Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/14/22
Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
759 PM PDT Wed Apr 13 2022
Breezy northwest winds will continue through this evening in the
mountains and in the Santa Ynez Range. Temperatures will be near
to slightly below normal through Friday. Some light rain is
possible north of Pt Conception Saturday, otherwise just a deep
marine layer and cooler temperatures. A warming trend is expected
Sunday through mid week, especially inland areas.
.SHORT TERM (WED-SAT)...13/758 PM.
Overall, a quiet evening across the forecast district. Latest
satellite and surface observations indicate clear skies for all
areas. Quick look at some AMDAR soundings indicate a shallow
inversion is developing around 400 feet deep. As for winds, some
northwesterly winds, gusting 35-45 MPH, are occurring across
southern Santa Barbara county.
Forecast-wise for the immediate short term, main issue will be the
winds. At this time, the northwesterly winds are localized enough
that do not see the need for any advisories at this time. These
northwesterly winds will gradually diminish overnight. Otherwise,
clear skies are anticipated overnight. However with the shallow
inversion developing, there is about a 20-30% chance of some
stratus/fog across the immediate coast of LA county late tonight.
Overall, current forecast has good handle on the immediate short
term. So, no significant updates are anticipated.
***From Previous Discussion***
Fairly benign weather pattern next couple days and really the next
several. There`s still enough northerly flow across the western
part of the forecast area to generate some gusty Sundowner winds
through the Santa Ynez Range though it`s a marginal advisory event
and will pass that torch onto the next shift. Otherwise, onshore
flow to the east has already started increasing and that trend
will continue through Saturday morning as a weak front approaches
from the north. There`s a small chance of some marine layer clouds
returning to some of the coast Thursday but a much better chance
Friday and especially Saturday just ahead of the cold front. In
fact Saturday we should be looking at a marine layer depth of at
least 3000` with low clouds well into the valleys and even up some
of the lower coastal slopes.
Model ensemble solutions definitely favoring some light precip
across SLO County Saturday as the front moves through, and
possibly as far south as Pt Conception but little if anything to
the south other than the deeper marine layer and maybe some
morning drizzle. Rain amounts up north expected to a quarter inch
Temperatures will hover near today`s levels through Friday, mostly
at or a couple degrees below normal. Then turning a little cooler
Saturday as the front rolls through.
.LONG TERM (SUN-WED)...13/154 PM.
A very modest warming trend will begin Sunday as weak high
pressure aloft builds in from the west. A light northerly gradient
will likely set up across the western part of the area generating
some breezy northerly winds through at least early next week.
However, models maintain at least a moderate onshore flow to the
east through mid week and heights don`t really rise too much so
not surprising to see forecast highs starting to drop back from
earlier solutions. May have to eventually beef up the marine layer
coverage for the coastal areas as even the northerly gradient has
weakened so the absence of low clouds in some coastal areas may
be a bit optimistic.
At 2253Z at KLAX, there was no marine layer and no inversion.
Overall high confidence in the 00Z TAFs through the period, with
VFR conditions expected. The exception is for KSMX and the LA
Coastal sites where there is a 20 percent chance of low clouds,
mainly between 06Z-09Z for KSMX and from 09Z-15Z at KLAX and
KLGB. Gusty northerly winds will continue to affect western Santa
Barbara County and the LA and Ventura Mountains through the
period. Lgt- mdt LLWS and turbc possible over and near the higher
terrain thru 00Z Friday.
KLAX...High confidence in the 00Z TAF with CAVU conds expected through
the period. There is a 20 percent chance of low clouds between
09Z-15Z, mostly likely in the LIFR-IFR category.
KBUR...High confidence in the 00Z TAF with CAVU conds expected
through the period.
Moderate to strong northwest to north winds will continue across
the Outer Waters, pushing into the Inner Waters at times (mainly W
Santa Barbara Channel and North of Point Sal), through at least
this weekend. A dwindling NW swell will allow large and dangerous
seas around 10 feet for these areas to subside well below 10 feet
for most areas tonight. SCA have been issued for all waters
except the Inner Waters south of Point Mugu. A marginal Gale
Warning is in effect with gusts to 35 knots through late tonight
for the Outer Waters south of Point Sal.
NW winds will diminish some during the morning hours, but are
expected to increase again Thursday afternoon and night with Gale
Force gusts again likely over the outer waters south of Point Sal.
PZ...Small Craft Advisory in effect until 5 AM PDT Thursday for
zones 645-650-670. (See LAXMWWLOX).
Gale Warning in effect until 5 AM PDT Thursday for zones
673-676. (See LAXMWWLOX).
Experimental Graphical Hazardous Weather Outlook at:
Area Forecast Discussion
National Weather Service Phoenix AZ
514 PM MST Wed Apr 13 2022
.UPDATE...00Z Aviation Discussion.
High pressure will continue to build into the region this week
resulting in widespread dry weather and gradually warming
temperatures. Readings will increase quickly through the rest of the
week with afternoon highs eventually reaching around 10 degrees
above normal early next week. This equates to temperatures
rebounding into the mid and upper 90s for lower elevation
Pronounced negative PV anomalies and deep troughing have shifted
into the central Conus this afternoon with strong NW flow in its
wake covering the Southwest. Through the remainder of the week,
negative height anomalies will migrate into the northern tier of the
United States while broad, low amplitude ridging and fast quasi-
zonal flow envelops the southern states. Low amplitude, progressive
flow will the predominant regime through at least the middle of next
week with periodic shortwaves in the northern stream temporarily
dampening the magnitude of the ridge.
Morning ACARS soundings sampled an atmospheric profile not terribly
dissimilar to Tuesday though recent objective analysis suggests some
moderation in the sfc-H7 layer. Steady warming of the entire
atmospheric profile will occur through the remainder of the week as
H5 height progressively increase from near 570dm to 578dm. Ensemble
temperature guidance spread is quite minimal yielding excellent
forecast confidence of afternoon readings reaching 4F-8F above
normal by the weekend. The only feature of note during this time
will be a modest shortwave rapidly propagating through the Great
Basin helping tighten the pressure gradient and briefly enhance
Upper level heights should increase further early next week marking
the warmest segment of this forecast period. While ensemble spread
remains small, GEFS membership continues to trend more dampened with
H5 heights while EPS tendencies suggest a somewhat more amplified
solution. Regardless, H5 heights above 580dm appear a near certainty
resulting in temperatures ~10F above normal. NBM probabilities of
reaching 100F across lower elevation communities continue to
generally hover in a 20-30% range. Somewhat larger pattern
amplification could begin to develop across the east Pacific towards
the middle of next week with moderate confidence of at least minor
height falls pulling temperatures closer to normal into the latte
half of the week.
.AVIATION...Updated at 0013Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
West to southwest breezes subside this evening and typical diurnal
trends will prevail through the TAF period. Easterly wind shift is
anticipated before midnight and the the west to southwest shift
Thursday is expected by 22-23Z with a period of southerly winds
and variability during the transition. Speeds in the afternoon up
to 7-10 kts, with gusts into the mid teens, are likely. Otherwise,
winds will be light. FEW to SCT high clouds will be seen at times
through the period.
Southeast California/Southwest Arizona including KIPL and KBLH:
Light winds will generally favor typical diurnal patterns at both
terminals, with extended periods of variability. FEW to SCT high
clouds are expected Thursday.
Saturday through Wednesday:
Under strengthening high pressure, dry conditions will persist while
temperatures warm to around 10F above average by early next week.
Wind speeds will be typical for mid April with the usual afternoon
upslope gustiness around 15-25 mph. Minimum afternoon humidity
levels should easily fall into the single digits following poor to
fair overnight recovery of only 15-35%. These weather conditions
will provide an excellent opportunity for any prescribed burning
during this time frame.
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