Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus66 ksto 271133 
afdsto

Area forecast discussion
National Weather Service Sacramento California
433 am PDT Mon Mar 27 2017

Synopsis...
weather system exits the region today with dry and milder weather
expected for norcal much of the week. Another system will brush
through the region Thursday with a few showers.

&&

Discussion...
radar shows some lingering showers over the northern Sierra from
about Butte/Plumas counties southward while much of the valley has
cleared out. Temperatures are a little cooler compared to 24 hours
ago and generally range from the upper 20s and 30s in the
mountains to the 40s and lower 50s elsewhere.

Most remaining showers expected to taper off early this morning
over the Sierra as the main upper trough shifts east. However,
high-res models indicate a few may linger into this afternoon as a
last batch of energy (presently along the Oregon coast) shifts
southeastward along the backside of the exiting trough. While some
residual travel impacts may linger this morning, most precip will
end and the remaining winter weather advisories will be dropped
at 5 am PDT.

Upper ridging along with northerly flow will then bring warming
and drying to interior norcal into mid-week. Northerly winds will
be breezy at times the next several days across the Central
Valley.

High temperatures will return to around average by Tuesday, then
warm about 5 more degrees on Wednesday.

Another fast moving weather system is forecast to clip the area
later Wednesday into Thursday. Most showers with this one are
expected over the mountains. It will bring cooler temperatures for
Thursday along with another round of breezy north winds as it too
moves to the east.

&&

Extended discussion (friday through monday)
dry weather returns to the region on Friday as the closed upper
low shifts eastward. An "inside slider" pattern is likely to
develop, hinting at breezy north winds across interior northern
California.

High pressure builds across California next weekend, bringing a
strong but relatively brief warming trend. Temperatures will be on
the order of 10 degrees warmer than normal in this timeframe.

Longer-range models diverge early next week. The GFS & Gem both
hint at some flavor of low pressure system moving through the
region, whereas the European model (ecmwf) maintains a stronger ridge. With a high
degree of uncertainty, our forecast reflects a blend of the
various solutions. Dang

&&

Aviation...
weather system has begun to shift eastward out of the region.
Valley taf sites will remain mostly dry today, though patchy
MVFR/IFR conditions will be possible through the morning. IFR/LIFR
conditions over the Sierra will continue into the afternoon.

South winds up to 10 kt will shift to the north 5-15 kt this
afternoon. Dang

&&

Sto watches/warnings/advisories...
Winter Weather Advisory until 5 am PDT early this morning for
western Plumas County/Lassen park.

Winter Weather Advisory until 8 am PDT this morning for west

National Weather Service Glossary of Abbreviations