FXUS66 KSTO 191820
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1120 AM PDT Tue May 19 2026

.KEY MESSAGES... 

 - Warm and dry weather prevails through the week and into the 
   weekend with areas of Moderate HeatRisk Wednesday-Friday

 - Periodically breezy onshore winds return by Thursday; strongest
   west-southwest winds in the Delta and vicinity locations

&&

.DISCUSSION...

...Today and Wednesday... 
As troughing over the Great Basin/Desert Southwest ejects 
eastward through the middle of the week, winds will continue to 
lessen relative to the past weekend. As ridging builds in offshore
of the Pacific Northwest, a deepening trough over SoCal/Baja will
leave interior NorCal underneath nebulous split flow mid to late 
week. Despite this, rising heights aloft will introduce gradually 
warming temperatures and areas of Moderate HeatRisk beginning on 
Wednesday. As a result, high temperatures in the 90s are expected 
in the Valley, with 70s to 80s at higher elevations.

...Thursday into the Weekend...
As the split flow pattern and higher heights aloft persist into 
the end of the week, warm temperatures and Moderate HeatRisk look 
to stick around through Friday. Warmest temperatures, into the mid
to upper 90s in the Valley, are anticipated on Thursday before 
gradually cooling toward and into the weekend. Despite some 
ensemble uncertainty, broad troughing aloft is on track to build 
in over the weekend helping to reinforce breezy onshore winds and 
temperatures nearer to normal for mid to late May. While 
periodically breezy onshore winds are expected to develop by 
Thursday evening, strongest winds are currently on track this 
weekend into early next week. 

&&

.AVIATION...

VFR conditions are expected over the next 24 hours. Light 
northerly winds less than 10 kts expected through the afternoon, 
becoming light and variable after 00z Wednesday. 

&&

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

$$