Alert archive / Texas / Mesoscale Discussions in 2011
Mesoscale Discussion 830
The Storm Prediction Center issued this mesoscale discussion at May 20, 2011, 5:34 PM CDT for 47 counties in Texas. It was in force for 116 min.
The area
The outline as issued.
The facts
- Issued
- May 20, 2011, 5:34 PM CDT (22:34 UTC)
- Expired
- May 20, 2011, 7:30 PM CDT
- In force
- 116 min
- Issued by
- the Storm Prediction Center
All 47 counties
Anderson County, TX, Bandera County, TX, Bastrop County, TX, Bell County, TX, Bexar County, TX, Blanco County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Cherokee County, TX, Collin County, TX, Comal County, TX, Dallas County, TX, Delta County, TX, Ellis County, TX, Falls County, TX, Fannin County, TX, Fayette County, TX, Freestone County, TX, Gillespie County, TX, Gonzales County, TX, Guadalupe County, TX, Hays County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Houston County, TX, Hunt County, TX, Kaufman County, TX, Kendall County, TX, Kerr County, TX, Lamar County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, McLennan County, TX, Medina County, TX, Milam County, TX, Navarro County, TX, Rains County, TX, Robertson County, TX, Rockwall County, TX, Travis County, TX, Van Zandt County, TX, Williamson County, TX
The radar
The Ft Hood radar (KGRK), 91 km from the middle of the area, began a volume at 22:38 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Fort Worth, TX (KFWD), launched 12:00Z, 10.6 hours before the alert went out and 159 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
- 2657 J/kg
- Mixed-layer CIN
- -30 J/kg
- Mixed-layer LCL
- 545 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 129 m²/s²
- 0-3 km storm-relative helicity
- 203 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.0
The text
As transmitted, in the capitals the NWS used until 2016.
386
ACUS11 KWNS 202234
SWOMCD
SPC MCD 202234
TXZ000-OKZ000-210030-
MESOSCALE DISCUSSION 0830
NWS STORM PREDICTION CENTER NORMAN OK
0534 PM CDT FRI MAY 20 2011
AREAS AFFECTED...PARTS OF THE ERN HALF OF TX
CONCERNING...SEVERE THUNDERSTORM WATCH 313...
VALID 202234Z - 210030Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 313
CONTINUES.
BROKEN LINE OF STORMS -- AND LEADING CLUSTER OF CONVECTION --
CONTINUES FROM THE HILL COUNTRY OF TX NEWD INTO NERN TX. THREAT FOR
LOCALLY DAMAGING WINDS AND HAIL CONTINUES.
LATEST RADAR SHOWS STRONG TO LOCALLY-SEVERE STORMS MOVING NEWD
ACROSS CENTRAL AND NERN TX...NEAR AND AHEAD OF A DRYLINE ACROSS
CENTRAL PARTS OF THE STATE. VERY MOIST/UNSTABLE PRE-DRYLINE
ENVIRONMENT ALONG WITH SHEAR MARGINALLY SUFFICIENT FOR SUPERCELLS
SUGGESTS A CONTINUATION OF STRONG CONVECTION -- AND LOCAL THREAT FOR
DAMAGING WIND GUSTS AND LARGE HAIL OVER THE NEXT FEW HOURS.
..GOSS.. 05/20/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...SHV...HGX...FWD...OUN...EWX...
LAT...LON 29379966 30099942 31219789 33109687 33789615 33749519
33649527 32589545 31269486 30919584 30379645 29299720
29379966SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 19, 7:47 PM CDT | Mesoscale Discussion | SPC | Baylor, Haskell, Knox, Wichita, Wilbarger | 118 min |
| May 19, 9:36 PM CDT | Mesoscale Discussion | SPC | Borden, Briscoe, Childress, Coke, Collingsworth, Cottle and 28 more | 84 min |
| May 19, 11:39 PM CDT | Severe Thunderstorm Watch | SPC | Baylor, Borden, Childress, Coke, Cottle, Dickens and 19 more | 6 hr |
| May 20, 2:58 AM CDT | Mesoscale Discussion | SPC | Baylor, Coke, Fisher, Foard, Glasscock, Haskell and 11 more | 92 min |
| May 20, 10:30 AM CDT | Mesoscale Discussion | SPC | Anderson, Bowie, Camp, Cass, Cherokee, Collin and 31 more | 60 min |
| May 20, 11:03 AM CDT | Tornado Watch | SPC | Bowie, Camp, Cass, Cherokee, Franklin, Gregg and 10 more | 7 hr |
| May 20, 12:08 PM CDT | Mesoscale Discussion | SPC | Anderson, Bandera, Bastrop, Bell, Blanco, Bosque and 56 more | 67 min |
| May 20, 12:28 PM CDT | Severe Thunderstorm Watch | SPC | Anderson, Bandera, Bastrop, Bell, Bexar, Blanco and 60 more | 10 hr |
| May 20, 1:28 PM CDT | Mesoscale Discussion | SPC | Bowie, Camp, Cass, Franklin, Gregg, Harrison and 8 more | 62 min |
| May 20, 4:00 PM CDT | Mesoscale Discussion | SPC | Anderson, Bowie, Camp, Cass, Delta, Franklin and 18 more | 60 min |
| May 20, 5:56 PM CDT | Tornado Watch | SPC | Bowie, Camp, Cass, Cherokee, Franklin, Gregg and 10 more | 3 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.