SPC Dec 16, 2024 Day 4-8 Severe Weather Outlook

Day 4-8 Outlook

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0347 AM CST Mon Dec 16 2024

Valid 191200Z - 241200Z

...DISCUSSION...
Medium range guidance is in fairly good agreement that an amplified
but progressive upper level pattern will overspread the CONUS during
the Day 4-8 period. A shortwave trough over the northern Plains
early on Day 4/Thu will deepen and spread east over the eastern half
of the CONUS through Day 6 or 7/Sat or Sun. Meanwhile, an amplified
upper ridge will build over the western states and spread east into
the Plains during this same time period. Spread among guidance
increases around Day 6-8/Sat-Mon, but still indicates that another
upper trough will emerge over the Plains and Midwest late in the
period. 

A surface cold front will move south and east into the Gulf of
Mexico and offshore the Atlantic coast on Thursday. This will clear
out any lingering boundary-layer moisture and persistent offshore
trajectories will mostly preclude much thunderstorm potential for
most of the forecast period. The exception may be on Day 7-8/Sun-Mon
as lee troughing allow for southeasterly flow to return across the
western Gulf and TX, bringing modest moisture northward across
southern/central TX. Nevertheless, severe-thunderstorm potential
appears low throughout the forecast period.

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