Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 301710
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1010 AM PDT MON MAY 30 2016

.SYNOPSIS...
Very warm weather expected this week as high pressure strengthens.

&&

.DISCUSSION...
A very warm week ahead with max temps some 10-15 degrees or more
above normal over much of interior Norcal.

High pressure cell just off the CA coast forecast to shift inland on
Tue...with the ridge axis shifting into Wrn NV/SErn CA on Wed. Max
temps today should warm into the mid to upper 90s in the Valley or
about 2-4 degrees most locations with more warming to come this
week. 850 mbs temps are forecast to be in the low to mid 20s deg C
with the ridge axis persisting over the Desert SW and Great Basin
maintaining the very warm temps this week.

Darkening in the water vapor imagery off the coast indicates strong
subsidence which should also move inland on Tue. This will squash
the marine layer...limit the influence of the Delta Breeze and
result in max temps some 10-17 degrees above normal...and possibly
the first 100+ reading this season. Bias corrected consensus of the
Max T models suggests a >70-99% chance of at least reaching the
century mark in the Valley on Tue. The average date for the first
100 at DTS is around June 18/19 near the summer solstice...and for
the RDD area around June 9. Max temp records for the date...May 31
are for KRDD/KSAC 103 in 2001...for DTS 106 in 2001...and for KSCK
107 in 2001.

Just a slight chance of some late day shower/storm activity along
the Sierra Crest S of Tahoe this afternoon...otherwise little if any
late day/early evening shower and thunderstorm activity is expected
over the northern Sierra this week until the flow backs to the
SE...possibly this weekend.   JHM

&&

.EXTENDED DISCUSSION (FRIDAY THROUGH MONDAY)...
Strong high pressure will rule the area through the end of the
work week into the start of the weekend with well above normal
temperatures. Models continue to advertise a closed upper low
approaching the CA coast by late Saturday into Sunday. Differences
remain with track of low and how far south into CA it will move
before being ingested into larger scale trough. GFS paints more
widespread precip, mainly across higher elevations. ECMWF with
further south solution/less widespread precipitation. For now,
have included chance of showers and thunderstorms across higher
elevations for the end of the weekend, until discrepancies are
better resolved. Regardless, should lend itself to some relief
from the heat with temperatures on Sunday around 5 to 10 degrees
cooler than Saturday and increasing flow through the Delta. CEO

&&

.AVIATION...
VFR conditions for TAF sites with light winds. A few
thunderstorms near the Sierra crest, south of Lake Tahoe this
afternoon/evening.

&&

.STO Watches/Warnings/Advisories...None.

&&

$$



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