Scientific Forecaster Discussion
Southwest California area forecast discussion
National Weather Service Los Angeles/Oxnard California
435 am PDT Friday Mar 14 2014
..updated aviation discussion...
high pressure and developing offshore flow will bring mostly clear
skies with well above normal daytime temperatures to much of the
region over the weekend. A cooling trend is expected Monday and
Tuesday as the upper high weakens and moves southeastward away from
the region. Some additional cooling is possible Wednesday and
Thursday as a weak upper low moves into the West Coast. No rain is
expected through the period.
Short term (today-sun)...some patchy low clouds and fog have
developed across coastal of valley sections of l.A. County and the
central coast early this morning. Do not expect any low clouds to
last too long this morning...with sunny skies expected in most areas
by middle or late morning. Rising heights and thicknesses may bring
some warming to the mountains and deserts. Onshore gradients and some
lingering marine influence should keep temperatures about the same as on
Thursday west of the mountains...although a couple of degrees of warming may
occur. Gusty northwest to north winds in the mountains today should remain below
Some gusty north winds will affect the Santa Ynez range and locations
through and below passes and canyons across the S coast of sba
County tonight...though winds should remain below advisory levels.
Low level flow will turn more northeasterly late tonight and Sat morning.
Expect little if any stratus...confined to the central coast and
coastal l.A. County if there is any. An upper ridge in the eastern
Pacific will amplify into the West Coast as it evolved into a close
upper high. Good height and thickness rises should bring several
degrees of warming to most areas on Sat...with additional warming
due to compressional heating of downslope NE flow west of the mountains
expect some gusty winds through and below passes and canyons in the
mountains and valleys of l.A. And vtu counties and possibly the vtu County
coastal plain Sat morning...but winds should remain below advisory.
Maximum temperatures may approach record levels in some coastal and valley
areas...mainly because daily records are especially low for middle
March in most areas.
Heights and thicknesses will peak across the region Sunday. While
low level gradients are forecast to turn onshore in the
afternoon...temperatures will start out higher on Sunday morning in most
areas...and will likely rise very quickly in the morning.
Therefore...expect maximum temperatures to be higher in most areas on
Sunday...although there will likely be a noticeable cool down across
the coastal plain in the afternoon...especially near the coast.
Long term (mon-thu)...the upper high will weaken and move southeastward
Monday and Tuesday...and onshore flow will increase. Expect several
degrees of cooling both days...although maximum temperatures should still be
above normal...even on Tuesday. The GFS shows additional height and
thickness falls Wednesday and Thursday as a weak upper low moves into the West
Coast. The ec keeps higher heights across the region Wednesday and
Thursday...with mostly minor changes in maximum temperatures. At this point...will
adjust temperatures up slightly for Wednesday and Thursday...but not make any major
changes. Dry weather is expected Monday through Thursday.
Aviation...high confidence with interior 12z tafs over next 24
hours. Lower confidence for central coast and la County coast. Vlifr
ceilings just pushed into the central coast. Should persist through 16z.
30 percent chance for IFR ceilings to develop across la County. There
will be patchy LIFR ceilings at kvny through 15z. Expect VFR ceilings after
18z in all areas.
Klax...VFR conditions expected through the period...except for 40
percent chance for IFR/MVFR ceilings through 16z. There will be a 30
percent chance for IFR ceilings after 10z tonight.
Kbur...VFR conditions expected through period. Except a 20 percent
chance for IFR ceilings between 12-15z
Small Craft Advisory (see laxmwwlox).