Cromberg, California Weather Forecast Discussion

768
FXUS65 KREV 200848
AFDREV
Area Forecast Discussion
National Weather Service Reno NV
148 AM PDT Sat Sep 20 2025
.KEY MESSAGES...
* Showers and isolated thunderstorms this afternoon for NE CA,
  northern Washoe, southern Mineral, and Mono counties.
* Cooler temperatures today, with a slight warming trend through
  next week.
* Another weather system possible as early as Tuesday.
&&
.DISCUSSION...
* For today, CAMs and HREF guidance are picking out two areas for
  scattered convection this afternoon after 1-2 PM. The first is
  in Mineral and Mono counties, while the other location is in
  Lassen and northern Washoe counties. Each area has a 15-20%
  chance for showers and thunderstorms. There is still decent
  moisture in place with PWATs around 0.5-0.6". And also decent
  instability with SBCAPE between 400-700 J/kg. Storms that
  develop will be capable of producing brief heavy rainfall,
  frequent lightning, gusty winds, and small hail. Other areas
  across western NV and the eastern Sierra will see less than a
  10% chance for precipitation.
* For Sunday, an upper low pressure currently at 33N/128W will
  continue to slowly track toward the SoCal coast while a trough
  and weak cold front will move through the northern Great Basin.
  The best chances for precipitation associated with this feature
  on Sunday will be south of US-50 in the eastern Sierra and out
  toward Mineral, Lyon, and Douglas counties, as well as into the
  inner-basin and ranges. By Monday into Tuesday, a ridge will
  will move into the northern Great Basin/Pacific Northwest with
  the aforementioned upper low pressure still over southern
  California. By Tuesday/Wednesday through the end of next week,
  model ensembles start to diverge in their solution with the
  evolution of the upper low and forecast confidence decreases.
  Some solutions bring the low pressure due north over the Sierra
  (with more precipitation), while others keep the low further
  south, then track over southern NV (less precipitation). For
  now, NBM guidance shows a broad area of 20-30% chances for
  precipitation, but expect this to change. -McKellar
&&
.AVIATION...
There is a 10-20% chance for showers and storms after 19z at KMMH.
Brief heavy rain is possible with MVFR ceilings. Otherwise, winds
will continue to be light and VFR conditions will prevail at all
other western NV and eastern Sierra terminals. -McKellar
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$

NWS REV Office Area Forecast Discussion