Severe Storm Outlook Narrative (AC)
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ACUS11 KWNS 171928
SPC MCD 171928

Mesoscale Discussion 1653
NWS Storm Prediction Center Norman OK
0228 PM CDT Sun Sep 17 2017

Areas affected...Eastern Plains of NM...western TX
Panhandle...northwest part of the TX South Plains...far southeast CO

Concerning...Severe potential...Watch possible

Valid 171928Z - 172130Z

Probability of Watch Issuance...60 percent

SUMMARY...Isolated to scattered severe gusts/large hail are possible
this afternoon through the early evening.

DISCUSSION...Visible satellite imagery trends over the past few
hours has shown convective growth transitioning from orphaning once
it became displaced from the higher terrain to subsequent convective
attempts becoming sustained as they move east into the High Plains.
This is most notably reflected in radar imagery with appreciably
strong cores developing from near Las Vegas, NM to east of the
Sacramento Mountains.  Surface observations show temperatures to the
south of the composite front have warmed into the 80s to lower 90s
degrees F while areas from near I-40 and north have in the upper 60s
to upper 70s.  Upslope flow will maintain a moisture-rich airmass
across the region with boundary layer dewpoints in the 50s.

RAP forecast soundings show a veering wind profile with
southwesterly flow increasing with height.  As a result, effective
shear ranging from around 25-kt over southern NM to 40-kt where
backed surface flow resides (north of I-40).  The moderate buoyancy
coupled with shear supportive for storm organization, including the
possibility for a few supercells, will favor storm intensification
through the remainder of the afternoon as storms move east into a
destabilizing boundary layer.  A tornado cannot be ruled out over
northeast NM, where hodographs are most favorable.  However, large
hail/severe gusts will likely be the primary threats with the
stronger storms.

..Smith/Guyer.. 09/17/2017

...Please see for graphic product...


LAT...LON   33300497 35540535 37130497 36600284 33490237 33300497 is the U.S. government's official web portal to all federal, state and local government web resources and services.