Alert archive / Texas / Mesoscale Discussions in 2017
Mesoscale Discussion 68
The Storm Prediction Center issued this mesoscale discussion at Jan 18, 2017, 1:49 AM CST for 9 counties in Texas. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- Jan 18, 2017, 1:49 AM CST (07:49 UTC)
- Expired
- Jan 18, 2017, 3:15 AM CST
- In force
- 86 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
Counties Austin County, TX, Colorado County, TX, Fort Bend County, TX, Harris County, TX, Liberty County, TX, Montgomery County, TX, San Jacinto County, TX, Waller County, TX, Wharton County, TX
The radar
The Houston radar (KHGX), 93 km from the middle of the area, began a volume at 07:48 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
Lake Charles Mun, LA (KLCH), launched 00:00Z, 7.8 hours before the alert went out and 260 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
- 508 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 635 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 28 m²/s²
- 0-3 km storm-relative helicity
- 104 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
The text
As transmitted.
091
ACUS11 KWNS 180749
SWOMCD
SPC MCD 180749
TXZ000-180915-
Mesoscale Discussion 0068
NWS Storm Prediction Center Norman OK
0149 AM CST Wed Jan 18 2017
Areas affected...Texas Gulf Coast
Concerning...Severe potential...Watch unlikely
Valid 180749Z - 180915Z
Probability of Watch Issuance...5 percent
SUMMARY...Isolated strong storms are possible early this morning
along portions of the Texas Gulf Coast. While a brief tornado or
damaging gust cannot be ruled out, a watch is not anticipated.
DISCUSSION...A cluster of strong thunderstorms is currently
affecting portions of Wharton, Fort Bend, and Harris counties TX.
These storms appear to be along a well-defined quasi-stationary
surface boundary. South of the boundary, moist and marginally
unstable surface conditions are present with dewpoints near 70F.
Modifying forecast soundings for these parameters would indicate an
environment minimally favorable for rotating storms capable of gusty
winds or a brief tornado. Recent trends in surface observations
suggest there may be a weak mesolow to the southwest of these
storms, which would potentially enhance the low level shear and lift
for the next few hours. While severe weather is possible, the risk
appears rather low and a watch is not currently anticipated.
..Hart/Peters.. 01/18/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...HGX...EWX...
LAT...LON 29819663 30699579 30799531 30569481 30099471 29259592
29029643 29369676 29819663SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 17, 7:08 PM CST | Mesoscale Discussion | SPC | Aransas, Calhoun, Duval, Jackson, Jim Wells, Kleberg and 5 more | 2 hr |
| Jan 18, 2:41 PM CST | Mesoscale Discussion | SPC | Jasper, Jefferson, Newton, Orange | 3 hr |
Nearby
Mesoscale Discussions in Texas, 2017Every mesoscale discussion in 2017
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.