Dec 8, 2016 2000 UTC Day 1 Convective Outlook
Updated: Thu Dec 8 19:33:17 UTC 2016 (20161208 2000Z Day 1 shapefile | 20161208 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20161208 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Tornado Graphic
20161208 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
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20161208 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
No Risk Areas Forecast
Probabilistic Large Hail Graphic
20161208 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 081933

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0133 PM CST Thu Dec 08 2016

   Valid 082000Z - 091200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   No severe thunderstorms are expected across the contiguous U.S.
   through tonight.

   ...Discussion...
   No changes have been made to the ongoing forecast.

   ..Cohen.. 12/08/2016

   .PREV DISCUSSION... /ISSUED 1029 AM CST Thu Dec 08 2016/

   ...SYNOPSIS...
   Broad cyclonic flow currently covers the CONUS with enhanced flow
   arcing from northern California through the central Plains, Ohio
   Valley, and Northeast. Strongest flow within this belt currently
   exists at the base of a shortwave trough tracking through the Ohio
   Valley. This shortwave trough and associated jet streak are expected
   to continue northeastward off the Northeast coast by Friday morning
   while the broadly cyclonic flow persists. Surface pattern is
   characterized by a strong polar high, currently centered over the
   northern High Plains and extending through the southern Plains and
   lower Mississippi river valley. This high is expected to gradually
   shift eastward throughout the day. 

   Cold and stable airmass associated with the surface high will keep
   overall thunderstorm prospects very low. Cold front has pushed off
   the south coast of Florida, with observations at MTH and EYW both
   reporting north winds. A strike or two is possible with any
   afternoon convection that develops as a result of a second frontal
   push but weak lapse rates and cool surface conditions are expected
   to keep thunder coverage below 10%. Weak upper forcing may glance
   the region during the second half of the period but the elevated
   nature of this convection and overall continued weak lapse rate
   should preclude thunder. 

   Isolated lightning strikes are also possible over and/or in the lee
   of Lake Erie and Ontario within any lake effect bands. Conditions
   for lake effect snow band induced lightning appears most favorable
   along and in the lee of Lake Ontario, where long wind fetches and
   slightly cooler temperatures aloft exist. As mentioned in the
   previous outlook discussion, anticipated lightning coverage is on
   the margins for inclusion, but it is close enough to maintain
   consistency with previous products.

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