Alert archive / Texas / Mesoscale Discussions in 2011
Mesoscale Discussion 522
The Storm Prediction Center issued this mesoscale discussion at Apr 22, 2011, 5:43 PM CDT for 23 counties in Texas. It was in force for 92 min.
The area
The outline as issued.
The facts
- Issued
- Apr 22, 2011, 5:43 PM CDT (22:43 UTC)
- Expired
- Apr 22, 2011, 7:15 PM CDT
- In force
- 92 min
- Issued by
- the Storm Prediction Center
All 23 counties
Archer County, TX, Callahan County, TX, Clay County, TX, Coleman County, TX, Comanche County, TX, Cooke County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Hood County, TX, Jack County, TX, Jones County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Taylor County, TX, Throckmorton County, TX, Wise County, TX, Young County, TX
The radar
The Dyess AFB radar (KDYX), 70 km from the middle of the area, began a volume at 22:45 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, 10.7 hours before the alert went out and 120 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
- 1318 J/kg
- Mixed-layer CIN
- -465 J/kg
- Mixed-layer LCL
- 1244 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 297 m²/s²
- 0-3 km storm-relative helicity
- 510 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.8
The text
As transmitted, in the capitals the NWS used until 2016.
317
ACUS11 KWNS 222243
SWOMCD
SPC MCD 222243
TXZ000-OKZ000-230015-
MESOSCALE DISCUSSION 0522
NWS STORM PREDICTION CENTER NORMAN OK
0543 PM CDT FRI APR 22 2011
AREAS AFFECTED...WRN N TX
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 222243Z - 230015Z
A WATCH IS LIKELY TO BE NEEDED OVER WRN N TX WHERE STORM INITIATION
IS LIKELY SOON. VERY LARGE HAIL...ALONG WITH STRONG OUTFLOW ARE
LIKELY.
SURFACE ANALYSIS SHOWS A LOW PRESSURE TROUGH EXTENDING SWWD AHEAD OF
A STALLING COLD FRONT FROM CNTRL OK INTO NWRN TX. LOW TO MID LEVEL
LAPSE RATES HAVE BECOME VERY STEEP AS A RESULT OF HEATING AND LITTLE
IF ANY CONVECTIVE INHIBITION EXISTS.
DUE TO STRONG VERTICAL MIXING...DEWPOINTS HAVE DROPPED INTO THE
UPPER 50S NEAR THE DRYLINE. HOWEVER...PRECIPITABLE WATER VALUES ARE
NEAR 1.50 INCHES NEAR DENTON...WHERE LOW CLOUDS HAMPERED MIXING
TODAY.
AS STORMS FORM NEAR THE HEAT...THEY WILL LIKELY TRAVEL ESEWD INTO A
VERY UNSTABLE AIR MASS. WHILE LOW LEVEL T/TD SPREADS WILL FAVOR
OUTFLOW PRODUCTION AND GUSTY WINDS AND MAY HAMPER TORNADO
POTENTIAL...FAVORABLE WLY FLOW ALOFT...COMBINED WITH AN INCREASING
LOW LEVEL JET THIS EVENING SHOULD BE MORE THAN SUFFICIENT TO SUSTAIN
SUPERCELLS WITH THE PRIMARY THREAT BEING EXTREMELY LARGE HAIL.
..JEWELL.. 04/22/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...FWD...OUN...SJT...
LAT...LON 32190039 33249946 33749898 34019834 33839722 33519674
32939701 32149755 32019815 31889884 31919979 32190039SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 9:15 PM CDT | Mesoscale Discussion | SPC | Archer, Baylor, Callahan, Coke, Coleman, Concho and 26 more | 60 min |
| Apr 22, 1:23 PM CDT | Mesoscale Discussion | SPC | Archer, Clay, Collin, Cooke, Delta, Denton and 18 more | 97 min |
| Apr 22, 6:10 PM CDT | Severe Thunderstorm Watch | SPC | Archer, Brown, Callahan, Clay, Coke, Coleman and 21 more | 6 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.