Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS01 KWNS 270514
SWODY1
SPC AC 270512

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1212 AM CDT Fri Apr 27 2018

Valid 271200Z - 281200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE PACIFIC NORTHWEST AND INTERMOUNTAIN WEST...

...SUMMARY...
Isolated strong thunderstorms capable of downburst winds and hail
may occur from parts of eastern Oregon into southwestern Idaho late
this afternoon into the evening.

...Eastern Oregon/Southwest Idaho/Far Northeast Nevada...
An upper-level low will approach the Oregon coast today as a belt of
stronger mid-level flow moves inland into the Pacific Northwest.  At
the surface, a trough will  deepen from northern Nevada into eastern
Oregon and southeast Washington. Thunderstorms are expected to
develop along the surface trough late this afternoon due to warming
surface temperatures and increasing large-scale ascent associated
with the approaching system. Forecast soundings during the early
evening along the surface trough show MUCAPE values up to 500 J/kg
with 700 to 500 mb lapse rates of 8.0 to 8.5 C/km. This combined
with moderate deep-layer shear could be enough for a marginal severe
threat. Hail and strong gusty winds will be the primary threats.

..Broyles/Gleason.. 04/27/2018

$$


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