Alert archive / Texas / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 209
The Storm Prediction Center issued this severe thunderstorm watch at Apr 30, 2012, 2:39 PM CDT for 18 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 30, 2012, 2:39 PM CDT (19:39 UTC)
- Expired
- Apr 30, 2012, 9:15 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
Counties Borden County, TX, Brewster County, TX, Crane County, TX, Dawson County, TX, Ector County, TX, Howard County, TX, Jeff Davis County, TX, Martin County, TX, Midland County, TX, Mitchell County, TX, Pecos County, TX, Presidio County, TX, Reeves County, TX, Scurry County, TX, Terrell County, TX, Upton County, TX, Ward County, TX, Winkler County, TX
The radar
The Midland/Odessa radar (KMAF), 211 km from the middle of the area, began a volume at 19:40 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
- 30%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
13 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 30, 3:28 PM CDT | Severe Thunderstorm Warning | MAF | Brewster, Jeff Davis, Pecos | 62 min |
| Apr 30, 4:09 PM CDT | Severe Thunderstorm Warning | MAF | Brewster | 66 min |
| Apr 30, 4:31 PM CDT | Severe Thunderstorm Warning | MAF | Brewster, Pecos | 59 min |
| Apr 30, 4:38 PM CDT | Severe Thunderstorm Warning | MAF | Brewster | 52 min |
| Apr 30, 5:04 PM CDT | Severe Thunderstorm Warning | MAF | Borden, Scurry | 56 min |
| Apr 30, 5:16 PM CDT | Severe Thunderstorm Warning | MAF | Brewster | 59 min |
| Apr 30, 5:24 PM CDT | Severe Thunderstorm Warning | MAF | Brewster | 51 min |
| Apr 30, 5:57 PM CDT | Severe Thunderstorm Warning | MAF | Borden, Scurry | 63 min |
| Apr 30, 6:16 PM CDT | Severe Thunderstorm Warning | MAF | Brewster | 39 min |
| Apr 30, 6:17 PM CDT | Severe Thunderstorm Warning | MAF | Howard, Martin | 58 min |
| Apr 30, 6:40 PM CDT | Severe Thunderstorm Warning | MAF | Borden, Scurry | 65 min |
| Apr 30, 6:52 PM CDT | Flash Flood Warning | MAF | Borden, Scurry | 3 hr |
| Apr 30, 7:43 PM CDT | Severe Thunderstorm Warning | MAF | Borden, Scurry | 62 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
Midland Regional, TX (KMAF), launched 12:00Z, 7.7 hours before the alert went out and 211 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
- 1590 J/kg
- Mixed-layer CIN
- -246 J/kg
- Mixed-layer LCL
- 1149 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 155 m²/s²
- 0-3 km storm-relative helicity
- 184 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
833
WWUS20 KWNS 301935
SEL9
SPC WW 301935
TXZ000-010300-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 209
NWS STORM PREDICTION CENTER NORMAN OK
235 PM CDT MON APR 30 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
SOUTHWEST TEXAS
EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 235 PM UNTIL
1000 PM CDT.
HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60
STATUTE MILES EAST AND WEST OF A LINE FROM 95 MILES SOUTH
SOUTHEAST OF MARFA TEXAS TO 20 MILES WEST NORTHWEST OF MIDLAND
TEXAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.
OTHER WATCH INFORMATION...CONTINUE...WW 208...
DISCUSSION...INCIPIENT TSTM DEVELOPMENT IS UNDERWAY ALONG THE DAVIS
MOUNTAINS W OF FST. INFLOW AIR MASS IS CHARACTERIZED BY A
HOT...MOIST BOUNDARY LAYER WITH MLCAPE OF 2000-3000 J/KG. THIS
INSTABILITY COMBINED WITH A VERTICALLY VEERING WIND PROFILE AND
30-35 KT OF DEEP-LAYER SHEAR WILL SUPPORT SUPERCELL STORM MODES WITH
THE PRIMARY HAZARD BEING LARGE HAIL.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 27015.
...MEADSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 29, 7:23 PM CDT | Severe Thunderstorm Watch | SPC | Andrews, Bailey, Borden, Briscoe, Castro, Cochran and 14 more | 4 hr |
| Apr 29, 7:33 PM CDT | Mesoscale Discussion | SPC | Carson, Dallam, Gray, Hansford, Hartley, Hemphill and 8 more | 87 min |
| Apr 29, 8:55 PM CDT | Severe Thunderstorm Watch | SPC | Armstrong, Carson, Collingsworth, Donley, Gray, Hemphill and 6 more | 6 hr |
| Apr 29, 10:04 PM CDT | Mesoscale Discussion | SPC | Armstrong, Borden, Briscoe, Carson, Castro, Childress and 29 more | 86 min |
| Apr 29, 10:31 PM CDT | Mesoscale Discussion | SPC | Dallam, Hansford, Lipscomb, Ochiltree, Sherman | 119 min |
| Apr 29, 10:50 PM CDT | Severe Thunderstorm Watch | SPC | Bailey, Borden, Castro, Cochran, Dawson, Garza and 11 more | 4 hr |
| Apr 30, 12:38 AM CDT | Mesoscale Discussion | SPC | Armstrong, Carson, Collingsworth, Donley, Gray, Hansford and 9 more | 37 min |
| Apr 30, 2:15 AM CDT | Mesoscale Discussion | SPC | Briscoe, Castro, Crosby, Dickens, Floyd, Garza and 5 more | 30 min |
| Apr 30, 2:08 PM CDT | Mesoscale Discussion | SPC | Crane, Ector, Midland, Pecos, Terrell, Upton | 97 min |
| Apr 30, 2:58 PM CDT | Mesoscale Discussion | SPC | Armstrong, Bailey, Briscoe, Carson, Castro, Cochran and 21 more | 62 min |
| Apr 30, 3:36 PM CDT | Severe Thunderstorm Watch | SPC | Armstrong, Bailey, Briscoe, Carson, Castro, Childress and 35 more | 7 hr |
| Apr 30, 5:19 PM CDT | Mesoscale Discussion | SPC | Gray, Hemphill, Lipscomb, Ochiltree, Roberts, Wheeler | 56 min |
| Apr 30, 5:42 PM CDT | Tornado Watch | SPC | Armstrong, Briscoe, Carson, Childress, Collingsworth, Donley and 12 more | 7 hr |
| Apr 30, 6:11 PM CDT | Mesoscale Discussion | SPC | Baylor, Borden, Callahan, Coke, Coleman, Concho and 48 more | 2 hr |
| Apr 30, 6:54 PM CDT | Severe Thunderstorm Watch | SPC | Archer, Baylor, Callahan, Coke, Coleman, Concho and 33 more | 6 hr |
Nearby
Severe Thunderstorm Watches in Texas, 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.