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000
ACUS11 KWNS 212135
SWOMCD
SPC MCD 212135
OKZ000-KSZ000-TXZ000-COZ000-NMZ000-220000-

Mesoscale Discussion 0808
NWS Storm Prediction Center Norman OK
0435 PM CDT Sun May 21 2017

Areas affected...Portions of southeastern CO...far southwestern
KS...northeastern NM...and the TX/OK Panhandles

Concerning...Severe potential...Watch unlikely

Valid 212135Z - 220000Z

Probability of Watch Issuance...5 percent

SUMMARY...A very isolated large hail and gusty wind threat should
persist through the early evening. Watch issuance is not expected.

DISCUSSION...Isolated convective development across southeastern CO
and northeastern NM is associated with low-level upslope flow and
modest large-scale ascent attendant to an upper trough over the
Great Basin. Low-level moisture remains quite limited across this
region due to a prior frontal passage, but surface dewpoints have
generally increased into the mid to upper 40s. With modestly steep
lapse rates around 7 C/km in the 700-500 mb layer present over this
area, a narrow axis of weak instability (MLCAPE up to 1000 J/kg) has
developed as of 2130Z. Coupled with 30-40 kt of effective bulk
shear, this weak instability will be sufficient for some updraft
organization. A very isolated large hail and strong/gusty wind
threat should be realized with the strongest cores through the early
evening hours before the loss of daytime heating reduces
instability. Given the marginal thermodynamic environment, the
overall severe threat is expected to remain too isolated to warrant
watch issuance, even as convective coverage increases over the next
several hours.

..Gleason/Hart.. 05/21/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...DDC...AMA...PUB...ABQ...

LAT...LON   36410114 35300219 34560342 34690474 35330487 36330482
            37020456 37660303 37830207 37720152 37070118 36410114