Alert archive / Texas / Tornado Watches in 2015
Tornado Watch 122
The Storm Prediction Center issued this tornado watch at Apr 26, 2015, 5:39 PM CDT for 7 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 26, 2015, 5:39 PM CDT (22:39 UTC)
- Expired
- Apr 26, 2015, 7:56 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
Counties Brazoria County, TX, Fort Bend County, TX, Galveston County, TX, Harris County, TX, Jackson County, TX, Matagorda County, TX, Wharton County, TX
The radar
The Houston radar (KHGX), 67 km from the middle of the area, began a volume at 22:41 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
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 26, 5:51 PM CDT | Severe Thunderstorm Warning | HGX | Brazoria, Fort Bend, Wharton | 39 min |
| Apr 26, 6:16 PM CDT | Severe Thunderstorm Warning | HGX | Brazoria, Fort Bend, Matagorda, Wharton | 29 min |
| Apr 26, 6:49 PM CDT | Severe Thunderstorm Warning | HGX | Brazoria, Fort Bend, Galveston | 41 min |
| Apr 26, 7:24 PM CDT | Severe Thunderstorm Warning | HGX | Brazoria, Galveston, Harris | 23 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
Corpus Christi, TX (KCRP), launched 12:00Z, 10.7 hours before the alert went out and 232 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
- 930 J/kg
- Mixed-layer CIN
- -334 J/kg
- Mixed-layer LCL
- 1354 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- 24 m²/s²
- 0-3 km storm-relative helicity
- 181 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
As transmitted, in the capitals the NWS used until 2016.
652
WWUS20 KWNS 262237
SEL2
SPC WW 262237
TXZ000-CWZ000-270300-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 122
NWS STORM PREDICTION CENTER NORMAN OK
540 PM CDT SUN APR 26 2015
THE NWS STORM PREDICTION CENTER HAS ISSUED A
* TORNADO WATCH FOR PORTIONS OF
PARTS OF THE UPPER TEXAS COASTAL PLAIN
COASTAL WATERS
* EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 540 PM UNTIL
1000 PM CDT.
* PRIMARY THREATS INCLUDE...
A COUPLE TORNADOES POSSIBLE
SCATTERED LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 2.5
INCHES IN DIAMETER POSSIBLE
ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
SUMMARY...ISOLATED SUPERCELL IN WHARTON COUNTY WILL LIKELY PERSIST
WHILE MOVING GENERALLY EWD/ESEWD TOWARD THE AREA IMMEDIATELY S OF
HOUSTON. THE STORM ENVIRONMENT WILL BE SUFFICIENT TO MAINTAIN
SUPERCELL STRUCTURES...WITH AN ATTENDANT RISK FOR ISOLATED VERY
LARGE HAIL/DAMAGING WINDS...ALONG WITH A TORNADO OR TWO FOR THE NEXT
FEW HOURS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 35 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 25 MILES NORTH NORTHWEST OF
PALACIOS TEXAS TO 5 MILES SOUTHEAST OF GALVESTON TEXAS. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU2).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 119...WW 120...WW 121...
AVIATION...TORNADOES AND 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
600. MEAN STORM MOTION VECTOR 28015.
...THOMPSONSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 26, 10:55 AM CDT | Mesoscale Discussion | SPC | Archer, Baylor, Bosque, Brown, Callahan, Clay and 30 more | 2 hr |
| Apr 26, 1:06 PM CDT | Tornado Watch | SPC | Archer, Baylor, Brown, Callahan, Childress, Clay and 27 more | 7 hr |
| Apr 26, 2:04 PM CDT | Mesoscale Discussion | SPC | Collingsworth | 2 hr |
| Apr 26, 2:52 PM CDT | Severe Thunderstorm Watch | SPC | Collingsworth, Donley, Wheeler | 5 hr |
| Apr 26, 2:54 PM CDT | Mesoscale Discussion | SPC | Archer, Baylor, Brown, Callahan, Clay, Coleman and 27 more | 2 hr |
| Apr 26, 3:18 PM CDT | Mesoscale Discussion | SPC | Armstrong, Carson, Dallam, Hartley, Moore, Potter | 117 min |
| Apr 26, 4:54 PM CDT | Tornado Watch | SPC | Bell, Bosque, Comanche, Coryell, Dallas, Eastland and 17 more | 6 hr |
| Apr 26, 5:24 PM CDT | Mesoscale Discussion | SPC | Brazoria, Chambers, Fort Bend, Galveston, Harris, Wharton | 96 min |
| Apr 26, 5:51 PM CDT | Mesoscale Discussion | SPC | Brown, Coleman, Comanche, Eastland, Erath, Hamilton | 84 min |
| Apr 26, 6:44 PM CDT | Mesoscale Discussion | SPC | Brown, Coleman, Concho, Kimble, McCulloch, Mason and 2 more | 2 hr |
Nearby
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.