Alert archive / Texas / Mesoscale Discussions in 2018
Mesoscale Discussion 643
The Storm Prediction Center issued this mesoscale discussion at Jun 4, 2018, 6:46 PM CDT for 20 counties in Texas. It was in force for 119 min.
The area
The outline as issued.
The facts
- Issued
- Jun 4, 2018, 6:46 PM CDT (23:46 UTC)
- Expired
- Jun 4, 2018, 8:45 PM CDT
- In force
- 119 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
Counties Anderson County, TX, Angelina County, TX, Cherokee County, TX, Ellis County, TX, Freestone County, TX, Henderson County, TX, Hill County, TX, Houston County, TX, Kaufman County, TX, Leon County, TX, Limestone County, TX, Nacogdoches County, TX, Navarro County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Trinity County, TX, Van Zandt County, TX
The radar
The Shreveport radar (KSHV), 166 km from the middle of the area, began a volume at 23:47 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
Shreveport, LA (KBAD), launched 12:00Z, 11.8 hours before the alert went out and 176 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1607 m above ground
- 0-6 km bulk shear
- 5 kt
- 0-1 km storm-relative helicity
- -17 m²/s²
- 0-3 km storm-relative helicity
- 14 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
320
ACUS11 KWNS 042346
SWOMCD
SPC MCD 042346
TXZ000-050145-
Mesoscale Discussion 0643
NWS Storm Prediction Center Norman OK
0646 PM CDT Mon Jun 04 2018
Areas affected...East Texas
Concerning...Severe potential...Watch unlikely
Valid 042346Z - 050145Z
Probability of Watch Issuance...5 percent
SUMMARY...Isolated storms may pose a hail or localized wind threat
this evening, but expected coverage should preclude the need for a
watch.
DISCUSSION...Isolated cells have recently developed near a stalled
front across eastern TX, with a very warm and moist air mass west of
the boundary. This area is also under the influence of an old MCV,
which may be enhancing convergence a bit as the unstable air
gradually spreads northeast across the front. Winds aloft remain
relatively weak, suggesting short-lived cells are possible in the
vicinity of the front. This threat may persist for several hours
through the evening as the weak low-level warm advection persists.
Marginal hail or a locally strong downburst are possible.
..Jewell/Grams.. 06/04/2018
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LCH...SHV...HGX...FWD...
LAT...LON 30759451 31299621 31629715 32119756 32649702 32789627
32549536 32179456 31829397 31309369 30899380 30759451SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 3, 8:39 PM CDT | Mesoscale Discussion | SPC | Culberson, Hudspeth, Jeff Davis, Loving, Presidio, Reeves | 96 min |
| Jun 3, 9:34 PM CDT | Severe Thunderstorm Watch | SPC | Andrews, Borden, Callahan, Coke, Coleman, Concho and 33 more | 7 hr |
| Jun 3, 11:21 PM CDT | Mesoscale Discussion | SPC | Borden, Dawson, Martin | 114 min |
| Jun 4, 2:50 AM CDT | Mesoscale Discussion | SPC | Bell, Blanco, Brown, Burnet, Callahan, Coke and 32 more | 85 min |
Nearby
Mesoscale Discussions in Texas, 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.