Thornton, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

359
FXUS66 KSTO 202114
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
214 PM PDT Fri Sep 20 2024

.Synopsis...
Dry weather is expected over interior NorCal throughout the
weekend and into next week with an overall warming trend
increasing high temperatures to above normal by early next week.
This will result in Moderate HeatRisk on Monday and Tuesday,
mainly in the Valley. Elevated Fire Weather Conditions early next
week due to northerly winds and low humidity, primarily in the
northern and western Sacramento Valley.

&&

.Discussion...
A gradual warm up continues today, with high temperatures
expected to reach the low to mid 90s in the Valley, and 70s to 80s
at higher elevations. This trend continues through the weekend
and into early next week, as ridging progresses out over the west
coast. By Monday, the NBM is showing an 30 to 60% probability of
temperatures at or above 95 degrees in the Valley, though
conditions should remain below 100 degrees.

Additionally on Monday, the positioning of the ridge to the north
with a trough to the southeast will cause a pressure gradient that
will bring breezy to gusty northerly and easterly winds early next
week. Winds will be strongest in the northern Sacramento Valley
along the I-5 corridor, with the NBM showing a 40-75% probability of
winds over 25 mph. This will coincide with low daytime relative
humidities, generally around the mid teens to low 20% range. With
these factors combined, Elevated Fire Weather Conditions are
expected in the early part of next week in that area.

&&

.EXTENDED DISCUSSION (Tuesday THROUGH Friday)...
Elevated Fire Weather Conditions continue into Tuesday, though
the period of most concern will be over after Monday night, as the
upper level ridging begins to shift eastward on Tuesday. A couple
of back to back short wave troughs are then expected to move
through the Pacific NW on Wednesday and Thursday, bringing
temperatures back to seasonable levels across interior NorCal.
Friday, high pressure begins to build over the Desert SW, bringing
elevated 500 mb heights to interior NorCal as well as the
potential for slightly warming temperatures (though still
remaining near normal).

&&

.AVIATION...
VFR conditions over interior NorCal next 24 hrs. Surface wind
mainly below 12 kts except in the vicinity of Delta, where
southwesterly gust up to 20 kts possible, and in vicinity of
Redding area where 20-25 kts northerly gusts possible.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$