Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus66 ksto 241125 
afdsto

Area forecast discussion
National Weather Service Sacramento California
325 am PST Fri Feb 24 2017



Synopsis...
flooding concerns continue as runoff from the recent rain
continues to work its way downstream adding stress to waterways. A
couple of weak but cold storms move through around Saturday and Monday.
An extended period of dry weather starts the middle of next week.
&&

Discussion...
mainly fair skies over the County Warning Area this morning as norcal sits under
upper northwest flow between low pressure over the central U.S and
a weak system dropping down the Pacific northwest coast. The fair
skies and cool northwest flow are making for a cold morning.
Valley temperatures are currently running about 1 to 3 degrees
below 24 hours ago so expect many locations will drop to near
freezing. This means lots of valley dwellers will be using ice
scrapers before going to work today. As the day progresses, skies
will cloud over as the upper low drops down from the north. Cloud
cover and cool airmass will keep daytime highs today below normal.
By the end of today the northern mountains could see a few light
showers. The threat of light showers will continue to spread
southward overnight with a chance of showers over the entire County Warning Area
by mid day Saturday as the upper trough sinks over norcal. Still
appears that most of the energy from this system will remain
offshore so precipitation amounts will be fairly minimal. Snow
levels over the northern mountains will be relatively low at
between 1000 and 2000 feet. With low qpf, snow accumulations will
be low but snow ratios of 15 to 1 or higher could make for a few
inches of snow causing minor travel issues. Upper trough shifts
south of the forecast area by early Sunday bringing an end to the
shower threat most areas. Another upper low follows quickly on the
heals of the Saturday system dropping out of the Pacific northwest
and into norcal by Sunday afternoon. Light shower chances will
exist over the region again mainly Sunday night and early Monday.
A more eastward track of this system will make it a slightly
wetter one for the County Warning Area but precipitation totals remain on the low
side. Snow totals from Sunday to Monday will come to just a few
inches but with the snow levels again between 1000 and 2000 feet
over the northern mountains, minor travel impacts are likely.

&&
Extended discussion (tuesday through friday)

Slight chance of snow showers over the higher terrain of the
Sierra Nevada Tuesday otherwise drier weather sets up through the
extended forecast period as upper ridge builds over interior
norcal. Warming trend expected with highs in the mid to upper 60s
for the Central Valley towards the end of next week.

&&

Aviation...

Wly flow Alf with VFR conds ovr intr norcal tda. Upr low digs S
off the northwest California CST tngt into Sat with areas MVFR/IFR poss in
shwrs...mnly omtns. Sn lvls arnd 020 tngt into Sat mrng.

&&

Sto watches/warnings/advisories...
Flash Flood Watch through Saturday morning for Carquinez Strait
and Delta.

National Weather Service Glossary of Abbreviations