Alert archive / Texas / Mesoscale Discussions in 2018
Mesoscale Discussion 1321
The Storm Prediction Center issued this mesoscale discussion at Aug 18, 2018, 5:34 PM MDT for 5 states. It was in force for 116 min.
The area
The outline as issued.
The facts
- Issued
- Aug 18, 2018, 5:34 PM MDT (23:34 UTC)
- Expired
- Aug 18, 2018, 7:30 PM MDT
- In force
- 116 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 60%
All 36 counties
Baca County, CO, Prowers County, CO, Grant County, KS, Greeley County, KS, Hamilton County, KS, Haskell County, KS, Kearny County, KS, Meade County, KS, Morton County, KS, Seward County, KS, Stanton County, KS, Stevens County, KS, Harding County, NM, Quay County, NM, Union County, NM, Beaver County, OK, Cimarron County, OK, Texas County, OK, Armstrong County, TX, Carson County, TX, Dallam County, TX, Deaf Smith County, TX, Gray County, TX, Hansford County, TX, Hartley County, TX, Hemphill County, TX, Hutchinson County, TX, Lipscomb County, TX, Moore County, TX, Ochiltree County, TX, Oldham County, TX, Parmer County, TX, Potter County, TX, Randall County, TX, Roberts County, TX, Sherman County, TX
The radar
The Amarillo radar (KAMA), 144 km from the middle of the area, began a volume at 23:34 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
Amarillo Airport, TX (KAMA), launched 12:00Z, 11.6 hours before the alert went out and 144 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
- 58 J/kg
- Mixed-layer CIN
- -119 J/kg
- Mixed-layer LCL
- 1200 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 25 m²/s²
- 0-3 km storm-relative helicity
- 38 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted.
523
ACUS11 KWNS 182334
SWOMCD
SPC MCD 182334
TXZ000-OKZ000-KSZ000-COZ000-NMZ000-190130-
Mesoscale Discussion 1321
NWS Storm Prediction Center Norman OK
0634 PM CDT Sat Aug 18 2018
Areas affected...the southern High Plains
Concerning...Severe potential...Watch possible
Valid 182334Z - 190130Z
Probability of Watch Issuance...60 percent
SUMMARY...Storms are expected to continue developing southeastward
toward the OK/TX panhandle region, with an overall increase in
coverage through evening. A few storms may produce severe wind or
hail.
DISCUSSION...Scattered storms currently exist from western KS into
northeast NM, ahead of a weak cold front and shortwave trough aloft.
The area is characterized by a moderately unstable air mass with
modest lapse rates aloft, and weakly veering winds with height.
Storm mode has been mixed through early evening, but a more linear
structure has formed over northeast NM, which will be entering into
the western Panhandles shortly. Other slow-moving cells persist over
western KS, with isolated severe hail cores noted on radar.
As the shortwave trough continues to shift southeast, lift will be
maintained over the region. Visible satellite imagery shows a
substantial CU field over the TX/OK Panhandles, indicative of little
if any inhibition and likely supportive of continued storm
formation/sustenance. As such, a watch will be considered.
..Jewell/Thompson.. 08/18/2018
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DDC...GLD...LUB...AMA...PUB...ABQ...
LAT...LON 35850475 36790370 37670274 38360237 38660204 38490155
38150100 37650046 37220028 36270003 35470029 34990085
34640185 34410275 34740363 35080434 35300463 35850475SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 12:25 PM MDT | Mesoscale Discussion | SPC | Baca, Bent, Cheyenne, Crowley, El Paso, Kiowa and 5 more | 2 hr |
| Aug 18, 12:47 PM MDT | Severe Thunderstorm Watch | SPC | Baca, Bent, Cheyenne, Crowley, Elbert, El Paso and 8 more | 7 hr |
| Aug 18, 2:26 PM MDT | Mesoscale Discussion | SPC | Phillips, Sedgwick | 3 hr |
| Aug 18, 2:50 PM MDT | Mesoscale Discussion | SPC | Baca, Bent, Cheyenne, Crowley, Elbert, El Paso and 7 more | 55 min |
| Aug 18, 5:55 PM MDT | Severe Thunderstorm Watch | SPC | Finney, Grant, Gray, Hamilton, Haskell, Kearny and 5 more | 3 hr |
Nearby
Mesoscale Discussions in Texas, 2018Mesoscale Discussions in Kansas, 2018Mesoscale Discussions in New Mexico, 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.