Alert archive / Texas / Mesoscale Discussions in 2006

Mesoscale Discussion 2139

October 18, 200617 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Oct 18, 2006, 8:01 PM CDT for 17 counties in Texas. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued: Oct 18, 2006, 8:01 PM CDT (01:01 UTC)
Expired: Oct 18, 2006, 9:00 PM CDT
In force: 59 min
Issued by: the Storm Prediction Center

Counties Anderson County, TX, Bell County, TX, Brazos County, TX, Burleson County, TX, Falls County, TX, Freestone County, TX, Henderson County, TX, Houston County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, McLennan County, TX, Milam County, TX, Navarro County, TX, Robertson County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 108 km from the middle of the area, began a volume at 01:02 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

Fort Worth, TX (KFWD), launched 00:00Z, 1.0 hours before the alert went out and 189 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 661 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 170 m²/s²
0-3 km storm-relative helicity: 353 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 190101
SWOMCD
SPC MCD 190101 
TXZ000-190200-

MESOSCALE DISCUSSION 2139
NWS STORM PREDICTION CENTER NORMAN OK
0801 PM CDT WED OCT 18 2006

AREAS AFFECTED...EAST TX

CONCERNING...SEVERE THUNDERSTORM WATCH 836...

VALID 190101Z - 190200Z

A SEVERE THREAT SHOULD CONTINUE ACROSS ECNTRL TO NE TX FOR SEVERAL
MORE HOURS. HAIL AND WIND DAMAGE WILL BE THE PRIMARY THREATS WITH
THE ACTIVITY. A WW MAY NEED TO BE CONSIDERED EAST OF WW 836.

A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS IS ONGOING IN ECNTRL TX
ALONG A COLD FRONT EXTENDING NORTHEAST TO SOUTHWEST ACROSS THE
REGION. LOW-LEVEL CONVERGENCE IS VERY STRONG ALONG THE FRONT AND
THIS SHOULD SUPPORT CONTINUED DEVELOPMENT LATE THIS EVENING. THE
THUNDERSTORMS ARE LOCATED IN THE ERN PART OF WW 836 AND SHOULD BEGIN
TO AFFECT AREAS EAST OF THE WATCH IN 1-2 HOURS. BECAUSE OF THIS...
AN ADDITIONAL WW MAY BE NEEDED. THE CONVECTION IS LOCATED ON THE NRN
EDGE OF AN AXIS OF MODERATE INSTABILITY NEAR THE CENTER OF A 60 KT
MID-LEVEL JET. THE VERY STRONG VERTICAL SHEAR ASSOCIATED WITH THE
JET SHOULD BE FAVORABLE FOR SUPERCELLS. WIND DAMAGE AND HAIL WILL BE
POSSIBLE DUE TO THE STEEP LOW-LEVEL LAPSE RATES AND STRONG VERTICAL
SHEAR.

..BROYLES.. 10/19/2006

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

ATTN...WFO...SHV...HGX...FWD...EWX...

30989558 30189693 30749795 31159795 32099676 32459584
31709504

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 18, 11:52 PM CDT	Mesoscale Discussion	SPC	Austin, Brazoria, Chambers, Colorado, DeWitt, Fort Bend and 13 more	113 min
Oct 19, 3:03 AM CDT	Mesoscale Discussion	SPC	Brazoria, Chambers, Galveston, Hardin, Harris, Jasper and 6 more	117 min

Nearby

Mesoscale Discussions in Texas, 2006 Every mesoscale discussion in 2006

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.