Mesoscale Discussion 1204
NWS Storm Prediction Center Norman OK
0751 PM CDT Fri Jun 30 2017
Areas affected...Texas Panhandle and portions of northeast New
Concerning...Severe potential...Watch possible
Valid 010051Z - 010245Z
CORRECTED FOR LINE TYPE AND LAT/LONS
Probability of Watch Issuance...60 percent
SUMMARY...Ongoing thunderstorms across northeast New Mexico are
expected to persist into the evening hours. Large hail and strong,
gusty winds will be possible with these thunderstorms. Additional
thunderstorms may develop farther east/southeast over portions of
the Texas Panhandle. Large hail and strong thunderstorm winds would
be possible with these activity. The area will continue to be
monitored for a possible Severe Thunderstorm watch.
DISCUSSION...Thunderstorms across northeast New Mexico and extreme
southern Colorado will continue into the evening. Here,
most-unstable CAPE values between around 1000 J/kg and deep layer
shear between 40-50 knots will support thunderstorm updraft
organization, leading to a large hail and strong thunderstorm wind
risk persisting into the evening. At least initially, the relatively
isolated nature of the risk should preclude the need for a severe
Farther east, across portions of the Texas Panhandle a more
favorable environment for thunderstorms appears to be in place. The
combination of steep mid-level lapse rates (9 C/km) and surface
dewpoints in the mid-50s to lower-60s have yielded most-unstable
CAPE values on the order of 2000-3000 J/kg. Additionally, deep-layer
shear remains on the order of 50 knots. Despite the 00Z/01 July
sounding from Amarillo, TX, being capped, numerical guidance,
including the 18Z NAM and multiple runs of the ESRL-HRRR, are
insistent on the development of additional thunderstorms later this
evening across this region.
Latest water vapor imagery suggests a subtle speed max/short-wave
trough may be moving east-southeast across southern Colorado. Ascent
with this mid-level feature may be the thunderstorm
initiating/maintaining mechanism this evening into the overnight.
Given the aforementioned favorable environment, a severe
thunderstorm watch may become necessary should additional
thunderstorm initiation become likely.
Confidence in this scenario is sufficiently high to warrant the
introduction of 15% wind and hail probabilities (and a categorical
Slight Risk) with the forthcoming 01Z Convective Outlook.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 34190501 34960496 35560454 36170359 36330287 36300213
35830120 34499996 33689990 33160026 32770119 33020254