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Sussex County in southern Delaware...
South central New Castle County in northern Delaware...
Kent County in central Delaware...
Talbot County in eastern Maryland...
Queen Anne's County in northeastern Maryland...
Caroline County in eastern Maryland...
Central Kent County in northeastern Maryland...
* Until 800 PM EDT
* At 706 PM EDT, severe thunderstorms were located along a line
extending from near Smyrna to Oakland to Romancoke, moving south at
35 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Minor damage to vehicles is possible. Expect damage to
trees and power lines.
* Locations impacted include...
Dover, Easton, Georgetown, Centerville, Talbot, Smyrna, Milford,
Seaford, Denton, Centreville, Laurel, Harrington, Romancoke,
Camden, Clayton, Lewes, Federalsburg, Milton, Bridgeville and
Greensboro.
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 3869 7577 3857 7604 3876 7632 3867 7634
3876 7638 3875 7635 3886 7626 3879 7620
3879 7619 3896 7625 3884 7637 3885 7638
3901 7620 3911 7624 3909 7593 3947 7554
3893 7529 3881 7506 3845 7548
TIME...MOT...LOC 2306Z 339DEG 30KT 3929 7553 3898 7585 3890 7635
HAIL...1.00IN
WIND...60MPH
$$
SFJ1 follow-up statement
443
WWUS51 KPHI 182340
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
740 PM EDT FRI AUG 18 2017
DEC001-003-005-MDC011-029-035-041-190000-
/O.CON.KPHI.SV.W.0173.000000T0000Z-170819T0000Z/
Sussex DE-New Castle DE-Kent DE-Talbot MD-Queen Anne's MD-
Caroline MD-Kent MD-
740 PM EDT FRI AUG 18 2017
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR SUSSEX...SOUTH CENTRAL NEW CASTLE...KENT...TALBOT...QUEEN
ANNE'S...CAROLINE AND CENTRAL KENT COUNTIES...
At 740 PM EDT, severe thunderstorms were located along a line
extending from 7 miles north of Bowers to Andrewsville to near St.
Michaels, moving east at 25 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Minor damage to vehicles is possible. Expect damage to
trees and power lines.
Locations impacted include...
Dover, Easton, Georgetown, Centerville, Talbot, Smyrna, Milford,
Seaford, Denton, Centreville, Laurel, Harrington, Romancoke, Camden,
Clayton, Lewes, Federalsburg, Milton, Bridgeville and Greensboro.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
In addition to large hail and damaging winds...frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember...if you can hear thunder...you are close
enough to be struck by lightning.
&&
LAT...LON 3869 7577 3857 7604 3876 7632 3867 7634
3876 7638 3875 7635 3886 7626 3879 7620
3879 7619 3896 7625 3884 7637 3885 7638
3901 7620 3911 7624 3909 7593 3947 7554
3893 7529 3881 7506 3845 7548
TIME...MOT...LOC 2340Z 289DEG 20KT 3917 7535 3886 7567 3878 7617
HAIL...1.00IN
WIND...60MPH
$$
SFJThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 3:39 AM EDT | Flash Flood Watch | PHI | Kent, New Castle, Sussex | 18 hr |
| Aug 18, 5:03 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 42 min |
| Aug 18, 5:20 PM EDT | Areal Flood Advisory | PHI | New Castle | 3 hr |
| Aug 18, 5:39 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 66 min |
| Aug 18, 6:10 PM EDT | Severe Thunderstorm Warning | PHI | Kent | 65 min |
| Aug 18, 6:12 PM EDT | Areal Flood Advisory | PHI | Kent, New Castle | 3 hr |
| Aug 18, 6:20 PM EDT | Special Weather Statement | PHI | Sussex | 25 min |
| Aug 18, 6:38 PM EDT | Special Weather Statement | PHI | New Castle | 37 min |
| Aug 18, 6:48 PM EDT | Special Weather Statement | PHI | New Castle | 27 min |
| Aug 18, 7:33 PM EDT | Areal Flood Advisory | PHI | Kent, Sussex | 3 hr |
| Aug 18, 7:53 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 48 min |
| Aug 18, 4:29 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 61 min |
| Aug 18, 4:57 PM EDT | Areal Flood Advisory | PHI | Cecil | 3 hr |
Nearby
Severe Thunderstorm Warnings in Maryland, 2017Severe Thunderstorm Warnings in Delaware, 2017Every 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.