Alert archive / Texas / Tornado Watches in 2015

Tornado Watch 65

April 16, 201516 counties in Texas

The Storm Prediction Center issued this tornado watch at Apr 16, 2015, 8:36 PM CDT for 16 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Apr 16, 2015, 8:36 PM CDT (01:36 UTC)
Expired
Apr 17, 2015, 12:00 AM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Austin County, TX, Brazoria County, TX, Chambers County, TX, Colorado County, TX, Fort Bend County, TX, Galveston County, TX, Hardin County, TX, Harris County, TX, Jefferson County, TX, Liberty County, TX, Matagorda County, TX, Montgomery County, TX, Orange County, TX, Waller County, TX, Washington County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 62 km from the middle of the area, began a volume at 01:40 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
30%
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
30%
One or more hailstones of 2 inches or more
30%
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.

IssuedProductOfficeCountiesLasted
Apr 16, 8:57 PM CDTSevere Thunderstorm WarningHGXAustin, Colorado, Fort Bend, Waller, Wharton48 min
Apr 16, 9:03 PM CDTFlash Flood WarningHGXChambers, Harris, Liberty117 min
Apr 16, 9:45 PM CDTSevere Thunderstorm WarningHGXFort Bend30 min
Apr 16, 9:59 PM CDTFlash Flood WarningLCHHardin, Jasper, Jefferson, Newton, Orange3 hr
Apr 16, 10:14 PM CDTSevere Thunderstorm WarningHGXBrazoria, Fort Bend46 min
Apr 16, 10:54 PM CDTFlash Flood WarningHGXChambers, Harris, Liberty3 hr
Apr 17, 12:00 AM CDTFlash Flood WarningHGXHarris2 hr

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 00:00Z, 1.6 hours before the alert went out and 296 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.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 00:00Z on 2015-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2661 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Corpus Christi, TX at 00:00Z on 2015-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 126 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
2661 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
705 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
126 m²/s²
0-3 km storm-relative helicity
152 m²/s²
Significant tornado parameter
2.6
Supercell composite
13.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

934 
WWUS20 KWNS 170132
SEL5  
SPC WW 170132
TXZ000-CWZ000-170500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 65
NWS STORM PREDICTION CENTER NORMAN OK
830 PM CDT THU APR 16 2015

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  SOUTHEAST TEXAS
  COASTAL WATERS

* EFFECTIVE THIS THURSDAY NIGHT FROM 830 PM UNTIL MIDNIGHT CDT.

* PRIMARY THREATS INCLUDE...
  A COUPLE TORNADOES POSSIBLE
  ISOLATED VERY LARGE HAIL EVENTS TO 2 INCHES IN DIAMETER POSSIBLE
  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

SUMMARY...SCATTERED SEVERE THUNDERSTORMS WITH A RISK FOR A COUPLE
TORNADOES...LARGE HAIL...AND LOCALLY DAMAGING WIND EXPECTED TO
PERSIST OVER PARTS OF SOUTHEAST TEXAS THROUGH EARLY FRIDAY.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 45 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 75 MILES WEST NORTHWEST OF
ANGLETON TEXAS TO 10 MILES NORTHEAST OF PORT ARTHUR TEXAS.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU5).

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...THIS TORNADO WATCH REPLACES SEVERE
THUNDERSTORM WATCH NUMBER 60. WATCH NUMBER 60 WILL NOT BE IN
EFFECT AFTER 830 PM CDT. CONTINUE...WW 59...WW 61...WW 62...WW
63...WW 64...

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 25025.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 16, 7:08 PM CDTMesoscale DiscussionSPCCollingsworth, Wheeler2 hr
Apr 16, 7:16 PM CDTMesoscale DiscussionSPCArcher, Baylor, Briscoe, Brown, Callahan, Childress and 41 more89 min
Apr 16, 7:44 PM CDTMesoscale DiscussionSPCDallam, Hansford, Sherman61 min
Apr 16, 8:20 PM CDTMesoscale DiscussionSPCBrazoria, Chambers, Colorado, Fort Bend, Galveston, Harris and 2 more85 min
Apr 16, 10:20 PM CDTMesoscale DiscussionSPCAndrews, Armstrong, Borden, Briscoe, Carson, Castro and 32 more2 hr
Apr 16, 11:33 PM CDTMesoscale DiscussionSPCAustin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 6 more87 min
Apr 16, 11:59 PM CDTSevere Thunderstorm WatchSPCCollingsworth, Donley, Gray, Hemphill, Roberts, Wheeler5 hr
Apr 17, 1:10 AM CDTMesoscale DiscussionSPCBorden, Childress, Cottle, Crosby, Dawson, Dickens and 13 more95 min
Apr 17, 2:02 AM CDTMesoscale DiscussionSPCCollingsworth, Donley, Gray, Hemphill, Lipscomb, Roberts and 1 more88 min
Apr 17, 4:43 AM CDTMesoscale DiscussionSPCHardeman62 min
Apr 17, 10:26 AM CDTMesoscale DiscussionSPCBandera, Bexar, Blanco, Burnet, Comal, Edwards and 12 more2 hr
Apr 17, 10:55 AM CDTMesoscale DiscussionSPCBaylor, Brown, Callahan, Coke, Coleman, Concho and 15 more2 hr
Apr 17, 11:53 AM CDTSevere Thunderstorm WatchSPCArcher, Atascosa, Bandera, Baylor, Bee, Bell and 73 more7 hr
Apr 17, 1:31 PM CDTMesoscale DiscussionSPCAtascosa, Bee, Calhoun, DeWitt, Dimmit, Frio and 12 more89 min
Apr 17, 3:06 PM CDTMesoscale DiscussionSPCBriscoe, Carson, Childress, Collingsworth, Donley, Gray and 8 more84 min
Apr 17, 3:22 PM CDTMesoscale DiscussionSPCAransas, Bee, Brazoria, Calhoun, Colorado, DeWitt and 11 more113 min
Apr 17, 3:30 PM CDTSevere Thunderstorm WatchSPCAransas, Atascosa, Austin, Bastrop, Brazoria, Brazos and 30 more6 hr
Apr 17, 5:02 PM CDTMesoscale DiscussionSPCArcher, Baylor, Bosque, Brown, Callahan, Clay and 28 more88 min
Apr 17, 5:41 PM CDTMesoscale DiscussionSPCAransas, Atascosa, Bee, Brazoria, Brooks, Calhoun and 26 more94 min
Apr 17, 6:57 PM CDTTornado WatchSPCAransas, Bee, Brooks, Calhoun, Duval, Goliad and 16 more5 hr

Nearby

Tornado Watches in Texas, 2015Every tornado 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.