Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 2242

October 9, 201124 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Oct 9, 2011, 7:53 AM CDT for 24 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Oct 9, 2011, 7:53 AM CDT (12:53 UTC)
Expired
Oct 9, 2011, 11:00 AM CDT
In force
3 hr
Issued by
the Storm Prediction Center
All 24 counties

Austin County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Calhoun County, TX, Colorado County, TX, DeWitt County, TX, Fayette County, TX, Fort Bend County, TX, Goliad County, TX, Grimes County, TX, Harris County, TX, Jackson County, TX, Lavaca County, TX, Lee County, TX, Matagorda County, TX, Milam County, TX, Montgomery County, TX, Refugio County, TX, Robertson County, TX, Victoria County, TX, Waller County, TX, Washington County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 117 km from the middle of the area, began a volume at 12:53 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.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 0.9 hours before the alert went out and 251 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 12:00Z on 2011-10-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2278 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 12:00Z on 2011-10-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.1939Sfc1 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
2278 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
766 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

021 
ACUS11 KWNS 091254
SWOMCD
SPC MCD 091253
TXZ000-091600-

MESOSCALE DISCUSSION 2242
NWS STORM PREDICTION CENTER NORMAN OK
0753 AM CDT SUN OCT 09 2011

AREAS AFFECTED...ECNTRL AND SE TX

CONCERNING...HEAVY RAINFALL

VALID 091253Z - 091600Z

HEAVY RAINFALL WILL CONTINUE TO BE POSSIBLE WITHIN THE STRONGER
CELLS EMBEDDED IN A LINE MOVING INTO SE TX. RAINFALL RATES OF 1 INCH
PER HOUR MAY OCCUR AS THE LINE PASSES SLOWLY FROM WEST TO EAST THIS
MORNING.

A LINE OF STRONG THUNDERSTORMS ALONG THE TX COASTAL PLAIN IS LOCATED
ON THE NRN END OF AN AXIS OF VERY MOIST AIR WITH SFC DEWPOINTS NEAR
70 F. THE LINE IS LOCATED NEAR A MAXIMUM IN PRECIPITABLE WATER
VALUES WITH MESOANALYSIS SUGGESTING PW VALUES ARE ABOVE 1.75 INCHES
ACROSS MOST OF THE MIDDLE TX COASTAL PLAIN FROM HOUSTON SWWD TO
CORPUS CHRISTI. THIS ALONG WITH A SLOW EWD MOVEMENT AROUND 20 KT
SHOULD BE FAVORABLE FOR HEAVY RAINFALL WITH 1 INCH PER HOUR RATES
POSSIBLE WITH THE MORE INTENSE CORES. THE SRN END OF THE LINE IS
NEAR THE STRONGEST INSTABILITY AND MAY BE FAVORED WITH THE GREATEST
HEAVY RAINFALL THREAT.

..BROYLES.. 10/09/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...HGX...FWD...CRP...EWX...

LAT...LON   30209501 30579544 30959599 31289670 31179729 30819736
            30429724 29489743 28519768 28109739 28119700 28369643
            29009558 29399496 29699478 29929479 30209501

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 8, 11:32 PM CDTMesoscale DiscussionSPCBandera, Blanco, Bosque, Brown, Burnet, Comanche and 25 more2 hr
Oct 9, 2:40 AM CDTMesoscale DiscussionSPCAtascosa, Bee, Bexar, Blanco, Burnet, Caldwell and 21 more3 hr

Nearby

Mesoscale Discussions in Texas, 2011Every mesoscale discussion in 2011

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.