SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1105 AM CST Thu Feb 06 2025
Valid 071200Z - 081200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Aside from some potential for a couple of weak thunderstorms across
parts of the northern Rockies vicinity, the risk for thunderstorms
appears negligible across much of the U.S., Friday through Friday
night.
...Discussion...
Models indicate that broad mid/upper ridging will be maintained
across the subtropical latitudes, from northern Mexico through the
western Atlantic, and a prominent influence across the southern into
central tier of the U.S. through this period, downstream of
persistent ridging in the northern mid-latitudes, and troughing in
the southern mid- to subtropic latitudes, of the eastern Pacific.
To the east of the northeastern Pacific ridging, broad mean
troughing, with more progressive embedded smaller-scale
perturbations, is forecast to linger across British Columbia and
the Pacific Northwest, while developing eastward across the Canadian
Prairies, northern U.S. Rockies and Great Plains.
Beneath this regime, guidance indicates potential for modest surface
cyclogenesis across eastern Colorado through areas near/south of the
Kansas/Oklahoma border vicinity. There appears better consensus
among the models, particularly the ECENS/ECMWF and GEFS/GFS. But
this output may still be having issues handling ongoing reinforcing
cold intrusions to the lee of Rockies. The NAM and Rapid Refresh
remain slower to erode the colder boundary-layer across the Texas
South Plains into central Oklahoma vicinity, and are slower and
weaker with the evolving surface wave.
Otherwise, a gradual erosion, from south to north, of the shallow
leading edge of the entrenched cold air mass is possible, beneath a
continuing southerly to westerly return flow across parts of the
southeastern Great Plains into southern Mid Atlantic. However, it
appears that associated moisture emanating from a modifying western
Gulf boundary layer will not become supportive of more than weak
destabilization, or an appreciable risk for thunderstorms, due to
negligible forcing for ascent and warm, capping layers aloft.
...Pacific Northwest into northern Great Plains...
Models do indicate that forcing for ascent and cooling mid-levels
may contribute to pockets of weak destabilization across parts of
the Pacific Northwest into northern Great Plains during this period.
However, based on the latest NAM and Rapid Refresh forecast
soundings, the calibrated High Resolution Ensemble Forecast guidance
might be too aggressive with probabilities for thunderstorms across
the eastern Great Basin into northern Rockies vicinity for Friday
afternoon and evening. Instability will probably be sufficient to
support scattered to numerous snow and rain showers. However,
whether the boundary layer in higher elevations warms enough, or
convection initiating in lower elevations deepens through
sufficiently cold layers aloft, to support an appreciable risk for
lightning remains a bit unclear.
..Kerr.. 02/06/2025
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