Alert archive / Texas / Tornado Watches in 2009

Tornado Watch 81

March 27, 200912 counties in Texas

The Storm Prediction Center issued this tornado watch at Mar 27, 2009, 4:49 PM CDT for 12 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Mar 27, 2009, 4:49 PM CDT (21:49 UTC)
Expired
Mar 27, 2009, 8:00 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Brazoria County, TX, Chambers County, TX, Galveston County, TX, Hardin County, TX, Harris County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Tyler County, TX

The radar

The Houston radar (KHGX), 104 km from the middle of the area, began a volume at 21:49 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
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Mar 27, 4:59 PM CDTSevere Thunderstorm WarningLCHHardin, Tyler61 min
Mar 27, 5:02 PM CDTSevere Thunderstorm WarningHGXLiberty, Polk28 min
Mar 27, 5:04 PM CDTTornado WarningLCHHardin, Tyler26 min
Mar 27, 5:13 PM CDTSevere Thunderstorm WarningHGXHarris, Liberty, Montgomery47 min
Mar 27, 5:24 PM CDTSevere Thunderstorm WarningHGXBrazoria, Harris35 min
Mar 27, 5:31 PM CDTTornado WarningLCHHardin, Tyler29 min
Mar 27, 5:56 PM CDTSevere Thunderstorm WarningHGXLiberty49 min
Mar 27, 5:56 PM CDTSevere Thunderstorm WarningLCHHardin, Jasper, Newton, Tyler49 min
Mar 27, 6:00 PM CDTSevere Thunderstorm WarningLCHHardin, Jefferson60 min
Mar 27, 6:19 PM CDTTornado WarningLCHJasper, Newton26 min
Mar 27, 6:21 PM CDTSevere Thunderstorm WarningHGXChambers, Liberty39 min
Mar 27, 6:31 PM CDTSevere Thunderstorm WarningLCHNewton44 min
Mar 27, 6:58 PM CDTSevere Thunderstorm WarningLCHHardin, Jasper, Jefferson, Orange62 min
Mar 27, 7:48 PM CDTSevere Thunderstorm WarningLCHNewton, Orange42 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

Lake Charles Mun, LA (KLCH), launched 12:00Z, 9.8 hours before the alert went out and 131 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, Lake Charles Mun, LA at 12:00Z on 2009-03-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1993 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, Lake Charles Mun, LA at 12:00Z on 2009-03-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 square meters per square second.19395878Sfc1 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
1993 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
509 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
-15 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 26, 7:32 PM CDTSevere Thunderstorm WatchSPCCooke, Denton, Fannin, Grayson, Jack, Montague and 1 more4 hr
Mar 26, 9:13 PM CDTMesoscale DiscussionSPCAngelina, Cherokee, Hardin, Jasper, Jefferson, Nacogdoches and 6 more92 min
Mar 26, 11:34 PM CDTMesoscale DiscussionSPCDallam, Hartley, Moore, Oldham, Sherman4 hr
Mar 27, 2:55 AM CDTMesoscale DiscussionSPCArmstrong, Carson, Dallam, Deaf Smith, Hansford, Hartley and 9 more4 hr
Mar 27, 8:04 AM CDTMesoscale DiscussionSPCCollingsworth, Donley, Gray, Hemphill, Lipscomb, Ochiltree and 2 more4 hr
Mar 27, 10:24 AM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bastrop, Bell, Brazoria and 43 more96 min
Mar 27, 11:48 AM CDTSevere Thunderstorm WatchSPCAustin, Brazos, Burleson, Chambers, Grimes, Hardin and 16 more5 hr
Mar 27, 12:30 PM CDTMesoscale DiscussionSPCCarson, Childress, Collingsworth, Donley, Gray, Hansford and 8 more6 hr
Mar 27, 12:33 PM CDTMesoscale DiscussionSPCAnderson, Bowie, Camp, Cass, Cherokee, Collin and 26 more57 min
Mar 27, 12:58 PM CDTTornado WatchSPCAnderson, Angelina, Bowie, Camp, Cass, Cherokee and 28 more7 hr
Mar 27, 3:34 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Bowie, Camp, Cass, Cherokee and 28 more56 min
Mar 27, 3:43 PM CDTMesoscale DiscussionSPCChambers, Hardin, Harris, Jasper, Jefferson, Liberty and 6 more62 min
Mar 27, 5:53 PM CDTMesoscale DiscussionSPCBowie, Cass97 min
Mar 27, 6:35 PM CDTTornado WatchSPCAngelina, Bowie, Camp, Cass, Cherokee, Gregg and 10 more7 hr

Nearby

Tornado Watches in Texas, 2009Every tornado watch in 2009

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.