Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 310409
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
909 PM PDT Wed Jul 30 2014
Another day of Sierra crest showers and thunderstorms tomorrow
(less coverage than today)...then a drying trend. Then a return
to Sierra showers and t-storms early/mid week next week.
Busy earlier with strong thunderstorms producing heavy rain. The
activity pushed toward the valley with some showers that popped up
in the valley. As temperatures continue to cool over the valley
this evening and the atmosphere becomes more stable the activity
will end. A weak wave off the coast is lifting north-northeast
overnight and delta breeze should increase slightly the next few
hours and the marine layer should increase slightly as well. Clouds
over the valley will gradually clear but overall it will be a slow
cool down overnight for the interior once again.
Afternoon thunderstorms are expected to develop once again in the
afternoon near the crest on Thursday with most of the activity to
the east of the crest. Little change is expected for Thursday in the
overall conditions other than less clouds over the interior and
slightly warmer temperatures.
Friday we may see a decrease in thunderstorm activity as the high
pressure region moves slightly eastward. Temperatures will remain
above normal. Saturday the activity pushes well to the east as a
weak wave moves towards the Pacific Northwest with the tail end of
the trough moving into California. Temperatures will also trend
slightly cooler each day.
.Extended Discussion (Sunday through Wednesday)
Upper ridge positioned over the Intermountain West Sunday as weak
upper trough moves through NorCal. Increased mid-level
southwesterly flow Sunday will keep the threat of afternoon
thunderstorms outside of the forecast area with only a slight
chance over the higher Sierra Nevada, south of Highway 50, on
Monday. Models then depict upper ridging from the Desert SW
rebuilding northwestward over Interior NorCal next week. Mid-level
flow begins to turn more southerly Tue and southeasterly Wed with
another slug of monsoonal moisture working its way into the
forecast area. Threat of afternoon thunderstorms expands
northward along the Sierra Tuesday, through Western Plumas into
the Shasta and coastal mountains Wednesday. Near normal high
temperatures expected through early next week then warming upwards
of 5 degrees above normal Wednesday.
Upr rdg movs E as SWly flow alf with EPAC upr trof incrs Thu. Isold
tstms poss ovr hyr mtn trrn of the Cstl rnge, Shasta, Plumas, and
Siernev aft 20z thru 05z Thu otrw VFR conds ovr Intr NorCal nxt 24
hrs. Isold SWly sfc wnd gsts to 25 kts poss ovr hyr mtn trnn and
thru Delta late aftns into eves.