Alert archive / Texas / Mesoscale Discussions in 2017
Mesoscale Discussion 340
The Storm Prediction Center issued this mesoscale discussion at Mar 26, 2017, 11:40 PM CDT for Milam County, Robertson County, Williamson County, Texas. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- Mar 26, 2017, 11:40 PM CDT (04:40 UTC)
- Expired
- Mar 27, 2017, 1:15 AM CDT
- In force
- 95 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
Counties Milam County, TX, Robertson County, TX, Williamson County, TX
The radar
The Ft Hood radar (KGRK), 41 km from the middle of the area, began a volume at 04:40 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, 4.7 hours before the alert went out and 213 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
- 892 J/kg
- Mixed-layer CIN
- -31 J/kg
- Mixed-layer LCL
- 1866 m above ground
- 0-6 km bulk shear
- 58 kt
- 0-1 km storm-relative helicity
- 184 m²/s²
- 0-3 km storm-relative helicity
- 259 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 12.6
The text
As transmitted.
510
ACUS11 KWNS 270441
SWOMCD
SPC MCD 270440
TXZ000-270615-
Mesoscale Discussion 0340
NWS Storm Prediction Center Norman OK
1140 PM CDT Sun Mar 26 2017
Areas affected...Parts of central Texas
Concerning...Severe potential...Watch unlikely
Valid 270440Z - 270615Z
Probability of Watch Issuance...5 percent
SUMMARY...Isolated strong/severe storm development is expected to
diminish to the south/southeast of the Waco/Temple area within the
next couple of hours.
DISCUSSION...Isolated vigorous convection persists across parts of
central Texas, to the south of Waco, in the presence of strong
vertical shear and moderately large mixed layer CAPE. Although
low-level moistening continues, the loss of daytime heating has
resulted in increasing inhibition for boundary layer parcels.
Activity does appear to be maintaining frequent lightning flash
rates, but radar data indicates at least some recent weakening of
convection. With upper support for large-scale ascent becoming more
unclear, and likely diminishing, weakening storm trends seem likely
to continue and result in increasingly negligible severe weather
potential through 06-07Z. Until then, lingering convection may be
capable of producing marginally severe hail and/or a few strong
surface gusts.
..Kerr/Thompson.. 03/27/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...HGX...FWD...EWX...
LAT...LON 31159701 31359650 30739637 30499707 30759800 30869718
31159701SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 26, 7:15 PM CDT | Mesoscale Discussion | SPC | Collin, Dallas, Delta, Ellis, Fannin, Grayson and 4 more | 90 min |
| Mar 26, 8:49 PM CDT | Severe Thunderstorm Watch | SPC | Bowie, Camp, Cass, Franklin, Morris, Red River and 1 more | 6 hr |
| Mar 27, 12:44 AM CDT | Mesoscale Discussion | SPC | Bowie, Cass, Franklin, Morris, Red River, Titus | 61 min |
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.