Alert archive / Maryland / Severe Thunderstorm Watches in 2015
Severe Thunderstorm Watch 320
The Storm Prediction Center issued this severe thunderstorm watch at Jun 20, 2015, 8:56 PM EDT for 5 states. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 20, 2015, 8:56 PM EDT (00:56 UTC)
- Expired
- Jun 21, 2015, 1:00 AM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
All 29 counties
Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Cecil County, MD, Dorchester County, MD, Kent County, MD, Queen Anne's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Mercer County, NJ, Ocean County, NJ, Salem County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA, Accomack County, VA, Northampton County, VA
The radar
The Dover AFB radar (KDOX), 30 km from the middle of the area, began a volume at 00:59 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 20%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 9:35 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Talbot | 55 min |
| Jun 20, 9:36 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Somerset, Wicomico | 54 min |
| Jun 20, 9:49 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 56 min |
| Jun 20, 9:57 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's | 63 min |
| Jun 20, 10:32 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 46 min |
| Jun 20, 11:48 PM EDT | Severe Thunderstorm Warning | AKQ | Accomack, Northampton | 42 min |
| Jun 21, 12:35 AM EDT | Severe Thunderstorm Warning | PHI | Sussex | 55 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.9 hours before the alert went out and 125 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
- 261 J/kg
- Mixed-layer CIN
- -134 J/kg
- Mixed-layer LCL
- 1179 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 16 m²/s²
- 0-3 km storm-relative helicity
- 75 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 8:37 PM EDT | Mesoscale Discussion | SPC | Kent, New Castle, Sussex | 53 min |
| Jun 20, 10:14 PM EDT | Mesoscale Discussion | SPC | Kent, Sussex | 61 min |
| Jun 21, 2:52 PM EDT | Mesoscale Discussion | SPC | Buchanan, Dickenson, Lee, Russell, Tazewell, Wise and 1 more | 113 min |
| Jun 21, 3:23 PM EDT | Severe Thunderstorm Watch | SPC | Alleghany, Bath, Bedford, Bland, Botetourt, Buchanan and 36 more | 5 hr |
Nearby
Severe Thunderstorm Watches in Maryland, 2015Severe Thunderstorm Watches in New Jersey, 2015Severe Thunderstorm Watches in Pennsylvania, 2015Every severe thunderstorm watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.