Dec 22, 2021 2000 UTC Day 1 Convective Outlook
Updated: Wed Dec 22 19:41:49 UTC 2021 (20211222 2000Z Day 1 shapefile | 20211222 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20211222 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 12,298 315,032 Aberdeen, WA...Coos Bay, OR...North Bend, OR...Astoria, OR...Newport, OR...
Probabilistic Tornado Graphic
20211222 2000 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
2 % 9,956 298,543 Coos Bay, OR...North Bend, OR...Astoria, OR...Newport, OR...Hoquiam, WA...
Probabilistic Damaging Wind Graphic
20211222 2000 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 12,357 315,163 Aberdeen, WA...Coos Bay, OR...North Bend, OR...Astoria, OR...Newport, OR...
Probabilistic Large Hail Graphic
20211222 2000 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
   SPC AC 221941

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0141 PM CST Wed Dec 22 2021

   Valid 222000Z - 231200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE COASTAL
   PACIFIC NORTHWEST...

   ...SUMMARY...
   A brief tornado and/or isolated damaging winds are possible along
   the Washington coast this afternoon, and along the Oregon to
   northern California coast this evening into the overnight.

   No changes are required to the existing outlook.

   ..Jewell.. 12/22/2021

   .PREV DISCUSSION... /ISSUED 1030 AM CST Wed Dec 22 2021/

   ...Pacific Northwest...
   A positive-tilt upper trough off the coast of southern British
   Columbia will continue to amplify and dig southeastward as it
   approaches the Pacific Northwest tonight. A related cold front will
   spread inland across coastal Washington later this afternoon/early
   evening and parts of Oregon tonight. Overall buoyancy will remain
   minimal, but low-topped convection should increase near the front
   later today. Wind profiles will be conditionally supportive of brief
   low-topped supercells. This potential may be relatively more
   probable along the Oregon coast early this evening as 50 kt 850-mb
   winds coincide with near-50F surface dew points and potentially a
   couple hundred J/kg SBCAPE. A brief tornado, isolated severe wind
   gusts, and small hail are all possible in the more robust low-topped
   convection consisting of showers and sporadic lightning flashes.

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z