Alert archive / Maryland / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 434
The Storm Prediction Center issued this severe thunderstorm watch at Jun 29, 2012, 4:34 AM EDT for 4 states. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 29, 2012, 4:34 AM EDT (08:34 UTC)
- Expired
- Jun 29, 2012, 7:48 AM EDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 28 counties
Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, City of Baltimore, MD, Harford County, MD, Howard County, MD, Kent County, MD, Queen Anne's County, MD, Talbot 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, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 78 km from the middle of the area, began a volume at 08:34 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
- 5%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- 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
- 70%
Warnings issued inside it
8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 29, 4:37 AM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Harford | 38 min |
| Jun 29, 4:46 AM EDT | Severe Thunderstorm Warning | PHI | New Castle | 48 min |
| Jun 29, 4:52 AM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Harford | 38 min |
| Jun 29, 5:00 AM EDT | Severe Thunderstorm Warning | PHI | Burlington, Camden, Gloucester, Hunterdon, Mercer, Monmouth and 2 more | 75 min |
| Jun 29, 5:03 AM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, City of Baltimore | 42 min |
| Jun 29, 5:23 AM EDT | Severe Thunderstorm Warning | PHI | Kent, New Castle | 67 min |
| Jun 29, 5:31 AM EDT | Severe Thunderstorm Warning | PHI | Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more | 59 min |
| Jun 29, 6:04 AM EDT | Severe Thunderstorm Warning | PHI | Burlington, Ocean | 41 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
Washington/Dulle, VA (KIAD), launched 00:00Z, 8.6 hours before the alert went out and 215 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2494 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 132 m²/s²
- 0-3 km storm-relative helicity
- 317 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 29, 6:03 PM EDT | Mesoscale Discussion | SPC | Allegany, Charles, Frederick, Garrett, Montgomery, Prince George's and 1 more | 87 min |
| Jun 29, 6:34 PM EDT | Severe Thunderstorm Watch | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 9 more | 6 hr |
| Jun 29, 7:51 PM EDT | Mesoscale Discussion | SPC | Allegany, Frederick, Garrett, Montgomery, Washington | 114 min |
| Jun 29, 3:41 AM EDT | Mesoscale Discussion | SPC | Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 4 more | 94 min |
| Jun 28, 8:53 PM EDT | Mesoscale Discussion | SPC | Erie | 97 min |
| Jun 29, 12:45 AM EDT | Mesoscale Discussion | SPC | Armstrong, Blair, Butler, Cambria, Cameron, Centre and 18 more | 90 min |
| Jun 29, 3:07 PM EDT | Mesoscale Discussion | SPC | Greene, Washington | 53 min |
Nearby
Severe Thunderstorm Watches in Maryland, 2012Severe Thunderstorm Watches in New Jersey, 2012Severe Thunderstorm Watches in Pennsylvania, 2012Every severe thunderstorm watch in 2012
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.