U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 100044 
Storm Prediction Center ac 100043 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0643 PM CST Mon Dec 09 2019 

Valid 100100z - 101200z 

..no severe thunderstorm areas forecast... 

thunderstorm threat has been extended to include portions of 
south-central Texas later tonight. 

..01z update... 

Well-defined upper low near the Arizona/Mexican border continues to move 
east-southeast toward The Big Bend region of West Texas. Scattered 
thunderstorms have been common beneath the cold upper trough, 
especially over southern Arizona into southwest nm. 00z sounding from tus 
exhibited appreciable SBCAPE (~450 j/kg), while downstream sounding 
at epz was notably stable. Even so, convective threat is expected to 
spread/develop east into Texas overnight along poleward side of surface 
front that should advance into the coastal plain by sunrise. Weak 
elevated buoyancy should prove adequate for a few thunderstorms as 
large-scale forcing spreads into Texas late. 

.Darrow.. 12/10/2019 


Mesoscale Discussion

acus11 kwns 091719 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 091718 

Mesoscale discussion 2191 
National Weather Service Storm Prediction Center Norman OK 
1118 am CST Mon Dec 09 2019 

Areas affected...northeast Iowa/southeast Minnesota into much of 

Concerning...heavy snow 

Valid 091718z - 092115z 

Summary...a quick onset of moderate to heavy snow is expected to 
persist for a few hours as it moves out of Iowa and Minnesota and 
into Wisconsin. 

Discussion...a band of snow coincident with a cold front and 
supported by deep frontogenetical lift is quickly progressing east 
across the upper Mississippi Valley, producing brief periods of 
heavy snow along with gusty winds. The heaviest part of the band 
currently stretches from far southeast Minnesota and northeast Iowa 
into west-central Wisconsin, and will likely maintain intensity for 
a few hours. With time, the band is likely to dissipate from south 
to north as the greatest ascent lifts north. 

.Jewell.. 12/09/2019 

..please see www.Spc.NOAA.Gov for graphic product... 


Latitude...Lon 42619216 43389186 44109143 44889099 45599058 46178970 
46128914 45768817 44628798 44168822 43099012 42679086 
42399128 42289210 42619216