FXUS66 KSTO 191647

Area Forecast Discussion
National Weather Service Sacramento CA
947 AM PDT Tue Jun 19 2018

Hot and dry weather this week, peaking this weekend.


An upper level ridge centered over Baja California has begun to
build over the state as a broad area of circulation over the
northern Rockies pulls eastward. The marine layer is running at
around 1500 feet deep this morning with moderate onshore flow
through the Delta. Temperatures across the interior are running
upwards of 10 degrees warmer than yesterday, owing mostly to
synoptic warming.

Northern California will remain under a neutral weather pattern
today and Wednesday, with high pressure to our south and a passing
shortwave to our north. This will keep a light to medium Delta
Breeze moderating temperatures in areas adjacent to the Delta.
Look for high temperatures in the 90s across the Valley, with 70s
to 80s over the mountains. These forecast temperatures are roughly
5 degrees warmer than normal for this time of year.

Temperatures will continue to warm up later this week as the
shortwave trough exits, and the upper ridge strengthens across the
West Coast. By Friday we are likely looking at widespread triple
digit temperatures across the Valley, and temperatures look to
warm further into the weekend.




High pressure ridging will bring hot weather to the area this
weekend, peaking on Saturday. High temperatures for Saturday are forecast
to be 12 to 17 degrees above normal, with 102-105 across the
Central Valley, 93-103 in the foothills, 73-93 in the mountains.
This will bring the potential for moderate to high heat risk, even
for the general population in a significant portion of the
Central Valley and the Delta and into the foothills. Sacramento
is currently forecast to reach 105, which is one degree shy of the
record of 106, set in 1988. Redding is also forecast to reach
105, which is well short of the record of 111, set in 2006.

Northerly winds and low humidity levels will increase fire danger
over the weekend, especially on Saturday.

Sunday may be a little less hot as the ridge axis shifts eastward
and flow shifts to more southwesterly. This will be felt most in
the Delta and adjacent areas, as a Delta breeze brings some
cooling later in the day and overnight. Monday is expected to see
more cooling but continued above normal temperatures, with Valley
highs generally in the 90s. Tuesday should be cooler yet, with
temperatures closer to normal. So, the good news is this heat
event will be relatively short.



VFR conditions continue over the next 24 hours. Dry weather is
expected. Winds at TAF sites will generally be less than 10kt. EK



Back to Main Forecast Discussion Page