Valid 082000Z – 091200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
Isolated thunderstorms might occur later tonight into early morning
Thursday, mostly across northern California and southwest Oregon. A
few thunderstorms are also possible over the northern Rockies and a
portion of the Northeast States, but coverage is expected to remain
No change was made to the previous convective outlook.
.PREV DISCUSSION… /ISSUED 1018 AM CST Wed Jan 08 2020/
…Southwest Oregon into northern California…
The next in a series of shortwave troughs will move into the Pacific
Northwest region late tonight. Steepening lapse rates and forcing
for ascent attending this feature will result in weak instability
(200-300 J/kg MUCAPE). This environment will promote scattered
showers and a few embedded thunderstorms, mainly within the
accompanying cold frontal zone.
A broad zone of steep mid-level lapse rates and modest forcing for
ascent attending a progressive shortwave trough will move through
the northern Rockies today resulting in very weak instability
(MUCAPE from 100-200 J/kg). Areas of widely scattered showers will
remain likely in this environment, and although a few lightning
flashes cannot be ruled out, coverage is expected to remain less
A progressive upper trough will move through the northeast states
this afternoon. Steep mid-level lapse rates within the thermal
through will promote weak instability (MUCAPE from 100-200 J/kg).
Widely scattered to scattered showers will continue developing in
this region this afternoon. A few lighting flashes might also occur,
but coverage is expected to remain sparse.