Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Sacramento California
906 PM PDT Tue may 5 2015

Synopsis...
dry weather will continue through early Wednesday before a cooler
and more unsettled pattern begins later Wednesday into the end of
the work week. Low pressure dropping southward from the Pacific
northwest will bring a chance for showers and thunderstorms,
mainly to the mountains.

&&

Discussion (today through friday)...
the low will start to drop southward over the area but seems a
little slower this evening on it's timing. This may limit the
amount of showers or thunderstorms over the area for Wednesday.
Snow levels look to be high during the daytime up around 7500 feet
or higher.

As the low shifts southward Wednesday night into Thursday morning
that's when we should see an increase in activity over the
interior and mountains. This may also be the best time period for
the valley to see any showers from this system. The central part
of the low drops down over the central coast with models
indicating showers likely over the mountains. Snow levels may drop
down to around 5000 feet during that time period but not much in
the way of snow is expected at that level. The better
accumulations will be above 7500 feet but a couple of inches down
to around 6500 feet look possible.

The low will continue to shift southward on Friday but wrap around
moisture from the low will continue chances for showers and
thunderstorms over the Sierra Nevada. Snow levels rise well above
pass levels to around 8000 feet or higher during the day.



Extended discussion (saturday through tuesday)

The weekend is expected to be generally dry as one low exits and
mesoscale ridging briefly builds in. High temperatures should be 3
to 6 degrees above normal levels. A few showers are possible in
the Sierra early Saturday, mainly south of Highway 50 by daybreak.
A weak system brushes by to the north late Sunday and into Monday,
bringing some showers to the northern mountains. The GFS suggests
there may be enough instability for some Monday afternoon
thunderstorms there, so will keep that possibility in the
forecast. The European model (ecmwf) keeps the low a little further north, limiting
precipitation to just some rain showers. There could be a few
lingering showers on Tuesday, but the weak system will mainly be
exiting. Ek

&&

Aviation...

General VFR conditions tonight into early Wednesday. Winds this
evening mainly southerly around 10kt except for the Delta 15-20
kts with gusts to 25 kts late this afternoon and early evening,
then weakening overnight. Winds becoming northerly over the
northern and central Sacramento Valley Wednesday by 12z...gusting
to 25 kt after 18z. Before winds in that area mix down in the
morning, there could be some stronger winds (30kt) around 300-1000
feet above the surface. Some showers developing over the Sierra
Wednesday, with some afternoon thunderstorms possible there. Ek



&&

Sto watches/warnings/advisories...
none.
&&

$$

National Weather Service Glossary of Abbreviations