Alert archive / Texas / Mesoscale Discussions in 2018
Mesoscale Discussion 976
The Storm Prediction Center issued this mesoscale discussion at Jul 1, 2018, 2:21 PM CDT for 22 counties in Oklahoma; 23 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 1, 2018, 2:21 PM CDT (19:21 UTC)
- Expired
- Jul 1, 2018, 4:45 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 45 counties
Atoka County, OK, Bryan County, OK, Carter County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Hughes County, OK, Jackson County, OK, Jefferson County, OK, Johnston County, OK, Kiowa County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK, Tillman County, OK, Archer County, TX, Baylor County, TX, Clay County, TX, Cooke County, TX, Denton County, TX, Foard County, TX, Grayson County, TX, Hardeman County, TX, Haskell County, TX, Jack County, TX, King County, TX, Knox County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Shackelford County, TX, Stephens County, TX, Tarrant County, TX, Throckmorton County, TX, Wichita County, TX, Wilbarger County, TX, Wise County, TX, Young County, TX
The radar
The Altus AFB radar (KFDR), 125 km from the middle of the area, began a volume at 19:22 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 12:00Z, 7.4 hours before the alert went out and 115 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
- 802 J/kg
- Mixed-layer CIN
- -272 J/kg
- Mixed-layer LCL
- 1080 m above ground
- 0-6 km bulk shear
- 7 kt
- 0-1 km storm-relative helicity
- -10 m²/s²
- 0-3 km storm-relative helicity
- 19 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
861
ACUS11 KWNS 011922
SWOMCD
SPC MCD 011921
OKZ000-TXZ000-012145-
Mesoscale Discussion 0976
NWS Storm Prediction Center Norman OK
0221 PM CDT Sun Jul 01 2018
Areas affected...North Texas...South-central Oklahoma
Concerning...Severe potential...Watch unlikely
Valid 011921Z - 012145Z
Probability of Watch Issuance...20 percent
SUMMARY...An isolated severe threat is likely to continue through
the afternoon across parts of north Texas and in the southern half
of Oklahoma. The threat should remain marginal and weather watch
issuance will probably not be needed.
DISCUSSION...Latest surface analysis shows a cold front across
western Oklahoma and northwest Texas with a very moist airmass in
place ahead of the front. Surface dewpoints in the 70s F are
contributing to moderate instability across north Texas and
south-central Oklahoma with MLCAPE values estimated in the 2000 to
2500 J/kg. Although deep-layer shear is generally weak across the
southern Plains, low-level lapse rates are becoming steep. The
thermodynamic environment may be enough to support marginally severe
wind gusts with the stronger multicells.
..Broyles/Hart.. 07/01/2018
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TSA...FWD...OUN...SJT...LUB...
LAT...LON 32649729 32479782 32459883 32739963 33160023 33660026
34509991 34959914 35149794 35299645 35169589 34669564
34169581 33629638 32919686 32649729SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 1, 6:22 PM CDT | Mesoscale Discussion | SPC | Andrews, Archer, Bailey, Baylor, Borden, Callahan and 44 more | 113 min |
Nearby
Mesoscale Discussions in Texas, 2018Mesoscale Discussions in Oklahoma, 2018Every mesoscale discussion in 2018
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.