Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 270407

Area Forecast Discussion
National Weather Service Sacramento CA
907 PM PDT Wed Apr 26 2017

Weak weather system will bring light precipitation today. Dry
weather Thursday through much of next week, with breezy north
winds Thursday and Friday.


Scattered showers continue this evening. Mostly over the
foothills and mountains. The HRRR indicates showers may persist in
the valley near Chico to Oroville through about midnight before
ending. For the foothills and mountains showers will continue to
decrease but linger until late tonight. Low clouds will likely
persist in the San Joaquin Valley overnight and may form over the
Southern Sacramento Valley as well. Northerly flow looks to start
early in the day so the low clouds should be dissipating fairly
rapidly in the morning from north to south. Sunny skies are
expected for Thursday but some cumulus clouds will likely linger
over the mountains during the daytime. Winds may be a little
breezy at times during the day but should mainly stay in the 10 to
15 mph range for most of the day. Stronger northerly winds are
still expected for Friday.

A shortwave trough is currently moving into the Pacific Northwest,
with moist westerly flow aloft across the region. In fact, blended
Total Precipitable Water (TPW) products suggest atmospheric
moisture content above 200% of normal for this time of year.
Forcing is rather weak, and so showery activity has been light,
not particularly widespread, and focused mainly over the
mountains. A few showers will still be possible across the Valley
through the evening, and precipitation should taper off over the
Sierra late tonight.

The upper air pattern amplifies beginning Thursday as the trough
deepens over the Great Basin, and a ridge of high pressure
strengthens over the eastern Pacific. This "inside slider" pattern
traditionally brings breezy north winds to Northern California,
and will be the case Thursday into Friday. Warmer weather is
expected for the weekend as high pressure builds into the region.



Warm and quiet will be the story for the exteneded period. The
ridge will weaken a bit on Sunday and we will see a short wave
pass to the north and east. Not expecting any rain with this but a
few clouds possible in the northeast part of the CWA. As the short
wave continues to track to the east of us it will bring breezy
winds for Monday and Tuesday but continued dry as a strong ridge
builds in. With that ridge building in we will see a warm up with
highs pushing 10-15 degrees above normal by Wednesday.


Light precipitation due to a weakening system will end late
tonight. Areas of MVFR conditions developing overnight south of
KMYV. Widespread IFR conditions improving over the Sierra on



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