Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Sacramento California
924 am PDT Fri Jul 25 2014
daytime temperatures will remain near to several degrees above
normal through the coming week. The Sierra crest will see a threat
of thunderstorms Sunday through much of next week and possibly as
far north as the Shasta County mountains on Wednesday.
Short term discussion...
temperatures are already running a few degrees warmer today than this
time yesterday. No updates this morning.
Most areas will see a little warming today as a large
high pressure ridge over the southern U.S. Builds westward. With
the marine layer squashed down to below 1000 feet and stable
southwest flow aloft over the north state...skies are clear this
morning. Most locations will see a degree or two of warming today
putting highs near to a few degrees above normal. Just a bit
higher temperatures are expected on Saturday under a slightly
warmer airmass. A more southerly flow aloft develops on Sunday as
a weak trough approaches the coast. Precipitable water proggs show
monsoon moisture just starting to move into the southern County Warning Area and
stability proggs show a slightly unstable environment along the
Sierra crest. Therefore...still including afternoon thunderstorm
threat for this area. Precipitable water proggs show moisture
pushing just a bit farther north on Monday so edged the T-storm
threat northward up the Sierra as well. Overall airmass stays
about the same so kept high temperatures fairly constant Sunday
and Monday. However, surface pattern shifts a bit more onshore
Sunday and Monday so near Delta areas may see a slight cooling.
Extended discussion (tuesday through friday)
Medium range models depicting little change through the extended
period as upper ridge axis over the western U.S. Remains over the
Great Basin while upper troughing remains over the eastern
Pacific. Monsoon moisture will continue to feed northward in
southerly flow aloft over the state. Stability proggs show best
threat of afternoon convection over the Sierra crest Tuesday and
over areas north of the County Warning Area. A small scale trough clipping the
northwest corner of the state may bring the afternoon thunderstorm
threat southward into the Shasta County mountains on Wednesday.
Models show a more southwest flow aloft on Thursday which may keep
any thunderstorm threat mainly north and east of the forecast area
Thursday through Friday. For the remainder of the forecast
area...fair skies are forecast with continued above normal
VFR conditions with generally light winds the next 24 hours.