Mesoscale Discussion

ACUS11 KWNS 232256
SPC MCD 232255 
Mesoscale Discussion 1669
NWS Storm Prediction Center Norman OK
0555 PM CDT Sat Sep 23 2017
Areas affected...Portions of southeastern NM and far west TX
Concerning...Severe potential...Watch unlikely 
Valid 232255Z - 240100Z
Probability of Watch Issuance...5 percent
SUMMARY...A couple instances of large hail and strong/damaging winds
may occur with isolated supercells over the next several hours. The
overall severe threat is expected to remain very isolated, and watch
issuance is not anticipated.
DISCUSSION...A couple supercells have developed late this afternoon
within a modest low-level upslope flow regime across parts of
southeastern NM and far west TX. Winds strengthen to around 35-40 kt
at mid levels as a highly amplified large-scale trough remains
centered over the Great Basin. A veering wind profile per recent
VWPs from KMAF is also contributing to around 35-45 kt of effective
bulk shear, which will allow for continued supercell structures
through the evening. A narrow corridor of weak to moderate
instability has developed across this region where some clearing has
occurred. Given ongoing supercell structures and recent MRMS MESH
data, isolated large hail will continue to be a threat. Strong to
locally damaging winds may also occur where low-level lapse rates
have steepened due to diurnal heating. Both instability and shear
weaken with eastward extent, and with the loss of diurnal heating
that will occur later this evening, storms should eventually
decrease in intensity. The ongoing threat for large hail and
strong/damaging winds is expected to remain too isolated to warrant
watch issuance.
..Gleason/Edwards.. 09/23/2017
...Please see for graphic product...
LAT...LON   31010570 31880547 32730498 33590412 33770282 32930238
            31820227 30880244 29910268 29440348 29500409 29720467
            30500499 31010570