Storm Prediction Center Dec 27, 2021 0600 UTC Day 1 Convective Outlook

Dec 27, 2021 0600 UTC Day 1 Convective Outlook

Updated: Mon Dec 27 05:51:00 UTC 2021 (

)

Probabilistic to Categorical Outlook Conversion Table

Categorical Graphic

Day 1 Risk	Area (sq. mi.)	Area Pop.	Some Larger Population Centers in Risk Area
No Risk Areas Forecast

Probabilistic Tornado Graphic

20211227 1200 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
No Risk Areas Forecast

Probabilistic Damaging Wind Graphic

20211227 1200 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
No Risk Areas Forecast

Probabilistic Large Hail Graphic

20211227 1200 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 270551

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1151 PM CST Sun Dec 26 2021

   Valid 271200Z - 281200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Isolated thunderstorms will be possible Monday across parts of the
   mid and upper Ohio Valley vicinity and across a portion of the
   California coast.  Thunderstorms will be possible late Monday night
   over portions of the southern and central Plains.

   ...Synopsis...
   A longwave trough will remain established over much of the western
   U.S. Monday while several disturbances rotate around the large-scale
   flow.  One prominent shortwave trough will move east/northeast
   across the Great Lakes, OH Valley and portions of the northeast U.S.
   during the day.  Farther west, another shortwave trough will extend
   from CA into the Great Basin early Monday and move steadily
   southeast/east through Monday night.  

   Showers, with isolated elevated thunderstorms, will likely be
   ongoing Monday morning in the vicinity of a warm front across
   OH/western PA, aided by weakening warm/moist advection.  In the wake
   of morning convection, isolated thunderstorms may develop as a cold
   front moves east during the afternoon/evening.  Surface dew points
   in the mid/upper 50s should result in marginal instability at best,
   with SBCAPE of 100-400 J/kg ahead of the cold front.

   A cold front will also move onshore across the central/southern CA
   coast Monday, accompanied by showers and isolated thunderstorms. 
   Although a sporadic lightning flash will be possible across much of
   the Great Basin and vicinity associated with cool mid-level
   temperatures and large-scale ascent, weak instability appears most
   likely to be confined near the coast and will maintain the 10
   percent thunder probability line in that area.

   Weak elevated instability is expected along a developing warm front
   across northeast OK/southeast KS late Monday night, and a modestly
   strengthening low-level jet should provide lift for thunderstorm
   development after 06z Tuesday. 

   Severe thunderstorms are not expected anywhere across the CONUS
   Monday.

   ..Bunting/Moore.. 12/27/2021

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z