Severe Storm Outlook Narrative (AC)
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ACUS02 KWNS 170636
SPC AC 170635

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1235 AM CST Wed Jan 17 2018

Valid 181200Z - 191200Z


Isolated thunderstorms are possible along the Pacific Northwest
coast Thursday into Thursday night.

A powerful southwesterly mid/upper jet will sink southward along the
Pacific Northwest coastline Thursday. Concurrently, strong
southwesterlies will also spread farther inland towards the northern
High Plains through the period. Downstream ridging will gradually
flatten in response, while slowly shifting southeast across the
Desert Southwest and central Plains. To its southeast, a weak
impulse will cross from northern Mexico into far southern Texas
Thursday night.

...Pacific Northwest...
Behind the aforementioned southwesterly jet, cold mid-level temps
(around -30 to -34 C at 500mb) will overspread parts of the Pacific
Northwest. Increasing low/mid-level instability, combined with
adequate boundary-layer moisture near the coast, will promote
scattered convection through the period. Forecast soundings indicate
that a few updrafts should deepen enough for isolated lightning
strikes along the Washington, Oregon, and northern California

...South Texas...
As a weak impulse crosses the Rio Grande late in the period,
cooling/moistening mid levels over south Texas will generate weak
elevated buoyancy. While a thunderstorm cannot be ruled out,
forecast soundings indicate nascent updrafts will struggle with
dry-air entrainment near 700-600mb, likely precluding deep

..Picca.. 01/17/2018

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