Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0229 AM CST Tue Dec 16 2025

Valid 181200Z - 191200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE LOWER OHIO AND TENNESSEE VALLEYS...

...SUMMARY...
Isolated damaging wind gusts are possible across portions of the
Lower Ohio and Tennessee Valleys on Thursday.

...Synopsis...
A strong mid-level jet streak will round the base of the mid-level
trough across the central Plains early Thursday and emerge across
the Ohio Valley by Thursday afternoon/evening. This trough will
continue east and take on a more neutral to perhaps negative tilt by
early Friday across the East Coast. A strong (sub 990mb) surface low
will move from the Upper Midwest to southern Quebec with a trailing
cold front sweeping from the Midwest to the East Coast. 

...OH/TN Valleys...
A line of convection will likely be in its infancy along the cold
front in Illinois and Missouri at the beginning of the period.
Low-level moisture will continue to advect north ahead of this cold
front and result in some weak destabilization. The mid-50s dewpoints
will likely struggle to make it north of the Ohio River given the
snowpack across the region, despite very strong low-level moisture
advection. However, south of this snowpack there will likely be a
zone where the strong forcing along the cold front can overcome only
marginally unstable surface parcels. This strongly forced convective
line amid 60-70 knots of background flow (as low as 1km) will
support isolated damaging wind gusts through the afternoon. 

Greater instability is expected south of the TN/MS/AL border where
upper 50s to low 60s dewpoints are forecast. However, despite the
more favorable thermodynamics, the upper-level forcing will be
weaker. Therefore, it is unclear whether the line of storms will
continue that far south, and additional convection ahead of the
front will likely struggle given the weak lapse rates/minimal
heating. 

...Eastern Virginia into North Carolina...
Late in the period, as the cold front crosses the Appalachians,
moisture is expected to advect inland across eastern North Carolina
and eastern Virginia. A strong wind field will continue across the
region, and if sufficient instability can develop, a damaging wind
threat could materialize early Friday morning. However, the degree
of destabilization remains uncertain and will depend on how quickly
the cold air damming can erode. A solution such as the 00Z NAM (with
60F dewpoints into the DelMarva) would certainly result in some
threat, but most other guidance keeps dewpoints in the mid 50s with
minimal instability. Trends will be monitored closely in this region
in later outlooks and probabilities may be added if the forecast
trends towards greater instability.

..Bentley.. 12/16/2025

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0256 AM CST Tue Dec 16 2025

Valid 191200Z - 241200Z

...DISCUSSION...
A line of storms will likely be ongoing from portions of the
Northeast into the mid-Atlantic and Carolinas Friday morning. If
sufficient destabilization can occur, a few isolated damaging wind
gusts will be possible before the front moves offshore. In the wake
of this cold front, an extended period of low severe potential
begins. By Saturday afternoon, moisture is forecast to advect inland
across East Texas and Louisiana, but no thunderstorm activity is
expected. 60s dewpoints will remain along the Gulf Coast from Texas
to inland Louisiana and Mississippi through the weekend and into
early next week. However, building heights aloft will limit
thunderstorm potential for much of the extended. Even if some
thunderstorms occur early next week, as indicated by the 00Z ECMWF
across MS/TN, they will likely remain south of the stronger
mid-level flow and without strong destabilization, will be unlikely
to be severe.