RSS Mesoscale Discussions from Storm Prediction Center
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0639 PM CST Tue Jan 21 2025
Valid 220100Z - 221200Z
...NO THUNDERSTORM AREAS FORECAST...
...SUMMARY...
The risk for thunderstorms appears negligible across the U.S.
tonight.
...01Z Update...
Generally dry and/or stable conditions prevail across much of the
nation. East of the Rockies, downslope warming has contribute to
some moderation of temperatures across the northern and central
Great Plains. Otherwise, cold surface ridging remains entrenched
across the southern Great Plains and Gulf Basin through much of the
Atlantic Seaboard and offshore Atlantic waters.
The surface front near the shallow leading edge of this air mass did
shift back inland across the mid/upper Florida Keys and southeastern
Florida coastal areas. However, models indicate that warm/dry
layers aloft (evident in 22/00Z observed soundings) will suppress
deep convective development rooted within weak boundary-layer
instability, before the front advances back across and offshore of
coastal areas later tonight, in the wake of a developing frontal
wave across the southwestern Atlantic.
..Kerr.. 01/22/2025
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SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1037 PM CST Tue Jan 21 2025
Valid 221200Z - 231200Z
...NO THUNDERSTORM AREAS FORECAST...
...SUMMARY...
The risk for thunderstorms appears negligible across the U.S. today
through tonight.
...Discussion...
Models indicate that mid-level ridging across the far western
Canadian Provinces will become suppressed by another short wave
perturbation emerging from the upstream mid-latitude Pacific, but
not before downstream troughing continues to dig southeast and south
of the northern U.S. Rockies. This will reinforce larger scale
troughing across much of the interior into eastern United States.
Although surface ridging initially across much of the Gulf Coast and
Atlantic Seaboard is forecast to weaken, seasonably cold and stable
boundary-layer conditions may be slow to moderate. It appears that
another expansive surface ridge will build across the Great
Basin/Rockies into the Great Plains, with a reinforcing intrusion of
arctic air surging through much of the upper Mississippi Valley and
northeastern Great Plains, today through 12Z Thursday.
..Kerr.. 01/22/2025
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