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Area forecast discussion 
National Weather Service San Joaquin Valley - Hanford California
239 PM PDT Friday Jul 31 2015

Synopsis...
monsoon moisture over the region will continue to produce showers
and thunderstorm each afternoon and evening mainly over the
mountains. A drying trend expected by Sunday as upper level winds
become more southwesterly.

&&

Discussion...
a remnant vorticity maximum provided a few storm early this morning. The
disturbance has pushed into ncal leaving clearing skies. Cumulus
clouds forming this afternoon over the mountains. Weather radar
shows several storms developing over the Sierra high country.
Satellite estimates of preciptable water indicate lots of
moisture across central California. Precipitable water values remain around two sigmas
above normal. While the NAM model prognosticated some heavy precipitation
across the Sierra through this evening. However the middle level flow
remains moderate out of the southeast. Thus storms will provide brief
periods of heavy rain. The storms will move at a fast pace
towards the north and limit the potential for flash flooding. Do
not see any weather disturbances to maintain or initiate
convection overnight. Thus expect any storm activity to diminish
during the evening. An upper low off the coast will move further
north Saturday. This will turn the middle level flow further south
bringing a dryer air from the south. The drier airmass will into
the central coast Saturday limiting the convective storm potential
across the Diablo and Tehachapi Mountains. Expect any thunderstorm
activity mainly over the Sierra and foothills triggered by daytime
heating and upslope wind convergence. The drying trend and
diminishing storm threat will continue on Sunday as the flow turns
more SW. An upper low will reform off the West Coast early next
week and maintain the a dry SW middle level flow. At the lower levels
a cool onshore flow into the interior will bring temperatures
slightly below normal for much of next week.

&&

Aviation...
scattered thunderstorms with local MVFR ceilings and mountain
obscurations can be expected over the Sierra through Saturday.
Otherwise...VFR conditions will prevail across the central
California interior during the next 24 hours.

&&

Air quality issues...
on Friday July 31 2015... unhealthy in Madera County. Unhealthy
for sensitive groups in Fresno... Merced and Tulare counties.
Further information is available at valleyair.Org

&&

Certainty...

The level of certainty for days 1 and 2 is medium.
The level of certainty for days 3 through 7 is medium.

This information is provided as part of a trial project conducted
by the National Weather Service San Joaquin Valley - Hanford.
Certainty levels include low...medium...and high. Please visit
www.Weather.Gov/hnx/certainty.Php /all lower case/ for additional
information and/or to provide feedback.

&&

Climate...
records
site date hi_max:year lo_max:year hi_min:year lo_min:year

Kfat 07-31 114:1908 83:1976 81:1908 53:1895
kfat 08-01 112:1908 79:1933 86:1908 56:1888
kfat 08-02 112:1908 83:1953 82:1908 53:1956

Kbfl 07-31 110:1943 85:1985 81:2014 55:1905
kbfl 08-01 112:1979 86:1985 80:2000 53:1912
kbfl 08-02 109:1979 86:1976 84:1977 53:1912
&&

Hnx watches/warnings/advisories...
none.
&&

$$

Public...mv
AVN/fw...durfee
previous discussion...bean
synopsis...Rowe

Weather.Gov/Hanford

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