Severe Storm Outlook Narrative (AC)
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ACUS11 KWNS 102111
SPC MCD 102111

Mesoscale Discussion 0112
NWS Storm Prediction Center Norman OK
0311 PM CST Sat Mar 10 2018

Areas of eastern Oklahoma and into Arkansas

Concerning...Severe potential...Watch possible

Valid 102111Z - 102345Z

Probability of Watch Issuance...60 percent

SUMMARY...Showers and scattered thunderstorms continue to gradually
increase from parts of northeastern Oklahoma east-southeast into
central Arkansas.  Risk for hail is expected as storms continue to
slowly intensify over the next couple of hours.  A severe
thunderstorm watch may be needed in the next hour or so.

DISCUSSION...Latest radar loop shows convection developing near a
surface baroclinic zone extending from eastern Oklahoma across
central Arkansas, as modest low-level moisture (upper 50s to low 60s
dewpoints) continues to return northward.  The moisture increase is
contributing to CAPE values near 1000 -- though likely still
elevated above a slightly stable boundary layer (particularly north
of the baroclinic zone).  While the primary upper impulse remains
well to the northwest of the region, a more subtle disturbance
crossing the Oklahoma/Kansas border appears to be aiding in ascent
focused near the surface boundary -- thus supporting ongoing storm

While guidance from several different CAM solutions shows more
robust convection (and implied severe risk) not evolving until the
23-00Z time frame, the present/ongoing development is not well
indicated with CAM output.  Therefore, in conjunction with some
degree of organization evident in these early updrafts, aided by
amply strong bulk shear, severe risk -- mainly in the form of large
hail -- may likewise increase earlier than initially expected.
Present indications are that increases in convective intensity will
remain gradual, but that a watch may become necessary within the
next hour or so.

..Goss/Hart.. 03/10/2018

...Please see for graphic product...


LAT...LON   35959517 36059488 36009387 35509243 34769172 34059177
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