Alert archive / Texas / Mesoscale Discussions in 2016

Mesoscale Discussion 423

April 20, 201620 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2016, 1:37 AM CDT for 20 counties in Texas. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued: Apr 20, 2016, 1:37 AM CDT (06:37 UTC)
Expired: Apr 20, 2016, 2:30 AM CDT
In force: 53 min
Issued by: the Storm Prediction Center

Counties Brown County, TX, Callahan County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Dallas County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Hood County, TX, Johnson County, TX, Palo Pinto County, TX, Parker County, TX, Runnels County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Taylor County, TX, Wise County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 92 km from the middle of the area, began a volume at 06:37 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, 6.6 hours before the alert went out and 101 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1336 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 102 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

712 
ACUS11 KWNS 200638
SWOMCD
SPC MCD 200637 
TXZ000-200730-

MESOSCALE DISCUSSION 0423
NWS STORM PREDICTION CENTER NORMAN OK
0137 AM CDT WED APR 20 2016

AREAS AFFECTED...PORTIONS OF NORTH TX

CONCERNING...SEVERE THUNDERSTORM WATCH 98...

VALID 200637Z - 200730Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 98
CONTINUES.

SUMMARY...GUSTY WINDS AND SMALL HAIL MAY PERSIST A COUPLE MORE
HOURS. HOWEVER THE SEVERE THREAT WILL CONTINUE TO DIMINISH INTO THE
EARLY MORNING HOURS. A NEW WATCH IS NOT EXPECTED DOWNSTREAM OF
SEVERE THUNDERSTORM WATCH 98.

DISCUSSION...THUNDERSTORMS HAVE GENERALLY WEAKENED ACROSS NORTH
TEXAS EARLY THIS MORNING AS THE OUTFLOW BOUNDARY HAS SURGED AHEAD OF
THE QLCS. THE EXCEPTION BEING ACROSS PARKER COUNTY WHERE A STRONGER
STORM PERSISTS NEAR THE COMMA HEAD OF THE EASTWARD ADVANCING SECTION
OF THE LINE. HOWEVER...OBSERVATION FROM KMWL AS THE BOWING SEGMENT
TRACKED OVERHEAD INDICATED STRONGEST GUSTS NEAR 35 KT. SOME
MARGINALLY SEVERE WINDS MAY STILL BE OCCURRING WITH THE BOWING
SEGMENT...BUT GIVEN THE STABILIZING BOUNDARY LAYER...SEVERE THREAT
WILL CONTINUE TO DIMINISH. MRMS MESH ALSO INDICATE SOME SMALL HAIL
MAY BE POSSIBLE...BUT THESE CORES ARE ALSO DIMINISHING. SEVERE
THUNDERSTORM WATCH 98 WILL LIKELY BE ALLOWED TO EXPIRE AT 08Z AND A
DOWNSTREAM WATCH IS NOT ANTICIPATED.

..LEITMAN.. 04/20/2016

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

ATTN...WFO...FWD...SJT...

LAT...LON   32580014 33459734 33709638 33349617 32699656 32399702
            32059745 31689859 31459941 31529984 32070022 32580014

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 19, 8:45 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Bell, Blanco, Borden, Bosque and 67 more	3 hr
Apr 19, 9:59 PM CDT	Severe Thunderstorm Watch	SPC	Brown, Callahan, Coleman, Comanche, Cooke, Eastland and 16 more	5 hr
Apr 19, 11:39 PM CDT	Mesoscale Discussion	SPC	Brown, Callahan, Coke, Coleman, Collin, Comanche and 25 more	2 hr
Apr 20, 2:41 PM CDT	Mesoscale Discussion	SPC	Concho, Crockett, Irion, Kimble, McCulloch, Mason and 6 more	2 hr
Apr 20, 4:54 PM CDT	Mesoscale Discussion	SPC	Armstrong, Borden, Briscoe, Carson, Childress, Collingsworth and 27 more	2 hr

Nearby

Mesoscale Discussions in Texas, 2016 Every mesoscale discussion in 2016

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.