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000
FXUS66 KLOX 031035
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
335 AM PDT TUE MAY 3 2016

.SYNOPSIS...

Night through morning low clouds and fog are expected for many
areas west of the mountains through Wednesday, followed by
partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers and thunderstorms Thursday through
Sunday, along with cooler conditions. Temperatures will likely
return to near normal early next week as high pressure returns.

&&

.SHORT TERM...(TDY-THU)

The marine layer is about a 1000 feet deep at the moment. But sfc
gradients are just barely onshore and there is no eddy to speak
of and as a result there are hardly any low clouds. It looks like
this mornings low clouds will be confined to the immediate central
coast and the long beach area. Otherwise skies will be sunny in
the morning and partly cloudy in the afternoon as some high level
cloud advect in ahead of an upper level trof. The sunshine and the
reduced onshore flow will allow all areas to warm a few degrees
from Mondays values.

A wise old long retired forecaster here once said of the marine
layer stratus "just forecast persistence and then you`ll only be
wrong once" Will foolishly go against this advice and once again
forecast a fairly robust marine layer stratus deck tonight on the
basis of the approaching upper level trof which will provide
enough low level lift to create the clouds. The onshore flow is
not really what it should be so may well be another stratus free
start to the day.

On Wednesday the trof cuts off into a closed low and approaches
the coast. clouds and onshore gradients will increase through the
day and hgts will fall. Look for max temps to fall 4 to 8 degrees
from todays readings.

The upper low moves from a point about 60 NM west of KSFO early
Thursday morning to a point 60 miles SW of Point Conception late
Thursday evening and then to the Needles area by afternoon
Friday. There is not much moisture to work with and am not
expecting too much rainfall maybe a quarter inch and more like a
tenth of an inch from hit or miss showers that will occur over the
two day period. The big question mark will be afternoon cloud
cover. If afternoon skies are partly cloudy the high sun angle sfc
heating below the cool upper air aloft will form a very good
convective environment. If skies are more on the overcast side of
things there will be much less in the way of shower activity. The
best chance of TSTMs on Thursday will be over the interior with
some vorticity moving overhead. On Friday the area will switch
over to all of LA and VTA counties as the cold pool aloft moves
directly overhead for maximum instability. snow levels will fall
to about 6000 feet and there could be some local accumulations at
the highest elevations.

.LONG TERM...(FRI-MON)

Scattered shower activity will persist Saturday across the
interior and especially the mtns as the upper low moves into SE
NV and spins several vort lobes into the area from the NE. In fact
if skies are fairly clear there could be quite a bit of afternoon
mtn convection.

The upper low will then pull so far to the east that it will no
longer affect Srn CA and a ridge will begin to nose in from the W.
This will kick off a clearing and warming trend.

&&

.AVIATION...03/1035Z...

At 1020Z, the marine inversion at KLAX was around 1400 feet. The
top of the inversion was 2300 feet with a temperature of 19 degrees
Celsius.

N of Point Conception...
Moderate confidence with 12z tafs. 30% percent chance that cigs
will scour out +/1 2 hours from tafs. low confidence for mvfr
cigs. good confidence that cigs will return back and be a bit
deeper with a better chance of ifr/low mvfr cigs.

S of Point Conception...Low to moderate confidence with areal
coverage and timing of stratus. 30 percent chance for ifr cigs for
klax and 30 percent chance that ifr cigs will not develop at klgb
this morning. Higher confidence for ifr/mvfr cigs across most
coastal sites later tonight. +/- 2 hours from current tafs.

KLAX...low to moderate confidence in 12Z TAF. 30 percent chance
for ifr cigs to develop between 12z-16z this morning. Higher
confidence for ifr/mvfr cigs and vsbys later this evening. +/- 2
hours from 12z taf time.

KBUR...high confidence in 12Z TAF for VFR conditions are
anticipated through the TAF period. There is a 30% chance of IFR
conditions 09Z-17Z Wed.

&&

.MARINE...03/200 AM...

High confidence for coastal waters remaining below SCA levels
through Friday morning. There is a 60% chance for SCA level winds
from Friday afternoon to late Friday night across the very
western portion of zone PZZ670 from Point Piedras Blancas to Point
Sal.

There is a 60% chance of patchy dense fog off the Orange County
Coast this morning...with less chance to 40% off the Los Angeles
County Coast.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...CK
MARINE...CK
SYNOPSIS...Sukup

weather.gov/losangeles



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000
FXUS66 KMTR 031032
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
332 AM PDT TUE MAY 3 2016

.SYNOPSIS....HIGH CLOUDS WILL PUSH INTO THE AREA TODAY AS A STORM
SYSTEM APPROACHES FROM THE PACIFIC. THE STORM SYSTEM WILL BRING
COOLER TEMPERATURES TO THE AREA BEGINNING WEDNESDAY ALONG WITH A
POSSIBILITY OF SHOWERS AND A RISK OF AFTERNOON THUNDERSTORMS...THESE
CONDITIONS ARE EXPECTED TO PERSIST INTO THE WEEKEND.

&&

.DISCUSSION...AS OF 3:32 AM PDT TUESDAY...THE CURRENT IR
SATELLITE IMAGE IS SHOWING HIGH CLOUDS PUSHING INTO THE FORECAST
AREA THIS MORNING AS A STORM SYSTEM CENTERED APPROXIMATELY 700
MILES OFFSHORE APPROACHES THE COAST. LOCAL OBSERVATIONS ARE ALSO
SHOWING LOW CLOUDS ALONG THE COAST AS WELL...WITH THE FORT ORD
PROFILER SHOWING A 1200 FOOT DEEP MARINE LAYER.

THE 0000Z ECMWF AND 0600 GFS40 HAVE INITIALIZED WELL WITH THE
CURRENT SYNOPTIC WEATHER PATTERN AND REMAIN IN GOOD AGREEMENT
THROUGH MUCH OF THE FORECAST PERIOD. BOTH MODELS BEGIN TO SLIDE
THE PREVIOUSLY MENTIONED STORM SYSTEM INTO THE CALIFORNIA COAST ON
WEDNESDAY...BRINGING COOLER TEMPERATURES...A POSSIBILITY OF
SHOWERS AND A RISK OF THUNDERSTORMS TO THE AREA. THE CENTER OF THE
STORM SYSTEM WILL SLOWLY PASS OVER THE AREA THURSDAY AND FRIDAY
MAINTAINING THE POSSIBILITY OF SHOWERS AND THE RISK OF AFTERNOON
THUNDERSTORMS. BY SATURDAY THE STORM CENTER WILL BE OVER THE GREAT
BASIN...PLACING CALIFORNIA IN AN AREA OF RETURN FLOW WHICH WILL
PROVIDE A GOOD ENVIRONMENT FOR SHOWERS AND A RISK OF AFTERNOON
THUNDERSTORMS.

HIGH PRESSURE IS ANTICIPATED TO BEGIN TO BUILD OVER THE EASTERN
PACIFIC AND THE CALIFORNIA COAST ON SUNDAY...BRINGING AN END TO
THE SHOWER ACTIVITY. A GRADUAL WARM UP CAN BE EXPECTED NEXT WEEK
AS THE RIDGE OF HIGH PRESSURE ESTABLISHES ITSELF OVER THE WEST
COAST.

&&

.AVIATION...AS OF 10:30 PM PDT MONDAY...2000 FOOT MARINE LAYER IN
PLACE. SOUTHERLY FLOW ALONG THE COAST HAS ALLOWED STRATUS TO
SPREAD INTO SNS AND MRY EARLY TONIGHT. THE STRATUS WILL SPREAD
INTO THE EAST BAY AFTER 06Z AND BEND AROUND THE SOUTH BAY
REACHING SFO LAST. AN APPROACHING UPPER LEVEL TROUGH IS EXPECTED
TO KEEP STRATUS IN UNTIL 18Z OR LATER ON TUESDAY.

VICINITY OF KSFO...VFR THROUGH THE AIRPORT EVENING RUSH. MVFR CIGS
SPREADING FROM THE SOUTH REACHING SFO BY 11-12Z. CLEARING AROUND
18-19Z.

SFO BRIDGE APPROACH...SAME AS KSFO. MVFR CIGS OVER THE SOUTHERN
PART OF THE APPROACH AFTER 09-10Z SPREADING NORTH.

MONTEREY BAY TERMINALS...MVFR CIGS POSSIBLY LOWERING TO IFR
OCCASIONALLY. CLEARING BY 18Z.

&&

.MARINE...AS OF 03:03 AM PDT TUESDAY...BUILDING HIGH PRESSURE OVER
THE EASTERN PACIFIC WILL KEEP LIGHT TO MODERATE NORTHERLY WINDS
THROUGH THURSDAY. AN UPPER LEVEL LOW WILL MOVE THROUGH THE REGION
THURSDAY BRINGING A SLIGHT CHANCE FOR THUNDERSTORMS THURSDAY AND
FRIDAY. LOW PRESSURE INLAND WILL ALLOW NORTHWEST WINDS TO INCREASE
FRIDAY AND SATURDAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY FROM 1 PM

&&

$$

PUBLIC FORECAST: LARRY
AVIATION: W PI
MARINE: MM


VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
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000
FXUS66 KSGX 031028
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
328 AM PDT TUE MAY 3 2016

.SYNOPSIS...
THROUGH WEDNESDAY...A COOLING TREND WILL DEVELOP NEAR THE COAST
AND SPREAD INLAND AS A SLOW MOVING LOW PRESSURE SYSTEM OVER THE
EASTERN PACIFIC MOVES TOWARD THE CALIFORNIA COAST. THE MARINE
LAYER WILL DEEPEN SIGNIFICANTLY WEDNESDAY NIGHT INTO THURSDAY WITH
LIGHT SHOWERS DEVELOPING ALONG AND WEST OF THE MOUNTAINS LATE
WEDNESDAY NIGHT INTO THURSDAY. FOR THURSDAY AFTERNOON THROUGH
FRIDAY NIGHT...THE LOW PRESSURE SYSTEM WILL MOVE INLAND THROUGH
SOUTHERN CALIFORNIA AND INTO THE SOUTHWEST STATES WITH SCATTERED
SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS WITH GUSTY WEST WINDS
FOR THE MOUNTAINS THURSDAY AND FRIDAY. THE CHANCE OF SHOWERS AND
SLIGHT CHANCE OF THUNDERSTORMS WILL CONTINUE INTO THE
WEEKEND...MAINLY DURING THE AFTERNOON AND EARLY EVENING WITH
GREATEST COVERAGE OVER THE MOUNTAINS.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

EARLY THIS MORNING...SATELLITE IMAGERY SHOWS AREAS OF STRATUS OFF
THE SAN DIEGO COUNTY COAST WITH PATCHY STRATUS EXTENDING INLAND
INTO AREAS NEAR THE ORANGE AND SAN DIEGO COUNTY COAST. NOT MUCH
INLAND SPREAD OF THE STRATUS IS EXPECTED EARLY THIS MORNING WITH
EASTERLY LOWER LEVEL FLOW ABOVE THE STRATUS.

FOR TODAY AND WEDNESDAY...A LOW PRESSURE SYSTEM OVER THE EASTERN
PACIFIC WILL MOVE TOWARDS THE CALIFORNIA COAST WITH INCREASING
HIGH CLOUDS AND INCREASING ONSHORE FLOW. COOLING WILL SPREAD
INLAND TODAY AND WEDNESDAY WITH GUSTY WEST WINDS IN THE MOUNTAINS
AND DESERTS WEDNESDAY. GREATER STRATUS COVERAGE IS EXPECTED FOR
TONIGHT INTO WEDNESDAY MORNING WITH STRATUS EXTENDING INTO THE
WESTERN VALLEYS.

FOR WEDNESDAY NIGHT INTO THURSDAY MORNING...MORE SIGNIFICANT
DEEPENING OF THE MARINE LAYER IS EXPECTED WITH STRATUS PUSHING
ONTO THE LOWER COASTAL MOUNTAIN SLOPES. HIGHER RESOLUTION MODELS
CONTINUE TO SHOW LIGHT SHOWERS DEVELOPING ALONG AND WEST OF THE
MOUNTAINS LATE WEDNESDAY NIGHT INTO THURSDAY AS THE MARINE LAYER
DEEPENS.

THE MODELS ARE IN REASONABLY GOOD AGREEMENT IN MOVING THE CENTER
OF A CLOSED UPPER LEVEL LOW PRESSURE SYSTEM FROM JUST OFF THE
CENTRAL CALIFORNIA COAST EARLY THURSDAY...THROUGH SOUTHERN
CALIFORNIA ON FRIDAY...TO NEAR LAS VEGAS FOR SATURDAY AND SATURDAY
NIGHT...WITH THE LOW PRESSURE SYSTEM THEN WEAKENING AND MOVING
EAST FOR SUNDAY AND MONDAY.

HIGHER RESOLUTION MODELS SHOW SCATTERED SHOWERS...MAINLY ALONG AND
WEST OF THE MOUNTAINS...FOR THURSDAY AFTERNOON AND NIGHT.
SCATTERED SHOWERS WILL CONTINUE FOR FRIDAY AND FRIDAY NIGHT. THE
COLDEST AIR AT 500 MB BEGINS TO SPREAD INTO FAR SOUTHERN
CALIFORNIA ON THURSDAY AFTERNOON WITH THE COLDEST AIR ALOFT FOR
THURSDAY NIGHT AND FRIDAY. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS FOR WESTERN PORTIONS OF SOUTHERN CALIFORNIA THURSDAY
AFTERNOON...AND ALMOST ANYWHERE ACROSS FAR SOUTHERN CALIFORNIA
THURSDAY NIGHT FRIDAY.

DUE TO THE CONVECTIVE NATURE OF THE PRECIPITATION...PRECIPITATION
AMOUNTS WILL BE SOMEWHAT VARIABLE...BUT RAINFALL IS EXPECTED TO
RANGE FROM AROUND ONE QUARTER INCH NEAR THE COAST TO ONE HALF TO
ONE INCH IN THE MOUNTAINS THROUGH FRIDAY EVENING. BRIEF HEAVY
DOWNPOURS ARE POSSIBLE ALONG AND WEST OF THE MOUNTAINS THURSDAY
NIGHT AND FRIDAY IN BANDS OF SHOWERS AND IN ISOLATED
THUNDERSTORMS.

THE SNOW LEVEL WILL LOWER TO AROUND 6500 FEET THURSDAY NIGHT AND
6000 TO 6500 FEET FRIDAY AND FRIDAY NIGHT. SNOWFALL OF 4 TO 8
INCHES IS POSSIBLE...MAINLY ABOVE 6500 TO 7000 FEET THURSDAY NIGHT
AND FRIDAY.

FOR SATURDAY AND SUNDAY...SCATTERED SHOWERS WILL CONTINUE AND ARE
MORE LIKELY DURING THE AFTERNOON AND EARLY EVENING EACH DAY WITH
GREATER COVERAGE OVER THE MOUNTAINS. THE SLIGHT CHANCE OF
THUNDERSTORMS WILL CONTINUE FOR SATURDAY AFTERNOON AND EARLY
EVENING WITH MAINLY SHOWERS FOR SUNDAY AS THE COLDER AIR ALOFT
MOVES EAST. DRY AND WARMER FOR EARLY NEXT WEEK AS THE LOW PRESSURE
SYSTEM WEAKENS AND MOVES EAST.

&&

.AVIATION...
030900Z...AREAS OF LOW CLOUDS WILL CONTINUE TO DEVELOP MAINLY NEAR
THE COAST WITH BASES 1000-1500 FEET MSL AND TOPS TO 2200 FEET. LOCAL
VIS AOB 5SM ALONG INLAND EXTENT AND ON HIGHER COASTAL TERRAIN.
SCATTER OUT BY 15-17Z. LOW CLOUDS WITH SIMILAR BASES AND TOPS WILL
DEVELOP ALONG THE COAST AGAIN OVERNIGHT AFTER 04Z.
OTHERWISE...MOSTLY CLEAR TODAY AND TONIGHT WITH SOME HIGH CLOUDS
LATE IN THE DAY.

&&

.MARINE...
200 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SATURDAY.
EXCEPT A STORM SYSTEM WILL BRING A SLIGHT CHANCE OF THUNDERSTORMS
THURSDAY AFTERNOON THROUGH FRIDAY NIGHT.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&

$$

PUBLIC...17
AVIATION/MARINE...MM



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000
FXUS65 KPSR 031028
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
328 AM MST TUE MAY 3 2016

.SYNOPSIS...
TEMPERATURES WILL QUICKLY WARM TUESDAY AND PEAK WEDNESDAY UNDER HIGH
PRESSURE. SOME LOWER DESERTS WILL APPROACH TRIPLE DIGITS. THE HEAT
WILL NOT LAST LONG AS ANOTHER STORM SYSTEM ROLLS IN FROM THE
PACIFIC. WINDS WILL INCREASE WEDNESDAY AND BE STRONGEST THURSDAY
LEADING TO AREAS OF BLOWING DUST. FRIDAY INTO THE WEEKEND WILL
FEATURE BELOW NORMAL TEMPERATURES...VARIOUS CLOUD COVER...AND MODEST
CHANCES FOR RAIN.

&&

.DISCUSSION...
OVERNIGHT WATER VAPOR LOOPS OVER THE N.A. CONTINENT THIS MORNING
HERALD A HIGHLY AMPLIFIED WAVE PATTERN AND RIDGING BUILDING OVER THE
SOUTHWEST STATES. HIGH PRESSURE ANCHORED OVER THE INTERMOUNTAIN WEST
EXTENDS WELL NORTH INTO CANADIAN NORTHWEST TERRITORIES AND IS PINCHED
BETWEEN TWO DEEP TROUGHS OVER THE NORTHEAST PACIFIC AND THE
CENTRAL/EASTERN CONUS. COMPACT AND TRAILING UPPER SHORTWAVE THAT
BROUGHT SCATTERED PRECIP ACTIVITY TO THE NORTHERN AZ MOUNTAIN
YESTERDAY CONTINUES TO WEAKEN IN TERMS OF 500MB HEIGHTS BUT MAINTAINS
A SUBTLE CIRCULATION AS IT SLOWLY ROTATES EASTWARD. RIDGE HEIGHTS
OVER SOUTHERN CA ARE PUSHING EASTWARD AND WILL BEGIN TO SETTLE OVER
THE SOUTHWEST STATES TODAY AND WEDNESDAY...INTRODUCING A SHARP
WARMING TREND TO DAYTIME TEMPERATURES.

CONSENSUS AND NAM/GFS MOS HAVE BEGUN TO ADVERTISE 100F FOR PHOENIX
ON WEDNESDAY. UNDERSTANDING EVEN THE WARM BIASED BC GUIDANCE HAS THE
INFLUENCE OF THE LAST FEW DAYS OF BELOW AVERAGE TEMPERATURES...FELT
COMFORTABLE ENOUGH NUDGING UP FORECAST VALUES TO 100F FOR PHOENIX.
CLIMATOLOGICAL FIRST OBSERVANCE OVER THE LAST NORMAL PERIOD /98-10/
FALLS ON MAY 2ND...SO WE ARE CLOSE. YUMA STILL HAS TO HIT THEIR FIRST
100F OF 2016 ALSO...WITH APRIL 22ND THEIR AVERAGE FIRST OBSERVANCE
OVER THE LAST NORMAL PERIOD. YUMA COULD GET CLOSE ON WEDNESDAY
HOWEVER...500MB HEIGHTS BEGIN TO FALL ACROSS THE WESTERN FORECAST
AREA ZONES BY WEDNESDAY /SOUTH OF 580DM/ RELEGATING THEIR CHANCES
DEPENDENT TO THE WAA AND STRONG SOUTHERLY FLOW THAT BEGINS DURING
THE DAY.

WHILE THE WARMTH WILL BE THE MAIN HEADLINE WEDNESDAY...SOUTHERLY
WINDS WILL BECOME NOTICEABLE STRONGER AS THE AFOREMENTIONED PACIFIC
TROUGH BEGINS TO MOVE INTO THE WEST COAST. WINDS WILL BECOME STRONGER
FOR THURSDAY AS 55-PLUS KT 500MB AND 80-PLUS KT 300MB JET NOSES INTO
THE AREA AHEAD OF THE MAIN LOW CIRCULATION. DUST AND ASSOCIATED VSBY
RESTRICTIONS ARE PRESENT FOR WEDNESDAY WITH A MORE LOCAL FOCUS...BUT
BECOME A REGIONAL CONCERN ACROSS THE MAJORITY OF THE LOWER DESERT
ELEVATIONS THURSDAY. FORECAST SFC WINDS CONTINUE TO SIT WITHIN GEFS
UPPER PERCENTILE FORECASTS AND NEAR WIND ADVISORY THRESHOLDS.
COMBINATION OF STRONG WINDS AND LOW HUMIDITIES LEND THEMSELVES TO
FIRE WEATHER CONCERNS AS WELL THURSDAY AND AS SUCH A FIRE WEATHER
WATCH HAS BEEN POSTED FOR THE CENTRAL AZ ZONES/DISTRICTS JUST EAST OF
THE CO RIVER VALLEY. BY THURSDAY AFTERNOON THE UPPER LOW CENTER IN
PLOTTED NORTH OF THE L.A. BASIN...JUST OFF-SHORE.

MOISTURE PARAMETERS...PWAT OUTPUTS FROM GFS/GEFS AND MIXING RATIOS
FROM ECMWF...ARE BEGINNING TO FOCUS ON THE FIRST WAVE OF ACTIONABLE
MOISTURE IN COMBINATION WITH A VORT MAX/FROPA FOR
FRIDAY...PARTICULARLY IN THE AFTERNOON HOURS. STRONG UPSTREAM
HEIGHTS AND LL JET WINDS DOWN THE CA COAST SHOULD BE ABLE TO
TRANSPORT MARINE MOISTURE INLAND FOR FRIDAY WITH PWATS HEADING NORTH
TOWARD 0.75 INCH VALUES. FURTHER IMPROVEMENT OF GEFS REFORECAST POPS
AND FINER TIMING DETAILS LEAD ME TO NUDGE FCST POPS FOR FRIDAY INTO
THE CHANCE CATEGORY ACROSS SOUTH-CENTRAL AZ AND ALSO INCLUDE MENTION
OF THUNDER. TIMING OF COLDEST TEMPERATURES ALOFT AND LIS ARE NOT
PERFECTLY ALIGNED WITH PEAK HEATING...BUT GIVEN VERTICAL MOTION
ASSOCIATED WITH THE HEIGHT FALLS TRANSITIONING INTO THE AREA FELT
THUNDER MENTION WAS WARRANTED. SIGNIFICANT COOLING TREND IS STILL ON
TAP...WITH HIGHS DIPPING BACK INTO THE 70S/LOW 80S FOR MOST DESERT
LOCALES AND UPPER 60S/LOW 70S FOR THE NEARBY FOOTHILLS AND HIGHER
TERRAIN FOR FRIDAY AND SATURDAY.

HEADING INTO THE WEEKEND THE FORECAST REMAINS BROADLY COVERED BY
SLIGHT CHANCE POPS...COOLER TEMPERATURES AND PARTLY TO MOSTLY CLOUDY
SKIES. THIS LATEST TROUGH CUTOFFS...SIMILAR TO SYSTEMS EARLIER THIS
SPRING...AND BEGINS TO SEND EMBEDDED SHORTWAVE/VORT LOBES THROUGH THE
REGION AT VARIOUS TIMES. LATEST DETERMINISTIC AND ENSEMBLE STORM
TRACK FORECASTS EVENTUALLY DRAW THE SYSTEM EASTWARD BY EARLY NEXT
WEEK WITH PACIFIC HIGH PRESSURE TRANSITIONING INTO THE WEST.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND...
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

AS HIGH PRESSURE ALOFT SLOWLY BUILDS INTO THE AREA FROM THE WEST
TONIGHT...WE SHOULD SEE LIGHT AND MOSTLY DIURNAL WINDS UNDER
GENERALLY CLEAR SKIES. WE MAY SEE A FEW HIGH BASED CUMULUS FORM
AGAIN IN THE AFTERNOON ON TUESDAY BUT NOTHING OF CONSEQUENCE FOR
AVIATION. AGAIN...WINDS WILL BE LIGHT VARIABLE OR LIGHT DIURNAL NEXT
24 HOURS...ESPECIALLY OVER THE CENTRAL DESERTS AND IN THE GREATER
PHOENIX AREA. MOST WINDS WILL BE AOA 10KT AT THE TAF SITES THROUGH
TUESDAY AFTERNOON AT LEAST. NO AVIATION IMPACTS EXPECTED AT ANY
TERMINAL FOR AT LEAST THE NEXT 24 HOURS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
WINDS WILL INCREASE WEDNESDAY AND ONCE AGAIN THURSDAY AS A STORM
SYSTEM MOVES INTO THE SOUTHWEST. THERE WILL LIKELY BE A SEVERAL HOUR
WINDOW THURSDAY AFTERNOON WHERE WINDS AND HUMIDITY VALUES HIT
CRITICAL THRESHOLDS ACROSS PORTIONS OF MARICOPA...PINAL...AND GILA
COUNTIES. QUESTIONS REMAIN ON FUEL LEVELS DUE TO RECENT RAINS AND
CURRENT GREEN LEVELS. MUCH COOLER TEMPERATURES...LESS WIND...AND
HIGHER HUMIDITY LEVELS ARE EXPECTED FRIDAY THROUGH THE WEEKEND ALONG
WITH THE POSSIBILITY OF WETTING RAINS.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
     EVENING FOR AZZ132-133.

CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...NOLTE
AVIATION...CB
FIRE WEATHER...INIGUEZ



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000
FXUS65 KREV 030939
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
239 AM PDT TUE MAY 3 2016

.SYNOPSIS...
A few showers and thunderstorms are possible this afternoon and
evening, then thunderstorm chances increase Wednesday with a few
strong storms possible. More widespread rain and high elevation
snow, with possible thunderstorms will continue Thursday and into
the weekend as low pressure remains over the region.

&&

.SHORT TERM...
Made a few changes to the details, but the overall idea of the
transition to a wet pattern remains on track. High confidence in
a wet week, especially as we get to Wednesday and Thursday. The
main changes were to decrease the thunderstorm potential into
Wednesday and also trim back pops near/east of Highway 95. The
system is moving in slightly slower so snow levels look to remain
above 8-9000 feet at least through the short term.

The upper low that will affect the region into the weekend is near
135W and slowly making its way toward the coast. Moisture begins
to increase today in the Sierra and extreme Western NV. However,
cloud cover increases and there is a nice stable layer around 450
mb. There is enough instability for some showers near the 395
corridor north of Bridgeport, but any thunderstorms look to be
isolated at best. Showers also will not be that heavy today,
although localized amounts up to 1/4" are possible.

The upper low is expected to near the coast Wednesday afternoon.
Instability and moisture increase with the best instability once
again near the 395 corridor. However, compared to previous runs,
it appears less than before. In addition, the upper jet streak is
slower to move east of the Sierra so the forcing does not look
quite as good. Factor in the cloud cover, and we may not see as
many thunderstorms, nor be as strong as it looked yesterday. I
kept the chances of showers near the 395 corridor high, but
trimmed them east of highway 95 where there is less moisture and
instability. I also cut back the thunderstorm potential to
scattered. This is still a decent number, but if the cloud cover
is too much it could be less.

The jet then does move east Wednesday night and the forcing is
better. Loss of heating may limit thunderstorm potential to
isolated, but showers should be quite numerous at least near and
east of the Sierra.

Thursday could be a potentially very active day as instability and
moisture increase even more. In addition, the upper forcing
remains favorable with the jet in a good location and diffluence
in the flow aloft. Kept showers likely for much of the area with a
chance of thunder. Some of these could be rather heavy if the
models are correct with the instability and forcing. The best
chances for these heavy showers continue to be centered on the
Reno-Tahoe area. Wallmann

.LONG TERM...Friday through Monday...

Expansive upper low will be centered over southern CA to begin
period, and move only slowly eastward through the weekend. This
will keep the cool and unsettled weather pattern going with
numerous showers and isolated-scattered thunderstorms. Being on
the north-northwest side of upper low, heavier and more persistent
bands of precipitation are likely to occur although confidence in
exact location/timing remains low-medium. Deterministic runs of
the GFS/ECMWF show two distinct periods where such heavier bands
could develop, late Friday into Saturday morning and again by
Saturday night/Sunday morning. However, these smaller scale
features are difficult to pinpoint so far out. Precipitation
totals overall continue to look impressive and some rises on
streams and creeks can be expected. Snow levels have trended a bit
higher from previous model runs but should still generally be
7000-8000 feet Fri-Sat before rising Sunday. So snow impacts
should remain confined to the highest passes during this event.
Anyone traveling or planning outdoor activities should prepare now
for a very active weather pattern which will include the
possibility of lightning and small hail.

The upper low is forecast to finally depart Monday with decreasing
showers and warmer temperatures. After highs in the 50s and 60s
Friday-Saturday, readings will rise into the 60s and 70s Sunday-
Monday. Model simulations are pointing to even warmer conditions
beyond Monday. Hohmann

&&

.AVIATION...

Scattered showers and isolated thunderstorms are possible this
afternoon and evening along and just east of the Sierra although
probability of a thunderstorm will be low. Showers and
thunderstorms will increase Wednesday through the weekend with
storms capable of heavy rain and small hail. Hohmann

&&

.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

$$

For more information from the National Weather Service visit...
http://weather.gov/reno



  [top]

000
FXUS66 KHNX 030930
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
230 AM PDT TUE MAY 3 2016

.SYNOPSIS...
A FEW LINGERING SHOWERS AND THUNDERSTORMS OVER THE SIERRA NEVADA
TODAY...OTHERWISE WEAK HIGH PRESSURE WILL BRING DRIER WEATHER AND
WARMER TEMPERATURES THROUGH TUESDAY. ANOTHER WEATHER SYSTEM WILL
MOVE INTO THE REGION WEDNESDAY INCREASING PRECIPITATION CHANCES FOR
THE SECOND PART OF THE WEEK.

&&

.DISCUSSION...THE AREA IS WEDGED BETWEEN TWO LOW PRESSURE SYSTEMS
TODAY AS WEAK HIGH PRESSURE REMAINS OVER CALIFORNIA. SOME HIGH
CLOUDS ARE STREAMING IN FROM THE WEST. MODELS INDICATE SOME
INSTABILITY AGAIN THIS AFTERNOON OVER THE SIERRA HOWEVER THE NAM
IS THE MOST BULLISH. WILL KEEP SOME SMALL POPS FOR AFTERNOON
THUNDER JUST IN CASE. SATELLITE IMAGERY SHOWS A RATHER STRONG
PACIFIC SYSTEM SWING TO THE EAST OUT ALONG 32N/130W AND THIS
FEATURE WILL BE THE MAIN WEATHER PRODUCER OVER THE NEXT FEW DAYS.

MODELS ARE IN GOOD AGREEMENT IN DEEPENING THIS LOW AND MOVING IT
TO A POSITION JUST WEST OF THE CENTRAL CALIFORNIA COAST BY
THURSDAY AND THEN MOVING IT ACROSS SOUTHERN CALIFORNIA ON FRIDAY.
MOISTURE LOOK PLENTIFUL WITH THIS SYSTEM AND GIVEN THE SPRING TIME
FRAME THE AREA SHOULD GET SOME DECENT SHOWERS AND THUNDERSTORMS.
MODELS GENERATE QUITE A BIT OF INSTABILITY OVER THE SIERRA AS
EARLY AS WEDNESDAY AFTERNOON BUT REALLY CRANK OUT SOME IMPRESSIVE
AND WIDESPREAD CAPE VALUE ON THURSDAY AFTERNOON AS THE LIFT AND
AFTERNOON HEATING COMBINE FOR A PRETTY GOOD POTENTIAL CONVECTIVE
EVENT. THIS LOOKS TO BE A MULTIPLE DAY EVENT FOR THUNDERSTORMS AS
ON FRIDAY THE LOW MOVES ACROSS SOUTHERN CALIFORNIA AS COLDER AIR
ASSOCIATED WITH THE LOW CENTER MOVES ACROSS CENTRAL CALIFORNIA.

BY SATURDAY THE CENTER OF LOW PRESSURE IS PROGGED TO MOVE INTO
SOUTHERN NEVADA HOWEVER RESIDUAL MOISTURE AND A SECONDARY
VORTICITY CENTER WILL MOVE ACROSS THE CENTRAL CALIFORNIA INTERIOR
PER THE GFS MODEL FOR WRAP AROUND SHOWERS AND YOU GUESSED IT,
THUNDERSTORMS. BY LATER SUNDAY AND MONDAY THE LOW IS FORECAST TO
MOVE EAST OF THE REGION WITH HIGH PRESSURE BUILDING IN FROM THE
WEST. ALL IN ALL A SHOWERY AND THUNDERY PERIOD OF WEATHER WITH
BENEFICIAL BUT LATE SEASON PRECIPITATION.

&&

.AVIATION... ISOLATED THUNDERSTORMS OVER THE SIERRA NEVADA DURING
THE AFTERNOON. OTHERWISE VFR CONDITIONS WILL PREVAIL OVER THE
CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS.

&&

.AIR QUALITY ISSUES...
NONE.

&&

.CERTAINTY...

THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.

CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AN/OR TO PROVIDE FEEDBACK.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

PUBLIC...DUDLEY
AVN/FW...MV
SYNOPSIS...WP

WEATHER.GOV/HANFORD




000
FXUS66 KHNX 030930
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
230 AM PDT TUE MAY 3 2016

.SYNOPSIS...
A FEW LINGERING SHOWERS AND THUNDERSTORMS OVER THE SIERRA NEVADA
TODAY...OTHERWISE WEAK HIGH PRESSURE WILL BRING DRIER WEATHER AND
WARMER TEMPERATURES THROUGH TUESDAY. ANOTHER WEATHER SYSTEM WILL
MOVE INTO THE REGION WEDNESDAY INCREASING PRECIPITATION CHANCES FOR
THE SECOND PART OF THE WEEK.

&&

.DISCUSSION...THE AREA IS WEDGED BETWEEN TWO LOW PRESSURE SYSTEMS
TODAY AS WEAK HIGH PRESSURE REMAINS OVER CALIFORNIA. SOME HIGH
CLOUDS ARE STREAMING IN FROM THE WEST. MODELS INDICATE SOME
INSTABILITY AGAIN THIS AFTERNOON OVER THE SIERRA HOWEVER THE NAM
IS THE MOST BULLISH. WILL KEEP SOME SMALL POPS FOR AFTERNOON
THUNDER JUST IN CASE. SATELLITE IMAGERY SHOWS A RATHER STRONG
PACIFIC SYSTEM SWING TO THE EAST OUT ALONG 32N/130W AND THIS
FEATURE WILL BE THE MAIN WEATHER PRODUCER OVER THE NEXT FEW DAYS.

MODELS ARE IN GOOD AGREEMENT IN DEEPENING THIS LOW AND MOVING IT
TO A POSITION JUST WEST OF THE CENTRAL CALIFORNIA COAST BY
THURSDAY AND THEN MOVING IT ACROSS SOUTHERN CALIFORNIA ON FRIDAY.
MOISTURE LOOK PLENTIFUL WITH THIS SYSTEM AND GIVEN THE SPRING TIME
FRAME THE AREA SHOULD GET SOME DECENT SHOWERS AND THUNDERSTORMS.
MODELS GENERATE QUITE A BIT OF INSTABILITY OVER THE SIERRA AS
EARLY AS WEDNESDAY AFTERNOON BUT REALLY CRANK OUT SOME IMPRESSIVE
AND WIDESPREAD CAPE VALUE ON THURSDAY AFTERNOON AS THE LIFT AND
AFTERNOON HEATING COMBINE FOR A PRETTY GOOD POTENTIAL CONVECTIVE
EVENT. THIS LOOKS TO BE A MULTIPLE DAY EVENT FOR THUNDERSTORMS AS
ON FRIDAY THE LOW MOVES ACROSS SOUTHERN CALIFORNIA AS COLDER AIR
ASSOCIATED WITH THE LOW CENTER MOVES ACROSS CENTRAL CALIFORNIA.

BY SATURDAY THE CENTER OF LOW PRESSURE IS PROGGED TO MOVE INTO
SOUTHERN NEVADA HOWEVER RESIDUAL MOISTURE AND A SECONDARY
VORTICITY CENTER WILL MOVE ACROSS THE CENTRAL CALIFORNIA INTERIOR
PER THE GFS MODEL FOR WRAP AROUND SHOWERS AND YOU GUESSED IT,
THUNDERSTORMS. BY LATER SUNDAY AND MONDAY THE LOW IS FORECAST TO
MOVE EAST OF THE REGION WITH HIGH PRESSURE BUILDING IN FROM THE
WEST. ALL IN ALL A SHOWERY AND THUNDERY PERIOD OF WEATHER WITH
BENEFICIAL BUT LATE SEASON PRECIPITATION.

&&

.AVIATION... ISOLATED THUNDERSTORMS OVER THE SIERRA NEVADA DURING
THE AFTERNOON. OTHERWISE VFR CONDITIONS WILL PREVAIL OVER THE
CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS.

&&

.AIR QUALITY ISSUES...
NONE.

&&

.CERTAINTY...

THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.

CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AN/OR TO PROVIDE FEEDBACK.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

PUBLIC...DUDLEY
AVN/FW...MV
SYNOPSIS...WP

WEATHER.GOV/HANFORD




000
FXUS66 KMTR 030536
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1036 PM PDT MON MAY 2 2016

.SYNOPSIS....DRY AND SEASONABLE CONDITIONS WILL PERSISTS THROUGH
TUESDAY. A WEATHER SYSTEM WILL THEN APPROACH THE CALIFORNIA COAST
BY MIDWEEK AND BRING A CHANCE OF SHOWERS AND POTENTIALLY
THUNDERSTORMS TO THE REGION FROM WEDNESDAY INTO THE START OF THE
UPCOMING WEEKEND. TEMPERATURES WILL ALSO COOL TO NEAR OR BELOW
SEASONAL AVERAGES THROUGH LATE WEEK.

&&

.DISCUSSION...AS OF 8:57 PM PDT MONDAY...A SUMMERLIKE PATTERN
RESIDES ACROSS THE DISTRICT THIS EVENING WITH A WELL DEFINED
MARINE LAYER IN PLACE ALONG THE COAST. THE MARINE LAYER CURRENTLY
STAND AROUND 2000 FT DEEP PER THE FORT ORD PROFILER WITH CEILINGS
BEING REPORTED AROUND 1000 FEET ALONG THE COAST FROM ARCATA SOUTH
THROUGH MONTEREY. LINGERING LOW CLOUDS AND STRENGTHENING ONSHORE
FLOW SIGNIFICANTLY IMPACTED TEMPERATURES TODAY WITH HIGHS COOLING
ANYWHERE FROM 5 TO 15 DEGREES FROM YESTERDAY. HIGHS FINISHED OF
THE DAY IN THE UPPER 50S TO LOW 60S ALONG THE COAST AND 70S TO LOW
80S INLAND. BRADLEY WAS OUR WARM SPOT TODAY WITH A HIGH OF 90. LOW
CLOUDS WILL INEVITABLE FILL IN OVERNIGHT UNDER A 2000 FOOT MARINE
LAYER WITH A SLOW BURNOFF ANTICIPATED ONCE AGAIN TUESDAY. LOW
CLOUDS AND A STRENGTHENING ONSHORE GRADIENT WILL LIKELY RESULT IN
SLIGHTLY COOLER TEMPERATURES ON TUESDAY BUT OTHERWISE A REPEAT OF
TODAY.

ON TUESDAY NIGHT INTO WEDNESDAY AN UPPER LEVEL TROUGH IS FORECAST TO
DEEPENING OFF THE CALIFORNIA COAST. THIS TROUGH IS ANTICIPATED TO
FORM A CLOSED LOW ON WEDNESDAY AND GRADUALLY MOVE EASTWARD OVER
NORTHERN AND CENTRAL CALIFORNIA WEDNESDAY NIGHT INTO THURSDAY. AS
THE LOW APPROACHES AND A COOLER AIRMASS SETTLES IN OVER THE
REGION TEMPERATURES WILL COOL ACROSS THE BOARD. AN INCREASED
CHANCE OF SHOWERS IS ANTICIPATED AS THIS SYSTEM MOVES INLAND.
ISOLATED AFTERNOON THUNDERSTORMS WILL ALSO BE POSSIBLE AS THE COLD
CORE MOVES ACROSS THE AREA.

UNSETTLED WEATHER IS EXPECTED TO CONTINUE THROUGH SATURDAY AS THE
UPPER TROUGH SLOWLY SHIFT EAST. TEMPERATURES WILL RETURN TO
SEASONAL NORMS AND WEATHER CONDITIONS WILL QUIET DOWN BY SUNDAY AS
AN UPPER LEVEL RIDGE BEGINS TO FILL IN BEHIND THE DEPARTING UPPER
TROUGH.

&&

.AVIATION...AS OF 10:30 PM PDT MONDAY...2000 FOOT MARINE LAYER IN
PLACE. SOUTHERLY FLOW ALONG THE COAST HAS ALLOWED STRATUS TO
SPREAD INTO SNS AND MRY EARLY TONIGHT. THE STRATUS WILL SPREAD
INTO THE EAST BAY AFTER 06Z AND BEND AROUND THE SOUTH BAY
REACHING SFO LAST. AN APPROACHING UPPER LEVEL TROUGH IS EXPECTED
TO KEEP STRATUS IN UNTIL 18Z OR LATER ON TUESDAY.

VICINITY OF KSFO...VFR THROUGH THE AIRPORT EVENING RUSH. MVFR CIGS
SPREADING FROM THE SOUTH REACHING SFO BY 11-12Z. CLEARING AROUND
18-19Z.

SFO BRIDGE APPROACH...SAME AS KSFO. MVFR CIGS OVER THE SOUTHERN
PART OF THE APPROACH AFTER 09-10Z SPREADING NORTH.

MONTEREY BAY TERMINALS...MVFR CIGS POSSIBLY LOWERING TO IFR
OCCASIONALLY. CLEARING BY 18Z.

&&

.MARINE...AS OF 10:30 PM PDT MONDAY...WINDS WILL REMAIN LIGHT
THROUGH THURSDAY. AN UPPER LEVEL LOW WILL MOVE THROUGH THE WATERS
THURSDAY THEN MOVE INLAND OVER SOUTHERN CALIFORNIA FRIDAY. THIS
WILL BRING A SLIGHT CHANCE FOR THUNDERSTORMS THURSDAY AND FRIDAY.
LOW PRESSURE INLAND WILL ALLOW NORTHWEST WINDS TO INCREASE FRIDAY
AND SATURDAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...NONE.

$$

PUBLIC FORECAST: CW
AVIATION: W PI
MARINE: W PI


VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA



  [top]

000
FXUS66 KSTO 030525
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1025 PM PDT MON MAY 2 2016

.Synopsis...

Showers and thunderstorms will increase in coverage across
Northern California on Wednesday and Thursday. The storm system
will linger through the weekend, which will cause more chances for
showers and storms.

.Discussion...
Not much in the way of shower and thunderstorm activity today...as
a more stable atmosphere moved in. High clouds are increasing
ahead disturbance approaching from the Pacific. Dry weather with
generally light winds overnight...current forecast is on track and
no updates are needed.

.Previous Discussion...

Water vapor analysis and upper level model guidance indicates an
upper level high pressure system positioned over the northern third
of the CONUS, while a trough of low pressure is positioned in the
eastern Pacific this afternoon. An influx of moisture and cloud
cover is beginning to move into Northern California.

High resolution short term model output shows chances for
thunderstorms (mainly over the foothills and the Sierras) this
afternoon and Tuesday afternoon.  Storms that may develop could
bring brief heavy downpours and small hail.

As the upper level trough pushes eastward Tuesday night, showers and
storms should increase in coverage across much of Northern
California for Wednesday and Thursday.  The greatest instability in
the atmospheric profile should be positioned over the mountains,
thus resulting in the greater threat for thunderstorms. The valley
also has chances to see thunderstorms, but the risk is lower than
the upper elevations. The GFS and ECMWF are in good agreement to
the amplitude and progression of the upper level trough feature,
and both models indicate a slow moving, lingering system. Because
the storm system does not move much from Wednesday to Thursday,
unsettled weather should continue across the region through
Thursday night.

Snow levels should remain at and above 7000 feet, so some mountain
passes could be affected for this weather pattern. Travel may
become difficult for some mountain passes Wednesday night through
Thursday.

.EXTENDED DISCUSSION (Friday THROUGH Monday)

Negative anomaly (minus 3) 5H closed low over Socal on Fri forecast
to track slowly ENEwd to near the 4-Corners through the upcoming
weekend. The deep low finally relaxes its dominance on Norcal wx by
Mon as high pressure builds inland. Cyclonic flow and wrap around
moisture will keep a cool and unsettled weather pattern over most of
our CWA through the weekend...followed by a drying and warming trend
early next week. The GFS/GEM show strong ridging over the area
then...while the ECMWF shows a weak trof moving trough the Pac NW
and Nrn Rockys. Will keep some "silent PoPs" over the mtns for now.

Can`t rule out the potential for thunderstorms given the pattern
especially over our interior mtns as long as the cyclonic flow/wrap
around moisture pattern continues through Sun. 02/12z GFS
instability progs favor the Trinity/Shasta Co mtns for now...but
this can vary in future model runs. Winter may not be over yet
either as snow levels could easily lower to pass levels in
convective showers.

Temps will gradually warm through the period. Maxes will start out
just a little below normal over the Nrn portion of the CWA to 5-10
degrees or more cooler than normal over the Srn portion on Fri...to
a few degrees above normal on Mon. Forecast highs in the low to mid
70s in the Central Vly on Friday are forecast to warm into the
low to mid 80s Monday. JHM


&&

.AVIATION...

VFR conditions for TAF sites next 24 hours with increasing
high clouds. Light winds generally under 10 kts. Scattered
afternoon/evening thunderstorms over the mountains.




&&

.STO Watches/Warnings/Advisories...
None.
&&

$$




000
FXUS66 KLOX 030509
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1009 PM PDT MON MAY 2 2016

.SYNOPSIS...

Night through morning low clouds and fog are expected for many
areas west of the mountains through Wednesday, followed by
partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers and thunderstorms Thursday through
Sunday, along with cooler conditions. Temperatures will likely
return to near normal early next week as high pressure returns.

&&

.UPDATE...

Latest sounding data (VBG and AMDAR) indicates marine inversion
ranging from 1200 feet deep north of Point Conception to about
800 feet south of Point Conception. With weaker onshore gradients,
slightly increasing 500 MB heights and no forecasted eddy, do not
expect much deepening of the marine inversion overnight. So,
will expect stratus/fog to become rather widespread across the
Central Coast and Santa Ynez Valley. For areas south of Point
Conception, will expect stratus to develop across the coastal
plain, but should be rather limited in the coastal valleys (due to
no expected deepening of the marine inversion). Otherwise, some
high level clouds will drift in overnight.

Earlier, an update was issued to scale back stratus/fog coverage
across the coastal valleys of Ventura and Los Angeles counties.
Otherwise, current forecast looks to be in good shape in the
immediate short term.

&&

.SHORT TERM...(Tonight-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)

Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...03/0507Z...

At 0507Z, the marine inversion at KLAX was based at 800 feet. The
top of the inversion was 1800 feet with a temperature of 21
degrees Celsius.

Overall, moderate confidence in 06Z TAF package. Moderate
confidence in stratus/fog returning to coastal TAF sites this
evening and overnight, but low confidence in timing. There is a
10% chance of stratus reaching into the coastal valley TAF sites
overnight.

KLAX...moderate confidence in 06Z TAF. Moderate confidence in
stratus returning overnight, but low confidence in timing (could
develop 2-4 hours earlier than current 12Z forecast).

KBUR...high confidence in 06Z TAF as VFR conditions are
anticipated through the TAF period. There is a 10% chance of IFR
conditions 09Z-17Z.

&&

.MARINE...02/830 PM...

For the Outer Waters, moderate to high confidence in current
forecast. High confidence in winds and seas remaining below SCA
levels through Tuesday night. From Wednesday through Friday, winds
will increase and there is a chance of SCA level winds developing
(especially in the afternoon and evening hours).

For the Inner Waters, high confidence in current forecast. High
confidence that winds and seas will remain below SCA levels
through Friday (although there is a 20% chance of SCA level gusts
Thursday and Friday afternoon across the waters north of Point Sal
as well as western sections of the southern Inner Waters).

Given the limited depth of the marine inversion, there could be
some patchy dense fog across the coastal waters late tonight and
Tuesday morning.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...RAT/MJ
AVIATION...RAT
MARINE...RAT
SYNOPSIS...Sukup

weather.gov/losangeles




000
FXUS66 KLOX 030509
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1009 PM PDT MON MAY 2 2016

.SYNOPSIS...

Night through morning low clouds and fog are expected for many
areas west of the mountains through Wednesday, followed by
partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers and thunderstorms Thursday through
Sunday, along with cooler conditions. Temperatures will likely
return to near normal early next week as high pressure returns.

&&

.UPDATE...

Latest sounding data (VBG and AMDAR) indicates marine inversion
ranging from 1200 feet deep north of Point Conception to about
800 feet south of Point Conception. With weaker onshore gradients,
slightly increasing 500 MB heights and no forecasted eddy, do not
expect much deepening of the marine inversion overnight. So,
will expect stratus/fog to become rather widespread across the
Central Coast and Santa Ynez Valley. For areas south of Point
Conception, will expect stratus to develop across the coastal
plain, but should be rather limited in the coastal valleys (due to
no expected deepening of the marine inversion). Otherwise, some
high level clouds will drift in overnight.

Earlier, an update was issued to scale back stratus/fog coverage
across the coastal valleys of Ventura and Los Angeles counties.
Otherwise, current forecast looks to be in good shape in the
immediate short term.

&&

.SHORT TERM...(Tonight-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)

Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...03/0507Z...

At 0507Z, the marine inversion at KLAX was based at 800 feet. The
top of the inversion was 1800 feet with a temperature of 21
degrees Celsius.

Overall, moderate confidence in 06Z TAF package. Moderate
confidence in stratus/fog returning to coastal TAF sites this
evening and overnight, but low confidence in timing. There is a
10% chance of stratus reaching into the coastal valley TAF sites
overnight.

KLAX...moderate confidence in 06Z TAF. Moderate confidence in
stratus returning overnight, but low confidence in timing (could
develop 2-4 hours earlier than current 12Z forecast).

KBUR...high confidence in 06Z TAF as VFR conditions are
anticipated through the TAF period. There is a 10% chance of IFR
conditions 09Z-17Z.

&&

.MARINE...02/830 PM...

For the Outer Waters, moderate to high confidence in current
forecast. High confidence in winds and seas remaining below SCA
levels through Tuesday night. From Wednesday through Friday, winds
will increase and there is a chance of SCA level winds developing
(especially in the afternoon and evening hours).

For the Inner Waters, high confidence in current forecast. High
confidence that winds and seas will remain below SCA levels
through Friday (although there is a 20% chance of SCA level gusts
Thursday and Friday afternoon across the waters north of Point Sal
as well as western sections of the southern Inner Waters).

Given the limited depth of the marine inversion, there could be
some patchy dense fog across the coastal waters late tonight and
Tuesday morning.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...RAT/MJ
AVIATION...RAT
MARINE...RAT
SYNOPSIS...Sukup

weather.gov/losangeles




000
FXUS66 KSGX 030406
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
906 PM PDT MON MAY 2 2016

.SYNOPSIS...
DRY AND SLIGHTLY WARMER ON TUESDAY UNDER WEAK HIGH PRESSURE ALOFT.
COOLER ON WEDNESDAY WITH A DEEPENING MARINE LAYER AS A STORM SYSTEM
DEVELOPS AND APPROACHES THE NORTHERN CALIFORNIA COAST. THE STORM
WILL DROP SOUTHEAST OVER SOCAL ON FRIDAY...THEN MOVE SLOWLY OFF TO
THE NORTHEAST. GUSTY WESTERLY WINDS WILL DEVELOP OVER THE MOUNTAINS
AND DESERTS ON THURSDAY WITH SCATTERED SHOWERS AND POSSIBLE
THUNDERSTORMS BREAKING OUT. THE UNSETTLED CONDITIONS WILL CONTINUE
THROUGH SATURDAY...FOLLOWED BY WARMER AND DRIER WEATHER NEXT WEEK.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

CONVECTIVE CLOUDS EARLIER IN THE DAY HAD MOSTLY DISSIPATED BY 9 PM
PDT...BUT IR SATELLITE IMAGERY SHOWED SOME AREAS OF LOW CLOUDS ALONG
THE COAST. THE 00Z MIRAMAR SOUNDING HAD A 5 DEGREE C INVERSION BASED
NEAR 1850 FT. WEST WINDS AROUND 10 KT BELOW THE INVERSION BECAME
EASTERLY AROUND 10 KT ABOVE TO 10K FT. SURFACE PRESSURE GRADIENTS
WERE 2-3 MBS OFFSHORE FROM NV...AND 3-5 MBS ONSHORE TO THE LOWER
DESERTS RESULTING IN MOSTLY LIGHT WINDS.

THERE WAS A CONSIDERABLE AMOUNT OF HAZE THIS EVENING AND DEWPOINTS
HAVE CLIMBED INTO THE MID 50S ALONG THE COASTAL STRIP...SO SOME FOG
WILL LIKELY DEVELOP INLAND BEFORE MARINE CLOUDS BECOME MORE
EXTENSIVE. WEAK EASTERLY FLOW IN THE MID-LEVELS SHOULD HELP
THICKNESS CLIMB TOMORROW UNDER FAIR SKIES. SO AWAY FROM THE
IMMEDIATE COAST...IT WILL BE WARMER.

TUESDAY WILL BE THE WARMEST DAY INLAND...THEN A COOLING TREND SETS
IN AS ONSHORE FLOW STRENGTHENS AND THE MARINE LAYER BUILDS WEDNESDAY
INTO THURSDAY. THERE IS HIGH CONFIDENCE FOR THE DEVELOPMENT OF A
LARGE CUT-OFF LOW PRESSURE CENTER OFF THE NOCAL COAST WED NIGHT...
WITH A TRACK SE...OVER SOCAL BY FRI. AS CYCLONIC FLOW INCREASES OVER
THE REGION AND SURFACE PRESSURE FALLS OVER THE INTERIOR...THE
WESTERLY WINDS WILL BEGIN TO HOWL ONCE AGAIN OVER THE MTS/DESERTS.
THE PATTERN SUGGESTS AT LEAST ADVISORY STRENGTH WINDS IN MANY AREAS.

SINCE THIS STORM IS COMING FROM THE NORTH...MOISTURE WILL BE A BIT
MORE LIMITED (PW 0.65-0.80 INCH)...SO WIDESPREAD HEAVY PRECIP IS NOT
EXPECTED. HOWEVER...IT WILL BE SUFFICIENT FOR ISOLATED HEAVY
RAINFALL EVENTS STARTING SOMETIME ON THU. THE ACTIVITY SHOULD BE
SCATTERED AND DRIVEN BY IMPULSES OF ENERGY SWIRLING AROUND THE LARGE
AREA OF LOW PRESSURE ALOFT. THUNDERSTORMS ARE EXPECTED AT TIMES DUE
TO THE INSTABILITY AND COLD AIR ALOFT THROUGH SATURDAY. THE SNOW
LEVEL WILL START OUT AROUND 7000 FEET..THEN DROP CLOSER TO 6000
FEET...AND BRIEFLY LOWER IN THUNDERSTORMS. THIS UNSETTLED SPRINGTIME
PATTERN SUGGESTS WATERSPOUTS WILL BE POSSIBLE AS WELL.

TEMPERATURES WILL DROP THROUGH FRIDAY...THE COLDEST DAY OF THE WEEK
WHEN TEMPERATURES WILL NOT REACH THE 70S...EXCEPT IN THE LOWER
DESERTS. DRY WITH GRADUAL WARMING SUNDAY THROUGH TUESDAY AS THE
STORM LOSES ITS GRIP ON THE REGION.

&&

.AVIATION...

030320Z...PATCHY STRATUS WITH BASES 1000-1500 FT MSL WILL CONTINUE
TO DEVELOP ALONG THE COAST AND SPREAD AND SPREAD 20-25 MI INLAND BY
12Z. LOW CONFIDENCE IN TIMING OF ONSET AT KSAN AND KSNA. LOCAL VIS
OF 3-5SM POSSIBLE WHERE STRATUS NEARS HIGHER TERRAIN IN THE VALLEYS.
STRATUS CLEARING 17-19Z...RETURNING TO THE COASTAL AIRPORTS AFTER
04/02Z WITH BASES NEAR 1500 FT MSL.

MOUNTAINS/DESERTS...MOSTLY CLEAR WITH UNRESTRICTED VIS THROUGH TUE
EVENING.

&&

.MARINE...
830 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH WEDNESDAY.
A STORM SYSTEM WILL BRING WIND GUSTS AROUND 25 KT AND CHOPPY SEAS
THURSDAY NIGHT INTO FRIDAY...AS WELL AS SHOWERS AND POSSIBLE
THUNDERSTORMS ON FRIDAY.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&

$$

PUBLIC...JAD
AVIATION/MARINE...SS




000
FXUS66 KMTR 030357
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
857 PM PDT MON MAY 2 2016

.SYNOPSIS....DRY AND SEASONABLE CONDITIONS WILL PERSISTS THROUGH
TUESDAY. A WEATHER SYSTEM WILL THEN APPROACH THE CALIFORNIA COAST
BY MIDWEEK AND BRING A CHANCE OF SHOWERS AND POTENTIALLY
THUNDERSTORMS TO THE REGION FROM WEDNESDAY INTO THE START OF THE
UPCOMING WEEKEND. TEMPERATURES WILL ALSO COOL TO NEAR OR BELOW
SEASONAL AVERAGES THROUGH LATE WEEK.

&&

.DISCUSSION...AS OF 8:57 PM PDT MONDAY...A SUMMERLIKE PATTERN
RESIDES ACROSS THE DISTRICT THIS EVENING WITH A WELL DEFINED
MARINE LAYER IN PLACE ALONG THE COAST. THE MARINE LAYER CURRENTLY
STAND AROUND 2000 FT DEEP PER THE FORT ORD PROFILER WITH CEILINGS
BEING REPORTED AROUND 1000 FEET ALONG THE COAST FROM ARCATA SOUTH
THROUGH MONTEREY. LINGERING LOW CLOUDS AND STRENGTHENING ONSHORE
FLOW SIGNIFICANTLY IMPACTED TEMPERATURES TODAY WITH HIGHS COOLING
ANYWHERE FROM 5 TO 15 DEGREES FROM YESTERDAY. HIGHS FINISHED OF
THE DAY IN THE UPPER 50S TO LOW 60S ALONG THE COAST AND 70S TO LOW
80S INLAND. BRADLEY WAS OUR WARM SPOT TODAY WITH A HIGH OF 90. LOW
CLOUDS WILL INEVITABLE FILL IN OVERNIGHT UNDER A 2000 FOOT MARINE
LAYER WITH A SLOW BURNOFF ANTICIPATED ONCE AGAIN TUESDAY. LOW
CLOUDS AND A STRENGTHENING ONSHORE GRADIENT WILL LIKELY RESULT IN
SLIGHTLY COOLER TEMPERATURES ON TUESDAY BUT OTHERWISE A REPEAT OF
TODAY.

ON TUESDAY NIGHT INTO WEDNESDAY AN UPPER LEVEL TROUGH IS FORECAST TO
DEEPENING OFF THE CALIFORNIA COAST. THIS TROUGH IS ANTICIPATED TO
FORM A CLOSED LOW ON WEDNESDAY AND GRADUALLY MOVE EASTWARD OVER
NORTHERN AND CENTRAL CALIFORNIA WEDNESDAY NIGHT INTO THURSDAY. AS
THE LOW APPROACHES AND A COOLER AIRMASS SETTLES IN OVER THE
REGION TEMPERATURES WILL COOL ACROSS THE BOARD. AN INCREASED
CHANCE OF SHOWERS IS ANTICIPATED AS THIS SYSTEM MOVES INLAND.
ISOLATED AFTERNOON THUNDERSTORMS WILL ALSO BE POSSIBLE AS THE COLD
CORE MOVES ACROSS THE AREA.

UNSETTLED WEATHER IS EXPECTED TO CONTINUE THROUGH SATURDAY AS THE
UPPER TROUGH SLOWLY SHIFT EAST. TEMPERATURES WILL RETURN TO
SEASONAL NORMS AND WEATHER CONDITIONS WILL QUIET DOWN BY SUNDAY AS
AN UPPER LEVEL RIDGE BEGINS TO FILL IN BEHIND THE DEPARTING UPPER
TROUGH.

&&

.AVIATION...AS OF 5:00 PM PDT MONDAY...2000 FOOT MARINE LAYER IN
PLACE. SOUTHERLY FLOW ALONG THE COAST WILL ALLOW STRATUS TO SPREAD
INTO SNS AND MRY EARLY TONIGHT. THE STRATUS WILL SPREAD INTO THE
EAST BAY AFTER 06Z AND AROUND THE SOUTH BAY REACHING SFO LAST. SO
SFO AND THE APPROACH WILL STAY VFR THROUGH THE AIRPORT EVENING
RUSH. AN APPROACHING UPPER LEVEL TROUGH IS EXPECTED TO KEEP
STRATUS IN UNTIL 18Z OR LATER ON TUESDAY.

VICINITY OF KSFO...VFR THROUGH THE AIRPORT EVENING RUSH. MVFR CIGS
SPREADING FROM THE SOUTH REACHING SFO BY 10-11Z. WEST WINDS 14-17
KT THROUGH 04Z.

SFO BRIDGE APPROACH...SAME AS KSFO. MVFR CIGS OVER THE SOUTHERN
PART OF THE APPROACH AFTER 08-09Z SPREADING NORTH.

MONTEREY BAY TERMINALS...MVFR CIGS POSSIBLY LOWERING TO IFR AFTER
06Z.

&&

.MARINE...AS OF 08:05 PM PDT MONDAY...LIGHT WEST WINDS THIS
EVENING WILL GRADUALLY TURN NW INTO TUESDAY. LIGHT TO MODERATE NW
WIND AND SEAS WILL CONTINUE TUESDAY INTO WEDNESDAY AS A LATE
SEASON UPPER LOW APPROACHES THE REGION PRODUCING SCATTERED SHOWERS
THROUGH THE END OF THE WEEK. LIGHT SEAS MOST OF THE WEEK WILL
BUILD LATE THURSDAY INTO FRIDAY AS THE LOW DEPARTS AND STRONGER NW
WINDS ARRIVE.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

$$

PUBLIC FORECAST: CW
AVIATION/MARINE: W PI


VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
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000
FXUS66 KLOX 030330
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
830 PM PDT MON MAY 2 2016

.SYNOPSIS...

Night through morning low clouds and fog are expected for many
areas west of the mountains through Wednesday, followed by
partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers and thunderstorms Thursday through
Sunday, along with cooler conditions. Temperatures will likely
return to near normal early next week as high pressure returns.

&&

.UPDATE...

Latest sounding data (VBG and AMDAR) indicates marine inversion
ranging from 1200 feet deep north of Point Conception to about
800 feet south of Point Conception. With weaker onshore gradients,
slightly increasing 500 MB heights and no forecasted eddy, do not
expect much deepening of the marine inversion overnight. So,
will expect stratus/fog to become rather widespread across the
Central Coast and Santa Ynez Valley. For areas south of Point
Conception, will expect stratus to develop across the coastal
plain, but should be rather limited in the coastal valleys (due to
no expected deepening of the marine inversion). Otherwise, some
high level clouds will drift in overnight.

Earlier, an update was issued to scale back stratus/fog coverage
across the coastal valleys of Ventura and Los Angeles counties.
Otherwise, current forecast looks to be in good shape in the
immediate short term.

&&

.SHORT TERM...(MON-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)

Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...02/2245Z...

At 2245Z...the marine inversion at KLAX was based at 800 feet.
The top of the inversion was 1900 feet with a temperature of
20 degrees Celsius.

Overall, moderate confidence in 00Z TAF package. High confidence
in stratus/fog returning to coastal TAF sites this evening and
overnight, but low confidence in timing. There is a 20% chance of
stratus reaching into the coastal valley TAF sites overnight.

KLAX...moderate confidence in 00Z TAF. High confidence in stratus
returning overnight (with IFR conditions likely), but low
confidence in timing (+/- 3 hours of current 09Z forecast).

KBUR...high confidence in 00Z TAF as VFR conditions are
anticipated through the TAF period. There is a 20% chance of IFR
conditions 09Z-17Z.

&&

.MARINE...02/830 PM...

For the Outer Waters, moderate to high confidence in current
forecast. High confidence in winds and seas remaining below SCA
levels through Tuesday night. From Wednesday through Friday, winds
will increase and there is a chance of SCA level winds developing
(especially in the afternoon and evening hours).

For the Inner Waters, high confidence in current forecast. High
confidence that winds and seas will remain below SCA levels
through Friday (although there is a 20% chance of SCA level gusts
Thursday and Friday afternoon across the waters north of Point Sal
as well as western sections of the southern Inner Waters).

Given the limited depth of the marine inversion, there could be
some patchy dense fog across the coastal waters late tonight and
Tuesday morning.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...RAT/MJ
AVIATION...RAT
MARINE...RAT
SYNOPSIS...Sukup

weather.gov/losangeles




000
FXUS65 KPSR 030330
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
830 PM MST MON MAY 2 2016

.SYNOPSIS...
TEMPERATURES WILL QUICKLY WARM TUESDAY AND PEAK WEDNESDAY UNDER HIGH
PRESSURE. SOME LOWER DESERTS WILL APPROACH TRIPLE DIGITS. THE HEAT
WILL NOT LAST LONG AS ANOTHER STORM SYSTEM ROLLS IN FROM THE
PACIFIC. WINDS WILL INCREASE WEDNESDAY AND BE STRONGEST THURSDAY
LEADING TO AREAS OF BLOWING DUST. FRIDAY INTO THE WEEKEND WILL
FEATURE BELOW NORMAL TEMPERATURES...VARIOUS CLOUD COVER...AND MODEST
CHANCES FOR RAIN.

&&

.DISCUSSION...
WEAK UPPER LOW LINGERED OVER FAR NORTHWEST ARIZONA EARLY THIS
EVENING...AND IT WAS EASILY SEEN IN THE 00Z PLOT DATA WHICH DEPICTED
MODEST CYCLONIC SHEAR TO THE SOUTH OF THE LOW AND ACROSS THE
SOUTHERN DESERTS. DESPITE THE CYCLONIC NATURE OF THE FLOW...MOISTURE
OVER THE SOUTHERN DESERTS WAS LIMITED...CONFINED TO A THIN LAYER
NEAR 700MB...AND THE STABILITY ACROSS SOUTHERN ARIZONA WAS MUCH
GREATER THAN OVER NORTHERN ARIZONA. 00Z FLG SOUNDING SHOWED MODEST
CAPE AND NEGATIVE LIFTED INDICES...WHILE THE TUS RAOB WAS QUITE
STABLE WITH LI VALUES CLOSER TO PLUS 4. AS SUCH...CONVECTION THIS
AFTERNOON AND EARLY EVENING WAS CONFINED TO THE HIGHER TERRAIN OF
NORTHERN ARIZONA...WELL TO THE NORTH OF PHOENIX...AND THE SOUTHERN
DESERTS MERELY SAW A BIT OF HIGH BASED CUMULUS CLOUDS. AS OF 8 PM
MOST OF THOSE CLOUDS HAD DISSIPATED FOLLOWING SUNSET AND LACK OF
HEATING. FOR THE REST OF TONIGHT...AS THIS UPPER LOW CONTINUES TO
WEAKEN AND SHIFT NORTH...WE WILL SEE GENERALLY CLEAR SKIES ACROSS
THE SOUTHERN DESERTS ALONG WITH LIGHT AND MOSTLY DIURNAL WINDS.
FORECASTS LOOK TO BE IN GOOD SHAPE AND NO UPDATES ARE NEEDED AT THIS
TIME.

.PREVIOUS DISCUSSION...
CONVECTION HAS FLARED UP THIS AFTERNOON IN THE AREAS PREVIOUSLY
EXPECTED...JUST NORTH OF OUR FORECAST AREA. THIS WAS IN RESPONSE TO
THE UPPER LEVEL LOW NOW ENTERING NW ARIZONA. THIS SYSTEM IS WELL
HANDLED BY THE VARIOUS MODELING SYSTEMS AND WILL MOVE EAST TONIGHT
AND SHEAR OUT OVER NEW MEXICO TOMORROW AS THE HIGH AMPLITUDE
ANTICYCLONE CURRENTLY OVER WESTERN MONTANA ELONGATES AND ENCOMPASSES
THE ENTIRE WEST.

WARM UP CONTINUES TUESDAY AND INTO WEDNESDAY WHEN WE WILL SEE PEAK
TEMPERATURES. CURRENT FORECAST CONTINUES WITH 99 FOR PHOENIX THOUGH
GIVEN OUR TYPICAL FORECAST ERROR OF 2 DEGREES ON DAY 3 THERE IS
CERTAINLY A NON-ZERO CHANCE OF HITTING 100. THIS WOULD BE A BIT LATER
THAN THE 1981-2010 AVERAGE OF MAY 2. YUMA WILL ALSO BE CLOSE AT
FORECAST OF 98.

WINDS WILL PICK-UP WEDNESDAY AHEAD OF THE NEXT SYSTEM. CONFIDENCE ON
THE OVERALL EVOLUTION OF THE INCOMING CUT-OFF LOW IS FAIRLY HIGH AS
IT HAS BEEN FORECAST FOR MANY DAYS AT THIS POINT. SOUTH/SOUTHWEST
WINDS ON WEDNESDAY WILL LIKELY CAUSE SOME ISSUES INCLUDING BLOWING
DUST. WINDS WILL BE STRONGER ON THURSDAY AND THIS IS THE DAY WE MAY
EVENTUALLY NEED A WI.Y AND BD.Y. GEFS-BASED EXTREME FORECAST INDEX IS
HIGHLIGHTING THE PRE-FRONTAL WINDS THURSDAY TO BE IN THE 95TH
PERCENTILE WHICH HISTORICALLY CORRESPONDS TO ENOUGH WIND TO CAUSE
IMPACTS.

THE OTHER CONCERN AS THIS SYSTEM COMES IN IS WITH THE FIRE WEATHER
DANGER. IT DOES LOOK LIKE WE WILL HIT WIND AND HUMIDITY TRIGGERS FOR
A RF.W BUT FUELS ARE QUESTIONABLE AT THIS POINT GIVEN CURRENT
GREENNESS AND RECENT RAINS. WILL HOLD OFF ON ANY FW.A FOR OUR AREA
BUT IT IS HIGHLIGHTED IN THE FIRE WEATHER FORECAST.

EVENTUALLY THE SPECTER OF RAIN WILL COME WITH THE SYSTEM BUT NOT
UNTIL FRIDAY WHEN BETTER ISENTROPIC LIFT/MOISTURE FLUX/DYNAMICAL
COOLING/PVA ARRIVE. GEFS-BASED CALIBRATED POPS ARE SHOWING A BROAD
20-30 PERCENT CHANCE FOR SOME RAIN FRIDAY INTO SATURDAY THUS
INCREASED POPS A BIT. OVERALL DOESN/T APPEAR TO BE A WASHOUT EVENT BY
ANY MEANS. TEMPERATURES WILL ALSO COOL SIGNIFICANTLY...ON THE ORDER
OF 20 DEGREES FROM WEDNESDAY TO FRIDAY. HOW THE WEEKEND PLAYS OUT IS
STILL UP IN THE AIR AS MODELS NOTORIOUSLY HAVE A DIFFICULT TIME
RESOLVING THE MIGRATION OF CLOSED LOWS IN THE SOUTHWEST. OVERALL IT
WILL BE COOLER AND GENERALLY CLOUDY...RAIN CHANCES WILL LIKELY CHANGE
AS SPECIFICS ON INDIVIDUAL VORT LOBES COME INTO FOCUS IN THE DAYS
AHEAD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND...
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

AS HIGH PRESSURE ALOFT SLOWLY BUILDS INTO THE AREA FROM THE WEST
TONIGHT...WE SHOULD SEE LIGHT AND MOSTLY DIURNAL WINDS UNDER
GENERALLY CLEAR SKIES. WE MAY SEE A FEW HIGH BASED CUMULUS FORM
AGAIN IN THE AFTERNOON ON TUESDAY BUT NOTHING OF CONSEQUENCE FOR
AVIATION. AGAIN...WINDS WILL BE LIGHT VARIABLE OR LIGHT DIURNAL NEXT
24 HOURS...ESPECIALLY OVER THE CENTRAL DESERTS AND IN THE GREATER
PHOENIX AREA. MOST WINDS WILL BE AOA 10KT AT THE TAF SITES THROUGH
TUESDAY AFTERNOON AT LEAST. NO AVIATION IMPACTS EXPECTED AT ANY
TERMINAL FOR AT LEAST THE NEXT 24 HOURS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
WINDS WILL INCREASE WEDNESDAY AND ONCE AGAIN THURSDAY AS A STORM
SYSTEM MOVES INTO THE SOUTHWEST. THERE WILL LIKELY BE A SEVERAL HOUR
WINDOW THURSDAY AFTERNOON WHERE WINDS AND HUMIDITY VALUES HIT
CRITICAL THRESHOLDS ACROSS PORTIONS OF MARICOPA...PINAL...AND GILA
COUNTIES. QUESTIONS REMAIN ON FUEL LEVELS DUE TO RECENT RAINS AND
CURRENT GREEN LEVELS. MUCH COOLER TEMPERATURES...LESS WIND...AND
HIGHER HUMIDITY LEVELS ARE EXPECTED FRIDAY THROUGH THE WEEKEND ALONG
WITH THE POSSIBILITY OF WETTING RAINS.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...CB
PREVIOUS DISCUSSION...INIGUEZ
AVIATION...CB
FIRE WEATHER...INIGUEZ




000
FXUS65 KPSR 030330
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
830 PM MST MON MAY 2 2016

.SYNOPSIS...
TEMPERATURES WILL QUICKLY WARM TUESDAY AND PEAK WEDNESDAY UNDER HIGH
PRESSURE. SOME LOWER DESERTS WILL APPROACH TRIPLE DIGITS. THE HEAT
WILL NOT LAST LONG AS ANOTHER STORM SYSTEM ROLLS IN FROM THE
PACIFIC. WINDS WILL INCREASE WEDNESDAY AND BE STRONGEST THURSDAY
LEADING TO AREAS OF BLOWING DUST. FRIDAY INTO THE WEEKEND WILL
FEATURE BELOW NORMAL TEMPERATURES...VARIOUS CLOUD COVER...AND MODEST
CHANCES FOR RAIN.

&&

.DISCUSSION...
WEAK UPPER LOW LINGERED OVER FAR NORTHWEST ARIZONA EARLY THIS
EVENING...AND IT WAS EASILY SEEN IN THE 00Z PLOT DATA WHICH DEPICTED
MODEST CYCLONIC SHEAR TO THE SOUTH OF THE LOW AND ACROSS THE
SOUTHERN DESERTS. DESPITE THE CYCLONIC NATURE OF THE FLOW...MOISTURE
OVER THE SOUTHERN DESERTS WAS LIMITED...CONFINED TO A THIN LAYER
NEAR 700MB...AND THE STABILITY ACROSS SOUTHERN ARIZONA WAS MUCH
GREATER THAN OVER NORTHERN ARIZONA. 00Z FLG SOUNDING SHOWED MODEST
CAPE AND NEGATIVE LIFTED INDICES...WHILE THE TUS RAOB WAS QUITE
STABLE WITH LI VALUES CLOSER TO PLUS 4. AS SUCH...CONVECTION THIS
AFTERNOON AND EARLY EVENING WAS CONFINED TO THE HIGHER TERRAIN OF
NORTHERN ARIZONA...WELL TO THE NORTH OF PHOENIX...AND THE SOUTHERN
DESERTS MERELY SAW A BIT OF HIGH BASED CUMULUS CLOUDS. AS OF 8 PM
MOST OF THOSE CLOUDS HAD DISSIPATED FOLLOWING SUNSET AND LACK OF
HEATING. FOR THE REST OF TONIGHT...AS THIS UPPER LOW CONTINUES TO
WEAKEN AND SHIFT NORTH...WE WILL SEE GENERALLY CLEAR SKIES ACROSS
THE SOUTHERN DESERTS ALONG WITH LIGHT AND MOSTLY DIURNAL WINDS.
FORECASTS LOOK TO BE IN GOOD SHAPE AND NO UPDATES ARE NEEDED AT THIS
TIME.

.PREVIOUS DISCUSSION...
CONVECTION HAS FLARED UP THIS AFTERNOON IN THE AREAS PREVIOUSLY
EXPECTED...JUST NORTH OF OUR FORECAST AREA. THIS WAS IN RESPONSE TO
THE UPPER LEVEL LOW NOW ENTERING NW ARIZONA. THIS SYSTEM IS WELL
HANDLED BY THE VARIOUS MODELING SYSTEMS AND WILL MOVE EAST TONIGHT
AND SHEAR OUT OVER NEW MEXICO TOMORROW AS THE HIGH AMPLITUDE
ANTICYCLONE CURRENTLY OVER WESTERN MONTANA ELONGATES AND ENCOMPASSES
THE ENTIRE WEST.

WARM UP CONTINUES TUESDAY AND INTO WEDNESDAY WHEN WE WILL SEE PEAK
TEMPERATURES. CURRENT FORECAST CONTINUES WITH 99 FOR PHOENIX THOUGH
GIVEN OUR TYPICAL FORECAST ERROR OF 2 DEGREES ON DAY 3 THERE IS
CERTAINLY A NON-ZERO CHANCE OF HITTING 100. THIS WOULD BE A BIT LATER
THAN THE 1981-2010 AVERAGE OF MAY 2. YUMA WILL ALSO BE CLOSE AT
FORECAST OF 98.

WINDS WILL PICK-UP WEDNESDAY AHEAD OF THE NEXT SYSTEM. CONFIDENCE ON
THE OVERALL EVOLUTION OF THE INCOMING CUT-OFF LOW IS FAIRLY HIGH AS
IT HAS BEEN FORECAST FOR MANY DAYS AT THIS POINT. SOUTH/SOUTHWEST
WINDS ON WEDNESDAY WILL LIKELY CAUSE SOME ISSUES INCLUDING BLOWING
DUST. WINDS WILL BE STRONGER ON THURSDAY AND THIS IS THE DAY WE MAY
EVENTUALLY NEED A WI.Y AND BD.Y. GEFS-BASED EXTREME FORECAST INDEX IS
HIGHLIGHTING THE PRE-FRONTAL WINDS THURSDAY TO BE IN THE 95TH
PERCENTILE WHICH HISTORICALLY CORRESPONDS TO ENOUGH WIND TO CAUSE
IMPACTS.

THE OTHER CONCERN AS THIS SYSTEM COMES IN IS WITH THE FIRE WEATHER
DANGER. IT DOES LOOK LIKE WE WILL HIT WIND AND HUMIDITY TRIGGERS FOR
A RF.W BUT FUELS ARE QUESTIONABLE AT THIS POINT GIVEN CURRENT
GREENNESS AND RECENT RAINS. WILL HOLD OFF ON ANY FW.A FOR OUR AREA
BUT IT IS HIGHLIGHTED IN THE FIRE WEATHER FORECAST.

EVENTUALLY THE SPECTER OF RAIN WILL COME WITH THE SYSTEM BUT NOT
UNTIL FRIDAY WHEN BETTER ISENTROPIC LIFT/MOISTURE FLUX/DYNAMICAL
COOLING/PVA ARRIVE. GEFS-BASED CALIBRATED POPS ARE SHOWING A BROAD
20-30 PERCENT CHANCE FOR SOME RAIN FRIDAY INTO SATURDAY THUS
INCREASED POPS A BIT. OVERALL DOESN/T APPEAR TO BE A WASHOUT EVENT BY
ANY MEANS. TEMPERATURES WILL ALSO COOL SIGNIFICANTLY...ON THE ORDER
OF 20 DEGREES FROM WEDNESDAY TO FRIDAY. HOW THE WEEKEND PLAYS OUT IS
STILL UP IN THE AIR AS MODELS NOTORIOUSLY HAVE A DIFFICULT TIME
RESOLVING THE MIGRATION OF CLOSED LOWS IN THE SOUTHWEST. OVERALL IT
WILL BE COOLER AND GENERALLY CLOUDY...RAIN CHANCES WILL LIKELY CHANGE
AS SPECIFICS ON INDIVIDUAL VORT LOBES COME INTO FOCUS IN THE DAYS
AHEAD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND...
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

AS HIGH PRESSURE ALOFT SLOWLY BUILDS INTO THE AREA FROM THE WEST
TONIGHT...WE SHOULD SEE LIGHT AND MOSTLY DIURNAL WINDS UNDER
GENERALLY CLEAR SKIES. WE MAY SEE A FEW HIGH BASED CUMULUS FORM
AGAIN IN THE AFTERNOON ON TUESDAY BUT NOTHING OF CONSEQUENCE FOR
AVIATION. AGAIN...WINDS WILL BE LIGHT VARIABLE OR LIGHT DIURNAL NEXT
24 HOURS...ESPECIALLY OVER THE CENTRAL DESERTS AND IN THE GREATER
PHOENIX AREA. MOST WINDS WILL BE AOA 10KT AT THE TAF SITES THROUGH
TUESDAY AFTERNOON AT LEAST. NO AVIATION IMPACTS EXPECTED AT ANY
TERMINAL FOR AT LEAST THE NEXT 24 HOURS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
WINDS WILL INCREASE WEDNESDAY AND ONCE AGAIN THURSDAY AS A STORM
SYSTEM MOVES INTO THE SOUTHWEST. THERE WILL LIKELY BE A SEVERAL HOUR
WINDOW THURSDAY AFTERNOON WHERE WINDS AND HUMIDITY VALUES HIT
CRITICAL THRESHOLDS ACROSS PORTIONS OF MARICOPA...PINAL...AND GILA
COUNTIES. QUESTIONS REMAIN ON FUEL LEVELS DUE TO RECENT RAINS AND
CURRENT GREEN LEVELS. MUCH COOLER TEMPERATURES...LESS WIND...AND
HIGHER HUMIDITY LEVELS ARE EXPECTED FRIDAY THROUGH THE WEEKEND ALONG
WITH THE POSSIBILITY OF WETTING RAINS.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...CB
PREVIOUS DISCUSSION...INIGUEZ
AVIATION...CB
FIRE WEATHER...INIGUEZ




000
FXUS66 KMTR 030004
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
504 PM PDT MON MAY 2 2016

.SYNOPSIS....DRY AND SEASONABLE CONDITIONS WILL PERSISTS THROUGH
TUESDAY. A WEATHER SYSTEM WILL THEN APPROACH THE CALIFORNIA COAST
BY MIDWEEK AND BRING A CHANCE OF SHOWERS AND POTENTIALLY
THUNDERSTORMS TO THE REGION FROM WEDNESDAY INTO THE START OF THE
UPCOMING WEEKEND. TEMPERATURES WILL ALSO COOL TO NEAR OR BELOW
SEASONAL AVERAGES THROUGH LATE WEEK.

&&

.DISCUSSION...AS OF 01:49 PM PDT MONDAY...A WELL ESTABLISHED
MARINE LAYER THAT RETURNED TO THE REGION YESTERDAY EVENING REMAINS
IN PLACE AND HAS RESULTED IN LOW CLOUDS ALONG MUCH OF THE
COASTLINE. AS A RESULT AND WITH THE RETURN TO A MORE PREDOMINATE
ONSHORE FLOW, TEMPERATURES REGION WIDE THIS AFTERNOON ARE RUNNING
A FEW (INLAND) TO AS MUCH AS 15 DEGREES COOLER (NEAR THE COAST)
COMPARED TO 24 HOURS AGO. MEANWHILE, INLAND AREAS REMAIN UNDER
MOSTLY SUNNY CONDITION WITH TEMPERATURES IN THE 70S TO NEAR 80 IN
THE WARMEST INLAND VALLEY LOCATIONS. DO EXPECT THE LOW CLOUDS TO
PUSH BACK INLAND THIS EVENING AND SPREAD INTO THE VALLEYS
OVERNIGHT. CONDITIONS ON TUESDAY WILL CHANGE VERY LITTLE, YET
COULD SEE A FEW DEGREES OF COOLING INLAND AS ONSHORE FLOW
INCREASES SLIGHTLY.

FOR THE SECOND HALF OF THE WEEK, AN UPPER LEVEL TROUGH IS FORECAST
TO DEVELOP OVER THE EASTERN PACIFIC. AS THE TROUGH APPROACHES THE
COAST, THE FORECAST MODELS SHOW A CLOSED MID/UPPER LEVEL LOW
DEVELOPING OFF OF THE NORTHERN OR CENTRAL CALIFORNIA COAST LATE
WEDNESDAY INTO THURSDAY. THIS WILL RESULT IN COOLER TEMPERATURES
REGION-WIDE AND INCREASED CHANCES FOR ISOLATED TO SCATTERED SHOWERS
FROM WEDNESDAY AFTERNOON THROUGH SATURDAY. WITH THAT SAID,
WIDESPREAD RAINFALL IS NOT EXPECTED AT THIS TIME GIVEN THE LACK OF A
DEEP MOISTURE SOURCE AND STRONGER MID/UPPER LEVEL SUPPORT. HOWEVER,
WITH THE CENTER OF THE LOW FORECAST TO MOVE INLAND OVER THE REGION,
THERE WILL BE A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS LATE THIS
WEEK AS A COLDER AND MORE UNSTABLE AIR MASS REMAINS OVERHEAD. CANNOT
RULE OUT A FEW THUNDERSTORMS WITH SMALL HAIL AS WELL.

THE UPPER LEVEL TROUGH IS THEN FORECAST TO SHIFT INLAND BY SUNDAY AS
AN UPPER LEVEL RIDGE BUILDS OVER THE EASTERN PACIFIC. THIS SHOULD
BRING AN END TO THE UNSETTLED WEATHER CONDITIONS OVER THE REGION
LATE SATURDAY INTO SUNDAY. TEMPERATURES LATE IN THE WEEKEND WILL
ALSO SLOWLY REBOUND BACK TO NEAR SEASONAL AVERAGES.

&&

.AVIATION...AS OF 5:00 PM PDT MONDAY...2000 FOOT MARINE LAYER IN
PLACE. SOUTHERLY FLOW ALONG THE COAST WILL ALLOW STRATUS TO SPREAD
INTO SNS AND MRY EARLY TONIGHT. THE STRATUS WILL SPREAD INTO THE
EAST BAY AFTER 06Z AND AROUND THE SOUTH BAY REACHING SFO LAST. SO
SFO AND THE APPROACH WILL STAY VFR THROUGH THE AIRPORT EVENING
RUSH. AN APPROACHING UPPER LEVEL TROUGH IS EXPECTED TO KEEP
STRATUS IN UNTIL 18Z OR LATER ON TUESDAY.

VICINITY OF KSFO...VFR THROUGH THE AIRPORT EVENING RUSH. MVFR CIGS
SPREADING FROM THE SOUTH REACHING SFO BY 10-11Z. WEST WINDS 14-17
KT THRPUGH 04Z.

SFO BRIDGE APPROACH...SAME AS KSFO. MVFR CIGS OVER THE SOUTHERN
PART OF THE APPROACH AFTER 08-09Z SPREADING NORTH.

MONTEREY BAY TERMINALS...MVFR CIGS POSSIBLY LOWERING TO IFR AFTER
06Z.

&&

.MARINE...AS OF 5:00 PM PDT MONDAY...LIGHT WEST WINDS THIS
EVENING WILL GRADUALLY TURN NW INTO TUESDAY. LIGHT TO MODERATE NW
WIND AND SEAS WILL CONTINUE TUESDAY INTO WEDNESDAY AS A LATE
SEASON UPPER LOW APPROACHES THE REGION PRODUCING SCATTERED SHOWERS
THROUGH THE END OF THE WEEK. LIGHT SEAS MOST OF THE WEEK WILL
BUILD LATE THURSDAY INTO FRIDAY AS THE LOW DEPARTS AND STRONGER NW
WINDS ARRIVE.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...NONE.

$$

PUBLIC FORECAST: RGASS
AVIATION: W PI
MARINE: W PI


VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO

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WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA




000
FXUS66 KMTR 030004
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
504 PM PDT MON MAY 2 2016

.SYNOPSIS....DRY AND SEASONABLE CONDITIONS WILL PERSISTS THROUGH
TUESDAY. A WEATHER SYSTEM WILL THEN APPROACH THE CALIFORNIA COAST
BY MIDWEEK AND BRING A CHANCE OF SHOWERS AND POTENTIALLY
THUNDERSTORMS TO THE REGION FROM WEDNESDAY INTO THE START OF THE
UPCOMING WEEKEND. TEMPERATURES WILL ALSO COOL TO NEAR OR BELOW
SEASONAL AVERAGES THROUGH LATE WEEK.

&&

.DISCUSSION...AS OF 01:49 PM PDT MONDAY...A WELL ESTABLISHED
MARINE LAYER THAT RETURNED TO THE REGION YESTERDAY EVENING REMAINS
IN PLACE AND HAS RESULTED IN LOW CLOUDS ALONG MUCH OF THE
COASTLINE. AS A RESULT AND WITH THE RETURN TO A MORE PREDOMINATE
ONSHORE FLOW, TEMPERATURES REGION WIDE THIS AFTERNOON ARE RUNNING
A FEW (INLAND) TO AS MUCH AS 15 DEGREES COOLER (NEAR THE COAST)
COMPARED TO 24 HOURS AGO. MEANWHILE, INLAND AREAS REMAIN UNDER
MOSTLY SUNNY CONDITION WITH TEMPERATURES IN THE 70S TO NEAR 80 IN
THE WARMEST INLAND VALLEY LOCATIONS. DO EXPECT THE LOW CLOUDS TO
PUSH BACK INLAND THIS EVENING AND SPREAD INTO THE VALLEYS
OVERNIGHT. CONDITIONS ON TUESDAY WILL CHANGE VERY LITTLE, YET
COULD SEE A FEW DEGREES OF COOLING INLAND AS ONSHORE FLOW
INCREASES SLIGHTLY.

FOR THE SECOND HALF OF THE WEEK, AN UPPER LEVEL TROUGH IS FORECAST
TO DEVELOP OVER THE EASTERN PACIFIC. AS THE TROUGH APPROACHES THE
COAST, THE FORECAST MODELS SHOW A CLOSED MID/UPPER LEVEL LOW
DEVELOPING OFF OF THE NORTHERN OR CENTRAL CALIFORNIA COAST LATE
WEDNESDAY INTO THURSDAY. THIS WILL RESULT IN COOLER TEMPERATURES
REGION-WIDE AND INCREASED CHANCES FOR ISOLATED TO SCATTERED SHOWERS
FROM WEDNESDAY AFTERNOON THROUGH SATURDAY. WITH THAT SAID,
WIDESPREAD RAINFALL IS NOT EXPECTED AT THIS TIME GIVEN THE LACK OF A
DEEP MOISTURE SOURCE AND STRONGER MID/UPPER LEVEL SUPPORT. HOWEVER,
WITH THE CENTER OF THE LOW FORECAST TO MOVE INLAND OVER THE REGION,
THERE WILL BE A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS LATE THIS
WEEK AS A COLDER AND MORE UNSTABLE AIR MASS REMAINS OVERHEAD. CANNOT
RULE OUT A FEW THUNDERSTORMS WITH SMALL HAIL AS WELL.

THE UPPER LEVEL TROUGH IS THEN FORECAST TO SHIFT INLAND BY SUNDAY AS
AN UPPER LEVEL RIDGE BUILDS OVER THE EASTERN PACIFIC. THIS SHOULD
BRING AN END TO THE UNSETTLED WEATHER CONDITIONS OVER THE REGION
LATE SATURDAY INTO SUNDAY. TEMPERATURES LATE IN THE WEEKEND WILL
ALSO SLOWLY REBOUND BACK TO NEAR SEASONAL AVERAGES.

&&

.AVIATION...AS OF 5:00 PM PDT MONDAY...2000 FOOT MARINE LAYER IN
PLACE. SOUTHERLY FLOW ALONG THE COAST WILL ALLOW STRATUS TO SPREAD
INTO SNS AND MRY EARLY TONIGHT. THE STRATUS WILL SPREAD INTO THE
EAST BAY AFTER 06Z AND AROUND THE SOUTH BAY REACHING SFO LAST. SO
SFO AND THE APPROACH WILL STAY VFR THROUGH THE AIRPORT EVENING
RUSH. AN APPROACHING UPPER LEVEL TROUGH IS EXPECTED TO KEEP
STRATUS IN UNTIL 18Z OR LATER ON TUESDAY.

VICINITY OF KSFO...VFR THROUGH THE AIRPORT EVENING RUSH. MVFR CIGS
SPREADING FROM THE SOUTH REACHING SFO BY 10-11Z. WEST WINDS 14-17
KT THRPUGH 04Z.

SFO BRIDGE APPROACH...SAME AS KSFO. MVFR CIGS OVER THE SOUTHERN
PART OF THE APPROACH AFTER 08-09Z SPREADING NORTH.

MONTEREY BAY TERMINALS...MVFR CIGS POSSIBLY LOWERING TO IFR AFTER
06Z.

&&

.MARINE...AS OF 5:00 PM PDT MONDAY...LIGHT WEST WINDS THIS
EVENING WILL GRADUALLY TURN NW INTO TUESDAY. LIGHT TO MODERATE NW
WIND AND SEAS WILL CONTINUE TUESDAY INTO WEDNESDAY AS A LATE
SEASON UPPER LOW APPROACHES THE REGION PRODUCING SCATTERED SHOWERS
THROUGH THE END OF THE WEEK. LIGHT SEAS MOST OF THE WEEK WILL
BUILD LATE THURSDAY INTO FRIDAY AS THE LOW DEPARTS AND STRONGER NW
WINDS ARRIVE.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...NONE.

$$

PUBLIC FORECAST: RGASS
AVIATION: W PI
MARINE: W PI


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000
FXUS66 KLOX 022246
AFDLOX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
346 PM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through Sunday.

&&

.SHORT TERM...(TDY-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)

Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...02/2245Z...

At 2245Z...the marine inversion at KLAX was based at 800 feet.
The top of the inversion was 1900 feet with a temperature of
20 degrees Celsius.

Overall, moderate confidence in 00Z TAF package. High confidence
in stratus/fog returning to coastal TAF sites this evening and
overnight, but low confidence in timing. There is a 20% chance of
stratus reaching into the coastal valley TAF sites overnight.

KLAX...moderate confidence in 00Z TAF. High confidence in stratus
returning overnight (with IFR conditions likely), but low
confidence in timing (+/- 3 hours of current 09Z forecast).

KBUR...high confidence in 00Z TAF as VFR conditions are
anticipated through the TAF period. There is a 20% chance of IFR
conditions 09Z-17Z.

&&

.MARINE...02/200 pM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. There will be a minimally
better chance of SCA conds Wednesday. Advisory level winds are
possible across the outer waters by Thursday.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through Tuesday afternoon
      For zones 40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Jackson
AVIATION...RAT
MARINE...Sweet
SYNOPSIS...KJ

weather.gov/losangeles



  [top]

000
FXUS66 KEKA 022244
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
344 PM PDT MON MAY 2 2016

.SYNOPSIS...A TROUGH OF LOW PRESSURE AND ASSOCIATED COLD FRONT
WILL APPROACH THE AREA TONIGHT AND MOVE THROUGH THE REGION
TUESDAY. A RETURN OF LOW CLOUDS AND FOG IS LIKELY FOR THE COAST
WHILE A THREAT OF LIGHT RAIN SHOWERS PERSISTS FOR ALL THE REGION
THROUGH THE REMAINDER OF THE WEEK.

&&

.DISCUSSION...AN APPROACHING UPPER TROUGH OF LOW PRESSURE AND
ASSOCIATED COLD FRONT IS ENHANCING INSTABILITY ACROSS THE INTERIOR
THIS AFTERNOON. SCATTERED SHOWERS ARE FORMING OVER THE SOUTH FORK
RIDGE AS WELL AS WESTERN SISIKOU COUNTY AND MAY FLOAT OVER CENTRAL
AND DEL NORTE COUNTY LATER THIS AFTERNOON. THE SHOWERS ARE FAIRLY
LIGHT IN INTENSITY AND DO NOT EXPECT A LOT OF RAINFALL. ALL
SHOWERS SHOULD DIMINISH AFTER SUNSET. THE OTHER CHANGE TODAY IS
THE NORTHERLY DRIFT OF STRATUS ALONG THE COAST THAT HAS ENVELOPED
MUCH OF THE ENTIRE WEST COAST OF CA. LOCALLY THERE STILL EXISTS A
HOLE OVER HUMBOLDT BAY BAY BUT IT IS SLOWLY FILLING IN AND BY
LATE TONIGHT THE LOW CLOUDS AND FOG SHOULD HAVE A GOOD GRIP ON
MOST OF THE LITTORAL ZONE OF THE ENTIRE NORTH COAST. LIGHT
ONSHORE FLOW SHOULD PREVAIL FOR MOST THE NEXT SEVERAL DAYS THUS
COASTAL LOW CLOUDS SHOULD REMAIN QUITE PERSISTENT...EXCEPT FOR
SOME BRIEF AFTERNOON CLEARING WHICH IS POSSIBLE. STILL
ANTICIPATING SOME INTERIOR SHOWER AND THUNDERSTORM ACTIVITY ACROSS
THE EASTERN INTERIOR MOUNTAINS OVER THE NEXT SEVERAL DAYS. THIS IS
MAINLY IN RESPONSE TO THE PINCHING OF AN UPPER LOW PRESSURE SYSTEM
THAT WILL CUT OFF AND MOVE INTO THE BAY AREA. THE NET RESULT WILL
BE SOME MOIST SOUTHERLY FLOW INTO THE CWA WHICH IS ALWAYS A GOOD
INGREDIENT FOR SHOWER AND TSTORM ACTIVITY. THIS PATTERN LOOKS TO
PERSIST THROUGH AT LEAST FRIDAY...BEFORE THE LOW BEGINS TO PULL
OFF TO THE EAST WHICH WOULD BRING A MORE DRIER STABLE REGIME TO
THE REGION TOWARD NEXT WEEKEND.


&&

.AVIATION...A LARGE AREA OF MARINE CLOUDS OFFSHORE...COMBINED
WITH A SOUTHERLY SURGE SOUTH OF MENDOCINO...STARTED IMPACTING THE
NORTH COAST BY MID MORNING...AND FINALLY SURGED ONSHORE BY 12 NOON.
CIGS AT COASTAL AIRPORTS THEN DROPPED INTO IFR BUT HAVE BASICALLY
HOVERED AROUND 1000 FEET (LOW MVFR)THROUGH AFTERNOON. EXPECT EVEN
MORE VARIABLE CLOUDS OVERNIGHT AHEAD OF AN APPROACHING TROUGH AND
ASSOCIATED FRONTAL SYSTEM. TUESDAY MORNING SHOULD SEE MOST CIGS MVFR-
VFR WITH POSSIBLE LATE MORNING (INTERMITTENT)DRIZZLE...BUT ANY RAIN
OR RAINSHOWERS WILL PROBABLY OCCUR AFTER MIDDAY. INTERIOR AREAS:
ANY AVIATION THREAT WAS MOSTLY CONVECTIVE AS MODERATE CUMULUS
BUILDUPS DEVELOPED OVER THE MOUNTAINS...ESPECIALLY ALONG THE
SOUTHFORK MOUNTAIN RANGE AND ALONG THE HUMBOLDT AND TRINITY COUNTY
LINE. 2 PM SATELLITE AND RADAR PICTURES SHOWED SOME WEAK SHOWERS
OVER THE MOUNTAINS NORTH-SOUTH FROM WEITCHPEC TO DINSMORE AND
FOREST GLEN.


&&

.MARINE...GUSTY SOUTHERLY WINDS AROUND THE CAPE WILL SUBSIDE
TONIGHT AS A STRATUS SURGE ABATES. WINDS WILL SLOWLY SWITCH TO N-NW
BY TUE AS HIGH PRESSURE BUILDS OFFSHORE AND THE THERMAL TROUGH
SHIFTS INTO THE INTERIOR. HIGH PRESSURE WILL STRENGTHEN OFFSHORE BY
THE MIDDLE OF THE WEEK WITH A RETURN OF ROBUST NORTHERLY WINDS AND
LARGE STEEP WAVES ON WEDNESDAY. THIS WILL LIKELY CONTINUE THU THRU
FRI AND PERHAPS INTO SAT. GALE FORCE WINDS ARE LIKELY 10-60NM FROM
SHORE AND LOCALLY AROUND PT ST GEORGE AND CAPE MENDO MID TO LATE
WEEK. SEAS WILL BE DOMINATED BY STEEP LOCALLY GENERATED NORTHERLY
SEAS WHICH SHOULD HIT 13 TO 16 FT MID TO LATE IN THE WEEK. A COUPLE
OF SMALL LONG PERIOD WAVE GROUPS WILL ALSO BE IN THE MIX.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&

$$

VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA

FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/NWSEUREKA
HTTP://WWW.TWITTER.COM/NWSEUREKA

FOR FORECAST ZONE INFORMATION
SEE FORECAST ZONE MAP ONLINE:
HTTP://WWW.WEATHER.GOV/EUREKA/ZONEMAP.PNG




000
FXUS66 KHNX 022211
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
311 PM PDT MON MAY 2 2016

.SYNOPSIS...
A FEW LINGERING SHOWERS AND THUNDERSTORMS OVER THE SIERRA NEVADA
TODAY...OTHERWISE WEAK HIGH PRESSURE WILL BRING DRIER WEATHER AND
WARMER TEMPERATURES THROUGH TUESDAY. ANOTHER WEATHER SYSTEM WILL
MOVE INTO THE REGION WEDNESDAY INCREASING PRECIPITATION CHANCES FOR
THE SECOND PART OF THE WEEK.

&&

.DISCUSSION...
WEAK TROUGH NEAR KERN COUNTY IS KICKING OFF A FEW SHOWERS ACROSS
THE KERN AND TULARE COUNTY MOUNTAINS...OTW JUST SOME CU ACROSS THE
SIERRA AND EVERY WARM TEMPS ACROSS THE ENTIRE INTERIOR CENCAL
AREA.

GUIDANCE IS IN GOOD AGREEMENT WITH THE UPPER RIDGE SHIFTING EAST
OVER US TODAY AND TOMORROW WITH MAINLY DRY CONDITIONS AND TEMPS
WELL ABOVE NORMAL. DIGGING UPPER LOW PRESSURE CENTER WILL SLIDE
SOUTH ALONG THE COAST FROM THE GULF AF AK WED AND MOVE INLAND
INTO NRN CA BY FRIDAY. WE WILL SEE A SLIGHT CHANCE OF SHOWERS
INCREASING ON WED ACROSS YOSEMITE. AS THE LOW CENTER PASSES BY ON
THURSDAY WE ARE EXPECTING MORE COVERAGE OF SHRA AND TSRA OVER
CENTRAL CA. SOME STORMS MAY BE STRONG THURSDAY AFTERNOON AS THE
BEST INSTABILITY AND LIFTING MECHANISMS WILL BE IN PLACE WITH A
100+ KNOT JET MOVING ACROSS THE AREA.

THE LOW CENTER IS PROGGED TO MOVE INLAND ON FRIDAY INTO SRN CA
WITH CONTINUED WRAP AROUND MOISTURE IMPACTING THE REGION WITH
CONTINUED CHANCES OF SHRA AND TSRA. THE LOW WILL BE VERY SLOW TO
MOVE EAST AS AN OMEGA BLOCK PATTERN WILL SET UP ACROSS THE US. THE
LOW MOVES INTO THE FOUR CORNERS AREA BEFORE FILLING AND WEAKENING
ON SUNDAY AND MOVING EAST ON MONDAY. RIDGING RETURNS ON MONDAY OF
NEXT WEEK WITH RETURN OF ABOVE NORMAL TEMPS AND DRY CONDITIONS.

&&

.AVIATION...
AREAS OF MVFR WITH LOCAL IFR POSSIBLE 18Z MONDAY THROUGH 06Z TUESDAY
DUE TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THE SIERRA
NEVADA. OTHERWISE VFR CONDITIONS WILL PREVAIL OVER THE CENTRAL
CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS.

&&

.AIR QUALITY ISSUES...
NONE.

&&

.CERTAINTY...

THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.

CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AN/OR TO PROVIDE FEEDBACK.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

PUBLIC/FW...JDB
AVN...ROWE
SYNOPSIS...WP

WEATHER.GOV/HANFORD




000
FXUS65 KREV 022208
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
308 PM PDT MON MAY 2 2016

.SYNOPSIS...

A few showers and thunderstorms are possible this evening, then
thunderstorm chances increase Tuesday and Wednesday with a few
strong storms possible by Wednesday. More widespread rain and high
elevation snow, with possible thunderstorms may continue Thursday
and into the weekend as low pressure remains over the region.

&&

.SHORT TERM...

Unsettled weather pattern will remain over the region through the
rest of the week as low pressure drops into the Western U.S. A
few isolated showers will continue in the Sierra this evening,
maybe an isolated thunderstorm, but overall shower activity will
be weak.

A large area of low pressure will move into the California Coast
Tuesday and Wednesday with increasing instability and moisture.
Isolated to scattered showers and thunderstorms are likely Tuesday
and Wednesday. A strong 100kt jet will push into our area with
good upper level diffluence. This will increase thunderstorm
coverage on Tuesday and potentially some stronger, more organized
storms on Wednesday as the left exit region moves over the Sierra
and western NV. Heavy rainfall, small hail, gusty winds, and
frequent lightning will be possible on Tuesday and Wednesday,
with the best chances being on Wednesday. There may be a limiting
of convection on Wednesday if we get too much cloud cover,
although with the dynamics of this jet/low pressure system we
should at least see isolated to scattered thunderstorms.

Shower activity will continue Wednesday night into Thursday as low
pressure continues to send moisture into the region. A deformation
zone looks set up over the region on Thursday, with widespread
moderate rainfall and localized areas of heavier rainfall within
the convective/deformation bands. Heaviest precipitation looks to
be around the Reno-Carson City-Minden-Lake Tahoe areas, although
this may shift north or south as we get closer to the event.

Latest operational model runs and ensembles continue to be in
good agreement overall with high chances for rain, thunderstorms,
and high elevation snow. Forecaster confidence is fairly high
regarding these wet conditions into Thursday night, although
details on the location of heaviest precipitation is only medium
for now. Hoon

.LONG TERM...Friday through Monday...

A slow moving upper low will remain across the region and provide
potential for showers and thunderstorms through the weekend. The
core of the low will dip south near Las Vegas leaving western Nevada
and the northern Sierra within a region of wrap around moisture and
precipitation. Instability should be sufficient to maintain
scattered showers and thunderstorms Friday and Saturday with
diminishing chances Sunday into Monday.

Ensemble spreads and model consistency remain well behaved so
confidence remains good that we will remain in a wet and cool
pattern through the weekend. Snow levels Friday will begin around
7,000 feet Friday and will rise through the weekend as the low
begins to pull away. Nonetheless, heavier banded precipitation could
locally drag down snow levels and may still create snow
accumulations with travel impacts across higher Sierra passes this
weekend. Otherwise, mainly looking for rain showers with scattered
thunderstorms capable of producing locally heavy rain and abundant
small hail. Additional periods of heavy rainfall during this wet
period may also result in rises in some small creeks and streams.

Those with outdoor recreation plans this weekend should be prepared
for rapidly changing conditions in and near showers and storms.
Those on the lake waters and with other outdoor recreation plans
will be subject to lightning/small hail/heavy rain through Sunday.
The low should pull far enough east by Monday so most shower and
storm activity should come to close. Fuentes

&&

.AVIATION...

Scattered showers will prevail through early evening but
precipitation should remain on the lighter side. Otherwise, light
winds and VFR conditions expected through 18z Tuesday with another
round of lighter showers and thunderstorms mainly for Sierra
terminals Tuesday afternoon. Probabilities on Tuesday for KTRK/TVL
will remain around 30%/10%.

An approaching low pressure system will increase the chances for
showers and thunderstorms beginning Wednesday with widespread activity
expected by Thursday and Friday. Confidence is increasing that these
showers and storms will be better organized and stronger. These
storms will have the potential of producing gusty of outflow winds,
abundant small hail, lightning, and rapid reductions in visibility
in and near storms. Fuentes

&&

.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

$$

For more information from the National Weather Service visit...
http://weather.gov/reno




000
FXUS65 KREV 022208
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
308 PM PDT MON MAY 2 2016

.SYNOPSIS...

A few showers and thunderstorms are possible this evening, then
thunderstorm chances increase Tuesday and Wednesday with a few
strong storms possible by Wednesday. More widespread rain and high
elevation snow, with possible thunderstorms may continue Thursday
and into the weekend as low pressure remains over the region.

&&

.SHORT TERM...

Unsettled weather pattern will remain over the region through the
rest of the week as low pressure drops into the Western U.S. A
few isolated showers will continue in the Sierra this evening,
maybe an isolated thunderstorm, but overall shower activity will
be weak.

A large area of low pressure will move into the California Coast
Tuesday and Wednesday with increasing instability and moisture.
Isolated to scattered showers and thunderstorms are likely Tuesday
and Wednesday. A strong 100kt jet will push into our area with
good upper level diffluence. This will increase thunderstorm
coverage on Tuesday and potentially some stronger, more organized
storms on Wednesday as the left exit region moves over the Sierra
and western NV. Heavy rainfall, small hail, gusty winds, and
frequent lightning will be possible on Tuesday and Wednesday,
with the best chances being on Wednesday. There may be a limiting
of convection on Wednesday if we get too much cloud cover,
although with the dynamics of this jet/low pressure system we
should at least see isolated to scattered thunderstorms.

Shower activity will continue Wednesday night into Thursday as low
pressure continues to send moisture into the region. A deformation
zone looks set up over the region on Thursday, with widespread
moderate rainfall and localized areas of heavier rainfall within
the convective/deformation bands. Heaviest precipitation looks to
be around the Reno-Carson City-Minden-Lake Tahoe areas, although
this may shift north or south as we get closer to the event.

Latest operational model runs and ensembles continue to be in
good agreement overall with high chances for rain, thunderstorms,
and high elevation snow. Forecaster confidence is fairly high
regarding these wet conditions into Thursday night, although
details on the location of heaviest precipitation is only medium
for now. Hoon

.LONG TERM...Friday through Monday...

A slow moving upper low will remain across the region and provide
potential for showers and thunderstorms through the weekend. The
core of the low will dip south near Las Vegas leaving western Nevada
and the northern Sierra within a region of wrap around moisture and
precipitation. Instability should be sufficient to maintain
scattered showers and thunderstorms Friday and Saturday with
diminishing chances Sunday into Monday.

Ensemble spreads and model consistency remain well behaved so
confidence remains good that we will remain in a wet and cool
pattern through the weekend. Snow levels Friday will begin around
7,000 feet Friday and will rise through the weekend as the low
begins to pull away. Nonetheless, heavier banded precipitation could
locally drag down snow levels and may still create snow
accumulations with travel impacts across higher Sierra passes this
weekend. Otherwise, mainly looking for rain showers with scattered
thunderstorms capable of producing locally heavy rain and abundant
small hail. Additional periods of heavy rainfall during this wet
period may also result in rises in some small creeks and streams.

Those with outdoor recreation plans this weekend should be prepared
for rapidly changing conditions in and near showers and storms.
Those on the lake waters and with other outdoor recreation plans
will be subject to lightning/small hail/heavy rain through Sunday.
The low should pull far enough east by Monday so most shower and
storm activity should come to close. Fuentes

&&

.AVIATION...

Scattered showers will prevail through early evening but
precipitation should remain on the lighter side. Otherwise, light
winds and VFR conditions expected through 18z Tuesday with another
round of lighter showers and thunderstorms mainly for Sierra
terminals Tuesday afternoon. Probabilities on Tuesday for KTRK/TVL
will remain around 30%/10%.

An approaching low pressure system will increase the chances for
showers and thunderstorms beginning Wednesday with widespread activity
expected by Thursday and Friday. Confidence is increasing that these
showers and storms will be better organized and stronger. These
storms will have the potential of producing gusty of outflow winds,
abundant small hail, lightning, and rapid reductions in visibility
in and near storms. Fuentes

&&

.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

$$

For more information from the National Weather Service visit...
http://weather.gov/reno




000
FXUS66 KSTO 022200
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
300 PM PDT MON MAY 2 2016

.Synopsis...

An approaching upper level disturbance will bring chances for
showers and thunderstorms this afternoon mainly for the foothills
and the Sierra.  Chances for showers and thunderstorms will increase
in coverage across Northern California on Wednesday and Thursday.
The storm system will linger through the weekend, which will cause
more chances for showers and storms.

.Short Term Discussion (Today through Thursday Night)...

Water vapor analysis and upper level model guidance indicates an
upper level high pressure system positioned over the northern third
of the CONUS, while a trough of low pressure is positioned in the
eastern Pacific this afternoon. An influx of moisture and cloud
cover is beginning to move into Northern California.

High resolution short term model output shows chances for
thunderstorms (mainly over the foothills and the Sierras) this
afternoon and Tuesday afternoon.  Storms that may develop could
bring brief heavy downpours and small hail.

As the upper level trough pushes eastward Tuesday night, showers and
storms should increase in coverage across much of Northern
California for Wednesday and Thursday.  The greatest instability in
the atmospheric profile should be positioned over the mountains,
thus resulting in the greater threat for thunderstorms. The valley
also has chances to see thunderstorms, but the risk is lower than
the upper elevations. The GFS and ECMWF are in good agreement to
the amplitude and progression of the upper level trough feature,
and both models indicate a slow moving, lingering system. Because
the storm system does not move much from Wednesday to Thursday,
unsettled weather should continue across the region through
Thursday night.

Snow levels should remain at and above 7000 feet, so some mountain
passes could be affected for this weather pattern. Travel may
become difficult for some mountain passes Wednesday night through
Thursday.

.EXTENDED DISCUSSION (Friday THROUGH Monday)

Negative anomaly (minus 3) 5H closed low over Socal on Fri forecast
to track slowly ENEwd to near the 4-Corners through the upcoming
weekend. The deep low finally relaxes its dominance on Norcal wx by
Mon as high pressure builds inland. Cyclonic flow and wrap around
moisture will keep a cool and unsettled weather pattern over most of
our CWA through the weekend...followed by a drying and warming trend
early next week. The GFS/GEM show strong ridging over the area
then...while the ECMWF shows a weak trof moving trough the Pac NW
and Nrn Rockys. Will keep some "silent PoPs" over the mtns for now.

Can`t rule out the potential for thunderstorms given the pattern
especially over our interior mtns as long as the cyclonic flow/wrap
around moisture pattern continues through Sun. 02/12z GFS
instability progs favor the Trinity/Shasta Co mtns for now...but
this can vary in future model runs. Winter may not be over yet
either as snow levels could easily lower to pass levels in
convective showers.

Temps will gradually warm through the period. Maxes will start out
just a little below normal over the Nrn portion of the CWA to 5-10
degrees or more cooler than normal over the Srn portion on Fri...to
a few degrees above normal on Mon. Forecast highs in the low to mid
70s in the Central Vly on Friday are forecast to warm into the
low to mid 80s Monday. JHM

&&

.AVIATION...

VFR conditions for TAF sites next 24 hours with increasing
high clouds. Light winds generally under 10 kts. Scattered
afternoon/evening thunderstorms over the mountains.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$




000
FXUS65 KPSR 022121
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
221 PM MST MON MAY 2 2016

.SYNOPSIS...
TEMPERATURES WILL QUICKLY WARM TUESDAY AND PEAK WEDNESDAY UNDER HIGH
PRESSURE. SOME LOWER DESERTS WILL APPROACH TRIPLE DIGITS. THE HEAT
WILL NOT LAST LONG AS ANOTHER STORM SYSTEM ROLLS IN FROM THE
PACIFIC. WINDS WILL INCREASE WEDNESDAY AND BE STRONGEST THURSDAY
LEADING TO AREAS OF BLOWING DUST. FRIDAY INTO THE WEEKEND WILL
FEATURE BELOW NORMAL TEMPERATURES...VARIOUS CLOUD COVER...AND MODEST
CHANCES FOR RAIN.

&&

.DISCUSSION...
CONVECTION HAS FLARED UP THIS AFTERNOON IN THE AREAS PREVIOUSLY
EXPECTED...JUST NORTH OF OUR FORECAST AREA. THIS WAS IN RESPONSE TO
THE UPPER LEVEL LOW NOW ENTERING NW ARIZONA. THIS SYSTEM IS WELL
HANDLED BY THE VARIOUS MODELING SYSTEMS AND WILL MOVE EAST TONIGHT
AND SHEAR OUT OVER NEW MEXICO TOMORROW AS THE HIGH AMPLITUDE
ANTICYCLONE CURRENTLY OVER WESTERN MONTANA ELONGATES AND ENCOMPASSES
THE ENTIRE WEST.

WARM UP CONTINUES TUESDAY AND INTO WEDNESDAY WHEN WE WILL SEE PEAK
TEMPERATURES. CURRENT FORECAST CONTINUES WITH 99 FOR PHOENIX THOUGH
GIVEN OUR TYPICAL FORECAST ERROR OF 2 DEGREES ON DAY 3 THERE IS
CERTAINLY A NON-ZERO CHANCE OF HITTING 100. THIS WOULD BE A BIT LATER
THAN THE 1981-2010 AVERAGE OF MAY 2. YUMA WILL ALSO BE CLOSE AT
FORECAST OF 98.

WINDS WILL PICK-UP WEDNESDAY AHEAD OF THE NEXT SYSTEM. CONFIDENCE ON
THE OVERALL EVOLUTION OF THE INCOMING CUT-OFF LOW IS FAIRLY HIGH AS
IT HAS BEEN FORECAST FOR MANY DAYS AT THIS POINT. SOUTH/SOUTHWEST
WINDS ON WEDNESDAY WILL LIKELY CAUSE SOME ISSUES INCLUDING BLOWING
DUST. WINDS WILL BE STRONGER ON THURSDAY AND THIS IS THE DAY WE MAY
EVENTUALLY NEED A WI.Y AND BD.Y. GEFS-BASED EXTREME FORECAST INDEX IS
HIGHLIGHTING THE PRE-FRONTAL WINDS THURSDAY TO BE IN THE 95TH
PERCENTILE WHICH HISTORICALLY CORRESPONDS TO ENOUGH WIND TO CAUSE
IMPACTS.

THE OTHER CONCERN AS THIS SYSTEM COMES IN IS WITH THE FIRE WEATHER
DANGER. IT DOES LOOK LIKE WE WILL HIT WIND AND HUMIDITY TRIGGERS FOR
A RF.W BUT FUELS ARE QUESTIONABLE AT THIS POINT GIVEN CURRENT
GREENNESS AND RECENT RAINS. WILL HOLD OFF ON ANY FW.A FOR OUR AREA
BUT IT IS HIGHLIGHTED IN THE FIRE WEATHER FORECAST.

EVENTUALLY THE SPECTER OF RAIN WILL COME WITH THE SYSTEM BUT NOT
UNTIL FRIDAY WHEN BETTER ISENTROPIC LIFT/MOISTURE FLUX/DYNAMICAL
COOLING/PVA ARRIVE. GEFS-BASED CALIBRATED POPS ARE SHOWING A BROAD
20-30 PERCENT CHANCE FOR SOME RAIN FRIDAY INTO SATURDAY THUS
INCREASED POPS A BIT. OVERALL DOESN/T APPEAR TO BE A WASHOUT EVENT BY
ANY MEANS. TEMPERATURES WILL ALSO COOL SIGNIFICANTLY...ON THE ORDER
OF 20 DEGREES FROM WEDNESDAY TO FRIDAY. HOW THE WEEKEND PLAYS OUT IS
STILL UP IN THE AIR AS MODELS NOTORIOUSLY HAVE A DIFFICULT TIME
RESOLVING THE MIGRATION OF CLOSED LOWS IN THE SOUTHWEST. OVERALL IT
WILL BE COOLER AND GENERALLY CLOUDY...RAIN CHANCES WILL LIKELY CHANGE
AS SPECIFICS ON INDIVIDUAL VORT LOBES COME INTO FOCUS IN THE DAYS
AHEAD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND...
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

DRY WESTERLY FLOW WILL PERSIST THROUGH THE FORECAST PERIOD RESULTING
IN CLEAR SKIES ACROSS ALL OF OUR TAF SITES. EXPECT WINDS TO BE
AROUND 5 KNOTS OR LESS ACROSS SOUTHEAST CALIFORNIA TAF
SITES...LEADING TO VARIABLE WINDS THROUGH THE MORNING HOURS
TOMORROW...IN SOUTH-CENTRAL AND SOUTHWEST ARIZONA TAF SITES...WINDS
WILL REMAIN BELOW 10 KNOTS AND FOLLOW NORMAL DIURNAL TRENDS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
WINDS WILL INCREASE WEDNESDAY AND ONCE AGAIN THURSDAY AS A STORM
SYSTEM MOVES INTO THE SOUTHWEST. THERE WILL LIKELY BE A SEVERAL HOUR
WINDOW THURSDAY AFTERNOON WHERE WINDS AND HUMIDITY VALUES HIT
CRITICAL THRESHOLDS ACROSS PORTIONS OF MARICOPA...PINAL...AND GILA
COUNTIES. QUESTIONS REMAIN ON FUEL LEVELS DUE TO RECENT RAINS AND
CURRENT GREEN LEVELS. MUCH COOLER TEMPERATURES...LESS WIND...AND
HIGHER HUMIDITY LEVELS ARE EXPECTED FRIDAY THROUGH THE WEEKEND ALONG
WITH THE POSSIBILITY OF WETTING RAINS.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ
AVIATION...VASQUEZ
FIRE WEATHER...INIGUEZ




000
FXUS66 KLOX 022119
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
219 PM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through mainly Saturday. A warming trend is in
store for Sunday and Monday.

&&

.SHORT TERM...(TDY-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)


Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...02/1800Z.

AT 1741Z, the marine layer depth at KLAX was around 1000 feet.
The top of the inversion was around 2700 feet with a temperature
of 18 degrees Celsius.

good confidence in the 18z tafs. slow clearing is expected in
some areas...mainly from the ventura coast northward today. some
weak ridging is expected in the next 24 hours...so the depth of
the marine layer may drop slightly by tuesday morning...although
the nam12 model shows very little change in marine layer coverage.
the main change in the 18z taf package was to remove any mention
of marine clouds in the LA county valleys...in agreement with the
nam12 model.

KLAX...good confidence in the 18Z TAF. there is a 30 percent
chance of ceilings moving in 2 hours later than forecast.

KBUR..fair confidence in the 18Z TAF. there is a 30 percent chance
of marine clouds with ifr conditions late tonight and tuesday
morning.

&&

.MARINE...02/200 pM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. There will be a minimally
better chance of SCA conds Wednesday. Advisory level winds are
possible across the outer waters by Thursday.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Jackson
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...KJ

weather.gov/losangeles




000
FXUS66 KLOX 022119
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
219 PM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through mainly Saturday. A warming trend is in
store for Sunday and Monday.

&&

.SHORT TERM...(TDY-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)


Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...02/1800Z.

AT 1741Z, the marine layer depth at KLAX was around 1000 feet.
The top of the inversion was around 2700 feet with a temperature
of 18 degrees Celsius.

good confidence in the 18z tafs. slow clearing is expected in
some areas...mainly from the ventura coast northward today. some
weak ridging is expected in the next 24 hours...so the depth of
the marine layer may drop slightly by tuesday morning...although
the nam12 model shows very little change in marine layer coverage.
the main change in the 18z taf package was to remove any mention
of marine clouds in the LA county valleys...in agreement with the
nam12 model.

KLAX...good confidence in the 18Z TAF. there is a 30 percent
chance of ceilings moving in 2 hours later than forecast.

KBUR..fair confidence in the 18Z TAF. there is a 30 percent chance
of marine clouds with ifr conditions late tonight and tuesday
morning.

&&

.MARINE...02/200 pM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. There will be a minimally
better chance of SCA conds Wednesday. Advisory level winds are
possible across the outer waters by Thursday.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Jackson
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...KJ

weather.gov/losangeles




000
FXUS66 KMTR 022054
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
154 PM PDT MON MAY 2 2016

.SYNOPSIS....DRY AND SEASONABLE CONDITIONS WILL PERSISTS THROUGH
TUESDAY. A WEATHER SYSTEM WILL THEN APPROACH THE CALIFORNIA COAST
BY MIDWEEK AND BRING A CHANCE OF SHOWERS AND POTENTIALLY
THUNDERSTORMS TO THE REGION FROM WEDNESDAY INTO THE START OF THE
UPCOMING WEEKEND. TEMPERATURES WILL ALSO COOL TO NEAR OR BELOW
SEASONAL AVERAGES THROUGH LATE WEEK.

&&

.DISCUSSION...AS OF 01:49 PM PDT MONDAY...A WELL ESTABLISHED
MARINE LAYER THAT RETURNED TO THE REGION YESTERDAY EVENING REMAINS
IN PLACE AND HAS RESULTED IN LOW CLOUDS ALONG MUCH OF THE
COASTLINE. AS A RESULT AND WITH THE RETURN TO A MORE PREDOMINATE
ONSHORE FLOW, TEMPERATURES REGION WIDE THIS AFTERNOON ARE RUNNING
A FEW (INLAND) TO AS MUCH AS 15 DEGREES COOLER (NEAR THE COAST)
COMPARED TO 24 HOURS AGO. MEANWHILE, INLAND AREAS REMAIN UNDER
MOSTLY SUNNY CONDITION WITH TEMPERATURES IN THE 70S TO NEAR 80 IN
THE WARMEST INLAND VALLEY LOCATIONS. DO EXPECT THE LOW CLOUDS TO
PUSH BACK INLAND THIS EVENING AND SPREAD INTO THE VALLEYS
OVERNIGHT. CONDITIONS ON TUESDAY WILL CHANGE VERY LITTLE, YET
COULD SEE A FEW DEGREES OF COOLING INLAND AS ONSHORE FLOW
INCREASES SLIGHTLY.

FOR THE SECOND HALF OF THE WEEK, AN UPPER LEVEL TROUGH IS FORECAST
TO DEVELOP OVER THE EASTERN PACIFIC. AS THE TROUGH APPROACHES THE
COAST, THE FORECAST MODELS SHOW A CLOSED MID/UPPER LEVEL LOW
DEVELOPING OFF OF THE NORTHERN OR CENTRAL CALIFORNIA COAST LATE
WEDNESDAY INTO THURSDAY. THIS WILL RESULT IN COOLER TEMPERATURES
REGION-WIDE AND INCREASED CHANCES FOR ISOLATED TO SCATTERED SHOWERS
FROM WEDNESDAY AFTERNOON THROUGH SATURDAY. WITH THAT SAID,
WIDESPREAD RAINFALL IS NOT EXPECTED AT THIS TIME GIVEN THE LACK OF A
DEEP MOISTURE SOURCE AND STRONGER MID/UPPER LEVEL SUPPORT. HOWEVER,
WITH THE CENTER OF THE LOW FORECAST TO MOVE INLAND OVER THE REGION,
THERE WILL BE A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS LATE THIS
WEEK AS A COLDER AND MORE UNSTABLE AIR MASS REMAINS OVERHEAD. CANNOT
RULE OUT A FEW THUNDERSTORMS WITH SMALL HAIL AS WELL.

THE UPPER LEVEL TROUGH IS THEN FORECAST TO SHIFT INLAND BY SUNDAY AS
AN UPPER LEVEL RIDGE BUILDS OVER THE EASTERN PACIFIC. THIS SHOULD
BRING AN END TO THE UNSETTLED WEATHER CONDITIONS OVER THE REGION
LATE SATURDAY INTO SUNDAY. TEMPERATURES LATE IN THE WEEKEND WILL
ALSO SLOWLY REBOUND BACK TO NEAR SEASONAL AVERAGES.

&&

.AVIATION...AS OF 10:51 AM PDT MONDAY...FOR 18Z TAFS. 2000 FOOT
MARINE LAYER IN PLACE AND STRATUS RETREATING FROM MAJOR TERMINALS
EXCEPT KMRY. GENERALLY LIGHT SW WINDS THIS AFTERNOON FOR
SEABREEZE. MORE TYPICAL SUMMER LIKE PATTERN IN PLACE WITH SYNOPTIC
TROUGH APPROACHING AND PRE-EXISTING MARINE LAYER IN PLACE. EXPECT
MORE TYPICAL NIGHT TIME AND EARLY MORNING STRATUS INTRUSION OF
1500-2000 FT CLOUD DECK. BURN OFF TUESDAY COULD BE AFTER 18Z.

VICINITY OF KSFO...WEB CAMS SHOW SKIES RAPIDLY CLEARING WITH
LATEST 1 MINUTE DATA REPORTING SCT018. EXPECT VFR THE REST OF
THIS AFTERNOON AND EARLY EVENING. 18Z TAF SHOWS VFR THROUGH 06Z
SOME CONCERN THAT CIGS COULD RETURN A LITTLE EARLIER BUT ONSHORE
WINDS APPEAR FAIRLY LIGHT SO EXPECT CLOUD DECK TO HANG IN THE GAP
THROUGH THE EVENING.

SFO BRIDGE APPROACH...CLEAR THE REST OF THIS AFTERNOON AND EARLY
EVENING. HIGH CONFIDENCE FOR VISUALS THROUGH AT LEAST 03Z...THEN
HAZE AND LOW CLOUDS WILL WORK BACK IN MOST LIKELY AFTER 06Z BUT
COULD BE EARLIER.

MONTEREY BAY TERMINALS...CLOUD DECK TO HANG NEAR OR JUST WEST OF
KMRY TODAY. EXPECT MARINE LAYER TO SURGE BACK OVER KMRY AND KSNS
EARLY THIS EVENING.

&&

.MARINE...AS OF 10:51 AM PDT MONDAY...LIGHT SOUTHERLY WINDS THIS
MORNING WILL GRADUALLY TURN WEST BY THIS EVENING AND NW INTO
TUESDAY. LIGHT TO MODERATE NW WIND AND SEAS WILL CONTINUE LATER
TUESDAY INTO WEDNESDAY AS A LATE SEASON UPPER LOW APPROACHES THE
REGION PRODUCING SCATTERED SHOWERS THROUGH THE END OF THE WEEK.
LIGHT SEAS MOST OF THE WEEK WILL BUILD BY FRIDAY AS THE LOW
DEPARTS AND STRONGER NW WINDS ARRIVE.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

&&

$$

PUBLIC FORECAST: RGASS
AVIATION: R_WALBRUN
MARINE: R_WALBRUN


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000
FXUS66 KSGX 022049
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
149 PM PDT MON MAY 2 2016

.SYNOPSIS...
WEAK HIGH PRESSURE ALOFT WILL CREATE A SLIGHT WARMING TREND
THROUGH TUESDAY. AN APPROACHING UPPER-LEVEL LOW WILL CREATE
COOLER, WET AND BREEZY WEATHER AT TIMES THURSDAY THROUGH THE
WEEKEND. WEAK UPPER-LEVEL HIGH PRESSURE RETURNS EARLY NEXT WEEK
CREATING NEAR NORMAL HIGH TEMPERATURES AND DRY WEATHER.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

AT 1 PM PDT, WATER VAPOR SATELLITE IMAGERY DISPLAYED A WEAK
UPPER-LEVEL RIDGE JUST OFF THE SW CA COAST, AND AN UPPER-LEVEL
TROUGH FOLLOWING CLOSE BEHIND. VISIBLE SATELLITE SHOWED CUMULUS
OVER PORTIONS OF THE MOUNTAINS, DESERTS AND INLAND EMPIRE. SHOWERS
DEVELOPED OVER PORTIONS OF THE SAN BERNARDINO COUNTY MOUNTAINS
EARLIER TODAY, BUT CONVECTION HAS RECENTLY DIMINISHED. A FEW MORE
SHOWERS MAY DEVELOP OVER THE AREA BY LATE THIS AFTERNOON.
INCREASING HEIGHTS WILL HELP HIGH TEMPERATURES RISE AROUND 5 DEG F
ABOVE NORMAL TODAY AND TOMORROW. LOW CLOUDS WILL DEVELOP TONIGHT
OVER THE COAST AND AROUND 20-30 MILES INLAND.

AN UPPER-LEVEL LOW WILL BREAK OFF THE AFOREMENTIONED UPPER-LEVEL
TROUGH ON WEDNESDAY, AND SLOWLY HEAD TOWARDS SW CA. MODELS DEVELOP
PRECIPITATION OVER THE REGION AT TIMES THURSDAY MORNING THROUGH
SUNDAY. TIMING OF PRECIP WILL DEPEND ON WHEN WEAK VORTICITY-
MAXIMUMS MOVE ACROSS THE REGION, AND WHEN THE UPPER-LEVEL LOW
BECOMES CENTERED OVER THE AREA. H500 TEMPS OF -23 DEG C WILL
CREATE AN UNSTABLE ATMOSPHERE AND THE POSSIBILITY OF ISOLATED
THUNDERSTORMS ON FRIDAY AND EARLY SATURDAY. HEAVY PRECIPITATION
IS NOT EXPECTED AT THIS TIME DUE TO A WEAK MOISTURE TAP, WITH A
PRECIPITABLE WATER OF 0.50-0.75 INCHES. HOWEVER, PRECIP WILL VARY
DEPENDING ON SHOWER MOVEMENT. THE SNOW LEVEL BE AROUND 7000 FT
THURSDAY, DROP TO AROUND 6000 FT ON FRIDAY, THEN RISE BACK TO
AROUND 7000 FT BY SUNDAY. SOUTHWEST TO WEST WINDS WILL BE BREEZY
AT TIMES OVER THE MOUNTAINS AND DESERTS WEDNESDAY THROUGH
SATURDAY, WITH GUSTS TO AROUND 40 MPH POSSIBLE IN THE WINDIEST
LOCATIONS. FRIDAY WILL BE THE COLDEST DAY THIS WEEK AS HIGH
TEMPERATURES DIP 5 TO 15 DEG F BELOW SEASONAL NORMALS.

DRY WEATHER WILL DEVELOP NEXT MONDAY AS HEIGHTS BUILD WITH AN
APPROACHING WEAK UPPER-LEVEL RIDGE AND HIGH TEMPERATURES RISE TO
NEAR NORMAL.

&&

.AVIATION...
022030Z...CLEAR SKIES AND UNRESTRICTED VIS WILL PREVAIL THE REST OF
THIS AFTERNOON. STRATUS...WITH BASES 1500-2000 FT MSL AND TOPS TO
2500 FT MSL...WILL DEVELOP 01Z-05Z TONIGHT NEAR THE COAST AND SPREAD
20-25 MI INLAND BY 12Z TUE. TIMING OF ARRIVAL AT COASTAL AIRPORTS IS
LOW CONFIDENCE. HIGHER TERRAIN WILL BE LOCALLY OBSCURED LATE
TONIGHT. LOCAL SFC VIS 1-3 MI WILL OCCUR IN THE VALLEYS. MOST AREAS
WILL CLEAR 16-19Z TUE.

MOUNTAINS/DESERTS...ISOLD SHRA FROM CLOUDS AT/ABOVE 8000 FT WILL
CONTINUE THROUGH 01Z OVER THE MOUNTAINS...MAINLY SAN BERNARDINO
COUNTY. OTHERWISE...MOSTLY CLEAR SKIES AND UNRESTRICTED VIS WILL
PREVAIL THROUGH TUE.

&&

.MARINE...
130 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH WEDNESDAY.
A STORM SYSTEM WILL LIKELY BRING WIND GUSTS AROUND 25 KT AND
ASSOCIATED CHOPPY SEAS...RESULTING IN A SMALL CRAFT ADVISORY THU
NIGHT/FRI. SHOWERS AND EVEN AN ISOLATED TSTORM WILL BE POSSIBLE
FRI.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&

$$

PUBLIC...JJT
AVIATION/MARINE...MAXWELL




000
FXUS66 KLOX 021834
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1134 AM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through Sunday.

&&

.SHORT TERM...(TDY-WED)

Low clouds along the coast are clearing out to the beaches most
areas as expected, clearing out fastest over Los Angeles County
but holding on along the Santa Barbara south coast northward along
the central coast. Onshore gradients are a little weaker this
morning south of Point Conception while slightly stronger north.
Expect plenty of clear skies today all areas of Ventura and Los
Angeles County but would not be surprised to see cloud cover
continue along the immediate central coast. Visible satellite
imagery showing some cumulus buildup over the eastern San Gabriels
due to some remnant cold air aloft lagging behind the last system.
These may produce a few sprinkles to weak showers that area but
nothing significant. Expect a return of overnight low clouds
coastal areas tonight, and with a similar coverage as last night
due to fairly similar surface pressure gradients and marine layer
depth.

As heights rise today and tomorrow we should see some warmup most
areas. Temperatures over much of Los Angeles County are a few
degrees ahead of schedule this morning while areas north of Point
Conception are 5 to as much as 10 degrees cooler than yesterday at
this time due to a slightly stonger onshore push and more cloud
cover. The current temperature change pattern should hold true for
this afternoon`s high temps. Continued height rises will warm
things a few more degrees tomorrow when the weak ridge axis passes
by, and despite an increase in cloud cover ahead of the next
trough to move through the area for the second half of the week.

The trough to move through the area for the second half of the
week will start by cooling temperatures on Wednesday. Expect high
temperatures to cool down by 5 to 10 degrees from Tuesday`s highs most
areas, and under increasingly cloudy skies.



.LONG TERM...(THU-SUN)


GFS/EC agree that a cutoff low pressure system will slowly drift over
the forecast area Thursday and Friday, then slowly move east over
the weekend. There will be a chance for hit and miss showers in
most places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). The cold core
upper low (with 500 mb temperatures of -24 degrees Celsius) will
move across Southwest California sometime between Thursday
afternoon through Friday. The cold air aloft combined with early
May sunshine will be create enough instability to warrant a
slight chance of thunderstorms(especially over interior sections).
Right now it does not look like this system will have that much
moisture to work with and do not expect large rainfall amounts
with it. This system is cold enough that snow levels will likely
dip to between 5000 and 6000 feet.



&&

.AVIATION...02/1800Z.

AT 1741Z, the marine layer depth at KLAX was around 1000 feet.
The top of the inversion was around 2700 feet with a temperature
of 18 degrees Celsius.

good confidence in the 18z tafs. slow clearing is expected in
some areas...mainly from the ventura coast northward today. some
weak ridging is expected in the next 24 hours...so the depth of
the marine layer may drop slightly by tuesday morning...although
the nam12 model shows very little change in marine layer coverage.
the main change in the 18z taf package was to remove any mention
of marine clouds in the LA county valleys...in agreement with the
nam12 model.

KLAX...good confidence in the 18Z TAF. there is a 30 percent
chance of ceilings moving in 2 hours later than forecast.

KBUR..fair confidence in the 18Z TAF. there is a 30 percent chance
of marine clouds with ifr conditions late tonight and tuesday
morning.

&&

.MARINE...02/900 AM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. there will be a better chance
of SCA conds Wednesday. Advisory level winds are possible across
the outer waters by Wednesday night.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Jackson
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...KJ

weather.gov/losangeles




000
FXUS66 KMTR 021751
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1051 AM PDT MON MAY 2 2016

.SYNOPSIS....DRY AND SEASONABLE WEATHER IS FORECAST THROUGH
TOMORROW ALONG WITH COASTAL CLOUDS. A WEATHER SYSTEM WILL APPROACH
CALIFORNIA BY THE MIDDLE OF THE WEEK...BRINGING A CHANCE OF
SHOWERS AND A FEW THUNDERSTORMS BEGINNING WEDNESDAY LASTING INTO
THE WEEKEND...ALONG WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 09:00 AM PDT MONDAY...COASTAL STRATUS SPREAD
WELL INLAND OVERNIGHT AND CONTINUES TO IMPACT THE REGION THIS
MORNING ALONG WITH TEMPERATURES GENERALLY IN THE LOW TO MID 50S.
DO EXPECT A SLOW BURN-OFF OF LOW CLOUDS OVER INLAND VALLEYS THIS
MORNING WITH THE POTENTIAL FOR A BRIEF BREAK IN CLOUD COVER ALONG
THE COAST BY THIS AFTERNOON. THIS WILL RESULT IN GENERALLY A 3 TO
10 DEGREE COOL DOWN COMPARED TO YESTERDAY, MOST NOTABLE NEAR THE
COAST AS ONSHORE FLOW PERSISTS. THE ONGOING FORECAST REMAINS ON
TRACK AT THIS TIME AND NO UPDATES ARE ANTICIPATED. PLEASE SEE
PREVIOUS FORECAST DISCUSSION BELOW FOR FURTHER DETAILS.

&&

.PREV DISCUSSION...AS OF 3:00 AM PDT MONDAY...AS EXPECTED CLOUDS
RETURNED TO THE COAST YESTERDAY EVENING AND BASED OFF OF THE
SATELLITE FOG PRODUCT, THEY HAVE CONTINUED FOR THE OVERNIGHT HOURS
AND HAVE ALSO SPREAD INTO SOME ADJACENT VALLEY SPOTS. AFTER A WARM
WARM DAY YESTERDAY, SUBSTANTIAL COOLING CAN BE EXPECTED TODAY AS
MORE OF AN ONSHORE FLOW WILL BRING AIR OFF THE WATER AND ACROSS
OUR REGION. FOR SOME COASTAL SPOTS HIGHS TODAY WILL BE 10 OR MORE
DEGREES UNDER THE VALUES FROM SUNDAY. FARTHER INLAND, THE DROP IN
TEMPS WILL BE LESS ALTHOUGH MOST LOCATIONS WILL SEE AT LEAST A 3
TO 6 DEGREE DECREASE. TONIGHT SHOULD BE A REPEAT OF TODAY WITH
CLOUDS RETURNING TO THE COAST PLUS ADJACENT VALLEY LOCATIONS.

AFTER A QUIET DAY ON TUESDAY UNSETTLED WEATHER RETURNS STARTING
ON WEDNESDAY AS A LONGWAVE TROF NEARS THE COAST WHILE AN UPPER
LEVEL CUT-OFF LOW FORMS AT THE BASE OF THE TROF NEAR OUR CWA.
BEYOND THAT POINT, MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THE
LOW WILL VERY SLOWLY PROGRESS TO THE SOUTHEAST FOR THE REMAINDER
OF THE WEEK. WHERE THERE IS MORE DISAGREEMENT IS THE LOCATION OF
THE LOW PLUS THE MOST FAVORABLE LOCATIONS FOR ASSOCIATED MOISTURE
(ESPECIALLY WRAP-AROUND MOISTURE). THEREFORE, DECIDED TO KEEP
MOST SPOTS IN THE 20-30% CHANCE OF PRECIP FOR THE PERIOD. IN
ADDITION, BASED ON THE TRACK OF THE LOW PLUS GUIDANCE OUT TO 84
HOURS OFF THE NAM, KEPT A MENTION OF A SLIGHT CHANCE FOR T-STORMS
AND POSSIBLE SMALL HAIL. RAINFALL AMOUNTS WILL LIKELY BE MINOR
THROUGH THE PERIOD. COOLER TEMPS CAN ALSO BE EXPECTED -- MOSTLY
UPPER 50S TO UPPER 60S.

A RIDGE WILL BUILD IN BEHIND THE DEPARTING LOW FOR NEXT WEEK. THIS
WILL LEAD TO WARMER CONDITIONS ALONG WITH LITTLE TO NO RAIN.

&&

.AVIATION...AS OF 10:51 AM PDT MONDAY...FOR 18Z TAFS. 2000 FOOT
MARINE LAYER IN PLACE AND STRATUS RETREATING FROM MAJOR TERMINALS
EXCEPT KMRY. GENERALLY LIGHT SW WINDS THIS AFTERNOON FOR
SEABREEZE. MORE TYPICAL SUMMER LIKE PATTERN IN PLACE WITH SYNOPTIC
TROUGH APPROACHING AND PRE-EXISTING MARINE LAYER IN PLACE. EXPECT
MORE TYPICAL NIGHT TIME AND EARLY MORNING STRATUS INTRUSION OF
1500-2000 FT CLOUD DECK. BURN OFF TUESDAY COULD BE AFTER 18Z.

VICINITY OF KSFO...WEB CAMS SHOW SKIES RAPIDLY CLEARING WITH
LATEST 1 MINUTE DATA REPORTING SCT018. EXPECT VFR THE REST OF
THIS AFTERNOON AND EARLY EVENING. 18Z TAF SHOWS VFR THROUGH 06Z
SOME CONCERN THAT CIGS COULD RETURN A LITTLE EARLIER BUT ONSHORE
WINDS APPEAR FAIRLY LIGHT SO EXPECT CLOUD DECK TO HANG IN THE GAP
THROUGH THE EVENING.

SFO BRIDGE APPROACH...CLEAR THE REST OF THIS AFTERNOON AND EARLY
EVENING. HIGH CONFIDENCE FOR VISUALS THROUGH AT LEAST 03Z...THEN
HAZE AND LOW CLOUDS WILL WORK BACK IN MOST LIKELY AFTER 06Z BUT
COULD BE EARLIER.

MONTEREY BAY TERMINALS...CLOUD DECK TO HANG NEAR OR JUST WEST OF
KMRY TODAY. EXPECT MARINE LAYER TO SURGE BACK OVER KMRY AND KSNS
EARLY THIS EVENING.

&&

.MARINE...AS OF 10:51 AM PDT MONDAY...LIGHT SOUTHERLY WINDS THIS
MORNING WILL GRADUALLY TURN WEST BY THIS EVENING AND NW INTO
TUESDAY. LIGHT TO MODERATE NW WIND AND SEAS WILL CONTINUE LATER
TUESDAY INTO WEDNESDAY AS A LATE SEASON UPPER LOW APPROACHES THE
REGION PRODUCING SCATTERED SHOWERS THROUGH THE END OF THE WEEK.
LIGHT SEAS MOST OF THE WEEK WILL BUILD BY FRIDAY AS THE LOW
DEPARTS AND STRONGER NW WINDS ARRIVE.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY

&&

$$

PUBLIC FORECAST: RGASS
AVIATION: R_WALBRUN
MARINE: R_WALBRUN


VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO

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000
FXUS66 KLOX 021656
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
956 AM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through Sunday.

&&

.SHORT TERM...(TDY-WED)

Low clouds along the coast are clearing out to the beaches most
areas as expected, clearing out fastest over Los Angeles County
but holding on along the Santa Barbara south coast northward along
the central coast. Onshore gradients are a little weaker this
morning south of Point Conception while slightly stronger north.
Expect plenty of clear skies today all areas of Ventura and Los
Angeles County but would not be surprised to see cloud cover
continue along the immediate central coast. Visible satellite
imagery showing some cumulus buildup over the eastern San Gabriels
due to some remnant cold air aloft lagging behind the last system.
These may produce a few sprinkles to weak showers that area but
nothing significant. Expect a return of overnight low clouds
coastal areas tonight, and with a similar coverage as last night
due to fairly similar surface pressure gradients and marine layer
depth.

As heights rise today and tomorrow we should see some warmup most
areas. Temperatures over much of Los Angeles County are a few
degrees ahead of schedule this morning while areas north of Point
Conception are 5 to as much as 10 degrees cooler than yesterday at
this time due to a slightly stronger onshore push and more cloud
cover. The current temperature change pattern should hold true for
this afternoon`s high temps. Continued height rises will warm
things a few more degrees tomorrow when the weak ridge axis passes
by, and despite an increase in cloud cover ahead of the next
trough to move through the area for the second half of the week.

The trough to move through the area for the second half of the
week will start by cooling temperatures on Wednesday. Expect high
temperatures to cool down by 5 to 10 degrees from Tuesday`s highs most
areas, and under increasingly cloudy skies.

*** From previous discussion ***

.LONG TERM...(THU-SUN)


GFS/EC agree that a cutoff low pressure system will slowly drift over
the forecast area Thursday and Friday, then slowly move east over
the weekend. There will be a chance for hit and miss showers in
most places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). The cold core
upper low (with 500 mb temperatures of -24 degrees Celsius) will
move across Southwest California sometime between Thursday
afternoon through Friday. The cold air aloft combined with early
May sunshine will be create enough instability to warrant a
slight chance of thunderstorms(especially over interior sections).
Right now it does not look like this system will have that much
moisture to work with and do not expect large rainfall amounts
with it. This system is cold enough that snow levels will likely
dip to between 5000 and 6000 feet.



&&

.AVIATION...02/1145Z.

AT 11Z, the marine layer depth at KLAX was around 1800 feet.
The top of the inversion was around 3000 feet with a temperature
of 15 degrees Celsius.

Widespread stratus on the Central Coast and in the Santa Ynez
Valley early this morning, with IFR to LIFR conds. Expect IFR to
LIFR conds to push into the Salinas Valley. South of Pt
Conception, stratus with IFR conds was affecting the south
coast of Sba County and the Vtu County coast, with IFR to LIFR
conds beginning to spread into the Vtu County valleys. Stratus
across Los Angeles county has been confined to southern sections,
but was beginning to spread northward, and will likely affect all
coastal sections of L.A. county by daybreak. Cigs were higher
here, with mostly MVFR conditions. Expect rather slow clearing,
especially in coastal sections of Vtu and southern Sba Counties,
where clearing may not take place until early afternoon.
Widespread stratus is expected in all coastal and valley areas
tonight, with IFR conds north of Pt Conception and MVFR conds
south.

KLAX...Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance that cigs will not scatter out until at 21Z. There
is a 30 percent chance that cigs will not arrive tonight until
after 09Z.

KBUR..Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance of low MVFR or high IFR cigs between 13Z and 17Z
this morning. There is a 20 percent chance that cigs will not
arrive tonight until after 12Z.

&&

.MARINE...02/900 AM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. there will be a better chance
of SCA conds Wednesday. Advisory level winds are possible across
the outer waters by Wednesday night.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 10 AM PDT this
      morning For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Jackson/Rorke
AVIATION...DB
MARINE...DB
SYNOPSIS...KJ

weather.gov/losangeles




000
FXUS66 KLOX 021656
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
956 AM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through Sunday.

&&

.SHORT TERM...(TDY-WED)

Low clouds along the coast are clearing out to the beaches most
areas as expected, clearing out fastest over Los Angeles County
but holding on along the Santa Barbara south coast northward along
the central coast. Onshore gradients are a little weaker this
morning south of Point Conception while slightly stronger north.
Expect plenty of clear skies today all areas of Ventura and Los
Angeles County but would not be surprised to see cloud cover
continue along the immediate central coast. Visible satellite
imagery showing some cumulus buildup over the eastern San Gabriels
due to some remnant cold air aloft lagging behind the last system.
These may produce a few sprinkles to weak showers that area but
nothing significant. Expect a return of overnight low clouds
coastal areas tonight, and with a similar coverage as last night
due to fairly similar surface pressure gradients and marine layer
depth.

As heights rise today and tomorrow we should see some warmup most
areas. Temperatures over much of Los Angeles County are a few
degrees ahead of schedule this morning while areas north of Point
Conception are 5 to as much as 10 degrees cooler than yesterday at
this time due to a slightly stronger onshore push and more cloud
cover. The current temperature change pattern should hold true for
this afternoon`s high temps. Continued height rises will warm
things a few more degrees tomorrow when the weak ridge axis passes
by, and despite an increase in cloud cover ahead of the next
trough to move through the area for the second half of the week.

The trough to move through the area for the second half of the
week will start by cooling temperatures on Wednesday. Expect high
temperatures to cool down by 5 to 10 degrees from Tuesday`s highs most
areas, and under increasingly cloudy skies.

*** From previous discussion ***

.LONG TERM...(THU-SUN)


GFS/EC agree that a cutoff low pressure system will slowly drift over
the forecast area Thursday and Friday, then slowly move east over
the weekend. There will be a chance for hit and miss showers in
most places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). The cold core
upper low (with 500 mb temperatures of -24 degrees Celsius) will
move across Southwest California sometime between Thursday
afternoon through Friday. The cold air aloft combined with early
May sunshine will be create enough instability to warrant a
slight chance of thunderstorms(especially over interior sections).
Right now it does not look like this system will have that much
moisture to work with and do not expect large rainfall amounts
with it. This system is cold enough that snow levels will likely
dip to between 5000 and 6000 feet.



&&

.AVIATION...02/1145Z.

AT 11Z, the marine layer depth at KLAX was around 1800 feet.
The top of the inversion was around 3000 feet with a temperature
of 15 degrees Celsius.

Widespread stratus on the Central Coast and in the Santa Ynez
Valley early this morning, with IFR to LIFR conds. Expect IFR to
LIFR conds to push into the Salinas Valley. South of Pt
Conception, stratus with IFR conds was affecting the south
coast of Sba County and the Vtu County coast, with IFR to LIFR
conds beginning to spread into the Vtu County valleys. Stratus
across Los Angeles county has been confined to southern sections,
but was beginning to spread northward, and will likely affect all
coastal sections of L.A. county by daybreak. Cigs were higher
here, with mostly MVFR conditions. Expect rather slow clearing,
especially in coastal sections of Vtu and southern Sba Counties,
where clearing may not take place until early afternoon.
Widespread stratus is expected in all coastal and valley areas
tonight, with IFR conds north of Pt Conception and MVFR conds
south.

KLAX...Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance that cigs will not scatter out until at 21Z. There
is a 30 percent chance that cigs will not arrive tonight until
after 09Z.

KBUR..Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance of low MVFR or high IFR cigs between 13Z and 17Z
this morning. There is a 20 percent chance that cigs will not
arrive tonight until after 12Z.

&&

.MARINE...02/900 AM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. there will be a better chance
of SCA conds Wednesday. Advisory level winds are possible across
the outer waters by Wednesday night.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 10 AM PDT this
      morning For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Jackson/Rorke
AVIATION...DB
MARINE...DB
SYNOPSIS...KJ

weather.gov/losangeles




000
FXUS66 KSGX 021651
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
951 AM PDT MON MAY 2 2016

.SYNOPSIS...
WEAK HIGH PRESSURE ALOFT WILL CREATE A SLIGHT WARMING TREND
THROUGH TUESDAY. AN APPROACHING UPPER-LEVEL LOW WILL CREATE
COOLER, WET AND BREEZY WEATHER AT TIMES THURSDAY THROUGH THE
WEEKEND. WEAK UPPER-LEVEL HIGH PRESSURE RETURNS EARLY NEXT WEEK
CREATING NEAR NORMAL HIGH TEMPERATURES AND DRY WEATHER.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

AT 9 AM PDT, WATER VAPOR SATELLITE IMAGERY DISPLAYED A WEAK
UPPER-LEVEL RIDGE JUST OFF THE COAST OF SW CA, AND AN UPPER-LEVEL
TROUGH FOLLOWING CLOSE BEHIND. VISIBLE SATELLITE SHOWED STRATUS
OVER PORTIONS OF THE COASTAL WATERS AND SOME CUMULUS DEVELOPING
OVER THE SAN BERNARDINO COUNTY MOUNTAINS. RESIDUAL MOISTURE AND
DIURNAL HEATING WILL CREATE THE POSSIBILITY OF AN ISOLATED SHOWER
OR TWO OVER THE SAN BERNARDINO COUNTY MOUNTAINS THIS AFTERNOON.
HIGH-RES MODELS INDICATE ONLY LIGHT PRECIPITATION FOR THE PERIOD.
A CAP ON THIS MORNING`S KNKX SOUNDING WILL HELP LIMIT SHOWER
ACTIVITY. INCREASING HEIGHTS WILL HELP HIGH TEMPERATURES RISE
AROUND 5 DEG F ABOVE NORMAL TODAY AND TOMORROW. LOW CLOUDS WILL
DEVELOP TONIGHT OVER THE COAST AND AROUND 20-30 MILES INLAND.

AN UPPER-LEVEL LOW WILL BREAK OFF THE AFOREMENTIONED UPPER-LEVEL
TROUGH ON WEDNESDAY, AND SLOWLY HEAD TOWARDS SW CA. MODELS DEVELOP
PRECIPITATION OVER THE REGION AT TIMES THURSDAY MORNING THROUGH
SUNDAY. TIMING OF PRECIP WILL DEPEND ON WHEN WEAK VORTICITY-
MAXIMUMS MOVE ACROSS THE REGION, AND WHEN THE UPPER-LEVEL LOW
BECOMES CENTERED OVER THE AREA. H500 TEMPS OF -23 DEG C WILL
CREATE AN UNSTABLE ATMOSPHERE AND THE POSSIBILITY OF ISOLATED
THUNDERSTORMS ON FRIDAY. HEAVY PRECIPITATION IS NOT EXPECTED AT
THIS TIME DUE TO A WEAK MOISTURE TAP, WITH A PRECIPITABLE WATER
OF 0.50-0.75 INCHES. HOWEVER, PRECIP WILL VARY DEPENDING ON SHOWER
MOVEMENT. THE SNOW LEVEL BE AROUND 7000 FT THURSDAY, DROP TO
AROUND 6000 FT ON FRIDAY, THEN RISE BACK TO AROUND 7000 FT BY
SUNDAY. SOUTHWEST TO WEST WINDS WILL BE BREEZY AT TIMES IN THE
MOUNTAINS AND DESERTS WEDNESDAY THROUGH SATURDAY, WITH GUSTS TO
AROUND 40 MPH POSSIBLE IN THE WINDIEST LOCATIONS. FRIDAY WILL BE
THE COLDEST DAY THIS WEEK AS HIGH TEMPERATURES DIPPING 5 TO 15
DEG F BELOW SEASONAL NORMALS.

WARMER AND DRY WEATHER WILL DEVELOP NEXT MONDAY AS HEIGHTS BUILD
WITH AN APPROACHING WEAK UPPER-LEVEL RIDGE AND HIGH TEMPERATURES
RISE TO NEAR NORMAL.

&&

.AVIATION...
021630Z...EXCEPT FOR LOCAL BKN STRATUS ALONG THE IMMEDIATE
COAST...CLEAR SKIES AND UNRESTRICTED VIS WILL PREVAIL TODAY.
STRATUS...WITH BASES 1500-2000 FT MSL AND TOPS TO 2500 FT MSL...WILL
DEVELOP 01Z-05Z TONIGHT NEAR THE COAST AND SPREAD 20-25 MI INLAND BY
12Z TUE. HIGHER TERRAIN WILL BE LOCALLY OBSCURED LATE TONIGHT. LOCAL
SFC VIS 1-3 MI WILL OCCUR IN THE VALLEYS. MOST AREAS WILL CLEAR 16-
19Z TUE.

MOUNTAINS/DESERTS...ISOLD SHRA FROM CLOUDS AT/ABOVE 8000 FT ARE
POSSIBLE OVER THE MOUNTAINS...MAINLY SAN BERNARDINO COUNTY...20Z-01Z
THIS AFTERNOON. OTHERWISE...MOSTLY CLEAR SKIES WILL PREVAIL.

&&

.MARINE...
930 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH
WEDNESDAY. A STORM SYSTEM WILL LIKELY BRING WIND GUSTS 25-30 KT
AND ASSOCIATED CHOPPY SEAS...RESULTING IN A SMALL CRAFT ADVISORY
THU NIGHT/FRI. SHOWERS AND EVEN AN ISOLATED TSTORM WILL BE
POSSIBLE THU/FRI.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&

$$

PUBLIC...JJT
AVIATION/MARINE...MAXWELL




000
FXUS65 KPSR 021644
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
944 AM MST MON MAY 2 2016

.SYNOPSIS...
LOW PRESSURE WILL MAKE A SLOW EXIT TO THE EAST ACROSS NORTHERN AZ
TODAY...KEEPING THE FOCUS OF ANY LINGERING PRECIP ACTIVITY WELL NORTH
OF OUR FORECAST AREA. HIGH PRESSURE MOVING IN FROM THE WEST WILL
BUILD OVER THE DESERT SOUTHWEST THROUGH THURSDAY...RESULTING IN
MOSTLY CLEAR SKIES AND A STRONG WARMING TREND. ANOTHER PACIFIC
WEATHER SYSTEM WILL BEGIN TO MOVE INTO THE AREA FRIDAY AND FOR THE
COMING WEEKEND...BRINGING MUCH COOLER TEMPERATURES...BREEZY
CONDITIONS AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...
MINOR ADJUSTMENTS TO THE FORECAST THIS MORNING TO ACCOUNT FOR VARIOUS
TRENDS INCLUDING CLEAR SKY AND HIGHER HUMIDITY VALUES. TEMPERATURES
ARE PRETTY MUCH ON TRACK TO HIT FORECAST HIGHS THIS AFTERNOON. WE ARE
SEEING A PUSH OF EASTERLY WINDS ACROSS MARICOPA AND PINAL COUNTIES
THIS MORNING AND THAT SHOULD SUBSIDE BY EARLY AFTERNOON.

LAST SHORT WAVE IS ABOUT OVER LAS VEGAS THIS MORNING AND IT WILL MOVE
ACROSS NORTHERN ARIZONA TODAY. A MORE LAMINAR FLOW OVER SOUTHERN
CALIFORNIA AND SOUTHERN ARIZONA...WITH SOME MINOR WAA...WILL KEEP
PRECIPITATION CHANCES QUITE LOW. MOST OF THE CAMS ARE GENERATING A
LITTLE ACTIVITY OVER JOSHUA TREE NP AND WE WILL MAINTAIN A SLIGHT
CHANCE FOR RAIN THERE.

LOOKING AHEAD...MESSAGE OF THE DAY WILL INCLUDE WARMING TEMPERATURES
WITH THE FIRST 100 POSSIBLE FOR PHOENIX AND YUMA ON WEDNESDAY /BUT
NOT GUARANTEED AND NOT FORECAST AT THIS TIME/...STRONG WINDS THURSDAY
LIKELY GENERATING AREAS OF BLOWING DUST AND POSSIBLE DANGEROUS FIRE
WEATHER CONDITIONS...THEN THE COOL DOWN FOR THE WEEKEND WITH PERHAPS
A FEW SHOWERS. MORE DETAILS BELOW AND UPDATES THIS AFTERNOON.

PREVIOUS DISCUSSION...
HIGH-AMPLITUDE HIGH PRESSURE WILL TAKE A FEW-DAY HOLD OVER THE
INTERMOUNTAIN WEST ALLOWING DAYTIME TEMPERATURES TO TAKE ANOTHER RUN
AT THEIR WARMEST READINGS OF THE YEAR SO FAR BY MIDWEEK. 500MB
HEIGHTS STILL PROGGED INTO THE 576-582DM RANGE AND 850MB AFTN
TEMPERATURE QUICKLY HEAD NORTH OF 20 TO 25C AFTER MONDAY. MID TO
UPPER 90 DEGREE READINGS ARE ANTICIPATED FOR THE LOWER DESERT
ELEVATIONS TUESDAY AND WEDNESDAY. WEDNESDAY STILL PINNED TO BE THE
WARMEST DAY OF THE WEEK AND QUITE POSSIBLY THE YEAR AS THE RIDGE AXIS
BEGINS TO SHIFT TO OUR EAST AS STRONG SOUTHERLY FLOW DEVELOPS INTO
THE AREA ENHANCING WAA FROM THE SUBTROPICS. CONSENSUS GUIDANCE
SUPPORTING UPPER 90S FOR MANY OF THE DESERT SITES...WITH 100S STILL
POSSIBLE FOR THE WARMEST LOCALES SUCH AS TACNA AND EL CENTRO. THE
FIRST 100F FOR PHOENIX HAS POPPED INTO SOME OF THE LATEST GRIDDED
GUIDANCE WEDNESDAY...BUT ARE FROM MODEL PERFORMERS NOT TYPICAL OF
THOSE THAT DO WELL WITH HIGH PRESSURE PATTERNS.

THURSDAY THROUGH NEXT WEEKEND...
MODEL AGREEMENT AND TRENDS...BOTH IN THE DETERMINISTIC AND ENSEMBLE
SOLUTIONS...HAVE REMAINED IN EXCELLENT AGREEMENT OVER THE PAST
SEVERAL DAYS IN ADVERTISING A DEEP PACIFIC TROUGH MOVING INTO THE
SOUTHWEST BY THE LATE WEEK/EARLY WEEKEND. TROUGHING REACHES AS FAR
SOUTH AS THE NORTHERN BAJA PENINSULA AND MAINTAINS ITS COOL
TEMPERATURE PROFILE BY THURSDAY. DAYTIME TEMPERATURES WILL BEGIN TO
COOL ACROSS THE WESTERN FORECAST ZONES AS STRONG SOUTHERLY LOW-LEVEL
WINDS DEVELOP INTO THE REGION. JET-LEVEL WINDS BEGIN TO PUSH 100KTS
THURSDAY AFTERNOON...WITH LL WINDS AT 700MB AND 850MB ENCROACHING 35
TO 45 KTS. WINDS FORECAST TO BE AT THEIR STRONGEST ON THURSDAY...WITH
AREA WIDE SUSTAINED SFC SPEEDS PUSHING 25 MPH AND GUSTS 35 MPH OR
GREATER. WITH THE WINDS COMES THE THREAT FOR DUST...SO INCLUDED
MENTION OF BLOWING DUST IN THE GRIDS FOR BOTH WEDNESDAY AND THURSDAY
AS THE SYSTEM WINDS RAMP UP INTO THE AREA. THE ONE FORECAST ELEMENT
THAT REMAINS A BIT OF A UNKNOWN QUANTITY WILL BE THE MOISTURE...AS
PWAT FIELDS APPEAR TO STRUGGLE BREAKING PAST HALF INCH READINGS.
QPF/PRECIP PLOTS FROM THE DETERMINISTIC AS WELL AS THE GEFS
REFORECAST ARE NOT OVERLY EXCITED ABOUT ANY PERIODS OF PERSISTENT
RAINFALL INTO THE AREA ON THIS SYSTEM SWINGS IN OFF THE PACIFIC AND
SETTLES OVER THE AREA BY FRIDAY.

A WELCOME COOL-DOWN WILL RESULT FOR THE SOUTHWEST AS 500MB
TEMPERATURES BEGIN TO RUN COOLER THAN -20C ACROSS THE AREA...WITH
DAYTIME HIGHS DIPPING INTO THE UPPER 70S AND LOW 80S. AS WITH
PREVIOUS SYSTEMS...THE UPPER LOW FEATURE WILL TAKE UP RESIDENCE OVER
THE WEST INTO THE WEEKEND AND POSSIBLY VERY EARLY NEXT WEEK...AS IT
BECOMES THE WESTERN END OF A CONUS WIDE OMEGA BLOCK. VORTICITY PLOTS
INDICATE IT COULD BEGIN TO LOBE OUT...ALLOWING FOR ON AND OFF ROUNDS
OF BREEZINESS AND SOME PRECIP CHANCES TO OCCUR THROUGHOUT THE
SOUTHWEST STATES.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND...
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

DRY WESTERLY FLOW ALOFT WILL RESULT IN MOSTLY CLEAR SKIES THROUGH
23Z MON. LIGHT AND VARIABLE WINDS UNDER 7 KNOTS THROUGH 23ZZ MON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...

WEDNESDAY AND THURSDAY...

A HIGH PRESSURE SYSTEM WILL CONTINUE OVER THE REGION ON WEDNESDAY...
HOWEVER ANOTHER PACIFIC COLD FRONT WILL APPROACH THE WEST COAST
WEDNESDAY AFTERNOON...THEN MOVE THROUGH THE REGION THURSDAY. AS A
RESULT...BREEZY SOUTHWEST WINDS WILL DEVELOP WEDNESDAY AFTERNOON AND
EVENING...BECOMING VERY WINDY THURSDAY. SINCE RELATIVE HUMIDITIES
THURSDAY WILL RANGE FROM 10 TO 15 PERCENT...RED FLAG CONDITIONS MAY
BE REACHED ON THE SOUTHWEST AND SOUTH CENTRAL AZ DESERTS THURSDAY
AFTERNOON.

FRIDAY THROUGH SUNDAY...

AFTER THE COLD FRONTAL PASSAGE THURSDAY...A COOL AND RELATIVELY
MOIST AIRMASS WILL SETTLE OVER THE REGION THIS PERIOD. BREEZY WEST
WINDS MAY DEVELOP FRIDAY AFTERNOON...BUT BECOME MUCH LIGHTER
SATURDAY AND SUNDAY. MINIMUM RELATIVE HUMIDITIES WILL INCREASE AREA-
WIDE INTO THE 17 TO 24 PERCENT RANGE. A SLIGHT CHANCE OF SHOWERS...
UNDER A RELATIVELY COOL AND MOIST AIRMASS...WILL DEVELOP FRIDAY AND
SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ/NOLTE
AVIATION...VASQUEZ
FIRE WEATHER...VASQUEZ




000
FXUS66 KMTR 021627
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
927 AM PDT MON MAY 2 2016

.SYNOPSIS....DRY AND SEASONABLE WEATHER IS FORECAST THROUGH
TOMORROW ALONG WITH COASTAL CLOUDS. A WEATHER SYSTEM WILL APPROACH
CALIFORNIA BY THE MIDDLE OF THE WEEK...BRINGING A CHANCE OF
SHOWERS AND A FEW THUNDERSTORMS BEGINNING WEDNESDAY LASTING INTO
THE WEEKEND...ALONG WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 09:00 AM PDT MONDAY...COASTAL STRATUS SPREAD
WELL INLAND OVERNIGHT AND CONTINUES TO IMPACT THE REGION THIS
MORNING ALONG WITH TEMPERATURES GENERALLY IN THE LOW TO MID 50S.
DO EXPECT A SLOW BURN-OFF OF LOW CLOUDS OVER INLAND VALLEYS THIS
MORNING WITH THE POTENTIAL FOR A BRIEF BREAK IN CLOUD COVER ALONG
THE COAST BY THIS AFTERNOON. THIS WILL RESULT IN GENERALLY A 3 TO
10 DEGREE COOL DOWN COMPARED TO YESTERDAY, MOST NOTABLE NEAR THE
COAST AS ONSHORE FLOW PERSISTS. THE ONGOING FORECAST REMAINS ON
TRACK AT THIS TIME AND NO UPDATES ARE ANTICIPATED. PLEASE SEE
PREVIOUS FORECAST DISCUSSION BELOW FOR FURTHER DETAILS.

&&

.PREV DISCUSSION...AS OF 3:00 AM PDT MONDAY...AS EXPECTED CLOUDS
RETURNED TO THE COAST YESTERDAY EVENING AND BASED OFF OF THE
SATELLITE FOG PRODUCT, THEY HAVE CONTINUED FOR THE OVERNIGHT HOURS
AND HAVE ALSO SPREAD INTO SOME ADJACENT VALLEY SPOTS. AFTER A WARM
WARM DAY YESTERDAY, SUBSTANTIAL COOLING CAN BE EXPECTED TODAY AS
MORE OF AN ONSHORE FLOW WILL BRING AIR OFF THE WATER AND ACROSS
OUR REGION. FOR SOME COASTAL SPOTS HIGHS TODAY WILL BE 10 OR MORE
DEGREES UNDER THE VALUES FROM SUNDAY. FARTHER INLAND, THE DROP IN
TEMPS WILL BE LESS ALTHOUGH MOST LOCATIONS WILL SEE AT LEAST A 3
TO 6 DEGREE DECREASE. TONIGHT SHOULD BE A REPEAT OF TODAY WITH
CLOUDS RETURNING TO THE COAST PLUS ADJACENT VALLEY LOCATIONS.

AFTER A QUIET DAY ON TUESDAY UNSETTLED WEATHER RETURNS STARTING
ON WEDNESDAY AS A LONGWAVE TROF NEARS THE COAST WHILE AN UPPER
LEVEL CUT-OFF LOW FORMS AT THE BASE OF THE TROF NEAR OUR CWA.
BEYOND THAT POINT, MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THE
LOW WILL VERY SLOWLY PROGRESS TO THE SOUTHEAST FOR THE REMAINDER
OF THE WEEK. WHERE THERE IS MORE DISAGREEMENT IS THE LOCATION OF
THE LOW PLUS THE MOST FAVORABLE LOCATIONS FOR ASSOCIATED MOISTURE
(ESPECIALLY WRAP-AROUND MOISTURE). THEREFORE, DECIDED TO KEEP
MOST SPOTS IN THE 20-30% CHANCE OF PRECIP FOR THE PERIOD. IN
ADDITION, BASED ON THE TRACK OF THE LOW PLUS GUIDANCE OUT TO 84
HOURS OFF THE NAM, KEPT A MENTION OF A SLIGHT CHANCE FOR T-STORMS
AND POSSIBLE SMALL HAIL. RAINFALL AMOUNTS WILL LIKELY BE MINOR
THROUGH THE PERIOD. COOLER TEMPS CAN ALSO BE EXPECTED -- MOSTLY
UPPER 50S TO UPPER 60S.

A RIDGE WILL BUILD IN BEHIND THE DEPARTING LOW FOR NEXT WEEK. THIS
WILL LEAD TO WARMER CONDITIONS ALONG WITH LITTLE TO NO RAIN.
&&

.AVIATION...AS OF 4:46 AM PDT MONDAY...TRICKY FORECAST THIS
MORNING AS SOUTHERLY SURGE IS STILL IN EFFECT OVER THE REGION. THE
TYPICAL SPOTS WITH SOUTHERLY SURGES HAVE CIGS...MRY/SNS/STS.
HOWEVER...CLOUDS INSIDE SF BAY ARE SPOTTY. BASED ON LATEST
GUIDANCE AND TRENDS WILL KEEP CIGS IN SF BAY MORE LIMITED. KSJC IS
ALSO TRICKY AS CLOUDS ARE SLOWLY APPROACHING FROM THE SOUTH. VFR
THIS AFTERNOON FOR ALL AIRPORTS...BUT CIGS RETURN TONIGHT.

VICINITY OF KSFO...WILL HAVE TO KEEP A CLOSE EYE ON SFO...BUT CONF
FOR CIGS DEVELOPMENT IS LOW. FOR NOW...WILL KEEP VFR CONDITIONS AT
KSFO AND KOAK. MVFR CIGS DEVELOP TONIGHT.

SFO BRIDGE APPROACH...A SLIGHTLY HIGHER CHANCE FOR CIG
DEVELOPMENT...ESPECIALLY SOUTH OF THE APPROACH.

MONTEREY BAY TERMINALS...MVFR/IFR CIGS THROUGH 17Z. VFR THIS
AFTERNOON. MVFR/IFR CIGS RETURN TONIGHT.

&&

.MARINE...AS OF 09:00 AM PDT MONDAY...LIGHT SOUTHERLY WINDS THIS
MORNING WILL GRADUALLY TURN WEST BY THIS EVENING AND NW INTO
TUESDAY. LIGHT TO MODERATE NW WIND AND SEAS WILL CONTINUE LATER
TUESDAY INTO WEDNESDAY AS A LATE SEASON UPPER LOW APPROACHES THE
REGION PRODUCING SCATTERED SHOWERS THROUGH THE END OF THE WEEK.
LIGHT SEAS MOST OF THE WEEK WILL BUILD BY FRIDAY AS THE LOW
DEPARTS AND STRONGER NW WINDS ARRIVE.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY

&&

$$

PUBLIC FORECAST: RGASS
AVIATION: MM
MARINE: R_WALBRUN


VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO

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WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA




000
FXUS66 KEKA 021623 CCA
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
920 AM PDT MON MAY 2 2016

.SYNOPSIS...DRY AND WARM CONDITIONS WILL CONTINUE ACROSS THE AREA
TODAY AS A HIGH PRESSURE RIDGE PERSISTS ACROSS THE REGION. A TROUGH
OF LOW PRESSURE AND ASSOCIATED COLD FRONT WILL APPROACH THE AREA
TONIGHT AND MOVE THROUGH THE REGION TUESDAY. THIS SYSTEM WILL BE
ACCOMPANIED BY A THREAT OF LIGHT SHOWERS THROUGH THE REMAINDER OF
THE WEEK. &&

.DISCUSSION...A HIGH PRESSURE RIDGE EXTENDING ACROSS THE REGION
WILL MAINTAIN CLEAR TO PARTLY CLOUDY SKIES ACROSS THE AREA TODAY.
A WEAK COLD FRONT WILL APPROACH THE REGION TODAY AND MOVE ACROSS
THE AREA ON TUESDAY. THE APPROACHING FRONT WILL INCREASE
CLOUDINESS ACROSS THE REGION TONIGHT AND INCREASE CHANCES FOR
SHOWERS MOVING ACROSS PORTIONS OF THE AREA TUESDAY. PATCHY FOG MAY
DEVELOP ACROSS SOME COASTAL AREAS AND INTERIOR VALLEYS OVERNIGHT
TONIGHT AND EARLY TUESDAY MORNING. THE WINDS WILL REMAIN LIGHT THE
NEXT FEW DAYS. THERE IS A CHANCE FOR SHOWERS AND A SLIGHT CHANCE
FOR A FEW ISOLATED THUNDERSTORMS DEVELOPING ACROSS EXTREME
NORTHEAST DEL NORTE COUNTY AND THE INTERIOR MOUNTAINS EAST OF
WEAVERVILLE DURING THE AFTERNOONS AND EARLY EVENINGS TUESDAY
THROUGH THIS WEEKEND. SEASONAL TEMPERATURES AND WILL CONTINUE
ACROSS THE REGION THIS WEEK.

&&

.AVIATION...LOW CLOUD DECK ASSOCIATED WITH S SURGE OF WIND OVER THE
COASTAL WATERS HAS MADE IT TO JUST S OF CAPE MENDOCINO. THE NAM AND
RAP SEEM TO HAVE A FAIR HANDLE ON THIS CLOUDINESS. AS A RESULT...MAY
NEED TO SHIFT THE START TIME OF CEILINGS TO EARLIER IN THE FORECAST
CYCLE FOR KACV AND KCEC. VISIBILITY RESTRICTIONS IN FOG ARE ALSO
POSSIBLE LATE TODAY OR THIS EVENING AT THESE SITES. AT THIS
TIME...LOW CLOUDS AND FOG ARE NOT EXPECTED AT KUKI...BUT INLAND
PENETRATION OF LOW CLOUDS WILL NEED TO BE WATCHED S OF THE AREA
ALONG WITH BOUNDARY LAYER WIND DIRECTION TONIGHT. WINDS WILL BE
GENERALLY LIGHT ACROSS THE AREA. /SEC

&&

.MARINE...WINDS AND SEAS HAVE CONTINUED TO SUBSIDE. A FLOW REVERSAL
IS IN PROGRESS WITH LIGHT WINDS BECOME SOUTHERLY. SEA FOG IS
EXPECTED TO CONTINUE SPREADING N OVER THE COASTAL WATERS AND AROUND
CAPE MENDOCINO TODAY. WINDS IN THE SURGE MAY APPROACH 15 KTS
SUSTAINED. HIGH PRESSURE WILL RE-BUILD OFFSHORE BY THE MIDDLE OF THE
WEEK WITH A RETURN TO INCREASED NORTHERLY WINDS AND SHORT PERIOD
SEAS ON WEDNESDAY. THIS WILL LIKELY CONTINUE THRU THE END OF THE
FORECAST PERIOD...WITH GALE FORCE GUSTS LIKELY OFFSHORE AND THE
POTENTIAL FOR SUSTAINED GALES ON FRIDAY. NW SWELL OF BETWEEN 10 AND
15 SECONDS WILL CONTINUE EARLY IN THE WEEK...AND A SOUTHERLY
BACKGROUND SWELL OF AROUND 2 FT WILL CONTINUE THRU THE PERIOD.
/SEC

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&

$$

VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA

FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/NWSEUREKA
HTTP://WWW.TWITTER.COM/NWSEUREKA

FOR FORECAST ZONE INFORMATION
SEE FORECAST ZONE MAP ONLINE:
HTTP://WWW.WEATHER.GOV/EUREKA/ZONEMAP.PNG




000
FXUS66 KLOX 021156
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
456 AM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning low clouds and fog today and
Wednesday with slightly above normal temperatures in the morning. A
slow moving low pressure system will bring a chance of showers
and thunderstorms along with cooler conditions to the area
Thursday through the weekend.

&&

.SHORT TERM...(TDY-WED)

Low clouds are a little better organized this morning. The
gradients are about 3 MB onshore push both to the north and the
east and the marine layer inversion has strengthened both of which
are helping the marine layer stratus along. By dawn most of the
coasts and the vly will be covered with stratus. There will be
good clearing by the afternoon as there is no eddy and the onshore
push is not that strong. The barest of ridges pops up today and
this will allow for a little warming esp across the interior.
There is just enough residual moisture over the mtns to allow for
some afternoon cu but not enough lift or instability to form
showers.

Since the marine layer is already fairly well established the
stratus deck will reform a little quicker overnight. It will still
burn off pretty quickly. Skies will turn partly cloudy in the
afternoon as mid and esp high level clouds stream in the sw flow
ahead of an approaching trof. MDLs indicating quite a bit of
warming but with the ridge moving off and the increase of clouds
there will be...at best...only a degree or two of warming.

The trof will be right along the West Coast on Wednesday morning
and the lift associated with it will drive marine layer stratus
over the csts and vlys and onto the coastal slopes. Mid and high
level clouds will increase through the day. Onshore flow will
increase through the day as well. All of these trend will conspire
to cause a sharp drop in temperatures. Max temps will drop 5 to 10
degrees and will be 3 to 6 degrees below normal.

.LONG TERM...(THU-SUN)


GFS/EC agree that a cutoff low pressure system will slowly drift over
the forecast area Thursday and Friday, then slowly move east over
the weekend. There will be a chance for hit and miss showers in
most places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). The cold core
upper low (with 500 mb temperatures of -24 degrees Celsius) will
move across Southwest California sometime between Thursday
afternoon through Friday. The cold air aloft combined with early
May sunshine will be create enough instability to warrant a
slight chance of thunderstorms(especially over interior sections).
Right now it does not look like this system will have that much
moisture to work with and do not expect large rainfall amounts
with it. This system is cold enough that snow levels will likely
dip to between 5000 and 6000 feet.

&&

.AVIATION...02/1145Z.

AT 11Z, the marine layer depth at KLAX was around 1800 feet.
The top of the inversion was around 3000 feet with a temperature
of 15 degrees Celsius.

Widespread stratus on the Central Coast and in the Santa Ynez
Valley early this morning, with IFR to LIFR conds. Expect IFR to
LIFR conds to push into the Salinas Valley. South of Pt
Conception, stratus with IFR conds was affecting the south
coast of Sba County and the Vtu County coast, with IFR to LIFR
conds beginning to spread into the Vtu County valleys. Stratus
across Los Angeles county has been confined to southern sections,
but was beginning to spread northward, and will likely affect all
coastal sections of L.A. county by daybreak. Cigs were higher
here, with mostly MVFR conditions. Expect rather slow clearing,
especially in coastal sections of Vtu and southern Sba Counties,
where clearing may not take place until early afternoon.
Widespread stratus is expected in all coastal and valley areas
tonight, with IFR conds north of Pt Conception and MVFR conds
south.

KLAX...Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance that cigs will not scatter out until at 21Z. There
is a 30 percent chance that cigs will not arrive tonight until
after 09Z.

KBUR..Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance of low MVFR or high IFR cigs between 13Z and 17Z
this morning. There is a 20 percent chance that cigs will not
arrive tonight until after 12Z.

&&

.MARINE...02/330 AM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. There is a chance that a
Small Craft Advisory may be needed across the outer waters
Tuesday night, with a better chance of SCA conds Wednesday.
Advisory level winds are likely across the outer waters by
Wednesday night.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 10 AM PDT this
      morning For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...DB
MARINE...DB
SYNOPSIS...Smith

weather.gov/losangeles




000
FXUS66 KMTR 021153
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
453 AM PDT MON MAY 2 2016

.SYNOPSIS....DRY AND SEASONABLE WEATHER IS FORECAST THROUGH
TOMORROW ALONG WITH COASTAL CLOUDS. A WEATHER SYSTEM WILL
APPROACH CALIFORNIA BY THE MIDDLE OF THE WEEK...BRINGING A CHANCE
OF SHOWERS AND A FEW THUNDERSTORMS BEGINNING WEDNESDAY LASTING
INTO THE WEEKEND...ALONG WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 3:00 AM PDT MONDAY...AS EXPECTED CLOUDS
RETURNED TO THE COAST YESTERDAY EVENING AND BASED OFF OF THE
SATELLITE FOG PRODUCT, THEY HAVE CONTINUED FOR THE OVERNIGHT HOURS
AND HAVE ALSO SPREAD INTO SOME ADJACENT VALLEY SPOTS. AFTER A WARM
WARM DAY YESTERDAY, SUBSTANTIAL COOLING CAN BE EXPECTED TODAY AS
MORE OF AN ONSHORE FLOW WILL BRING AIR OFF THE WATER AND ACROSS
OUR REGION. FOR SOME COASTAL SPOTS HIGHS TODAY WILL BE 10 OR MORE
DEGREES UNDER THE VALUES FROM SUNDAY. FARTHER INLAND, THE DROP IN
TEMPS WILL BE LESS ALTHOUGH MOST LOCATIONS WILL SEE AT LEAST A 3
TO 6 DEGREE DECREASE. TONIGHT SHOULD BE A REPEAT OF TODAY WITH
CLOUDS RETURNING TO THE COAST PLUS ADJACENT VALLEY LOCATIONS.

AFTER A QUIET DAY ON TUESDAY UNSETTLED WEATHER RETURNS STARTING
ON WEDNESDAY AS A LONGWAVE TROF NEARS THE COAST WHILE AN UPPER
LEVEL CUT-OFF LOW FORMS AT THE BASE OF THE TROF NEAR OUR CWA.
BEYOND THAT POINT, MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THE
LOW WILL VERY SLOWLY PROGRESS TO THE SOUTHEAST FOR THE REMAINDER
OF THE WEEK. WHERE THERE IS MORE DISAGREEMENT IS THE LOCATION OF
THE LOW PLUS THE MOST FAVORABLE LOCATIONS FOR ASSOCIATED MOISTURE
(ESPECIALLY WRAP-AROUND MOISTURE). THEREFORE, DECIDED TO KEEP
MOST SPOTS IN THE 20-30% CHANCE OF PRECIP FOR THE PERIOD. IN
ADDITION, BASED ON THE TRACK OF THE LOW PLUS GUIDANCE OUT TO 84
HOURS OFF THE NAM, KEPT A MENTION OF A SLIGHT CHANCE FOR T-STORMS
AND POSSIBLE SMALL HAIL. RAINFALL AMOUNTS WILL LIKELY BE MINOR
THROUGH THE PERIOD. COOLER TEMPS CAN ALSO BE EXPECTED -- MOSTLY
UPPER 50S TO UPPER 60S.

A RIDGE WILL BUILD IN BEHIND THE DEPARTING LOW FOR NEXT WEEK. THIS
WILL LEAD TO WARMER CONDITIONS ALONG WITH LITTLE TO NO RAIN.
&&

.AVIATION...AS OF 4:46 AM PDT MONDAY...TRICKY FORECAST THIS
MORNING AS SOUTHERLY SURGE IS STILL IN EFFECT OVER THE REGION. THE
TYPICAL SPOTS WITH SOUTHERLY SURGES HAVE CIGS...MRY/SNS/STS.
HOWEVER...CLOUDS INSIDE SF BAY ARE SPOTTY. BASED ON LATEST
GUIDANCE AND TRENDS WILL KEEP CIGS IN SF BAY MORE LIMITED. KSJC IS
ALSO TRICKY AS CLOUDS ARE SLOWLY APPROACHING FROM THE SOUTH. VFR
THIS AFTERNOON FOR ALL AIRPORTS...BUT CIGS RETURN TONIGHT.

VICINITY OF KSFO...WILL HAVE TO KEEP A CLOSE EYE ON SFO...BUT CONF
FOR CIGS DEVELOPMENT IS LOW. FOR NOW...WILL KEEP VFR CONDITIONS AT
KSFO AND KOAK. MVFR CIGS DEVELOP TONIGHT.

SFO BRIDGE APPROACH...A SLIGHTLY HIGHER CHANCE FOR CIG
DEVELOPMENT...ESPECIALLY SOUTH OF THE APPROACH.

MONTEREY BAY TERMINALS...MVFR/IFR CIGS THROUGH 17Z. VFR THIS
AFTERNOON. MVFR/IFR CIGS RETURN TONIGHT.

&&

.MARINE...AS OF 04:45 AM PDT MONDAY...A SOUTHERLY SURGE WILL
CONTINUE TO MOVE UP THE NORTHERN CALIFORNIA COAST KEEPING
SOUTHERLY WINDS IN PLACE TODAY. WINDS WILL GRADUALLY BECOME
NORTHERLY TONIGHT AND TUESDAY. A MODERATE SWELL WILL MIX WITH A
SMALLER LONG PERIOD SOUTHERLY SWELL THIS WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY

&&

$$

PUBLIC FORECAST: BELL
AVIATION: MM
MARINE: MM


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000
FXUS66 KEKA 021108
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
408 AM PDT MON MAY 2 2016

.SYNOPSIS...DRY AND WARM CONDITIONS WILL CONTINUE ACROSS THE AREA
TODAY AS A HIGH PRESSURE RIDGE PERSIST ACROSS THE REGION. A COLD
FRONT WILL APPROACH THE AREA TODAY AND MOVE THROUGH THE REGION
TUESDAY. CLOUDINESS WILL BEGIN TO INCREASE TONIGHT AND THERE IS A
SLIGHT CHANCE TO CHANCE OF A FEW SHOWERS MOVING ACROSS PORTIONS OF
THE REGION TUESDAY ASSOCIATED WITH THE FRONT. TEMPERATURES WILL
DECREASE SLIGHTLY TUESDAY.

&&

.DISCUSSION...A HIGH PRESSURE RIDGE EXTENDING ACROSS THE REGION
WILL MAINTAIN CLEAR TO PARTLY CLOUDY SKIES ACROSS THE AREA TODAY.
A WEAK COLD FRONT WILL APPROACH THE REGION TODAY AND MOVE ACROSS
THE AREA ON TUESDAY. THE APPROACHING FRONT WILL INCREASE
CLOUDINESS ACROSS THE REGION TONIGHT AND INCREASE CHANCES FOR
SHOWERS MOVING ACROSS PORTIONS OF THE AREA TUESDAY. PATCHY FOG MAY
DEVELOP ACROSS SOME COASTAL AREAS AND INTERIOR VALLEYS OVERNIGHT
TONIGHT AND EARLY TUESDAY MORNING. THE WINDS WILL REMAIN LIGHT THE
NEXT FEW DAYS. THERE IS A CHANCE FOR SHOWERS AND A SLIGHT CHANCE
FOR A FEW ISOLATED THUNDERSTORMS DEVELOPING ACROSS EXTREME
NORTHEAST DEL NORTE COUNTY AND THE INTERIOR MOUNTAINS EAST OF
WEAVERVILLE DURING THE AFTERNOONS AND EARLY EVENINGS TUESDAY
THROUGH THIS WEEKEND. SEASONAL TEMPERATURES AND WILL CONTINUE
ACROSS THE REGION THIS WEEK.

&&

.AVIATION...LOW CLOUD DECK ASSOCIATED WITH S SURGE OF WIND OVER THE
COASTAL WATERS HAS MADE IT TO JUST S OF CAPE MENDOCINO. THE NAM AND
RAP SEEM TO HAVE A FAIR HANDLE ON THIS CLOUDINESS. AS A RESULT...MAY
NEED TO SHIFT THE START TIME OF CEILINGS TO EARLIER IN THE FORECAST
CYCLE FOR KACV AND KCEC. VISIBILITY RESTRICTIONS IN FOG ARE ALSO
POSSIBLE LATE TODAY OR THIS EVENING AT THESE SITES. AT THIS
TIME...LOW CLOUDS AND FOG ARE NOT EXPECTED AT KUKI...BUT INLAND
PENETRATION OF LOW CLOUDS WILL NEED TO BE WATCHED S OF THE AREA
ALONG WITH BOUNDARY LAYER WIND DIRECTION TONIGHT. WINDS WILL BE
GENERALLY LIGHT ACROSS THE AREA. /SEC

&&

.MARINE...WINDS AND SEAS HAVE CONTINUED TO SUBSIDE. A FLOW REVERSAL
IS IN PROGRESS WITH LIGHT WINDS BECOME SOUTHERLY. SEA FOG IS
EXPECTED TO CONTINUE SPREADING N OVER THE COASTAL WATERS AND AROUND
CAPE MENDOCINO TODAY. WINDS IN THE SURGE MAY APPROACH 15 KTS
SUSTAINED. HIGH PRESSURE WILL RE-BUILD OFFSHORE BY THE MIDDLE OF THE
WEEK WITH A RETURN TO INCREASED NORTHERLY WINDS AND SHORT PERIOD
SEAS ON WEDNESDAY. THIS WILL LIKELY CONTINUE THRU THE END OF THE
FORECAST PERIOD...WITH GALE FORCE GUSTS LIKELY OFFSHORE AND THE
POTENTIAL FOR SUSTAINED GALES ON FRIDAY. NW SWELL OF BETWEEN 10 AND
15 SECONDS WILL CONTINUE EARLY IN THE WEEK...AND A SOUTHERLY
BACKGROUND SWELL OF AROUND 2 FT WILL CONTINUE THRU THE PERIOD.
/SEC

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&

$$

VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA

FOLLOW US ON FACEBOOK AND TWITTER AT:
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HTTP://WWW.TWITTER.COM/NWSEUREKA

FOR FORECAST ZONE INFORMATION
SEE FORECAST ZONE MAP ONLINE:
HTTP://WWW.WEATHER.GOV/EUREKA/ZONEMAP.PNG




000
FXUS66 KHNX 021056
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
356 AM PDT MON MAY 2 2016

.SYNOPSIS...
A FEW LINGERING SHOWERS AND THUNDERSTORMS OVER THE SIERRA NEVADA
TODAY...OTHERWISE WEAK HIGH PRESSURE WILL BRING DRIER WEATHER AND
WARMER TEMPERATURES THROUGH TUESDAY. ANOTHER WEATHER SYSTEM WILL
MOVE INTO THE REGION WEDNESDAY INCREASING PRECIPITATION CHANCES
FOR THE SECOND PART OF THE WEEK.

&&

.DISCUSSION...
A WEAK SHORTWAVE DISTURBANCE MOVED THROUGH CENTRAL CALIFORNIA
SUNDAY TRIGGERING SHOWERS AND THUNDERSTORMS ACROSS THE MOUNTAINS
AND ALSO IN THE SAN JOAQUIN VALLEY. THIS DISTURBANCE WILL MOVE EAST
TODAY AS A RIDGE OF HIGH PRESSURE MOVES OVER THE REGION. ENOUGH
MOISTURE AND INSTABILITY REMAINS OVER THE SIERRA NEVADA TO
MAINTAIN A SLIGHT CHANCE OF SHOWERS OR THUNDERSTORMS TODAY.
OTHERWISE DRY WEATHER IS EXPECTED TODAY AND TUESDAY WITH ABOVE
NORMAL TEMPERATURES.

THE RIDGE AXIS SHIFTS EAST TOWARD THE ROCKIES ON TUESDAY...SETTING
UP AN OMEGA BLOCKING PATTERN ACROSS THE U.S. WITH A TROUGH OVER
THE EASTERN STATES AND A TROUGH OF LOW PRESSURE OFF THE WEST
COAST. THE GFS AND ECMWF ARE IN GOOD AGREEMENT WITH THIS TROUGH
DEVELOPING INTO A CLOSED LOW OFF THE CALIFORNIA COAST WEDNESDAY
THEN MOVING SLOWLY SOUTH WITH THE LOW CENTER HUGGING THE COAST
THURSDAY BEFORE BEGINNING TO MOVE INLAND ACROSS SOUTHERN
CALIFORNIA ON FRIDAY.

THIS SYSTEM MAY TRIGGER A FEW SHOWERS AND THUNDERSTORMS MAINLY IN
THE SIERRA ON WEDNESDAY AFTERNOON. BY THURSDAY THE LOW WILL
PROVIDE PLENTY OF INSTABILITY AND LIFT FOR A CHANCE OF SHOWERS AND
THUNDERSTORMS ACROSS THE ENTIRE REGION. AS THE LOW MOVES INLAND
FRIDAY...MOISTURE WRAPPING AROUND THE LOW WILL CONTINUE TO BRING
SHOWERS AND THUNDERSTORMS ACROSS THE AREA. THIS SYSTEM WILL ALSO
BRING COOLER TEMPERATURES...WITH AFTERNOON HIGH TEMPERATURES GOING
FROM 5-10 DEGREES ABOVE NORMAL TUESDAY TO ABOUT 10 DEGREES BELOW
NORMAL THURSDAY AND FRIDAY.

THE OMEGA BLOCKING PATTERN WILL BEGIN TO SHIFT EASTWARD
SATURDAY...ALLOWING THE CLOSED LOW TO BEGIN A SLOW SHIFT
EASTWARD. EXPECT ENERGY AND MOISTURE TO CONTINUE TO WRAP AROUND
THE LOW FOR AFTERNOON AND EVENING CONVECTION TO CONTINUE OVER THE
SIERRA SATURDAY AND SUNDAY. A CHANCE OF SHOWERS WILL CONTINUE IN
THE SAN JOAQUIN VALLEY SATURDAY...THEN JUST A SLIGHT CHANCE SUNDAY
AS THE LOW CONTINUES TO SHIFT EAST.

&&

.AVIATION...
AREAS OF MVFR WITH LOCAL IFR POSSIBLE 18Z MONDAY THROUGH 06Z
TUESDAY DUE TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THE
SIERRA NEVADA. OTHERWISE VFR CONDITIONS WILL PREVAIL OVER THE
CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS.

&&

.AIR QUALITY ISSUES...
NONE.

&&

.CERTAINTY...

THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.

CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AN/OR TO PROVIDE FEEDBACK.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

PUBLIC...BEAN
AVN/FW...JEB
SYNOPSIS...BEAN

WEATHER.GOV/HANFORD




000
FXUS66 KSTO 021052
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
352 AM PDT MON MAY 2 2016

.Synopsis...
Threat of afternoon showers and thunderstorms continues over the
mountains into Tuesday, then a more widespread chance Wednesday
into Friday. Cooling to near average by mid-week.

&&

.Discussion...
Mostly clear skies across interior NorCal early this morning as
most of the cloudiness associated with last evening`s showers and
thunderstorms has diminished. Temperatures are running a little
cooler across most of the region compared to 24 hours ago and
generally ranges from the 30s and 40s in the mountains to the 50s
and lower 60s elsewhere.

Large-scale pattern forecast to remain relatively unchanged today
and Tuesday, though large blocking ridge centered over the
northern Rockies is expected to slowly shift east with time. Weak
low beneath the ridge over central California will once again help
to pop some late day showers and thunderstorms, mainly over the
mountains, both today and Tuesday. Temperatures will remain above
average.

More widespread shower and thunderstorm activity, along with
cooler temperatures, is expected Wednesday and Thursday as
upstream trough forms a closed low near the Bay Area which then
drifts slowly toward SoCal.

&&

.Extended Discussion (Friday thru Monday)...
Upper low progged over SoCal Friday. Cyclonic flow and wrap around
moisture will keep a threat of showers and thunderstorms...mainly
over the mountains. Low tracks into Arizona Saturday, and main
threat for deep moist convection looks to be over the Sierra
Nevada and Western Plumas mountains. Oper GFS/GEM show another
wave dropping in from the NW Sunday to keep a threat of showers
over the mountains and possibly Northern Sacramento valley and
surrounding foothills. EC is drier with upper ridging building
inland. Models point to dry Monday as heights increase over
Interior NorCal. Warming trend expected through the extended
forecast period with highs in the Central Valley climbing from the
lower to mid 70s Friday into the upper 70s to lower 80s Monday.

&&

.Aviation...
Vrbl wnds alf tda bcmg incrsg Sly tngt into Tue as deep upr trof
in EPAC apchs. VFR conds ovr Intr NorCal thru 00z Wed exc isold
MVFR/IFR conds poss ovr mtns/fthls in shwrs or tstms btwn 20z-04z.
Sfc wnds genly blo 15 kts nxt 24 hrs exc gsty nr tstms.

&&

.STO Watches/Warnings/Advisories...None.

&&

$$




000
FXUS66 KSGX 021052
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
352 AM PDT MON MAY 2 2016

.SYNOPSIS...
LOW PRESSURE OVER THE SOUTHWESTERN STATES WILL WEAKEN WITH A
WARMING TREND THROUGH TUESDAY. RESIDUAL MOISTURE AND WEAK
INSTABILITY WILL BRING A SLIGHT CHANCE OF SHOWERS THIS AFTERNOON...
MAINLY NEAR THE SAN BERNARDINO MOUNTAINS. COOLING AND INCREASING
CLOUDS FOR WEDNESDAY AS A LOW PRESSURE SYSTEM MOVES SLOWLY ACROSS
THE EASTERN PACIFIC. FOR THURSDAY NIGHT INTO NEXT WEEKEND...A SLOW
MOVING LOW PRESSURE SYSTEM MOVING INTO THE SOUTHWESTERN STATES
WILL BRING MORE CLOUDS...A CHANCE OF SHOWERS...AND A SLIGHT
CHANCE OF THUNDERSTORMS.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

.SHORT TERM (TODAY THROUGH WEDNESDAY)...
WEAKENING LOW PRESSURE OVER THE SOUTHWEST STATES AND WEAK HIGH
PRESSURE NEAR THE CALIFORNIA COAST WILL CONTINUE AN INLAND
WARMING TREND INTO TUESDAY. A CONSENSUS OF THE HIGHER RESOLUTION
MODELS PERFORMED WELL ON SUNDAY IN THE SHOWING THE AFTERNOON AND
EARLY EVENING CONVECTION (SCATTERED SHOWERS AND ISOLATED
THUNDERSOTRMS)...WITH GREATEST COVERAGE OVER THE MOUNTAINS OF SAN
BERNARDINO AND RIVERSIDE COUNTIES. THOSE MODELS CONTINUE TO SHOW
THE POTENTIAL FOR SHOWERS THIS AFTERNOON...WITH A LITTLE LESS
COVERAGE THAN FOR SUNDAY AND FOCUSED MAINLY OVER THE SAN
BERNARDINO MOUNTAINS.

FOR WEDNESDAY...A SLOW MOVING LOW PRESSURE SYSTEM OVER THE EASTERN
PACIFIC WILL BRING INCREASING HIGH CLOUDS WITH THE BEGINNING OF A
COOLING TREND. INCREASING ONSHORE FLOW WILL BRING GUSTY WEST WINDS
TO THE MOUNTAINS AND DESERTS. OTHERWISE...THERE WILL AREAS OF
NIGHT AND MORNING COASTAL LOW CLOUDS AND FOG EXTENDING INTO
PORTIONS OF THE VALLEYS.

&&

.LONG TERM (THURSDAY THROUGH SUNDAY)...
A SLOW MOVING LOW PRESSURE SYSTEM OVER THE EASTERN PACIFIC WILL
MOVE SLOWLY INLAND THROUGH THE SOUTHWEST STATES. THIS WILL BRING
MORE CLOUDS...COOLING THROUGH FRIDAY FOLLOWED BY SLOW WARMING...AND
A CHANCE OF SHOWERS AND SLIGHT CHANCE OF THUNDERSTORMS. THERE
CONTINUE TO BE SOME RUN TO RUN AND MODEL TO MODEL DIFFERENCES WITH
THE DETAILS. SOME LIGHT MARINE LAYER PRECIPITATION IS POSSIBLE AS
EARLY AS LATE WEDNESDAY NIGHT AND EARLY THURSDAY. GREATER SHOWER
COVERAGE IS POSSIBLE FOR LATE THURSDAY INTO FRIDAY WITH SHOWERS
MORE DIURNALLY DRIVEN AND TERRAIN FOCUSED ON SATURDAY AND SUNDAY.
THE GFS MOVES THE COLDEST 500 MB TEMPERATURES ACROSS SOUTHERN
CALIFORNIA THURSDAY NIGHT AND FRIDAY WHICH WOULD BE THE MOST
FAVORABLE PERIOD FOR THUNDERSTORM DEVELOPMENT IN ADDITION TO THE
SHOWERS.

&&

.AVIATION...
020900Z...AREAS OF LOW CLOUDS WILL DEVELOP RANDOMLY IN ANY PART OF
THE COASTAL BASIN THIS MORNING. CIGS WILL BE AROUND 2000 FEET MSL
WITH TOPS TO 3000 FEET. SCATTER OUT WILL PREVAIL BY 16-17Z. LOW
CLOUDS TO DEVELOP AND MOVE ASHORE ANY TIME AFTER 02Z WITH SLIGHTLY
LOWER CIGS AT 1500 FEET MSL. IN MOUNTAINS/DESERTS...MOSTLY CLEAR
EXCEPT FOR CLOUDS BASED AT 8000 FEET MSL AND ISOLD SHRA/TSRA FROM 20-
01Z THIS AFTERNOON.

&&

.MARINE...

200 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH WEDNESDAY.
A STORM SYSTEM WILL BRING STRONGER WINDS AND CHOPPY SEAS THURSDAY
AND FRIDAY ALONG WITH SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&

$$

PUBLIC...17
AVIATION/MARINE/BEACHES...MM




000
FXUS66 KSTO 021052
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
352 AM PDT MON MAY 2 2016

.Synopsis...
Threat of afternoon showers and thunderstorms continues over the
mountains into Tuesday, then a more widespread chance Wednesday
into Friday. Cooling to near average by mid-week.

&&

.Discussion...
Mostly clear skies across interior NorCal early this morning as
most of the cloudiness associated with last evening`s showers and
thunderstorms has diminished. Temperatures are running a little
cooler across most of the region compared to 24 hours ago and
generally ranges from the 30s and 40s in the mountains to the 50s
and lower 60s elsewhere.

Large-scale pattern forecast to remain relatively unchanged today
and Tuesday, though large blocking ridge centered over the
northern Rockies is expected to slowly shift east with time. Weak
low beneath the ridge over central California will once again help
to pop some late day showers and thunderstorms, mainly over the
mountains, both today and Tuesday. Temperatures will remain above
average.

More widespread shower and thunderstorm activity, along with
cooler temperatures, is expected Wednesday and Thursday as
upstream trough forms a closed low near the Bay Area which then
drifts slowly toward SoCal.

&&

.Extended Discussion (Friday thru Monday)...
Upper low progged over SoCal Friday. Cyclonic flow and wrap around
moisture will keep a threat of showers and thunderstorms...mainly
over the mountains. Low tracks into Arizona Saturday, and main
threat for deep moist convection looks to be over the Sierra
Nevada and Western Plumas mountains. Oper GFS/GEM show another
wave dropping in from the NW Sunday to keep a threat of showers
over the mountains and possibly Northern Sacramento valley and
surrounding foothills. EC is drier with upper ridging building
inland. Models point to dry Monday as heights increase over
Interior NorCal. Warming trend expected through the extended
forecast period with highs in the Central Valley climbing from the
lower to mid 70s Friday into the upper 70s to lower 80s Monday.

&&

.Aviation...
Vrbl wnds alf tda bcmg incrsg Sly tngt into Tue as deep upr trof
in EPAC apchs. VFR conds ovr Intr NorCal thru 00z Wed exc isold
MVFR/IFR conds poss ovr mtns/fthls in shwrs or tstms btwn 20z-04z.
Sfc wnds genly blo 15 kts nxt 24 hrs exc gsty nr tstms.

&&

.STO Watches/Warnings/Advisories...None.

&&

$$




000
FXUS66 KSGX 021052
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
352 AM PDT MON MAY 2 2016

.SYNOPSIS...
LOW PRESSURE OVER THE SOUTHWESTERN STATES WILL WEAKEN WITH A
WARMING TREND THROUGH TUESDAY. RESIDUAL MOISTURE AND WEAK
INSTABILITY WILL BRING A SLIGHT CHANCE OF SHOWERS THIS AFTERNOON...
MAINLY NEAR THE SAN BERNARDINO MOUNTAINS. COOLING AND INCREASING
CLOUDS FOR WEDNESDAY AS A LOW PRESSURE SYSTEM MOVES SLOWLY ACROSS
THE EASTERN PACIFIC. FOR THURSDAY NIGHT INTO NEXT WEEKEND...A SLOW
MOVING LOW PRESSURE SYSTEM MOVING INTO THE SOUTHWESTERN STATES
WILL BRING MORE CLOUDS...A CHANCE OF SHOWERS...AND A SLIGHT
CHANCE OF THUNDERSTORMS.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

.SHORT TERM (TODAY THROUGH WEDNESDAY)...
WEAKENING LOW PRESSURE OVER THE SOUTHWEST STATES AND WEAK HIGH
PRESSURE NEAR THE CALIFORNIA COAST WILL CONTINUE AN INLAND
WARMING TREND INTO TUESDAY. A CONSENSUS OF THE HIGHER RESOLUTION
MODELS PERFORMED WELL ON SUNDAY IN THE SHOWING THE AFTERNOON AND
EARLY EVENING CONVECTION (SCATTERED SHOWERS AND ISOLATED
THUNDERSOTRMS)...WITH GREATEST COVERAGE OVER THE MOUNTAINS OF SAN
BERNARDINO AND RIVERSIDE COUNTIES. THOSE MODELS CONTINUE TO SHOW
THE POTENTIAL FOR SHOWERS THIS AFTERNOON...WITH A LITTLE LESS
COVERAGE THAN FOR SUNDAY AND FOCUSED MAINLY OVER THE SAN
BERNARDINO MOUNTAINS.

FOR WEDNESDAY...A SLOW MOVING LOW PRESSURE SYSTEM OVER THE EASTERN
PACIFIC WILL BRING INCREASING HIGH CLOUDS WITH THE BEGINNING OF A
COOLING TREND. INCREASING ONSHORE FLOW WILL BRING GUSTY WEST WINDS
TO THE MOUNTAINS AND DESERTS. OTHERWISE...THERE WILL AREAS OF
NIGHT AND MORNING COASTAL LOW CLOUDS AND FOG EXTENDING INTO
PORTIONS OF THE VALLEYS.

&&

.LONG TERM (THURSDAY THROUGH SUNDAY)...
A SLOW MOVING LOW PRESSURE SYSTEM OVER THE EASTERN PACIFIC WILL
MOVE SLOWLY INLAND THROUGH THE SOUTHWEST STATES. THIS WILL BRING
MORE CLOUDS...COOLING THROUGH FRIDAY FOLLOWED BY SLOW WARMING...AND
A CHANCE OF SHOWERS AND SLIGHT CHANCE OF THUNDERSTORMS. THERE
CONTINUE TO BE SOME RUN TO RUN AND MODEL TO MODEL DIFFERENCES WITH
THE DETAILS. SOME LIGHT MARINE LAYER PRECIPITATION IS POSSIBLE AS
EARLY AS LATE WEDNESDAY NIGHT AND EARLY THURSDAY. GREATER SHOWER
COVERAGE IS POSSIBLE FOR LATE THURSDAY INTO FRIDAY WITH SHOWERS
MORE DIURNALLY DRIVEN AND TERRAIN FOCUSED ON SATURDAY AND SUNDAY.
THE GFS MOVES THE COLDEST 500 MB TEMPERATURES ACROSS SOUTHERN
CALIFORNIA THURSDAY NIGHT AND FRIDAY WHICH WOULD BE THE MOST
FAVORABLE PERIOD FOR THUNDERSTORM DEVELOPMENT IN ADDITION TO THE
SHOWERS.

&&

.AVIATION...
020900Z...AREAS OF LOW CLOUDS WILL DEVELOP RANDOMLY IN ANY PART OF
THE COASTAL BASIN THIS MORNING. CIGS WILL BE AROUND 2000 FEET MSL
WITH TOPS TO 3000 FEET. SCATTER OUT WILL PREVAIL BY 16-17Z. LOW
CLOUDS TO DEVELOP AND MOVE ASHORE ANY TIME AFTER 02Z WITH SLIGHTLY
LOWER CIGS AT 1500 FEET MSL. IN MOUNTAINS/DESERTS...MOSTLY CLEAR
EXCEPT FOR CLOUDS BASED AT 8000 FEET MSL AND ISOLD SHRA/TSRA FROM 20-
01Z THIS AFTERNOON.

&&

.MARINE...

200 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH WEDNESDAY.
A STORM SYSTEM WILL BRING STRONGER WINDS AND CHOPPY SEAS THURSDAY
AND FRIDAY ALONG WITH SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&

$$

PUBLIC...17
AVIATION/MARINE/BEACHES...MM




000
FXUS66 KLOX 021044
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
344 AM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning low clouds and fog today and
Wednesday with slightly above normal temperatures in the morning. A
slow moving low pressure system will bring a chance of showers
and thunderstorms along with cooler conditions to the area
Thursday through the weekend.

&&

.SHORT TERM...(TDY-WED)

Low clouds are a little better organized this morning. The
gradients are about 3 MB onshore push both to the north and the
east and the marine layer inversion has strengthened both of which
are helping the marine layer stratus along. By dawn most of the
coasts and the vly will be covered with stratus. There will be
good clearing by the afternoon as there is no eddy and the onshore
push is not that strong. The barest of ridges pops up today and
this will allow for a little warming esp across the interior.
There is just enough residual moisture over the mtns to allow for
some afternoon cu but not enough lift or instability to form
showers.

Since the marine layer is already fairly well established the
stratus deck will reform a little quicker overnight. It will still
burn off pretty quickly. Skies will turn partly cloudy in the
afternoon as mid and esp high level clouds stream in the sw flow
ahead of an approaching trof. MDLs indicating quite a bit of
warming but with the ridge moving off and the increase of clouds
there will be...at best...only a degree or two of warming.

The trof will be right along the West Coast on Wednesday morning
and the lift associated with it will drive marine layer stratus
over the csts and vlys and onto the coastal slopes. Mid and high
level clouds will increase through the day. Onshore flow will
increase through the day as well. All of these trend will conspire
to cause a sharp drop in temperatures. Max temps will drop 5 to 10
degrees and will be 3 to 6 degrees below normal.

.LONG TERM...(THU-SUN)

GFS/EC agree that a cutoff low pressure system will slowly drift over
the forecast area Thursday and Friday, then slowly move east over
the weekend. There will be a chance for hit and miss showers in
most places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). The cold core
upper low (with 500 mb temperatures of -24 degrees Celsius) will
move across Southwest California sometime between Thursday
afternoon through Friday. The cold air aloft combined with early
May sunshine will be create enough instability to warrant a
slight chance of thunderstorms(especially over interior sections).
Right now it does not look like this system will have that much
moisture to work with and do not expect large rainfall amounts
with it. This system is cold enough that snow levels will likely
dip to between 5000 and 6000 feet.

&&

.AVIATION...

02/1130Z

AT 11Z, the marine layer depth was around 1100 feet at KLAX. The
top of the inversion was around 3800 feet with a temperature of 15
degrees Celsius.



KLAX...

KBUR...


&&

.MARINE...

01/900 PM

High confidence in light winds and diminishing seas through at
least Tuesday afternoon. There is a chance that a Small Craft
Advisory may be needed on Tuesday evening. Advisory level winds
will likely develop on Wednesday.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 10 AM PDT this
      morning For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...DB
MARINE...DB
SYNOPSIS...Smith

weather.gov/losangeles




000
FXUS65 KPSR 021037
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
340 AM MST MON MAY 2 2016

.UPDATE...AVIATION AND FIRE WEATHER DISCUSSIONS.

&&

.SYNOPSIS...
LOW PRESSURE WILL MAKE A SLOW EXIT TO THE EAST ACROSS NORTHERN AZ
TODAY...KEEPING THE FOCUS OF ANY LINGERING PRECIP ACTIVITY WELL NORTH
OF OUR FORECAST AREA. HIGH PRESSURE MOVING IN FROM THE WEST WILL
BUILD OVER THE DESERT SOUTHWEST THROUGH THURSDAY...RESULTING IN
MOSTLY CLEAR SKIES AND A STRONG WARMING TREND. ANOTHER PACIFIC
WEATHER SYSTEM WILL BEGIN TO MOVE INTO THE AREA FRIDAY AND FOR THE
COMING WEEKEND...BRINGING MUCH COOLER TEMPERATURES...BREEZY
CONDITIONS AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...
THE CLEARING TREND THAT BEGAN LAST EVENING HAS CONTINUED OVERNIGHT.
WITH THE CALMER WINDS AND CLEARER SKIES...TEMPERATURES HAVE COOLED
TO MILD READINGS FOR EARLY MAY WITH VALUES RANGING FROM THE MID 50S
TO LOW 60S ACROSS SOUTH-CENTRAL AZ AND MID 60S ACROSS SOUTHWESTERN AZ
AND SOUTHEAST CA. WATER VAPOR LOOPS AND 500MB PLOTS SHOW REX
BLOCK...ALBEIT SHORTLIVED...OVER THE WESTERN NORTH AMERICAN
CONTINENT. THE MAIN UPPER LOW CENTER FROM THIS WEEKEND CONTINUES
TRACKING ACROSS THE CENTRAL ROCKIES AND INTO THE PLAINS THIS AM WHILE
AN ADDITIONAL TRAILING VORT LOBE ON THE WESTERN FRINGE OF THE LOW
SPINS THROUGH CENTRAL CA. THIS SHORTWAVE WILL SWING THROUGH NORTHERN
PORTIONS OF AZ TODAY ALLOWING FOR ANOTHER ROUND OF PRECIP ACTIVITY
FOR THE MOUNTAINS WHILE LEAVING THE LOWER DESERT ELEVATIONS UNDER
SOME LIMITED AFTERNOON CU FIELDS AND WARMER TEMPERATURES. TREND IN
HEIGHT RISES WILL CONTINUE THROUGHOUT THE DAY AS PACIFIC HIGH
PRESSURE BEGINS TO TRANSITION IN THE FROM THE WEST...SHUNTING OFF THE
SHORTWAVE TO THE EAST AND COMBINING WITH THE HIGH CENTER LOCATED OVER
THE CANADIAN ROCKIES. LATEST BEST PERFORMING GUIDANCE INDICATE THE
90S WILL RETURN FOR THE WESTERN FORECAST ZONES WHILE THE SOUTH-
CENTRAL AZ ZONES CAN LOOK FOR TEMPERATURES PEAKING INTO THE UPPER
80S TODAY.

HIGH-AMPLITUDE HIGH PRESSURE WILL TAKE A FEW-DAY HOLD OVER THE
INTERMOUNTAIN WEST ALLOWING DAYTIME TEMPERATURES TO TAKE ANOTHER RUN
AT THEIR WARMEST READINGS OF THE YEAR SO FAR BY MIDWEEK. 500MB
HEIGHTS STILL PROGGED INTO THE 576-582DM RANGE AND 850MB AFTN
TEMPERATURE QUICKLY HEAD NORTH OF 20 TO 25C AFTER MONDAY. MID TO
UPPER 90 DEGREE READINGS ARE ANTICIPATED FOR THE LOWER DESERT
ELEVATIONS TUESDAY AND WEDNESDAY. WEDNESDAY STILL PINNED TO BE THE
WARMEST DAY OF THE WEEK AND QUITE POSSIBLY THE YEAR AS THE RIDGE AXIS
BEGINS TO SHIFT TO OUR EAST AS STRONG SOUTHERLY FLOW DEVELOPS INTO
THE AREA ENHANCING WAA FROM THE SUBTROPICS. CONSENSUS GUIDANCE
SUPPORTING UPPER 90S FOR MANY OF THE DESERT SITES...WITH 100S STILL
POSSIBLE FOR THE WARMEST LOCALES SUCH AS TACNA AND EL CENTRO. THE
FIRST 100F FOR PHOENIX HAS POPPED INTO SOME OF THE LATEST GRIDDED
GUIDANCE WEDNESDAY...BUT ARE FROM MODEL PERFORMERS NOT TYPICAL OF
THOSE THAT DO WELL WITH HIGH PRESSURE PATTERNS.

THURSDAY THROUGH NEXT WEEKEND...
MODEL AGREEMENT AND TRENDS...BOTH IN THE DETERMINISTIC AND ENSEMBLE
SOLUTIONS...HAVE REMAINED IN EXCELLENT AGREEMENT OVER THE PAST
SEVERAL DAYS IN ADVERTISING A DEEP PACIFIC TROUGH MOVING INTO THE
SOUTHWEST BY THE LATE WEEK/EARLY WEEKEND. TROUGHING REACHES AS FAR
SOUTH AS THE NORTHERN BAJA PENINSULA AND MAINTAINS ITS COOL
TEMPERATURE PROFILE BY THURSDAY. DAYTIME TEMPERATURES WILL BEGIN TO
COOL ACROSS THE WESTERN FORECAST ZONES AS STRONG SOUTHERLY LOW-LEVEL
WINDS DEVELOP INTO THE REGION. JET-LEVEL WINDS BEGIN TO PUSH 100KTS
THURSDAY AFTERNOON...WITH LL WINDS AT 700MB AND 850MB ENCROACHING 35
TO 45 KTS. WINDS FORECAST TO BE AT THEIR STRONGEST ON THURSDAY...WITH
AREA WIDE SUSTAINED SFC SPEEDS PUSHING 25 MPH AND GUSTS 35 MPH OR
GREATER. WITH THE WINDS COMES THE THREAT FOR DUST...SO INCLUDED
MENTION OF BLOWING DUST IN THE GRIDS FOR BOTH WEDNESDAY AND THURSDAY
AS THE SYSTEM WINDS RAMP UP INTO THE AREA. THE ONE FORECAST ELEMENT
THAT REMAINS A BIT OF A UNKNOWN QUANTITY WILL BE THE MOISTURE...AS
PWAT FIELDS APPEAR TO STRUGGLE BREAKING PAST HALF INCH READINGS.
QPF/PRECIP PLOTS FROM THE DETERMINISTIC AS WELL AS THE GEFS
REFORECAST ARE NOT OVERLY EXCITED ABOUT ANY PERIODS OF PERSISTENT
RAINFALL INTO THE AREA ON THIS SYSTEM SWINGS IN OFF THE PACIFIC AND
SETTLES OVER THE AREA BY FRIDAY.

A WELCOME COOL-DOWN WILL RESULT FOR THE SOUTHWEST AS 500MB
TEMPERATURES BEGIN TO RUN COOLER THAN -20C ACROSS THE AREA...WITH
DAYTIME HIGHS DIPPING INTO THE UPPER 70S AND LOW 80S. AS WITH
PREVIOUS SYSTEMS...THE UPPER LOW FEATURE WILL TAKE UP RESIDENCE OVER
THE WEST INTO THE WEEKEND AND POSSIBLY VERY EARLY NEXT WEEK...AS IT
BECOMES THE WESTERN END OF A CONUS WIDE OMEGA BLOCK. VORTICITY PLOTS
INDICATE IT COULD BEGIN TO LOBE OUT...ALLOWING FOR ON AND OFF ROUNDS
OF BREEZINESS AND SOME PRECIP CHANCES TO OCCUR THROUGHOUT THE
SOUTHWEST STATES.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND...
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

DRY WESTERLY FLOW ALOFT WILL RESULT IN MOSTLY CLEAR SKIES THROUGH
23Z MON. LIGHT AND VARIABLE WINDS UNDER 7 KNOTS THROUGH 23ZZ MON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...

WEDNESDAY AND THURSDAY...

A HIGH PRESSURE SYSTEM WILL CONTINUE OVER THE REGION ON WEDNESDAY...
HOWEVER ANOTHER PACIFIC COLD FRONT WILL APPROACH THE WEST COAST
WEDNESDAY AFTERNOON...THEN MOVE THROUGH THE REGION THURSDAY. AS A
RESULT...BREEZY SOUTWHEST WINDS WILL DEVELOP WEDNESDAY AFTERNOON AND
EVENING...BECOMING VERY WINDY THURSDAY. SINCE RELATIVE HUMIDITIES
THURSDAY WILL RANGE FROM 10 TO 15 PERCENT...RED FLAG CONDITIONS MAY
BE REACHED ON THE SOUTWHEST AND SOUTH CENTRAL AZ DESERTS THURSDAY
AFTERNOON.

FRIDAY THROUGH SUNDAY...

AFTER THE COLD FRONTAL PASSAGE THURSDAY...A COOL AND RELATIVELY
MOIST AIRMASS WILL SETTLE OVER THE REGION THIS PERIOD. BREEZY WEST
WINDS MAY DEVELOP FRIDAY AFTERNOON...BUT BECOME MUCH LIGHTER
SATURDAY AND SUNDAY. MINIMUM RELATIVE HUMIDITIES WILL INCREASE AREA-
WIDE INTO THE 17 TO 24 PERCENT RANGE. A SLIGHT CHANCE OF SHOWERS...
UNDER A RELATIVELY COOL AND MOIST AIRMASS...WILL DEVELOP FRIDAY AND
SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...NOLTE
AVIATION...VASQUEZ
FIRE WEATHER...VASQUEZ




000
FXUS65 KPSR 021023
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
323 AM MST MON MAY 2 2016

.SYNOPSIS...
LOW PRESSURE WILL MAKE A SLOW EXIT TO THE EAST ACROSS NORTHERN AZ
TODAY...KEEPING THE FOCUS OF ANY LINGERING PRECIP ACTIVITY WELL NORTH
OF OUR FORECAST AREA. HIGH PRESSURE MOVING IN FROM THE WEST WILL
BUILD OVER THE DESERT SOUTHWEST THROUGH THURSDAY...RESULTING IN
MOSTLY CLEAR SKIES AND A STRONG WARMING TREND. ANOTHER PACIFIC
WEATHER SYSTEM WILL BEGIN TO MOVE INTO THE AREA FRIDAY AND FOR THE
COMING WEEKEND...BRINGING MUCH COOLER TEMPERATURES...BREEZY
CONDITIONS AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...
THE CLEARING TREND THAT BEGAN LAST EVENING HAS CONTINUED OVERNIGHT.
WITH THE CALMER WINDS AND CLEARER SKIES...TEMPERATURES HAVE COOLED
TO MILD READINGS FOR EARLY MAY WITH VALUES RANGING FROM THE MID 50S
TO LOW 60S ACROSS SOUTH-CENTRAL AZ AND MID 60S ACROSS SOUTHWESTERN AZ
AND SOUTHEAST CA. WATER VAPOR LOOPS AND 500MB PLOTS SHOW REX
BLOCK...ALBEIT SHORTLIVED...OVER THE WESTERN NORTH AMERICAN
CONTINENT. THE MAIN UPPER LOW CENTER FROM THIS WEEKEND CONTINUES
TRACKING ACROSS THE CENTRAL ROCKIES AND INTO THE PLAINS THIS AM WHILE
AN ADDITIONAL TRAILING VORT LOBE ON THE WESTERN FRINGE OF THE LOW
SPINS THROUGH CENTRAL CA. THIS SHORTWAVE WILL SWING THROUGH NORTHERN
PORTIONS OF AZ TODAY ALLOWING FOR ANOTHER ROUND OF PRECIP ACTIVITY
FOR THE MOUNTAINS WHILE LEAVING THE LOWER DESERT ELEVATIONS UNDER
SOME LIMITED AFTERNOON CU FIELDS AND WARMER TEMPERATURES. TREND IN
HEIGHT RISES WILL CONTINUE THROUGHOUT THE DAY AS PACIFIC HIGH
PRESSURE BEGINS TO TRANSITION IN THE FROM THE WEST...SHUNTING OFF THE
SHORTWAVE TO THE EAST AND COMBINING WITH THE HIGH CENTER LOCATED OVER
THE CANADIAN ROCKIES. LATEST BEST PERFORMING GUIDANCE INDICATE THE
90S WILL RETURN FOR THE WESTERN FORECAST ZONES WHILE THE SOUTH-
CENTRAL AZ ZONES CAN LOOK FOR TEMPERATURES PEAKING INTO THE UPPER
80S TODAY.

HIGH-AMPLITUDE HIGH PRESSURE WILL TAKE A FEW-DAY HOLD OVER THE
INTERMOUNTAIN WEST ALLOWING DAYTIME TEMPERATURES TO TAKE ANOTHER RUN
AT THEIR WARMEST READINGS OF THE YEAR SO FAR BY MIDWEEK. 500MB
HEIGHTS STILL PROGGED INTO THE 576-582DM RANGE AND 850MB AFTN
TEMPERATURE QUICKLY HEAD NORTH OF 20 TO 25C AFTER MONDAY. MID TO
UPPER 90 DEGREE READINGS ARE ANTICIPATED FOR THE LOWER DESERT
ELEVATIONS TUESDAY AND WEDNESDAY. WEDNESDAY STILL PINNED TO BE THE
WARMEST DAY OF THE WEEK AND QUITE POSSIBLY THE YEAR AS THE RIDGE AXIS
BEGINS TO SHIFT TO OUR EAST AS STRONG SOUTHERLY FLOW DEVELOPS INTO
THE AREA ENHANCING WAA FROM THE SUBTROPICS. CONSENSUS GUIDANCE
SUPPORTING UPPER 90S FOR MANY OF THE DESERT SITES...WITH 100S STILL
POSSIBLE FOR THE WARMEST LOCALES SUCH AS TACNA AND EL CENTRO. THE
FIRST 100F FOR PHOENIX HAS POPPED INTO SOME OF THE LATEST GRIDDED
GUIDANCE WEDNESDAY...BUT ARE FROM MODEL PERFORMERS NOT TYPICAL OF
THOSE THAT DO WELL WITH HIGH PRESSURE PATTERNS.

THURSDAY THROUGH NEXT WEEKEND...
MODEL AGREEMENT AND TRENDS...BOTH IN THE DETERMINISTIC AND ENSEMBLE
SOLUTIONS...HAVE REMAINED IN EXCELLENT AGREEMENT OVER THE PAST
SEVERAL DAYS IN ADVERTISING A DEEP PACIFIC TROUGH MOVING INTO THE
SOUTHWEST BY THE LATE WEEK/EARLY WEEKEND. TROUGHING REACHES AS FAR
SOUTH AS THE NORTHERN BAJA PENINSULA AND MAINTAINS ITS COOL
TEMPERATURE PROFILE BY THURSDAY. DAYTIME TEMPERATURES WILL BEGIN TO
COOL ACROSS THE WESTERN FORECAST ZONES AS STRONG SOUTHERLY LOW-LEVEL
WINDS DEVELOP INTO THE REGION. JET-LEVEL WINDS BEGIN TO PUSH 100KTS
THURSDAY AFTERNOON...WITH LL WINDS AT 700MB AND 850MB ENCROACHING 35
TO 45 KTS. WINDS FORECAST TO BE AT THEIR STRONGEST ON THURSDAY...WITH
AREA WIDE SUSTAINED SFC SPEEDS PUSHING 25 MPH AND GUSTS 35 MPH OR
GREATER. WITH THE WINDS COMES THE THREAT FOR DUST...SO INCLUDED
MENTION OF BLOWING DUST IN THE GRIDS FOR BOTH WEDNESDAY AND THURSDAY
AS THE SYSTEM WINDS RAMP UP INTO THE AREA. THE ONE FORECAST ELEMENT
THAT REMAINS A BIT OF A UNKNOWN QUANTITY WILL BE THE MOISTURE...AS
PWAT FIELDS APPEAR TO STRUGGLE BREAKING PAST HALF INCH READINGS.
QPF/PRECIP PLOTS FROM THE DETERMINISTIC AS WELL AS THE GEFS
REFORECAST ARE NOT OVERLY EXCITED ABOUT ANY PERIODS OF PERSISTENT
RAINFALL INTO THE AREA ON THIS SYSTEM SWINGS IN OFF THE PACIFIC AND
SETTLES OVER THE AREA BY FRIDAY.

A WELCOME COOL-DOWN WILL RESULT FOR THE SOUTHWEST AS 500MB
TEMPERATURES BEGIN TO RUN COOLER THAN -20C ACROSS THE AREA...WITH
DAYTIME HIGHS DIPPING INTO THE UPPER 70S AND LOW 80S. AS WITH
PREVIOUS SYSTEMS...THE UPPER LOW FEATURE WILL TAKE UP RESIDENCE OVER
THE WEST INTO THE WEEKEND AND POSSIBLY VERY EARLY NEXT WEEK...AS IT
BECOMES THE WESTERN END OF A CONUS WIDE OMEGA BLOCK. VORTICITY PLOTS
INDICATE IT COULD BEGIN TO LOBE OUT...ALLOWING FOR ON AND OFF ROUNDS
OF BREEZINESS AND SOME PRECIP CHANCES TO OCCUR THROUGHOUT THE
SOUTHWEST STATES.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
WINDS WILL BE LIGHTER THAN NORMAL AS HIGH PRESSURE BUILDS INTO THE
REGION. OTHERWISE...SKIES WILL BE MAINLY CLEAR THROUGH TUESDAY
MORNING. FEW DIURNAL CU WITH BASES AROUND 9K FT ARE EXPECTED
MONDAY...THOUGH THEY WILL BE MOST CONCENTRATED ACROSS THE HIGHER
TERRAIN AND OUTSIDE OF THE PHOENIX VICINITY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
NO AVIATION WEATHER IMPACTS EXPECTED. WINDS WILL GENERALLY BE LIGHT
AND VARIABLE UNDER MAINLY CLEAR SKIES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS WITH TEMPERATURES ABOVE SEASONAL NORMALS TUESDAY THROUGH
THURSDAY. AN INCOMING WEATHER SYSTEM WILL CAUSE SOUTHERLY WINDS TO
INCREASE WEDNESDAY AND THURSDAY. THERE MAY BE A WINDOW THURSDAY
AFTERNOON OF STRONG WINDS AND LOW HUMIDITIES THAT REACH CRITICAL FIRE
WEATHER CONDITIONS FROM MARICOPA COUNTY AND TO THE EAST. CONDITIONS
WILL IMPROVE FRIDAY AND SATURDAY WHEN THE SYSTEM MOVES IN ALLOWING
TEMPERATURES TO COOL...HUMIDITIES TO COME UP...AND WINDS TO DECREASE.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...NOLTE
AVIATION...HIRSCH
FIRE WEATHER...INIGUEZ




000
FXUS65 KREV 021006
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
306 AM PDT MON MAY 2 2016

.SYNOPSIS...

Warmer temperatures are expected today with a slight chance for
showers and a few thunderstorms this afternoon. Thunderstorm
chances increase Tuesday and Wednesday with a few strong storms
possible by Wednesday. More widespread rain and high elevation
snow, with possible thunderstorms Thursday may continue into next
weekend as low pressure moves slowly across the region.

&&

.SHORT TERM...

Several days of active weather remain probable across the eastern
Sierra and western Nevada as a large low pressure system slowly
approaches the California coast by midweek. A gradual warming
trend is expected for the next couple of days with a few valleys
possibly reaching 80 degrees Tuesday, before some cooling arrives
by Wednesday especially west of US-95.

Today appears to be the least active weather day for the upcoming
week. A weak shortwave brushing across northern CA will lead to
some shower and isolated thunderstorm activity mainly across
northeast CA and near the Sierra this afternoon and early
evening. Most of these cells will move to the north or northwest.
Eastward progression of convection will be limited as a layer of
warmer air aloft should cap much of the activity across western
NV, although some brief late day showers can`t be ruled out.

For Tuesday and Wednesday, a large low pressure over the eastern
Pacific moves slowly east, reaching the California coast by
Wednesday. The increased upper level divergence ahead of this
low, along with an influx of moisture will bring increased chances
for showers and thunderstorms across the region. For Tuesday, the
better shower and thunderstorm potential favors northeast CA, the
northern Sierra, and far western Nevada with some activity
continuing overnight. On Wednesday, higher precip chances will
spread across much of western Nevada as well.

Wednesday could be interesting as upper level jet streak rotates
around the low with the favorable left exit region possibly
providing enhanced lift over parts of eastern CA and western NV.
Some uncertainty remains with the eventual location of this
enhanced lift, but areas between US-395 and US-95 could be
targeted for more organized and stronger storms with potential for
heavy rainfall, if sufficient instability is present. A limiting
factor would be if instability is reduced due to widespread cloud
cover, then the strength of the convection would be somewhat
inhibited due to the increased wind shear aloft. In this less
unstable scenario, areas of light to moderate rain may still occur
with more isolated thunder. We will continue to monitor guidance
trends as slight changes in timing and location of the upper jet
could bring either scenario Wednesday afternoon-evening. MJD/Dawn

.LONG TERM...Thursday through Sunday...

Not too much change this morning as a cool and wet pattern is on tap
for the end of the week. Model simulations continue to show lower
than average spread in track for an upper low that is cut off from
the main westerlies, taking it slowly eastward across srn CA/srn NV
and to AZ/UT during this period. Model QPF continues to be quite
impressive Thu-Sat with model averages indicating 0.50-1.00"
across western NV and 1.00-2.00" along the eastern Sierra. While
it is still too early to determine where heavier bands of showers
will develop, locally heavy rain could result in some rises of
small creeks and streams. Snow levels will generally run between
7000-8000 feet although they could dip a bit lower in heavier
bands of showers. So impacts from snow accumulations should remain
confined to the highest passes and mainly at night. In addition to
the rain and snow, thunderstorms will be possible each day with
lightning and abundant amounts of small hail possible.

By Sunday, the effects of the upper low itself will move out of
the region. However, abundant moisture and warmer surface
temperatures will keep showers and thunderstorms going with model
soundings indicating plenty of CAPE for a few strong slow moving
storms. After highs in the 50s and 60s Thu-Sat, temperatures will
warm back to 60s and 70s by early next week. Hohmann

&&

.AVIATION...

Scattered showers and isolated thunderstorms will stay confined
mainly to the Sierra crest this afternoon/early evening although a
stray shower could drift to the Hwy 395 corridor. So KTVL/KTRK will
see the best chance of a shower/storm, probabilities at 30%/10%
respectively. Otherwise, light winds and VFR through 18z Tue.
Hohmann

&&


.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

$$

For more information from the National Weather Service visit...
http://weather.gov/reno




000
FXUS66 KMTR 021000
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
300 AM PDT MON MAY 2 2016

.SYNOPSIS....DRY AND SEASONABLE WEATHER IS FORECAST THROUGH
TOMORROW ALONG WITH COASTAL CLOUDS. A WEATHER SYSTEM WILL
APPROACH CALIFORNIA BY THE MIDDLE OF THE WEEK...BRINGING A CHANCE
OF SHOWERS AND A FEW THUNDERSTORMS BEGINNING WEDNESDAY LASTING
INTO THE WEEKEND...ALONG WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 3:00 AM PDT MONDAY...AS EXPECTED CLOUDS
RETURNED TO THE COAST YESTERDAY EVENING AND BASED OFF OF THE
SATELLITE FOG PRODUCT, THEY HAVE CONTINUED FOR THE OVERNIGHT HOURS
AND HAVE ALSO SPREAD INTO SOME ADJACENT VALLEY SPOTS. AFTER A WARM
WARM DAY YESTERDAY, SUBSTANTIAL COOLING CAN BE EXPECTED TODAY AS
MORE OF AN ONSHORE FLOW WILL BRING AIR OFF THE WATER AND ACROSS
OUR REGION. FOR SOME COASTAL SPOTS HIGHS TODAY WILL BE 10 OR MORE
DEGREES UNDER THE VALUES FROM SUNDAY. FARTHER INLAND, THE DROP IN
TEMPS WILL BE LESS ALTHOUGH MOST LOCATIONS WILL SEE AT LEAST A 3
TO 6 DEGREE DECREASE. TONIGHT SHOULD BE A REPEAT OF TODAY WITH
CLOUDS RETURNING TO THE COAST PLUS ADJACENT VALLEY LOCATIONS.

AFTER A QUIET DAY ON TUESDAY UNSETTLED WEATHER RETURNS STARTING
ON WEDNESDAY AS A LONGWAVE TROF NEARS THE COAST WHILE AN UPPER
LEVEL CUT-OFF LOW FORMS AT THE BASE OF THE TROF NEAR OUR CWA.
BEYOND THAT POINT, MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THE
LOW WILL VERY SLOWLY PROGRESS TO THE SOUTHEAST FOR THE REMAINDER
OF THE WEEK. WHERE THERE IS MORE DISAGREEMENT IS THE LOCATION OF
THE LOW PLUS THE MOST FAVORABLE LOCATIONS FOR ASSOCIATED MOISTURE
(ESPECIALLY WRAP-AROUND MOISTURE). THEREFORE, DECIDED TO KEEP
MOST SPOTS IN THE 20-30% CHANCE OF PRECIP FOR THE PERIOD. IN
ADDITION, BASED ON THE TRACK OF THE LOW PLUS GUIDANCE OUT TO 84
HOURS OFF THE NAM, KEPT A MENTION OF A SLIGHT CHANCE FOR T-STORMS
AND POSSIBLE SMALL HAIL. RAINFALL AMOUNTS WILL LIKELY BE MINOR
THROUGH THE PERIOD. COOLER TEMPS CAN ALSO BE EXPECTED -- MOSTLY
UPPER 50S TO UPPER 60S.

A RIDGE WILL BUILD IN BEHIND THE DEPARTING LOW FOR NEXT WEEK. THIS
WILL LEAD TO WARMER CONDITIONS ALONG WITH LITTLE TO NO RAIN.
&&

.AVIATION...AS OF 10:30 PM PDT SUNDAY...SOUTHERLY FLOW ALONG THE
COAST WILL ALLOW LOW CLOUDS TO SPREAD INTO THE MRY BAY AREA EARLY
TONIGHT AND PARTS OF THE SFO BAY AREA LATE TONIGHT.

VICINITY OF KSFO...SCT-BKN010 FROM 12Z THROUGH 16Z.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY TERMINALS...MVFR/IFR CIGS THROUGH 17Z.

&&

.MARINE...AS OF 02:48 AM PDT MONDAY...A SOUTHERLY SURGE WILL
CONTINUE TO MOVE UP THE NORTHERN CALIFORNIA COAST KEEPING
SOUTHERLY WINDS IN PLACE TODAY. WINDS WILL GRADUALLY BECOME
NORTHERLY TONIGHT AND TUESDAY. A MODERATE SWELL WILL MIX WITH A
SMALLER LONG PERIOD SOUTHERLY SWELL THIS WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY

&&

$$

PUBLIC FORECAST: BELL
AVIATION: W PI
MARINE: MM


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000
FXUS66 KMTR 020536
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1036 PM PDT SUN MAY 1 2016

.SYNOPSIS....COASTAL LOW CLOUDS AND FOG WILL CONTINUE TO PUSH
NORTH IMPACTING THE COAST AND INLAND VALLEYS TONIGHT INTO MONDAY
MORNING. DRY AND SEASONABLE WEATHER IS FORECAST THROUGH TUESDAY.
A WEATHER SYSTEM WILL APPROACH CALIFORNIA BY THE MIDDLE OF THE
WEEK...BRINGING A CHANCE OF SHOWERS BEGINNING WEDNESDAY LASTING
INTO THE WEEKEND...ALONG WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 9:01 PM PDT SUNDAY...ACCORDING TO THE
EXPERIMENTAL GOES R IFR PROBABILITY SATELLITE IMAGE LOW CLOUDS AND
FOG ARE WORKING THEIR WAY UP THE BIG SUR AND SANTA CRUZ COAST AT
THIS HOUR. HALF MOON BAY IS ALSO REPORTING REDUCED VISIBILITY AND
LOW CLOUDS. THIS SOUTHERLY SURGE OF LOW CLOUDS AND FOG WILL
CONTINUE NORTHWARD IMPACTING THE COAST AND INLAND VALLEYS
OVERNIGHT INTO MONDAY MORNING. ACCORDING TO THE LATEST RUN OF THE
HRRR FORECAST MODEL...LOW CLOUDS AND FOG SHOULD CLEAR OUT OF THE
INLAND VALLEYS NOT LONG AFTER SUN RISE...BUT WILL REMAIN ALONG THE
COAST THROUGH LATE MORNING.

THE CURRENT SATELLITE WATER VAPOUR IMAGE IS SHOWING A TROUGH OF
LOW PRESSURE CENTERED IN THE GULF OF ALASKA WITH A RIDGE OF HIGH
PRESSURE CENTERED OVER THE SOUTHERN BORDER OF BRITISH COLUMBIA AND
ALBERTA CANADA. THE 0000Z GFS40 AND 1200Z ECMWF HAVE INITIALIZED
WELL WITH THESE FEATURES AND REMAIN IN GOOD AGREEMENT THROUGH AT
LEAST NEXT SATURDAY.

BOTH OF THESE MODELS SLIDE THE PREVIOUSLY MENTIONED TROUGH OF LOW
PRESSURE SOUTH TOWARDS CALIFORNIA...BRINGING THE POTENTIAL FOR
RAIN TO NORTHERN PORTIONS OF THE FORECAST AREA TUESDAY NIGHT
SPREADING SOUTH WEDNESDAY. INSTABILITY ASSOCIATED WITH THE COOL
UPPER LEVEL AIR OF THIS TROUGH OF LOW PRESSURE COULD SUPPORT A FEW
ISOLATED THUNDERSTORMS WEDNESDAY AFTERNOON AND EVENING. THE THREAT
OF SHOWERS AND ISOLATED THUNDERSTORMS WILL LINGER THROUGH
THURSDAY. BY FRIDAY THE LOW PRESSURE SYSTEM WILL BE ENTERING
ARIZONA...PLACING THE FORECAST AREA IN A GOOD POSITION FOR WRAP
AROUND SHOWERS INTO THE WEEKEND. THE CURRENT FORECAST PACKAGE DOES
A REASONABLE JOB WITH THE EXPECTED WEATHER CONDITIONS SO NO
UPDATES ARE NEEDED AT THIS TIME.

&&

.AVIATION...AS OF 10:30 PM PDT SUNDAY...SOUTHERLY FLOW ALONG THE
COAST WILL ALLOW LOW CLOUDS TO SPREAD INTO THE MRY BAY AREA EARLY
TONIGHT AND PARTS OF THE SFO BAY AREA LATE TONIGHT.

VICINITY OF KSFO...SCT-BKN010 FROM 12Z THROUGH 16Z.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY TERMINALS...MVFR/IFR CIGS THROUGH 17Z.

&&

.MARINE...AS OF 10:30 PM PDT SUNDAY...A THERMAL TROUGH ALONG THE
COAST WILL ALLOW SOUTHERLY FLOW TO DEVELOP OVER THE WATERS. WINDS
WILL SWITCH TO NORTHWEST ON TUESDAY. A MODERATE SWELL WILL MIX
WITH A SMALLER LONG PERIOD SOUTHERLY SWELL THIS WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
 .TNGT...NONE.

$$

PUBLIC FORECAST: LARRY
AVIATION: W PI
MARINE: W PI


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000
FXUS66 KSTO 020511
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1011 PM PDT SUN MAY 1 2016

.Synopsis...
Threat of afternoon showers and thunderstorms continues over the
mountains into Tuesday then a more widespread chance Wednesday
into Friday. Cooling to near normal midweek.

&&

.Discussion...
Scattered thunderstorms developed earlier today over the mountains
with isolated over the valley. Activity has diminished this
evening with skies turning mostly clear with generally light
winds. Current forecast is on track and no evening update will be
needed.

.Previous Discussion...
Thunderstorms and showers have developed along the western Sierra
slopes this afternoon. Current radar shows that most of the
thunderstorms are in El Dorado county and southward along the
Sierra. Latest HRRR run is showing that showers/thunderstorms will
gradually spread northward along the Sierra...reaching up to
around the Quincy-Chester area. HRRR also shows that
showers/thunderstorms could move into the foothills, especially
the Motherlode region along with some showers possible in the
Northern San Joaquin Valley this evening around Stockton and
Modesto. All shower activity should diminish by 9-10 pm tonight.
In the meantime, if you hear thunder, stay indoors for shelter to
avoid dangerous lightning and possible hail.

Meso low weakens over NorCal Monday although some lingering
chances for showers/thunderstorms possible along the higher
elevations of the Sierra. By Tuesday, a deep upper trough over the
Eastern Pacific Ocean will move into the West Coast which will
continue the threat of afternoon mountain showers and
thunderstorms. High temps trend down slightly on Tuesday as
synoptic cooling and onshore flow gradually increase over Interior
NorCal.

More notable cooling (5-10 degrees) on Wednesday as the
center of the low gets closer to interior NorCal. Valley highs
will be around the mid 70s with 50s and 60s along foothills and
mountains. Chance of showers will become more widespread on
Wednesday, covering much of our CWA. Instability with this low
will keep a slight chance of thunderstorm development in the mix,
too. JBB

&&
.EXTENDED DISCUSSION (Thursday THROUGH Sunday)

Forecast models are in decent agreement as to the position and
timing of the upper level low track and progression starting at the
beginning of the long term forecast period.  The high amplitude
trough of low pressure is a bit quicker as advertised by the GFS
heading into late Wednesday night to early Thursday morning, while
the ECMWF has the arrival into NorCal more into the early to mid
morning hours on Thursday. In either scenario, the incoming storm
system will bring the needed lift behind enough moisture to bring
showers and thunderstorm chances for the entire forecast area. The
system will not move very quick, and cool temperatures along with
chances for showers and thunderstorms will continue through next
weekend.

A cool down of temperatures is expected with a return to near normal
high temperatures in the low to mid 70s in the valley, 50s to 60s in
the foothills, and the low to mid 40s in the higher elevations on
Thursday and Friday.  Temperatures should return to slightly above
normal temperatures in the valley next weekend.
&&

.AVIATION...

VFR conditions are expected at the terminals for the next 24
hours. A slight chance of thunderstorms over the Sierra Cascade
range this afternoon and evening. Breezy north winds gusting to 20
mph over the Sacramento valley and foothills decreasing after 00z
today.
&&

.STO Watches/Warnings/Advisories...
None.
&&

$$




000
FXUS66 KSTO 020511
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1011 PM PDT SUN MAY 1 2016

.Synopsis...
Threat of afternoon showers and thunderstorms continues over the
mountains into Tuesday then a more widespread chance Wednesday
into Friday. Cooling to near normal midweek.

&&

.Discussion...
Scattered thunderstorms developed earlier today over the mountains
with isolated over the valley. Activity has diminished this
evening with skies turning mostly clear with generally light
winds. Current forecast is on track and no evening update will be
needed.

.Previous Discussion...
Thunderstorms and showers have developed along the western Sierra
slopes this afternoon. Current radar shows that most of the
thunderstorms are in El Dorado county and southward along the
Sierra. Latest HRRR run is showing that showers/thunderstorms will
gradually spread northward along the Sierra...reaching up to
around the Quincy-Chester area. HRRR also shows that
showers/thunderstorms could move into the foothills, especially
the Motherlode region along with some showers possible in the
Northern San Joaquin Valley this evening around Stockton and
Modesto. All shower activity should diminish by 9-10 pm tonight.
In the meantime, if you hear thunder, stay indoors for shelter to
avoid dangerous lightning and possible hail.

Meso low weakens over NorCal Monday although some lingering
chances for showers/thunderstorms possible along the higher
elevations of the Sierra. By Tuesday, a deep upper trough over the
Eastern Pacific Ocean will move into the West Coast which will
continue the threat of afternoon mountain showers and
thunderstorms. High temps trend down slightly on Tuesday as
synoptic cooling and onshore flow gradually increase over Interior
NorCal.

More notable cooling (5-10 degrees) on Wednesday as the
center of the low gets closer to interior NorCal. Valley highs
will be around the mid 70s with 50s and 60s along foothills and
mountains. Chance of showers will become more widespread on
Wednesday, covering much of our CWA. Instability with this low
will keep a slight chance of thunderstorm development in the mix,
too. JBB

&&
.EXTENDED DISCUSSION (Thursday THROUGH Sunday)

Forecast models are in decent agreement as to the position and
timing of the upper level low track and progression starting at the
beginning of the long term forecast period.  The high amplitude
trough of low pressure is a bit quicker as advertised by the GFS
heading into late Wednesday night to early Thursday morning, while
the ECMWF has the arrival into NorCal more into the early to mid
morning hours on Thursday. In either scenario, the incoming storm
system will bring the needed lift behind enough moisture to bring
showers and thunderstorm chances for the entire forecast area. The
system will not move very quick, and cool temperatures along with
chances for showers and thunderstorms will continue through next
weekend.

A cool down of temperatures is expected with a return to near normal
high temperatures in the low to mid 70s in the valley, 50s to 60s in
the foothills, and the low to mid 40s in the higher elevations on
Thursday and Friday.  Temperatures should return to slightly above
normal temperatures in the valley next weekend.
&&

.AVIATION...

VFR conditions are expected at the terminals for the next 24
hours. A slight chance of thunderstorms over the Sierra Cascade
range this afternoon and evening. Breezy north winds gusting to 20
mph over the Sacramento valley and foothills decreasing after 00z
today.
&&

.STO Watches/Warnings/Advisories...
None.
&&

$$




000
FXUS66 KSGX 020423
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
923 PM PDT SUN MAY 1 2016

.SYNOPSIS...
MOSTLY FAIR AND WARMER FOR MONDAY AND TUESDAY...WITH COASTAL LOW
CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS AND SLIGHT CHANCES
FOR SHOWERS OVER THE MOUNTAINS MONDAY AFTERNOON. COOLER WEDNESDAY
AND THURSDAY WITH INCREASING CLOUDS. EVEN COOLER FOR FRIDAY
THROUGH THE WEEKEND WITH MORE CLOUDS...PERIODS OF SHOWERS...AND
POSSIBLY SOME THUNDERSTORMS.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

THIS EVENING...MOSTLY CLOUDY INLAND AS THE DEBRIS CLOUDS FROM
EARLIER SHOWERS AND THUNDERSTORMS LINGER OVER THE REGION. A FEW
LIGHT SHOWERS COULD CONTINUE OVERNIGHT INTO THE EARLY MORNING. LOW
CLOUDS ARE FORMING ALONG THE COAST AND WILL INCREASE IN COVERAGE
OVERNIGHT...SPREADING SEVERAL MILES INLAND WITH FOG DEVELOPING
WHERE CLOUDS AND TERRAIN INTERSECT.

LINGERING MOISTURE IN THE LOW LEVELS AND CYCLONIC FLOW ALOFT WILL
KEEP SOME LOWER CLOUDS ALONG AND WEST OF THE MTNS THROUGH MONDAY.
SOME INSTABILITY WILL CONTINUE THE CHANCES FOR SHOWERS OVER THE
MTNS MON AFTERNOON. TEMPS INCREASE AS A WEAK HIGH PRESSURE RIDGE
MOVES IN FROM THE WEST. AS THE UPPER RIDGE MOVES EAST OVER THE
REGION...TUE WILL BE FAIR AND WARM AFTER THE COASTAL LOW CLOUDS
AND FOG BURN OFF BY LATE MORNING.

A COOLING TREND BEGINS ON WED AS ONSHORE FLOW INCREASES AHEAD OF A
DEEPENING LOW PRESSURE TROUGH OVER THE EASTERN PACIFIC. THIS WILL
BRING A DEEPENING MARINE LAYER WITH LOW CLOUDS AND FOG SPREADING
WELL INLAND WED MORNING. THE LOW CLOUDS AND FOG SHOULD BURN OFF BY
LATE MORNING FOR MOSTLY FAIR SKIES IN THE AFTERNOON.

LATEST DETERMINISTIC MODEL RUNS ARE IN PRETTY GOOD AGREEMENT
REGARDING THE GENERAL PATTERN AND DEVELOPMENT OF THE LOW PRESSURE
SYSTEM OVER THE EASTERN PACIFIC. THE TIMING...TRAJECTORY AND
ASSOCIATED WEATHER STILL REMAIN SOMEWHAT UNCERTAIN AS THE SYSTEM
INTENSIFIES AND MOVES INLAND ACROSS CALIFORNIA...ALTHOUGH
CONFIDENCE IS HIGH THAT IT WILL PRODUCE PERIODS OF GUSTY SW TO
WEST WINDS AND PRECIPITATION FOR FRI THROUGH NEXT WEEKEND. TSTMS
WILL ALSO BE POSSIBLE OVER SOCAL IF THE COLD AIR ASSOCIATED WITH
THE CLOSED UPPER LOW TAKES A FAVORABLE PATH.

&&

.AVIATION...
020400Z...COAST/VALLEYS...BKN-OVC CIGS WITH BASES BETWEEN 1500 AND
2500 FT MSL WILL CONTINUE TO DEVELOP THROUGH 13Z. GREATEST COVERAGE
AND EARLIEST ONSET OF CIGS WILL BE WITHIN 35 MILES OF THE COAST. LOW
CLOUD COVERAGE IS EXPECTED TO BE MORE DIFFUSE OVER THE INLAND EMPIRE
WITH FEW-BKN THROUGH 16Z. LOW CLOUDS WILL TRANSITION TO FEW-SCT FOR
ALL AREAS AFTER 16Z...WITH PREVAILING FEW-SCT AFTER 19Z. LIGHT
WESTERLY SEA BREEZES WILL OCCUR MONDAY AFTERNOON...WITH LOW CLOUDS
RETURNING TO THE COAST AFTER 02Z TUESDAY.

MOUNTAINS/DESERTS...SKC AND UNRESTRICTED VIS WILL PREVAIL THROUGH
18Z MONDAY. FROM 18Z MONDAY TO 03Z TUESDAY THERE WILL BE A SLIGHT
CHANCE OF A SHOWER OR ISOLATED THUNDERSTORM OVER THE MOUNTAINS.
OTHERWISE WINDS WILL BE LIGHT THROUGH THE DAY ON MONDAY.

&&

.MARINE...
900 PM...THROUGH WEDNESDAY...LIGHT WINDS EACH NIGHT AND MORNING,
FOLLOWED BY NORTHWEST WINDS 10-15 KT EACH AFTERNOON. BY THURSDAY AND
FRIDAY...A DEVELOPING WEATHER SYSTEM ALONG THE WEST COAST WILL BRING
STRONGER AND MORE CONSISTENT NORTHWEST WINDS AND A CHANCE FOR
SHOWERS AND THUNDERSTORMS. COMBINED SEAS WILL BE 3-5 FT THROUGH
WEDNESDAY...WITH COMBINED SEAS OF 4-8 FT POSSIBLE THURSDAY AND
FRIDAY.

&&

.BEACHES...
900 PM...A LONG PERIOD SOUTHERLY SWELL WILL SLOWLY DECLINE TONIGHT
THROUGH MONDAY. THIS WILL ALLOW THE SURF HEIGHTS TO FALL TO 3-6 FT
MONDAY ALONG LOCAL SOUTH AND SOUTHWEST FACING BEACHES. BEACHES WITH
A MORE WEST TO NORTHWEST ASPECT WILL SEE SURF OF 2-4 FT ON MONDAY.
THE POTENTIAL FOR MODERATE TO STRONG RIP AND LONGSHORE CURRENTS WILL
CONTINUE THROUGH MONDAY. THE SWELL WILL REMAIN MIXED TUESDAY THROUGH
FRIDAY...WITH A MODERATE PERIOD NORTHWEST SWELL BRINING CHOPPY
CONDITIONS THURSDAY AND FRIDAY.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.

PZ...NONE.

&&

$$

PUBLIC...PG
AVIATION/MARINE/BEACHES...BA




000
FXUS65 KPSR 020412
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
912 PM MST SUN MAY 1 2016

.SYNOPSIS...
THE LOW PRESSURE SYSTEM THAT BROUGHT SHOWERS AND BELOW-NORMAL
TEMPERATURES TO THE REGION OVER THE LAST FEW DAYS IS EXPECTED TO
MOVE OFF TO THE NORTHEAST TONIGHT AND MONDAY. THIS WILL ALLOW HIGH
PRESSURE TO REBUILD OVER THE DESERT SOUTHWEST FROM MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM IS STILL FORECAST TO MOVE INTO
THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING MUCH COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...
SKIES ARE CLEARING RAPIDLY ACROSS THE DESERT SOUTHWEST THIS EVENING.
THIS IS LIKELY A RESULT OF THE STRONG HEIGHT RISES...GENERALLY
AROUND 80 METERS AT 500 MB OVER THE PAST 12 HOURS. WINDS ALSO
CONTINUE TO SUBSIDE...WHICH WILL PROMOTE FAVORABLE CONDITIONS FOR
RADIATIONAL COOLING. LOW TEMPERATURES WILL AGAIN BE AT OR BELOW
NORMAL FOR MOST SPOTS. MINOR ADJUSTMENTS WERE MADE TO THE SHORT-TERM
FORECAST THIS EVENING...MAINLY TO ACCOUNT FOR THE CLEARING SKIES AND
TO ESSENTIALLY REMOVE ANY CHANCE OF MEASURABLE PRECIPITATION.

&&

.PREVIOUS DISCUSSION...

TONIGHT THROUGH MONDAY...

THE COLD UPPER LOW CENTER THAT BROUGHT BELOW-NORMAL TEMPERATURES AND
SHOWERS TO THE REGION OVER THE LAST FEW DAYS IS NOW LIFTING OUT TO
THE NORTHEAST...AS ANOTHER...MUCH WEAKER SHORTWAVE MOVES INLAND INTO
CENTRAL CA/NV. AS HEIGHTS/TEMPERATURES ALOFT GRADUALLY RISE THIS
EVENING AND TONIGHT...THE SPRINKLE/LIGHT SHOWER ACTIVITY THAT IS
BEING DETECTED THIS AFTERNOON ON RADAR ACROSS SOUTH-CENTRAL AZ IS
EXPECTED TO END AROUND/AFTER SUNSET...WITH SKIES BECOMING CLEAR-
PARTLY CLOUDY OVER ALL OF OUR CWA BY LATE TONIGHT. THE WARMING
AIRMASS WILL LIKELY KEEP OVERNIGHT LOWS A BIT WARMER AT MOST
LOCATIONS THAN WHAT WAS OBSERVED LAST NIGHT...IN SPITE OF LESS CLOUD
COVER. CONTINUED WARMING ALOFT WILL ALSO ALLOW TEMPERATURES TO WARM
UP INTO THE UPPER-80S TO NEAR 90 RANGE ON MONDAY UNDER MOSTLY CLEAR
SKIES. HOWEVER...THE AFOREMENTIONED SHORTWAVE...THAT IS NOW MOVING
INTO CENTRAL CA...WILL LIKELY KEEP MOST LOWER DESERT LOCATIONS BELOW
THE 90 DEGREE MARK ON MONDAY...AS IT MOVES EASTWARD OVER NORTHERN AZ.

TUESDAY THROUGH WEDNESDAY...

CURRENT GLOBAL MODEL SUITES CONTINUE TO SHOW RATHER STRONG HIGH
PRESSURE RIDGING BUILDING EASTWARD INTO THE REGION DURING THIS
PERIOD. THE COMBINATION OF 500MB HEIGHTS IN THE 578-580DM RANGE AND
1000-500MB THICKNESSES AOA 570DM...ALONG WITH MOSTLY CLEAR SKIES
WILL CERTAINLY ALLOW TEMPERATURES TO RISE WELL UP INTO THE 90S EACH
DAY...WITH WEDNESDAY LIKELY BEING THE WARMEST DAY...AS LOW-LEVEL
SOUTHERLY FLOW DEVELOPS OVER THE REGION. HOWEVER...OUTSIDE OF
PERHAPS A FEW OF THE VERY WARMEST SPOTS...IT STILL APPEARS THE MOST
LOCATIONS WILL SEE HIGHS FALL SHORT OF 100 DEGREES EACH DAY...WITH
EVEN THE WARMEST NUMERICAL GUIDANCE STILL KEEPING PHOENIX SKY HARBOR
BELOW 100 AS WELL.

THURSDAY THROUGH SUNDAY...

ALL OF THE GLOBAL MODEL SUITES...AND THE VAST MAJORITY OF THEIR
RESPECTIVE ENSEMBLE MEMBERS CONTINUE TO BRING ANOTHER COLD UPPER LOW
SOUTHWARD INTO THE REGION DURING THIS PERIOD...AS THE OVERALL LONG-
WAVE PATTERN OVER THE NORTH PACIFIC AND NORTH AMERICA UNDERGOES
SIGNIFICANT AMPLIFICATION. ALTHOUGH THIS NEW SYSTEM WILL LIKELY BE
AT LEAST AS COLD AS THE ONE THAT HAS AFFECTED US OVER THE PAST FEW
DAYS...IT APPEARS THAT IT WILL BE A SOMEWHAT DRIER ONE...LIKELY DUE
TO THE MORE NORTHERLY TRACK OF THE SYSTEM. HOWEVER THE OVERALL
IMPACTS FROM THIS NEW SYSTEM WILL LIKELY BE SIMILAR TO THE LAST ONE.
ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES BETWEEN THE
MODELS...IT NOW APPEARS THAT THIS UPPER LOW WILL BEGIN TO AFFECT OUR
CWA ON THURSDAY...BEGINNING TO COOL TEMPERATURES ACROSS THE
REGION...ESPECIALLY OVER SE CA AND THE LOWER COLORADO RIVER
VALLEY...WHILE ALSO SUBSTANTIALLY INCREASING THE WINDS AS WELL...AS
A 100+ KT JET PUSHES EASTWARD OVER THE REGION AHEAD OF THE MAIN
UPPER LOW...WITH ADVISORY-LEVEL WINDS...AREAS OF BLOWING DUST...AND
EVEN SOME FIRE WEATHER ISSUES A REAL POSSIBILITY. FURTHER
COOLING...AND EVEN A SLIGHT CHANCE FOR SHOWERS IS LIKELY FOR THE
FRIDAY-SUNDAY TIME PERIOD AS THE MAIN UPPER LOW MOVES VERY SLOWLY
EASTWARD ACROSS THE REGION...WITH AT LEAST ONE DAY OF HIGHS IN THE
70S ONCE AGAIN A POSSIBILITY FOR MANY LOWER DESERT LOCATIONS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
WINDS WILL BE LIGHTER THAN NORMAL AS HIGH PRESSURE BUILDS INTO THE
REGION. OTHERWISE...SKIES WILL BE MAINLY CLEAR THROUGH TUESDAY
MORNING. FEW DIURNAL CU WITH BASES AROUND 9K FT ARE EXPECTED MONDAY...THOUGH
THEY WILL BE MOST CONCENTRATED ACROSS THE HIGHER TERRAIN AND OUTSIDE
OF THE PHOENIX VICINITY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
NO AVIATION WEATHER IMPACTS EXPECTED. WINDS WILL GENERALLY BE LIGHT
AND VARIABLE UNDER MAINLY CLEAR SKIES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...

HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS WITH TEMPERATURES ABOVE SEASONAL NORMALS TUESDAY THROUGH
THURSDAY. AN INCOMING WEATHER SYSTEM WILL CAUSE SOUTHERLY WINDS TO
INCREASE WEDNESDAY AND THURSDAY. THERE MAY BE A WINDOW THURSDAY
AFTERNOON OF STRONG WINDS AND LOW HUMIDITIES THAT REACH CRITICAL
FIRE WEATHER CONDITIONS FROM MARICOPA COUNTY AND TO THE EAST.
CONDITIONS WILL IMPROVE FRIDAY AND SATURDAY WHEN THE SYSTEM MOVES IN
ALLOWING TEMPERATURES TO COOL...HUMIDITIES TO COME UP...AND WINDS TO
DECREASE.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...HIRSCH
FIRE WEATHER...INIGUEZ




000
FXUS66 KLOX 020406
AFDLOX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
906 PM PDT SUN MAY 1 2016

.SYNOPSIS...

A departing low pressure system will bring isolated showers and
thunderstorms through late this evening across interior areas. A
gradual warming trend is expected through Tuesday as high pressure
aloft briefly builds over the region. A slow moving low pressure
system may bring showers and thunderstorms with cooler conditions
to the area Thursday through the weekend.

&&

.UPDATE...

The latest satellite imagery indicates a broad trough of low
pressure centered over the Great Basin. A few showers remain over
mainly Los Angeles County this evening as shortwave troughs rotate
around the broader circulation. Another shortwave feature over the
Northern Sierras will drop south into Central California through
Monday and brush the area, while an upper-level ridge of high
pressure to the West near 33N and 130W will slowly build over the
region. The ridge will win out and should stabilize the
atmosphere. A few clouds will develop over the mountains on
Monday afternoon and evening, but a warming trend will take shape
across the area.

A few tweaks will be made to warm temperatures additionally for
Monday. An update will be issued shortly.

&&

.SHORT TERM...(SUN-WED)

NAM model cross sections showing ample low level moisture and
moderate-strong onshore flow next few days to maintain a high
probability of night and morning low clouds and fog across many
coastal/valley areas. Mild temperatures will continue next couple
of days, with gradual warming across interior sections. While,
there is some residual mid level moisture over the mountains on
Monday, only expecting some afternoon buildups as the atmosphere
begins to stabilize. By tuesday, a large upper low begins to
approach the west coast. This system will bring an increasae in
mid/high level clouds across the forecast area.

.LONG TERM...(THU-SUN)

12z GFS/ECMWF model solutions in general agreement that a cutoff
low pressure system will likely impact the forecast area sometime
between Thursday and Friday, then slowly drift east over the
weekend. There will be a chance for hit and miss showers in most
places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). Current
projections have cold core upper low (with 500 mb temperatures of
-24 degrees Celsius) moving across Southwest California sometime
between Thursday afternoon through Friday. With this cold air
aloft combined with early May sunshine providing good surface
heating, feel that there will be enough instability to warrant a
slight chance of thunderstorms(especially over interior sections),
and have added accordingly to the official forecast. This system
is cold enough that we could potentially see some snow impacts
in the local mountains, with snow levels projected to range
between 5000 and 6000 feet.

&&

.AVIATION...02/0000Z.

AT 00Z, the marine layer depth was around 1100 feet at KLAX. The
top of the inversion was around 3800 feet with a temperature of 15
degrees Celsius.

Moderate confidence in the current forecast. There is a chance of
IFR to MVFR conditions through 17Z at coastal terminals. There is
a chance that MVFR conditions could linger into 20Z at KOXR and
KSBA.

KLAX...VFR conditions will continue through 03Z, then there is a
70 percent chance of MVFR conditions through 13Z. MVFR conditions
will occur by 13Z at the latest. VFR conditions are expected to
redevelop around 17Z.

KBUR...VFR conditions will continue through 08Z, then there is a
60 percent chance of MVFR conditions. VFR conditions are expected
to redevelop between 15Z and 16Z.

&&

.MARINE...01/900 PM.

High confidence in light winds and diminishing seas through at
least Tuesday afternoon. There is a chance that a Small Craft
Advisory may be needed on Tuesday evening. Advisory level winds
will likely develop on Wednesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through Monday morning For
      zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Hall/Gomberg
AVIATION...Hall
MARINE...Hall
SYNOPSIS...Smith

weather.gov/losangeles




000
FXUS66 KMTR 020401
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
901 PM PDT SUN MAY 1 2016

.SYNOPSIS....COASTAL LOW CLOUDS AND FOG WILL CONTINUE TO PUSH
NORTH IMPACTING THE COAST AND INLAND VALLEYS TONIGHT INTO MONDAY
MORNING. DRY AND SEASONABLE WEATHER IS FORECAST THROUGH TUESDAY.
A WEATHER SYSTEM WILL APPROACH CALIFORNIA BY THE MIDDLE OF THE
WEEK...BRINGING A CHANCE OF SHOWERS BEGINNING WEDNESDAY LASTING
INTO THE WEEKEND...ALONG WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 9:01 PM PDT SUNDAY...ACCORDING TO THE
EXPERIMENTAL GOES R IFR PROBABILITY SATELLITE IMAGE LOW CLOUDS AND
FOG ARE WORKING THEIR WAY UP THE BIG SUR AND SANTA CRUZ COAST AT
THIS HOUR. HALF MOON BAY IS ALSO REPORTING REDUCED VISIBILITY AND
LOW CLOUDS. THIS SOUTHERLY SURGE OF LOW CLOUDS AND FOG WILL
CONTINUE NORTHWARD IMPACTING THE COAST AND INLAND VALLEYS
OVERNIGHT INTO MONDAY MORNING. ACCORDING TO THE LATEST RUN OF THE
HRRR FORECAST MODEL...LOW CLOUDS AND FOG SHOULD CLEAR OUT OF THE
INLAND VALLEYS NOT LONG AFTER SUN RISE...BUT WILL REMAIN ALONG THE
COAST THROUGH LATE MORNING.

THE CURRENT SATELLITE WATER VAPOUR IMAGE IS SHOWING A TROUGH OF
LOW PRESSURE CENTERED IN THE GULF OF ALASKA WITH A RIDGE OF HIGH
PRESSURE CENTERED OVER THE SOUTHERN BORDER OF BRITISH COLUMBIA AND
ALBERTA CANADA. THE 0000Z GFS40 AND 1200Z ECMWF HAVE INITIALIZED
WELL WITH THESE FEATURES AND REMAIN IN GOOD AGREEMENT THROUGH AT
LEAST NEXT SATURDAY.

BOTH OF THESE MODELS SLIDE THE PREVIOUSLY MENTIONED TROUGH OF LOW
PRESSURE SOUTH TOWARDS CALIFORNIA...BRINGING THE POTENTIAL FOR
RAIN TO NORTHERN PORTIONS OF THE FORECAST AREA TUESDAY NIGHT
SPREADING SOUTH WEDNESDAY. INSTABILITY ASSOCIATED WITH THE COOL
UPPER LEVEL AIR OF THIS TROUGH OF LOW PRESSURE COULD SUPPORT A FEW
ISOLATED THUNDERSTORMS WEDNESDAY AFTERNOON AND EVENING. THE THREAT
OF SHOWERS AND ISOLATED THUNDERSTORMS WILL LINGER THROUGH
THURSDAY. BY FRIDAY THE LOW PRESSURE SYSTEM WILL BE ENTERING
ARIZONA...PLACING THE FORECAST AREA IN A GOOD POSITION FOR WRAP
AROUND SHOWERS INTO THE WEEKEND. THE CURRENT FORECAST PACKAGE DOES
A REASONABLE JOB WITH THE EXPECTED WEATHER CONDITIONS SO NO
UPDATES ARE NEEDED AT THIS TIME.

&&

.AVIATION...AS OF 10:30 AM PDT SUNDAY...DRY OFFSHORE FLOW KEEPING
VFR TODAY. THE ONE FLY IN THE OINTMENT IN THE FORECAST IS A
POSSIBLE SOUTHERLY SURGE LATER TODAY. LATEST NAM AND WRF SHOW A
SOUTHERLY SURGE IMPACTING KMRY/KSNS...POSS MAKING IT INTO SF BAY
OVERNIGHT. CONF IS MARGINAL.

VICINITY OF KSFO...VFR.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY TERMINALS...VFR BECOMING MVFR LATE THIS EVENING AND
OVERNIGHT.

&&

.MARINE...AS OF 01:22 PM PDT SUNDAY...HIGH PRESSURE OVER THE
EASTERN PACIFIC WILL KEEP NORTHERLY WINDS OVER THE COASTAL WATERS
TODAY. LOCALLY GUSTY WINDS WILL BE POSSIBLE OVER THE OUTER WATERS
NORTH OF POINT REYES. SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT
AND EARLY MONDAY. A MODERATE SWELL WILL MIX WITH A SMALLER LONG
PERIOD SOUTHERLY SWELL THIS WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...NONE.

$$

PUBLIC FORECAST: LARRY
AVIATION: SIMS
MARINE: SIMS


VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA




000
FXUS66 KLOX 020039 AAA
AFDLOX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
539 PM PDT SUN MAY 1 2016

Updated Aviation section

.SYNOPSIS...

A departing low pressure system will bring the slight chance of
showers and thunderstorms through this evening across interior
areas. A gradual warming trend is expected through Tuesday as
high pressure aloft briefly builds into the region. A slow moving
low pressure system may bring showers and thunderstorms with
cooler conditions to the area Thursday through the weekend.

&&

.SHORT TERM...(TDY-WED)

Main short term impact is potential convective showers and thunderstorms
across interior sections of forecast area this afternoon and
evening. As of 2 pm, satellite imagery showing considerable
cumulus/towering cumulus clouds developing across interior
sections, mostly over the mountains. Doppler radar showing
a few storms producing rain showers over our local mountains
and interior valleys of SLO county, with only lightning strikes
so far being observed to our north in Kern county.

Weak upper level low pressure system centered over Central
California will bring some cyclonic flow and associated vort
energy across our forecast area this afternoon. Some residual
moisture across the region this afternoon, with precipitable
water values ranging between .7-.8 inches. With ample early May
sunshine and still some cold air aloft (500 mb temperatures as low
as -18 degrees celsius across interior sections), there will
likely be enough instability and moisture to continue generating
some showers over the mountains, deserts, and interior valleys
this afternoon and early evening. With latest NAM model soundings
showing lifted index values ranging between -2 and -4, and surface
based CAPE values between 300-700 J/kg, the convective parameters
indicate a slight chance thunderstorms is warranted this
afternoon/early evening across the mountains and deserts. With
the upper level wind flow from the northwest and mid level flow
from the northeast, could see some storms drift off the mountains
into the adjacent foothill portions of the valleys, as well as the
Santa Clarita Valley. If any thunderstorms do develop today, they
will likely be slow moving, capable of producing heavy rain with
localized flooding. Other potential thunderstorm impacts include
gusty winds, and small hail.

Meanwhile, low clouds have burned off the coast this afternoon.
NAM model cross sections showing ample low level moisture and
moderate-strong onshore flow next few days to maintain a high
probability of night and morning low clouds and fog across many
coastal/valley areas. Mild temperatures will continue next couple
of days, with gradual warming across interior sections.
While, there is some residual mid level moisture over the
mountains on Monday, only expecting some afternoon buildups
as the atmosphere begins to stabilize. By tuesday, a large
upper low begins to approach the west coast. This system will
bring an increasae in mid/high level clouds across the forecast
area.

.LONG TERM...(THU-SUN)

12z GFS/ECMWF model solutions in general agreement that a cutoff
low pressure system will likely impact the forecast area sometime
between Thursday and Friday, then slowly drift east over the
weekend. There will be a chance for hit and miss showers in most
places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). Current
projections have cold core upper low (with 500 mb temperatures of
-24 degrees Celsius) moving across Southwest California sometime
between Thursday afternoon through Friday. With this cold air
aloft combined with early May sunshine providing good surface
heating, feel that there will be enough instability to warrant a
slight chance of thunderstorms(especially over interior sections),
and have added accordingly to the official forecast. This system
is cold enough that we could potentially see some snow impacts
in the local mountains, with snow levels projected to range
between 5000 and 6000 feet.

&&

.AVIATION...02/0000Z.

AT 00Z, the marine layer depth was around 1100 feet at KLAX. The
top of the inversion was around 3800 feet with a temperature of 15
degrees Celsius.

Moderate confidence in the current forecast. There is a chance of
IFR to MVFR conditions through 17Z at coastal terminals. There is
a chance that MVFR conditions could linger into 20Z at KOXR and
KSBA.

KLAX...VFR conditions will continue through 03Z, then there is a
70 percent chance of MVFR conditions through 13Z. MVFR conditions
will occur by 13Z at the latest. VFR conditions are expected to
redevelop around 17Z.

KBUR...VFR conditions will continue through 08Z, then there is a
60 percent chance of MVFR conditions. VFR conditions are expected
to redevelop between 15Z and 16Z.


&&

.MARINE...01/200 pM.

There is rather high confidence that conds will remain below SCA
levels across the entire waters through at least Tue. Winds will
increase later in the week.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through Monday morning For
      zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Gomberg
AVIATION...Hall
MARINE...Sweet
SYNOPSIS...Munroe

weather.gov/losangeles




000
FXUS66 KLOX 020039 AAA
AFDLOX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
539 PM PDT SUN MAY 1 2016

Updated Aviation section

.SYNOPSIS...

A departing low pressure system will bring the slight chance of
showers and thunderstorms through this evening across interior
areas. A gradual warming trend is expected through Tuesday as
high pressure aloft briefly builds into the region. A slow moving
low pressure system may bring showers and thunderstorms with
cooler conditions to the area Thursday through the weekend.

&&

.SHORT TERM...(TDY-WED)

Main short term impact is potential convective showers and thunderstorms
across interior sections of forecast area this afternoon and
evening. As of 2 pm, satellite imagery showing considerable
cumulus/towering cumulus clouds developing across interior
sections, mostly over the mountains. Doppler radar showing
a few storms producing rain showers over our local mountains
and interior valleys of SLO county, with only lightning strikes
so far being observed to our north in Kern county.

Weak upper level low pressure system centered over Central
California will bring some cyclonic flow and associated vort
energy across our forecast area this afternoon. Some residual
moisture across the region this afternoon, with precipitable
water values ranging between .7-.8 inches. With ample early May
sunshine and still some cold air aloft (500 mb temperatures as low
as -18 degrees celsius across interior sections), there will
likely be enough instability and moisture to continue generating
some showers over the mountains, deserts, and interior valleys
this afternoon and early evening. With latest NAM model soundings
showing lifted index values ranging between -2 and -4, and surface
based CAPE values between 300-700 J/kg, the convective parameters
indicate a slight chance thunderstorms is warranted this
afternoon/early evening across the mountains and deserts. With
the upper level wind flow from the northwest and mid level flow
from the northeast, could see some storms drift off the mountains
into the adjacent foothill portions of the valleys, as well as the
Santa Clarita Valley. If any thunderstorms do develop today, they
will likely be slow moving, capable of producing heavy rain with
localized flooding. Other potential thunderstorm impacts include
gusty winds, and small hail.

Meanwhile, low clouds have burned off the coast this afternoon.
NAM model cross sections showing ample low level moisture and
moderate-strong onshore flow next few days to maintain a high
probability of night and morning low clouds and fog across many
coastal/valley areas. Mild temperatures will continue next couple
of days, with gradual warming across interior sections.
While, there is some residual mid level moisture over the
mountains on Monday, only expecting some afternoon buildups
as the atmosphere begins to stabilize. By tuesday, a large
upper low begins to approach the west coast. This system will
bring an increasae in mid/high level clouds across the forecast
area.

.LONG TERM...(THU-SUN)

12z GFS/ECMWF model solutions in general agreement that a cutoff
low pressure system will likely impact the forecast area sometime
between Thursday and Friday, then slowly drift east over the
weekend. There will be a chance for hit and miss showers in most
places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). Current
projections have cold core upper low (with 500 mb temperatures of
-24 degrees Celsius) moving across Southwest California sometime
between Thursday afternoon through Friday. With this cold air
aloft combined with early May sunshine providing good surface
heating, feel that there will be enough instability to warrant a
slight chance of thunderstorms(especially over interior sections),
and have added accordingly to the official forecast. This system
is cold enough that we could potentially see some snow impacts
in the local mountains, with snow levels projected to range
between 5000 and 6000 feet.

&&

.AVIATION...02/0000Z.

AT 00Z, the marine layer depth was around 1100 feet at KLAX. The
top of the inversion was around 3800 feet with a temperature of 15
degrees Celsius.

Moderate confidence in the current forecast. There is a chance of
IFR to MVFR conditions through 17Z at coastal terminals. There is
a chance that MVFR conditions could linger into 20Z at KOXR and
KSBA.

KLAX...VFR conditions will continue through 03Z, then there is a
70 percent chance of MVFR conditions through 13Z. MVFR conditions
will occur by 13Z at the latest. VFR conditions are expected to
redevelop around 17Z.

KBUR...VFR conditions will continue through 08Z, then there is a
60 percent chance of MVFR conditions. VFR conditions are expected
to redevelop between 15Z and 16Z.


&&

.MARINE...01/200 pM.

There is rather high confidence that conds will remain below SCA
levels across the entire waters through at least Tue. Winds will
increase later in the week.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through Monday morning For
      zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Gomberg
AVIATION...Hall
MARINE...Sweet
SYNOPSIS...Munroe

weather.gov/losangeles




000
FXUS66 KEKA 012203
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
303 PM PDT SUN MAY 1 2016

.SYNOPSIS...A HIGH PRESSURE RIDGE EXTENDING ACROSS THE REGION WILL
MAINTAIN DRY AND WARMER CONDITIONS ACROSS THE AREA THROUGH MONDAY.
TEMPERATURES WILL DECREASE SLIGHTLY MONDAY AND TUESDAY AS A COLD
FRONT APPROACHES AND MOVES THROUGH THE AREA INCREASING THE CHANCES
FOR A FEW SHOWERS AND INCREASING CLOUDINESS. A LOW PRESSURE SYSTEM
MAY MOVE INTO NORTH CENTRAL CA BRINING THUNDERSTORM CHANCES FOR
EASTERN TRINITY COUNTY THROUGH NEXT WEEK.

&&

.DISCUSSION...CLEAR TO PARTLY CLOUDY SKIES WILL CONTINUE ACROSS
THE REGION AS A HIGH PRESSURE RIDGE PERSIST ACROSS THE AREA...AND
LIGHT OFFSHORE FLOW KEEPS THE COAST WARM AND FOG/LOW CLOUD FREE.
THE OFFSHORE WIND COMPONANT WILL CEASE BY MONDAY FOR A RETURN OF
LOW CLOUDS AND LIKELY FOGGY CONDITIONS AT LEAST DURING THE NIGHTS
AND MORNINGS. A WEAK COLD FRONT AND GENERAL TROUGHINESS WILL
APPROACH AND MOVE THROUGH THE REGION MONDAY AND TUESDAY INCREASING
CLOUDINESS AND A SLIGHT CHANCE TO CHANCE FOR SHOWERS MOVING ACROSS
PORTIONS OF THE REGION. CLOUDINESS WILL INCREASE MONDAY AND
TUESDAY WHICH WILL COOL TEMPERATURES SLIGHTLY ACROSS THE REGION.
PATCHY FOG MAY DEVELOP ACROSS PORTIONS OF THE COASTAL AREAS AND
INLAND VALLEYS THROUGH MID WEEK. THE UPPER TROUGH MAY MORPH INTO
A CUT OFF LOW THAT THE GFS HAS MOVING SLOWLY INTO THE BAY AREA BY
THURSDAY. THIS WILL BRING SLIGHTLY ELEVATED CHANCES OF
THUNDERSTORMS AND PERSISTENT SHOWER CHANCES TO THE INTERIOR
MOUNTAINS MAINLY EAST OF WEAVERVILLE. OTHERWISE SEASONAL
TEMPERATURES AND FAIRLY NICE SPRING WEATHER SHOULD CONTINUE.


&&

.AVIATION...VFR WILL PREVAIL THROUGH THE REMAINDER OF THE DAY WITH
RELATIVELY LIGHT WINDS ACROSS THE REGION. OFFSHORE WINDS SHOULD BE
WEAKER TONIGHT SO CEILING DEVELOPMENT ALONG PARTS OF THE COAST WILL
NOT BE OUT OF QUESTION. VFR SHOULD CONTINUE ACROSS INTERIOR
LOCATIONS OVERNIGHT. MOUNTAIN SHOWERS WILL BE POSSIBLE MONDAY
AFTERNOON OTHERWISE EXPECT UPPER LEVEL CLOUDS TO INCREASE LATE IN
THE TAF PERIOD. KML


&&

.MARINE...STEEP WAVES CONTINUED TO SUBSIDE TODAY AS THE RELAXED
PRESSURE GRADIENT ALLOWED WINDS TO DECREASE. WINDS WILL BECOME LIGHT
AND SOUTHERLY ON MONDAY AS A SURFACE LOW FEATURE DRIFTS NORTHWARD.
THIS WILL MAINTAIN LIGHT TO MODERATE WINDS THROUGH THE EARLY HALF OF
THE WEEK BEFORE A RIDGE OF HIGH PRESSURE OFFSHORE BUILDS TOWARDS THE
WEST COAST. THIS WILL PINCH THE GRADIENT ONCE AGAIN AND BRING A
RETURN OF MODERATE TO FRESH NORTHERLY WINDS FOR THE LATE HALF OF THE
WEEK. A NORTHWESTERLY SWELL WILL OTHERWISE DOMINATE THE SEA STATE
FOR THE EARLY HALF OF THE WEEK WITH OVERALL WAVE HEIGHTS PREDICTED
TO REMAIN BELOW 10 FT. STEEP WAVES WILL BUILD ONCE THE WINDS START
INCREASING LATE IN THE WEEK WITH A SMALL LONG PERIOD SWELL EXPECTED
TO PROPAGATE THE WATERS THURSDAY INTO THE WEEKEND. KML


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&

$$

VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA

FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/NWSEUREKA
HTTP://WWW.TWITTER.COM/NWSEUREKA

FOR FORECAST ZONE INFORMATION
SEE FORECAST ZONE MAP ONLINE:
HTTP://WWW.WEATHER.GOV/EUREKA/ZONEMAP.PNG




000
FXUS66 KEKA 012203
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
303 PM PDT SUN MAY 1 2016

.SYNOPSIS...A HIGH PRESSURE RIDGE EXTENDING ACROSS THE REGION WILL
MAINTAIN DRY AND WARMER CONDITIONS ACROSS THE AREA THROUGH MONDAY.
TEMPERATURES WILL DECREASE SLIGHTLY MONDAY AND TUESDAY AS A COLD
FRONT APPROACHES AND MOVES THROUGH THE AREA INCREASING THE CHANCES
FOR A FEW SHOWERS AND INCREASING CLOUDINESS. A LOW PRESSURE SYSTEM
MAY MOVE INTO NORTH CENTRAL CA BRINING THUNDERSTORM CHANCES FOR
EASTERN TRINITY COUNTY THROUGH NEXT WEEK.

&&

.DISCUSSION...CLEAR TO PARTLY CLOUDY SKIES WILL CONTINUE ACROSS
THE REGION AS A HIGH PRESSURE RIDGE PERSIST ACROSS THE AREA...AND
LIGHT OFFSHORE FLOW KEEPS THE COAST WARM AND FOG/LOW CLOUD FREE.
THE OFFSHORE WIND COMPONANT WILL CEASE BY MONDAY FOR A RETURN OF
LOW CLOUDS AND LIKELY FOGGY CONDITIONS AT LEAST DURING THE NIGHTS
AND MORNINGS. A WEAK COLD FRONT AND GENERAL TROUGHINESS WILL
APPROACH AND MOVE THROUGH THE REGION MONDAY AND TUESDAY INCREASING
CLOUDINESS AND A SLIGHT CHANCE TO CHANCE FOR SHOWERS MOVING ACROSS
PORTIONS OF THE REGION. CLOUDINESS WILL INCREASE MONDAY AND
TUESDAY WHICH WILL COOL TEMPERATURES SLIGHTLY ACROSS THE REGION.
PATCHY FOG MAY DEVELOP ACROSS PORTIONS OF THE COASTAL AREAS AND
INLAND VALLEYS THROUGH MID WEEK. THE UPPER TROUGH MAY MORPH INTO
A CUT OFF LOW THAT THE GFS HAS MOVING SLOWLY INTO THE BAY AREA BY
THURSDAY. THIS WILL BRING SLIGHTLY ELEVATED CHANCES OF
THUNDERSTORMS AND PERSISTENT SHOWER CHANCES TO THE INTERIOR
MOUNTAINS MAINLY EAST OF WEAVERVILLE. OTHERWISE SEASONAL
TEMPERATURES AND FAIRLY NICE SPRING WEATHER SHOULD CONTINUE.


&&

.AVIATION...VFR WILL PREVAIL THROUGH THE REMAINDER OF THE DAY WITH
RELATIVELY LIGHT WINDS ACROSS THE REGION. OFFSHORE WINDS SHOULD BE
WEAKER TONIGHT SO CEILING DEVELOPMENT ALONG PARTS OF THE COAST WILL
NOT BE OUT OF QUESTION. VFR SHOULD CONTINUE ACROSS INTERIOR
LOCATIONS OVERNIGHT. MOUNTAIN SHOWERS WILL BE POSSIBLE MONDAY
AFTERNOON OTHERWISE EXPECT UPPER LEVEL CLOUDS TO INCREASE LATE IN
THE TAF PERIOD. KML


&&

.MARINE...STEEP WAVES CONTINUED TO SUBSIDE TODAY AS THE RELAXED
PRESSURE GRADIENT ALLOWED WINDS TO DECREASE. WINDS WILL BECOME LIGHT
AND SOUTHERLY ON MONDAY AS A SURFACE LOW FEATURE DRIFTS NORTHWARD.
THIS WILL MAINTAIN LIGHT TO MODERATE WINDS THROUGH THE EARLY HALF OF
THE WEEK BEFORE A RIDGE OF HIGH PRESSURE OFFSHORE BUILDS TOWARDS THE
WEST COAST. THIS WILL PINCH THE GRADIENT ONCE AGAIN AND BRING A
RETURN OF MODERATE TO FRESH NORTHERLY WINDS FOR THE LATE HALF OF THE
WEEK. A NORTHWESTERLY SWELL WILL OTHERWISE DOMINATE THE SEA STATE
FOR THE EARLY HALF OF THE WEEK WITH OVERALL WAVE HEIGHTS PREDICTED
TO REMAIN BELOW 10 FT. STEEP WAVES WILL BUILD ONCE THE WINDS START
INCREASING LATE IN THE WEEK WITH A SMALL LONG PERIOD SWELL EXPECTED
TO PROPAGATE THE WATERS THURSDAY INTO THE WEEKEND. KML


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&

$$

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000
FXUS66 KSTO 012150
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
250 PM PDT SUN MAY 1 2016

.Synopsis...
Threat of afternoon showers and thunderstorms continues over the
mountains into Tuesday then a more widespread chance Wednesday
into Friday. Cooling to near normal midweek.

&&

.Discussion...
Thunderstorms and showers have developed along the western Sierra
slopes this afternoon. Current radar shows that most of the
thunderstorms are in El Dorado county and southward along the
Sierra. Latest HRRR run is showing that showers/thunderstorms will
gradually spread northward along the Sierra...reaching up to
around the Quincy-Chester area. HRRR also shows that
showers/thunderstorms could move into the foothills, especially
the Motherlode region along with some showers possible in the
Northern San Joaquin Valley this evening around Stockton and
Modesto. All shower activity should diminish by 9-10 pm tonight.
In the meantime, if you hear thunder, stay indoors for shelter to
avoid dangerous lightning and possible hail.

Meso low weakens over NorCal Monday although some lingering
chances for showers/thunderstorms possible along the higher
elevations of the Sierra. By Tuesday, a deep upper trough over the
Eastern Pacific Ocean will move into the West Coast which will
continue the threat of afternoon mountain showers and
thunderstorms. High temps trend down slightly on Tuesday as
synoptic cooling and onshore flow gradually increase over Interior
NorCal.

More notable cooling (5-10 degrees) on Wednesday as the
center of the low gets closer to interior NorCal. Valley highs
will be around the mid 70s with 50s and 60s along foothills and
mountains. Chance of showers will become more widespread on
Wednesday, covering much of our CWA. Instability with this low
will keep a slight chance of thunderstorm development in the mix,
too. JBB

&&
.EXTENDED DISCUSSION (Thursday THROUGH Sunday)

Forecast models are in decent agreement as to the position and
timing of the upper level low track and progression starting at the
beginning of the long term forecast period.  The high amplitude
trough of low pressure is a bit quicker as advertised by the GFS
heading into late Wednesday night to early Thursday morning, while
the ECMWF has the arrival into NorCal more into the early to mid
morning hours on Thursday. In either scenario, the incoming storm
system will bring the needed lift behind enough moisture to bring
showers and thunderstorm chances for the entire forecast area. The
system will not move very quick, and cool temperatures along with
chances for showers and thunderstorms will continue through next
weekend.

A cool down of temperatures is expected with a return to near normal
high temperatures in the low to mid 70s in the valley, 50s to 60s in
the foothills, and the low to mid 40s in the higher elevations on
Thursday and Friday.  Temperatures should return to slightly above
normal temperatures in the valley next weekend.
&&

.AVIATION...

VFR conditions are expected at the terminals for the next 24
hours. Thunderstorms over the Sierra Cascade range this afternoon
and evening. Light winds.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$




000
FXUS65 KREV 012146
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
246 PM PDT SUN MAY 1 2016

.SYNOPSIS...

Warmer temperatures are expected today through Tuesday with a chance
for showers and a few thunderstorms each afternoon and evening.
Cooler conditions with more widespread rain, high elevation snow,
and a slight chance for thunderstorms are possible from Wednesday
through Sunday as low pressure moves slowly across the western
U.S.

&&

.SHORT TERM...

An area of high pressure is building to the north, focused over
northern Idaho and northwest Montana stretching into Canada. While
the Sierra and western Nevada will respond with warmer conditions,
lingering moisture and instability will lead to afternoon and
evening shower and thunderstorm development.

Showers with isolated thunderstorms have begun to form this
afternoon mainly along the Sierra and across the central Nevada
Basin and Range. These pulse storms will spread across the area,
but will be very hit or miss. Storms tomorrow are more likely to
form in northeast California and northwest Nevada as a weak
shortwave moves through these areas. Storm risks will include
lightning, small hail, and brief moderate to heavy rain.

A large area of low pressure approaches the west coast Tuesday,
slowly moving onshore on Wednesday. The increased upper level
divergence ahead of this feature, along with an influx of moisture
will bring better chances for shower and thunderstorms across the
region. Tuesday, the focus is more likely to be northeast CA, the
northern Sierra, and extreme northwest Nevada. On Wednesday,
chances will spread across northern Nevada and southern Sierra as
well.

Wednesday could be interesting as a jet segment nosing into the
region will bring increasing shear. This could help storms become
more organized/severe, but on the flip side could also be too much
shear and end up tearing the updrafts of the storms apart. We will
continue to monitor as slight changes in timing could bring either
scenario Wednesday afternoon. -Dawn

.LONG TERM...Thursday through Sunday...

An upper level low will provide a prolonged period of precipitation
midweek into next weekend. The center of the low will cross the Bay
Area Thursday which will result in increased moisture and
instability across the region. Much of the northern Sierra and
western Nevada will exist in diffluent flow aloft along with several
hundred J/kg of CAPE. As such, do expect widespread showers and
thunderstorms Thursday which may result in heavy rainfall,
abundant small hail, and gusty outflow winds.

Low ensemble spreads and consistent model agreement is yielding
higher confidence in this cooler and wet pattern. As this low
becomes detached from the mean flow, it will linger and be slow to
depart the region. This will result in a persistent chance of
showers and thunderstorms into the next weekend. Although difficult
to assign total precipitation amounts a week out, it is interesting
to note the low end of ensemble spreads depicting an inch of
rainfall across western Nevada by next weekend. This low won`t be a
particularly cold system but could see snow levels dip to some of
the higher pass levels. Travel impacts and slow downs will be
possible for these areas through next week. Fuentes

&&

.AVIATION...

Brief MVFR conditions possible through about 03z today with light
showers possible mainly for Sierra terminals(KTRK/KTVL/KMMH).
Isolated thunderstorms are possible as well but chances should
remain low at around 10-15%. Light winds will prevail Monday with
another chance of showers and isolated thunderstorms mainly for
KTRK/KTVL. Lesser chances expected for KRNO/KCXP/KMMH with about a
15% of rain showers Monday afternoon. Fuentes

&&

.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

$$

For more information from the National Weather Service visit...
http://weather.gov/reno




000
FXUS66 KLOX 012140
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
240 PM PDT SUN MAY 1 2016

.SYNOPSIS...
A departing low pressure system will bring the slight chance of
showers and thunderstorms through this evening across interior
areas. A gradual warming trend is expected through Tuesday as
high pressure aloft briefly builds into the region. A slow moving
low pressure system may bring showers and thunderstorms with
cooler conditions to the area Thursday through the weekend.

&&

.SHORT TERM...(TDY-WED)

Main short term impact is potential convective showers and thunderstorms
across interior sections of forecast area this afternoon and
evening. As of 2 pm, satellite imagery showing considerable
cumulus/towering cumulus clouds developing across interior
sections, mostly over the mountains. Doppler radar showing
a few storms producing rain showers over our local mountains
and interior valleys of SLO county, with only lightning strikes
so far being observed to our north in Kern county.

Weak upper level low pressure system centered over Central
California will bring some cyclonic flow and associated vort
energy across our forecast area this afternoon. Some residual
moisture across the region this afternoon, with precipitable
water values ranging between .7-.8 inches. With ample early May
sunshine and still some cold air aloft (500 mb temperatures as low
as -18 degrees celsius across interior sections), there will
likely be enough instability and moisture to continue generating
some showers over the mountains, deserts, and interior valleys
this afternoon and early evening. With latest NAM model soundings
showing lifted index values ranging between -2 and -4, and surface
based CAPE values between 300-700 J/kg, the convective parameters
indicate a slight chance thunderstorms is warranted this
afternoon/early evening across the mountains and deserts. With
the upper level wind flow from the northwest and mid level flow
from the northeast, could see some storms drift off the mountains
into the adjacent foothill portions of the valleys, as well as the
Santa Clarita Valley. If any thunderstorms do develop today, they
will likely be slow moving, capable of producing heavy rain with
localized flooding. Other potential thunderstorm impacts include
gusty winds, and small hail.

Meanwhile, low clouds have burned off the coast this afternoon.
NAM model cross sections showing ample low level moisture and
moderate-strong onshore flow next few days to maintain a high
probability of night and morning low clouds and fog across many
coastal/valley areas. Mild temperatures will continue next couple
of days, with gradual warming across interior sections.
While, there is some residual mid level moisture over the
mountains on Monday, only expecting some afternoon buildups
as the atmosphere begins to stabilize. By tuesday, a large
upper low begins to approach the west coast. This system will
bring an increasae in mid/high level clouds across the forecast
area.



.LONG TERM...(THU-SUN)

12z GFS/ECMWF model solutions in general agreement that a cutoff
low pressure system will likely impact the forecast area sometime
between Thursday and Friday, then slowly drift east over the
weekend. There will be a chance for hit and miss showers in most
places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). Current
projections have cold core upper low (with 500 mb temperatures of
-24 degrees Celsius) moving across Southwest California sometime
between Thursday afternoon through Friday. With this cold air
aloft combined with early May sunshine providing good surface
heating, feel that there will be enough instability to warrant a
slight chance of thunderstorms(especially over interior sections),
and have added accordingly to the official forecast. This system
is cold enough that we could potentially see some snow impacts
in the local mountains, with snow levels projected to range
between 5000 and 6000 feet.

&&

.AVIATION...01/1800Z

AT 1737Z at KLAX, the marine layer depth was 3300 feet. The top
of the inversion was around 3900 feet with a temperature of 13
degrees C.

a newly reinvigorated eddy was causing some ceiling issues in
southern la county. klax remains on the north edge of the cloud
shield. the clouds over coastal la county are expected to slowly
push to the east this afternoon as the sea breeze clears the skies
for a time. elsewhere...skies will be mostly clear this afternoon
except in the mountains and deserts where a stray thunderstorm is
possible during the afternoon.

tonight...there is moderate confidence in the development of
marine clouds across the coastal and valley sections for later
this evening and overnight. there is less confidence for the
central coast.

KLAX and kbur...moderate confidence in the 18z taf. mvfr
conditions are expected for the overnight hours extending into
monday morning.


&&

.MARINE...01/200 pM...

There is rather high confidence that conds will remain below SCA
levels across the entire waters through at least Tue. Winds will
increase later in the week.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 9 PM PDT this evening
      For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Gomberg
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Munroe

weather.gov/losangeles




000
FXUS66 KLOX 012125
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
225 PM PDT SUN MAY 1 2016

.SYNOPSIS...
A departing low pressure system will bring the slight chance of
showers and thunderstorms through this evening across interior
areas. A gradual warming trend is expected through Tuesday as
high pressure aloft briefly builds into the region. A slow moving
low pressure system may bring showers and thunderstorms with
cooler conditions to the area Thursday through the weekend.

&&

.SHORT TERM...(TDY-WED)

Main short term impact is potential convective showers and thunderstorms
across interior sections of forecast area this afternoon and
evening. As of 2 pm, satellite imagery showing considerable
cumulus/towering cumulus clouds developing across interior
sections, mostly over the mountains. Doppler radar showing
a few storms producing rain showers over our local mountains, with
only lightning strikes so far being observed to our north in Kern
county.

Weak upper level low pressure system centered over Central
California will bring some cyclonic flow and associated vort
energy across our forecast area this afternoon. Some residual
moisture across the region this afternoon, with precipitable
water values ranging between .7-.8 inches. With ample early May
sunshine and still some cold air aloft (500 mb temperatures as low
as -18 degrees celsius across interior sections), there will
likely be enough instability and moisture to continue generating
some showers over the mountains, deserts, and interior valleys
this afternoon and early evening. With latest NAM model soundings
showing lifted index values ranging between -2 and -4, and surface
based CAPE values between 300-700 J/kg, the convective parameters
indicate a slight chance thunderstorms is warranted this
afternoon/early evening across the mountains and deserts. With
the upper level wind flow from the northwest and mid level flow
from the northeast, could see some storms drift off the mountains
into the adjacent foothill portions of the valleys, as well as the
Santa Clarita Valley. If any thunderstorms do develop today, they
will likely be slow moving, capable of producing a brief heavy
downpour, gusty winds, and small hail.

Meanwhile, low clouds have burned off the coast this afternoon.
NAM model cross sections showing ample low level moisture and
moderate-strong onshore flow next few days to maintain a high
probability of night and morning low clouds and fog across many
coastal/valley areas. Mild temperatures will continue next couple
of days, with gradual warming across interior sections.
While, there is some residual mid level moisture over the
mountains on Monday, only expecting some afternoon buildups
as the atmosphere begins to stabilize. By tuesday, a large
upper low begins to approach the west coast. This system will
bring an increasae in mid/high level clouds across the forecast
area.



.LONG TERM...(THU-SUN)

12z GFS/ECMWF model solutions in general agreement that a cutoff
low pressure system will likely impact the forecast area sometime
between Thursday and Friday, then slowly drift east over the
weekend. There will be a chance for hit and miss showers in most
places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). Current
projections have cold core upper low (with 500 mb temperatures of
-24 degrees Celsius) moving across Southwest California sometime
between Thursday afternoon through Friday. With this cold air
aloft combined with early May sunshine providing good surface
heating, feel that there will be enough instability to warrant a
slight chance of thunderstorms(especially over interior sections),
and have added accordingly to the official forecast. This system
is cold enough that we could potentially see some snow impacts
in the local mountains, with snow levels projected to range
between 5000 and 6000 feet.



&&

.AVIATION...01/1800Z

AT 1737Z at KLAX, the marine layer depth was 3300 feet. The top
of the inversion was around 3900 feet with a temperature of 13
degrees C.

a newly reinvigorated eddy was causing some ceiling issues in
southern la county. klax remains on the north edge of the cloud
shield. the clouds over coastal la county are expected to slowly
push to the east this afternoon as the sea breeze clears the skies
for a time. elsewhere...skies will be mostly clear this afternoon
except in the mountains and deserts where a stray thunderstorm is
possible during the afternoon.

tonight...there is moderate confidence in the development of
marine clouds across the coastal and valley sections for later
this evening and overnight. there is less confidence for the
central coast.

KLAX and kbur...moderate confidence in the 18z taf. mvfr
conditions are expected for the overnight hours extending into
monday morning.


&&

.MARINE...01/200 pM...

There is rather high confidence that conds will remain below SCA
levels across the entire waters through at least Tue. Winds will
increase later in the week.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 9 PM PDT this evening
      For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Gomberg
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Munroe

weather.gov/losangeles




000
FXUS66 KHNX 012120
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
220 PM PDT SUN MAY 1 2016

.SYNOPSIS...
A FEW LINGERING SHOWERS AND THUNDERSTORMS OVER THE REGION
TODAY...THEN CLEARING SKIES AND WARMER TEMPERATURES MONDAY AND
TUESDAY AS WEAK HIGH PRESSURE MOVES OVER THE REGION. ANOTHER WEATHER
SYSTEM WILL MOVE INTO THE REGION WEDNESDAY INCREASING PRECIPITATION
CHANCES FOR THE SECOND PART OF THE WEEK.

&&

.DISCUSSION...
WEAK DISTURBANCE TRIGGERING SHRA AND TSRA THIS AFTERNOON ACROSS
THE SIERRA...TEHACHAPI AND DIABLO RANGE MOUNTAINS. TEMPS SLIGHTLY
ABOVE NORMAL TODAY ACROSS THE SJV...HOWEVER CLOUDS AND WEAK NE
FLOW ARE KEEPING DESERT TEMPS DOWN TODAY.

MODELS ARE BUILDING IN THE UPPER RIDGE ACROSS THE REGION ON MONDAY
AND CONTINUING THROUGH WEDNESDAY WITH ABOVE NORMAL TEMPS AND
DRY CONDITIONS EXPECTED.

FORECAST GUIDANCE IS CONTINUING TO GET MORE IN LINE WITH TIMING
AND TRACK OF A DIGGING CUT OFF LOW PRESSURE CENTER DROPPING OUT OF
THE GULF OF AK AND MOVING SOUTH ALONG THE WEST COAST BEFORE MOVING
INLAND ACROSS SOCAL FRIDAY EVENING. WE WILL BEGIN TO SEE THE
IMPACTS OF THIS SYSTEM THURSDAY AS STRONG PVA ALONG THE EAST SIDE
OF THE LOW WILL PROVIDE PLENTY OF LIFT ACROSS THE CWA FOR SHRA AND
TSRA...WHICH OF A FEW OF THE STORMS MAY BECOME STRONG THURSDAY
AFTERNOON.

THE LOW MOVES INLAND FRIDAY NIGHT AND WE WILL REMAIN UNSETTLED AS
WRAP AROUND MOISTURE AND CONTINUED INSTABILITY WILL TRIGGER SHRA
AND TSRA FRIDAY. THE CLOSED LOW IS VERY SLOW TO MOVE EAST AS AN
OMEGA BLOCKING PATTERN WILL BE SET UP AND THE UPPER LOW SETS UP
SHOP NEAR THE FOUR CORNERS AREA WITH WEAK DISTURBANCES ROTATING
AROUND IT THROUGH THE WEEKEND. AFTERNOON AND EVENING CONVECTION IS
EXPECTED SATURDAY AND SUNDAY IN THE SIERRA...WITH EVEN A SLIGHT
CHANCE OF SHOWERS IN THE SJV ON SATURDAY. THINGS DO SETTLE DOWN A
BIT ON SUNDAY AS THE BULK OF THE ENERGY IS WELL EAST OF THE
CENTRAL CA INTERIOR. WE ARE ONLY EXPECTING A SLIGHT CHANCE OF SHRA
IN THE SIERRA ON SUNDAY.

&&

.AVIATION...
EXPECT AREAS OF MVFR WITH LOCAL IFR POSSIBLE THROUGH 06Z MONDAY DUE
TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THE SIERRA
NEVADA...AS WELL AS THE KERN COUNTY MOUNTAIN AND DESERT AREAS.
LOCAL MVFR POSSIBLE IN ISOLATED SHOWERS OVER THE SAN JOAQUIN VALLEY
THROUGH 06Z MONDAY. OTHERWISE VFR CONDITIONS WILL PREVAIL OVER THE
CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS.

&&

.AIR QUALITY ISSUES...
NONE.

&&

.CERTAINTY...

THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.

CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AN/OR TO PROVIDE FEEDBACK.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

PUBLIC...JDB
AVN/FW...BSO
SYNOPSIS...WP

WEATHER.GOV/HANFORD




000
FXUS66 KLOX 012118
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
218 PM PDT SUN MAY 1 2016

.SYNOPSIS...
A departing low pressure system will bring the slight chance of
showers and thunderstorms through this evening across interior
areas. A gradual warming trend is expected through Tuesday as
high pressure aloft briefly builds into the region. A slow moving
low pressure system may bring showers and thunderstorms with
cooler conditions to the area Thursday through the weekend.

&&

.SHORT TERM...(TDY-WED)

Main short term impact is potential convective showers and
thunderstorms across interior sections of forecast area this
afternoon and evening. As of 2 pm, satellite imagery showing
considerable cumulus/towering cumulus clouds developing across
interior sections, mostly over the mountains. Doppler radar showing
a few storms producing rain showers over our local mountains, with
only lightning strikes so far being observed to our north in Kern
county.

Weak upper level low pressure system centered over Central
California will bring some cyclonic flow and associated vort
energy across our forecast area this afternoon. Some residual
moisture across the region this afternoon, with precipitable
water values ranging between .7-.8 inches. With ample early May
sunshine and still some cold air aloft (500 mb temperatures as low
as -18 degrees celsius across interior sections), there will
likely be enough instability and moisture to continue generating
some showers over the mountains, deserts, and interior valleys
this afternoon and early evening. With latest NAM model soundings
showing lifted index values ranging between -2 and -4, and surface
based CAPE values between 300-700 J/kg, the convective parameters
indicate a slight chance thunderstorms is warranted this
afternoon/early evening across the mountains and deserts. With
the upper level wind flow from the northwest and mid level flow
from the northeast, could see some storms drift off the mountains
into the adjacent foothill portions of the valleys, as well as the
Santa Clarita Valley. If any thunderstorms do develop today, they
will likely be slow moving, capable of producing a brief heavy
downpour, gusty winds, and small hail.

Meanwhile, low clouds have burned off the coast this afternoon.
NAM model cross sections showing ample low level moisture and
moderate-strong onshore flow next few days to maintain a high
probability of night and morning low clouds and fog across many
coastal/valley areas. Mild temperatures will continue next couple
of days, with gradual warming across interior sections.
While, there is some residual mid level moisture over the
mountains on Monday, only expecting some afternoon buildups
as the atmosphere begins to stabilize. By tuesday, a large
upper low begins to approach the west coast. This system will
bring an increase in mid/high level clouds across the forecast
area.

.LONG TERM...(THU-SUN)

12z GFS/ECMWF model solutions in general agreement that a cutoff
low pressure system will likely impact the forecast area sometime
between Thursday and Friday, then slowly drift east over the
weekend. There will be a chance for hit and miss showers in most
places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). Current
projections have cold core upper low (with 500 mb temperatures of
-24 degrees Celsius) moving across Southwest California sometime
between Thursday afternoon through Friday. With this cold air
aloft combined with early May sunshine providing good surface
heating, feel that there will be enough instability to warrant a
slight chance of thunderstorms(especially over interior sections),
and have added accordingly to the official forecast.

&&

.AVIATION...01/1800Z

AT 1737Z at KLAX, the marine layer depth was 3300 feet. The top
of the inversion was around 3900 feet with a temperature of 13
degrees C.

a newly reinvigorated eddy was causing some ceiling issues in
southern la county. klax remains on the north edge of the cloud
shield. the clouds over coastal la county are expected to slowly
push to the east this afternoon as the sea breeze clears the skies
for a time. elsewhere...skies will be mostly clear this afternoon
except in the mountains and deserts where a stray thunderstorm is
possible during the afternoon.

tonight...there is moderate confidence in the development of
marine clouds across the coastal and valley sections for later
this evening and overnight. there is less confidence for the
central coast.

KLAX and kbur...moderate confidence in the 18z taf. mvfr
conditions are expected for the overnight hours extending into
monday morning.


&&

.MARINE...01/200 pM...

There is rather high confidence that conds will remain below SCA
levels across the entire waters through at least Tue. Winds will
increase later in the week.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 9 PM PDT this evening
      For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Gomberg
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Munroe

weather.gov/losangeles




000
FXUS66 KMTR 012054
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
154 PM PDT SUN MAY 1 2016

.SYNOPSIS....AFTER A WARM DAY TODAY COASTAL FOG AND LOW CLOUDS
WILL LIKELY RETURN BY LATE TODAY OR TONIGHT. SEASONABLE AND DRY
WEATHER IS FORECAST MONDAY AND TUESDAY. A WEATHER SYSTEM WILL
APPROACH CALIFORNIA BY THE MIDDLE OF THE WEEK...BRINGING A CHANCE
OF SHOWERS FROM LATE WEDNESDAY THROUGH THE END OF THE WEEK...ALONG
WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 2:00 PM PDT SUNDAY...WARM DAY ACROSS OUR
ENTIRE REGION TODAY WITH MOST SPOTS 3 TO 7 DEGREES AHEAD OF
YESTERDAY. MODELS HAD BEEN HIGHLIGHTING THE WARM READINGS FOR
NEARLY A WEEK AND APPEAR TO HAVE DONE A GOOD JOB WITH THE VALUES.
A FEW SPOTS HAVE SEEN VERY IMPRESSIVE INCREASES FROM YESTERDAY. IN
PARTICULAR MONTEREY WHERE 79 DEGREES HAS NOW BEEN REACHED. THAT IS
17 AHEAD OF YESTERDAY.

A COOL DOWN IS STILL ON TRACK STARTING TOMORROW AS THE OFFSHORE
FLOW FLIPS TO MORE ONSHORE. AT THE SAME TIME CLOUDS WILL MOVE
BACK INTO THE PICTURE AND RETURN TO COASTAL SPOTS PLUS SOME
ADJACENT VALLEYS TONIGHT. SATELLITE ALREADY SHOWS THE CHANGE WITH
A MINOR SOUTHERLY SURGE CURRENTLY TAKING PLACE. VISIBLE IMAGE HAVE
A NARROW BAND OF CLOUDS NOW INTO WESTERN MONTEREY BAY. THESE
CLOUDS SHOULD CONTINUE TO ADVANCE NORTH AND EAST OVERNIGHT.

WITH AN ONSHORE FLOW IN PLACE FOR MONDAY AND TUESDAY COASTAL
CLOUDS CAN BE EXPECTED ALONG WITH COOLER TEMPERATURES. MOST SPOTS
WILL SEE A 5 TO 10 DEGREE DROP IN HIGHS COMPARED TO TODAY ALTHOUGH
LOCATIONS WELL INLAND WILL SEE ONLY MINOR CHANGES.

UNSETTLED WEATHER WILL RETURN TO OUR REGION STARTING ON WEDNESDAY
AS A LONGWAVE TROF MOVES TO THE WEST COAST. MODELS INDICATE THAT A
CUT-OFF LOW WILL THEN FORM BY THURSDAY NEAR OUR COAST BEFORE
SLOWLY ADVANCING TO THE EAST. AS IS ALWAYS THE CASE WITH CUT-OFF
LOWS, CONFIDENCE IS FAIRLY LOW WITH THE TRACK AND LOCATION OF THE
CENTER WHICH MAKES PIN-POINTING THE BEST CHANCE FOR MOISTURE
DIFFICULT. FOR NOW WENT WITH A MORE GENERAL CHANCE OF SHOWERS. IN
ADDITION, A SLIGHT CHANCED OF THUNDERSTORMS WAS ADDED DUE TO THE
LOCATION OF THE TROF/LOW PLUS MORE INSTABILITY (NAM ALREADY
SHOWING LIFTED VALUES TO MINUS 2 OVER THE NORTH BAY). THIS TIME
OF YEAR, COLDER SYSTEMS COMING FROM THE NORTH ARE A GOOD BET FOR
PRODUCING SOME LIGHTING AND/OR SMALL HAIL. COOLER TEMPERATURES CAN
ALSO BE EXPECTED WITH HIGHS OF ONLY UPPER 50S TO UPPER 60S FOR
THURSDAY AND FRIDAY. DEPENDING ON THE TRACK OF THE LOW, THERE MAY
BE ONLY A LIMITED INCREASE IN TEMPS SATURDAY.

LONGER RANGE FORECAST FOR NEXT WEEK FAVORS A RETURN TO WARMER
THAN NORMAL CONDITIONS WITH NEAR TO SLIGHTLY BELOW NORMAL
PRECIPITATION.

&&

.AVIATION...AS OF 10:30 AM PDT SUNDAY...DRY OFFSHORE FLOW KEEPING
VFR TODAY. THE ONE FLY IN THE OINTMENT IN THE FORECAST IS A
POSSIBLE SOUTHERLY SURGE LATER TODAY. LATEST NAM AND WRF SHOW A
SOUTHERLY SURGE IMPACTING KMRY/KSNS...POSS MAKING IT INTO SF BAY
OVERNIGHT. CONF IS MARGINAL.

VICINITY OF KSFO...VFR.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY TERMINALS...VFR BECOMING MVFR LATE THIS EVENING AND
OVERNIGHT.

&&

.MARINE...AS OF 01:22 PM PDT SUNDAY...HIGH PRESSURE OVER THE
EASTERN PACIFIC WILL KEEP NORTHERLY WINDS OVER THE COASTAL WATERS
TODAY. LOCALLY GUSTY WINDS WILL BE POSSIBLE OVER THE OUTER WATERS
NORTH OF POINT REYES. SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT
AND EARLY MONDAY. A MODERATE SWELL WILL MIX WITH A SMALLER LONG
PERIOD SOUTHERLY SWELL THIS WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

$$

PUBLIC FORECAST: BELL
AVIATION: SIMS
MARINE: SIMS


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000
FXUS65 KPSR 012049
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
150 PM MST MON MAY 2 2016


.SYNOPSIS...
THE LOW PRESSURE SYSTEM THAT BROUGHT SHOWERS AND BELOW-NORMAL
TEMPERATURES TO THE REGION OVER THE LAST FEW DAYS IS EXPECTED TO
MOVE OFF TO THE NORTHEAST TONIGHT AND MONDAY. THIS WILL ALLOW HIGH
PRESSURE TO REBUILD OVER THE DESERT SOUTHWEST FROM MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM IS STILL FORECAST TO MOVE INTO
THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING MUCH COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

TONIGHT THROUGH MONDAY...

THE COLD UPPER LOW CENTER THAT BROUGHT BELOW-NORMAL TEMPERATURES AND
SHOWERS TO THE REGION OVER THE LAST FEW DAYS IS NOW LIFTING OUT TO
THE NORTHEAST...AS ANOTHER...MUCH WEAKER SHORTWAVE MOVES INLAND INTO
CENTRAL CA/NV. AS HEIGHTS/TEMPERATURES ALOFT GRADUALLY RISE THIS
EVENING AND TONIGHT...THE SPRINKLE/LIGHT SHOWER ACTIVITY THAT IS
BEING DETECTED THIS AFTERNOON ON RADAR ACROSS SOUTH-CENTRAL AZ IS
EXPECTED TO END AROUND/AFTER SUNSET...WITH SKIES BECOMING CLEAR-
PARTLY CLOUDY OVER ALL OF OUR CWA BY LATE TONIGHT. THE WARMING
AIRMASS WILL LIKELY KEEP OVERNIGHT LOWS A BIT WARMER AT MOST
LOCATIONS THAN WHAT WAS OBSERVED LAST NIGHT...IN SPITE OF LESS CLOUD
COVER. CONTINUED WARMING ALOFT WILL ALSO ALLOW TEMPERATURES TO WARM
UP INTO THE UPPER-80S TO NEAR 90 RANGE ON MONDAY UNDER MOSTLY CLEAR
SKIES. HOWEVER...THE AFOMENTIONED SHORTWAVE...THAT IS NOW MOVING
INTO CENTRAL CA...WILL LIKELY KEEP MOST LOWER DESERT LOCATIONS BELOW
THE 90 DEGREE MARK ON MONDAY...AS IT MOVES EASTWARD OVER NORTHERN AZ.

TUESDAY THROUGH WEDNESDAY...

CURRENT GLOBAL MODEL SUITES CONTINUE TO SHOW RATHER STRONG HIGH
PRESSURE RIDGING BUILDING EASTWARD INTO THE REGION DURING THIS
PERIOD. THE COMBINATION OF 500MB HEIGHTS IN THE 578-580DM RANGE AND
1000-500MB THICKNESSES AOA 570DM...ALONG WITH MOSTLY CLEAR SKIES
WILL CERTAINLY ALLOW TEMPERATURES TO RISE WELL UP INTO THE 90S EACH
DAY...WITH WEDNESDAY LIKELY BEING THE WARMEST DAY...AS LOW-LEVEL
SOUTHERLY FLOW DEVELOPS OVER THE REGION. HOWEVER...OUTSIDE OF
PERHAPS A FEW OF THE VERY WARMEST SPOTS...IT STILL APPEARS THE MOST
LOCATIONS WILL SEE HIGHS FALL SHORT OF 100 DEGREES EACH DAY...WITH
EVEN THE WARMEST NUMERICAL GUIDANCE STILL KEEPING PHOENIX SKY HARBOR
BELOW 100 AS WELL.

THURSDAY THROUGH SUNDAY...

ALL OF THE GLOBAL MODEL SUITES...AND THE VAST MAJORITY OF THEIR
RESPECTIVE ENSEMBLE MEMBERS CONTINUE TO BRING ANOTHER COLD UPPER LOW
SOUTHWARD INTO THE REGION DURING THIS PERIOD...AS THE OVERALL LONG-
WAVE PATTERN OVER THE NORTH PACIFIC AND NORTH AMERICA UNDERGOES
SIGNIFICANT AMPLIFICATION. ALTHOUGH THIS NEW SYSTEM WILL LIKELY BE
AT LEAST AS COLD AS THE ONE THAT HAS AFFECTED US OVER THE PAST FEW
DAYS...IT APPEARS THAT IT WILL BE A SOMEWHAT DRIER ONE...LIKELY DUE
TO THE MORE NORTHERLY TRACK OF THE SYSTEM. HOWEVER THE OVERALL
IMPACTS FROM THIS NEW SYSTEM WILL LIKELY BE SIMILAR TO THE LAST ONE.
ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES BETWEEN THE
MODELS...IT NOW APPEARS THAT THIS UPPER LOW WILL BEGIN TO AFFECT OUR
CWA ON THURSDAY...BEGINNING TO COOL TEMPERATURES ACROSS THE
REGION...ESPECIALLY OVER SE CA AND THE LOWER COLORADO RIVER
VALLEY...WHILE ALSO SUBSTANTIALLY INCREASING THE WINDS AS WELL...AS
A 100+ KT JET PUSHES EASTWARD OVER THE REGION AHEAD OF THE MAIN
UPPER LOW...WITH ADVISORY-LEVEL WINDS...AREAS OF BLOWING DUST...AND
EVEN SOME FIRE WEATHER ISSUES A REAL POSSIBILITY. FURTHER
COOLING...AND EVEN A SLIGHT CHANCE FOR SHOWERS IS LIKELY FOR THE
FRIDAY-SUNDAY TIME PERIOD AS THE MAIN UPPER LOW MOVES VERY SLOWLY
EASTWARD ACROSS THE REGION...WITH AT LEAST ONE DAY OF HIGHS IN THE
70S ONCE AGAIN A POSSIBILITY FOR MANY LOWER DESERT LOCATIONS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... CLOUDS
NEAR THE 10KFT LEVEL WILL REMAIN IN THE PHX AREA THIS AFTERNOON BUT
BEGIN TO SUBSIDE AFTER 22Z. LIGHTER WINDS AND MUCH LESS CLOUDS
OVERNIGHT AND INTO MONDAY...THOUGH THERE COULD BE A FEW STRONGER
EASTERLY BREEZES MONDAY MORNING BETWEEN 16-19Z.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEAR SKY AND LIGHT WINDS FAVORING DIURNAL PATTERNS ACROSS THE AREA
THROUGH MONDAY AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.


.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...

HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS WITH TEMPERATURES ABOVE SEASONAL NORMALS TUESDAY THROUGH
THURSDAY. AN INCOMING WEATHER SYSTEM WILL CAUSE SOUTHERLY WINDS TO
INCREASE WEDNESDAY AND THURSDAY. THERE MAY BE A WINDOW THURSDAY
AFTERNOON OF STRONG WINDS AND LOW HUMIDITIES THAT REACH CRITICAL
FIRE WEATHER CONDITIONS FROM MARICOPA COUNTY AND TO THE EAST.
CONDITIONS WILL IMPROVE FRIDAY AND SATURDAY WHEN THE SYSTEM MOVES IN
ALLOWING TEMPERATURES TO COOL...HUMIDITIES TO COME UP...AND WINDS TO
DECREASE.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ




000
FXUS65 KPSR 012049
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
150 PM MST MON MAY 2 2016


.SYNOPSIS...
THE LOW PRESSURE SYSTEM THAT BROUGHT SHOWERS AND BELOW-NORMAL
TEMPERATURES TO THE REGION OVER THE LAST FEW DAYS IS EXPECTED TO
MOVE OFF TO THE NORTHEAST TONIGHT AND MONDAY. THIS WILL ALLOW HIGH
PRESSURE TO REBUILD OVER THE DESERT SOUTHWEST FROM MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM IS STILL FORECAST TO MOVE INTO
THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING MUCH COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

TONIGHT THROUGH MONDAY...

THE COLD UPPER LOW CENTER THAT BROUGHT BELOW-NORMAL TEMPERATURES AND
SHOWERS TO THE REGION OVER THE LAST FEW DAYS IS NOW LIFTING OUT TO
THE NORTHEAST...AS ANOTHER...MUCH WEAKER SHORTWAVE MOVES INLAND INTO
CENTRAL CA/NV. AS HEIGHTS/TEMPERATURES ALOFT GRADUALLY RISE THIS
EVENING AND TONIGHT...THE SPRINKLE/LIGHT SHOWER ACTIVITY THAT IS
BEING DETECTED THIS AFTERNOON ON RADAR ACROSS SOUTH-CENTRAL AZ IS
EXPECTED TO END AROUND/AFTER SUNSET...WITH SKIES BECOMING CLEAR-
PARTLY CLOUDY OVER ALL OF OUR CWA BY LATE TONIGHT. THE WARMING
AIRMASS WILL LIKELY KEEP OVERNIGHT LOWS A BIT WARMER AT MOST
LOCATIONS THAN WHAT WAS OBSERVED LAST NIGHT...IN SPITE OF LESS CLOUD
COVER. CONTINUED WARMING ALOFT WILL ALSO ALLOW TEMPERATURES TO WARM
UP INTO THE UPPER-80S TO NEAR 90 RANGE ON MONDAY UNDER MOSTLY CLEAR
SKIES. HOWEVER...THE AFOMENTIONED SHORTWAVE...THAT IS NOW MOVING
INTO CENTRAL CA...WILL LIKELY KEEP MOST LOWER DESERT LOCATIONS BELOW
THE 90 DEGREE MARK ON MONDAY...AS IT MOVES EASTWARD OVER NORTHERN AZ.

TUESDAY THROUGH WEDNESDAY...

CURRENT GLOBAL MODEL SUITES CONTINUE TO SHOW RATHER STRONG HIGH
PRESSURE RIDGING BUILDING EASTWARD INTO THE REGION DURING THIS
PERIOD. THE COMBINATION OF 500MB HEIGHTS IN THE 578-580DM RANGE AND
1000-500MB THICKNESSES AOA 570DM...ALONG WITH MOSTLY CLEAR SKIES
WILL CERTAINLY ALLOW TEMPERATURES TO RISE WELL UP INTO THE 90S EACH
DAY...WITH WEDNESDAY LIKELY BEING THE WARMEST DAY...AS LOW-LEVEL
SOUTHERLY FLOW DEVELOPS OVER THE REGION. HOWEVER...OUTSIDE OF
PERHAPS A FEW OF THE VERY WARMEST SPOTS...IT STILL APPEARS THE MOST
LOCATIONS WILL SEE HIGHS FALL SHORT OF 100 DEGREES EACH DAY...WITH
EVEN THE WARMEST NUMERICAL GUIDANCE STILL KEEPING PHOENIX SKY HARBOR
BELOW 100 AS WELL.

THURSDAY THROUGH SUNDAY...

ALL OF THE GLOBAL MODEL SUITES...AND THE VAST MAJORITY OF THEIR
RESPECTIVE ENSEMBLE MEMBERS CONTINUE TO BRING ANOTHER COLD UPPER LOW
SOUTHWARD INTO THE REGION DURING THIS PERIOD...AS THE OVERALL LONG-
WAVE PATTERN OVER THE NORTH PACIFIC AND NORTH AMERICA UNDERGOES
SIGNIFICANT AMPLIFICATION. ALTHOUGH THIS NEW SYSTEM WILL LIKELY BE
AT LEAST AS COLD AS THE ONE THAT HAS AFFECTED US OVER THE PAST FEW
DAYS...IT APPEARS THAT IT WILL BE A SOMEWHAT DRIER ONE...LIKELY DUE
TO THE MORE NORTHERLY TRACK OF THE SYSTEM. HOWEVER THE OVERALL
IMPACTS FROM THIS NEW SYSTEM WILL LIKELY BE SIMILAR TO THE LAST ONE.
ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES BETWEEN THE
MODELS...IT NOW APPEARS THAT THIS UPPER LOW WILL BEGIN TO AFFECT OUR
CWA ON THURSDAY...BEGINNING TO COOL TEMPERATURES ACROSS THE
REGION...ESPECIALLY OVER SE CA AND THE LOWER COLORADO RIVER
VALLEY...WHILE ALSO SUBSTANTIALLY INCREASING THE WINDS AS WELL...AS
A 100+ KT JET PUSHES EASTWARD OVER THE REGION AHEAD OF THE MAIN
UPPER LOW...WITH ADVISORY-LEVEL WINDS...AREAS OF BLOWING DUST...AND
EVEN SOME FIRE WEATHER ISSUES A REAL POSSIBILITY. FURTHER
COOLING...AND EVEN A SLIGHT CHANCE FOR SHOWERS IS LIKELY FOR THE
FRIDAY-SUNDAY TIME PERIOD AS THE MAIN UPPER LOW MOVES VERY SLOWLY
EASTWARD ACROSS THE REGION...WITH AT LEAST ONE DAY OF HIGHS IN THE
70S ONCE AGAIN A POSSIBILITY FOR MANY LOWER DESERT LOCATIONS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... CLOUDS
NEAR THE 10KFT LEVEL WILL REMAIN IN THE PHX AREA THIS AFTERNOON BUT
BEGIN TO SUBSIDE AFTER 22Z. LIGHTER WINDS AND MUCH LESS CLOUDS
OVERNIGHT AND INTO MONDAY...THOUGH THERE COULD BE A FEW STRONGER
EASTERLY BREEZES MONDAY MORNING BETWEEN 16-19Z.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEAR SKY AND LIGHT WINDS FAVORING DIURNAL PATTERNS ACROSS THE AREA
THROUGH MONDAY AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.


.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...

HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS WITH TEMPERATURES ABOVE SEASONAL NORMALS TUESDAY THROUGH
THURSDAY. AN INCOMING WEATHER SYSTEM WILL CAUSE SOUTHERLY WINDS TO
INCREASE WEDNESDAY AND THURSDAY. THERE MAY BE A WINDOW THURSDAY
AFTERNOON OF STRONG WINDS AND LOW HUMIDITIES THAT REACH CRITICAL
FIRE WEATHER CONDITIONS FROM MARICOPA COUNTY AND TO THE EAST.
CONDITIONS WILL IMPROVE FRIDAY AND SATURDAY WHEN THE SYSTEM MOVES IN
ALLOWING TEMPERATURES TO COOL...HUMIDITIES TO COME UP...AND WINDS TO
DECREASE.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ




000
FXUS66 KSGX 012025
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
125 PM PDT SUN MAY 1 2016

.SYNOPSIS...
LOW PRESSURE OVER THE SOUTHWESTERN STATES WILL WEAKEN...WITH A
WARMING TREND THROUGH TUESDAY. RESIDUAL MOISTURE AND INSTABILITY
WILL STILL SUPPORT SCATTERED SHOWERS...AND POSSIBLE THUNDERSTORM
DEVELOPMENT AFTERNOONS AND EVENINGS...NEAR THE MOUNTAINS. COOLER
WEDNESDAY AS ONSHORE FLOW BUILDS THE MARINE LAYER AHEAD OF AN
ONCOMING LOW PRESSURE CENTER LATE IN THE WEEK. THIS STORM SYSTEM
WILL BRING COOLER WEATHER...MORE CLOUDS....AND PERIODS OF SHOWERS
AND THUNDERSTORMS INTO THE WEEKEND.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

AT 1 PM PDT...MARINE CLOUDS COVERING COASTAL AREAS MUCH OF THE
MORNING HAD THINNED WHILE FARTHER INLAND...CLOUDS WERE BUILDING OVER
THE MTS. SHOWERS HAVE DEVELOPED ON RADAR OVER NORTHERN VENTURA
COUNTY. ONSHORE SURFACE PRESSURE GRADIENTS WERE WEAK...AND WINDS
GENERALLY LIGHT.

FOR THE REMAINDER OF TODAY...SHOWERS WILL BE DEVELOPING OVER THE MTS
WITH A CHANCE FOR ISOLATED THUNDERSTORMS. MOISTURE IS SUFFICIENT...
AND THE 18Z NAM HAS NEGATIVE LIFTED INDEX VALUES OVER THE MTS. MOST
OF THE HI RES MODELS GENERATE SPOTTY PRECIP THERE AS WELL LATER IN
THE DAY. BRIEF HEAVY RAIN IS POSSIBLE BASED ON PW OF OVER 3/4 INCH.

LINGERING MOISTURE IN THE LOW LEVELS AND CYCLONIC FLOW ALOFT WILL
KEEP SOME LOWER CLOUDS ALONG AND WEST OF THE MTS THROUGH MONDAY.
SLIGHTLY WARMER ON MONDAY AS HEIGHTS SLOWLY RISE. THERE IS ONE LAST
SHORTWAVE THAT IS FORECAST TO SLIP OVER AND EAST OF THE AREA...
ACCOMPANIED BY INCREASING WESTERLY FLOW ALOFT. LINGERING INSTABILITY
WILL CONTINUE A THREAT OF ISOLATED SHOWER DEVELOPMENT OVER THE MTS...
AND THE INCREASING WESTERLY FLOW ALOFT WILL STEER ANY THAT MANAGE TO
FORM ONTO THE DESERT SLOPES LATE IN THE DAY.

WEDNESDAY WILL BE A TRANSITION DAY AS ONSHORE FLOW INCREASES AHEAD
OF A DEEPENING LONGWAVE TROUGH OVER THE FAR EASTPAC. COOLER MOST
AREAS...BUT FAIR AFTER MORNING MARINE CLOUDS AND FOG DISSIPATE.

MODEL SOLUTIONS CONTINUE TO COALESCE AROUND THE ARRIVAL OF A CUT-OFF
LOW PRESSURE CENTER LATE IN THE WEEK. THE LATEST GUIDANCE SHOWS A
DEEPENING LONGWAVE TROUGH JUST OFFSHORE OF THE WEST COAST ON WED. A
CUT-OFF DEVELOPS OFF THE NOCAL COAST THU MORNING AND SLOWLY CHURNS
SOUTH ALONG THE CA COAST THROUGH FRI...MOVING INLAND OVER SOCAL ON
SAT...ACCOMPANIED BY SHOWERS AND ISOLATED THUNDERSTORMS. WESTERLY
WINDS WILL BE INCREASING AS EARLY AS WED OVER THE MTS/DESERTS...
LIKELY PEAKING ON THU. A FEW SHOWERS COULD BREAK OUT ON THU...BUT THE
HIGHER PROBABILITY FOR WIDESPREAD SHOWERS WILL COME ON THU NIGHT/FRI
MORNING.

CONFIDENCE IS HIGH FOR THE DEVELOPMENT OF THIS SYSTEM...BUT
SIGNIFICANT DIFFERENCES REMAIN WITH THE EVOLUTION THROUGH MON. THE
ECMWF MODEL DOES NOT EJECT THE SYSTEM COMPLETELY UNTIL SUN NIGHT...
WHILE THE 12Z GFS SENDS IT PACKING SAT NIGHT WITH ONLY SOME
RESIDUAL WRAP AROUND MOISTURE INTO THE MTS FOR SUN. CHANCE POPS ARE
IN THE FORECAST TO COVER THIS PERIOD FOR NOW...AND GIVEN THE DYNAMICS
AND COLD AIR...A FEW THUNDERSTORMS ARE LIKELY TO POP UP AS WELL.

LOOK FOR DRY AND MUCH WARMER WEATHER NEXT WEEK AS THE GUIDANCE
INDICATES RIDGE BUILDING OVER CA.

&&

.AVIATION...
012000Z...COAST/VALLEYS...SCT-BKN CLOUD LAYERS BETWEEN 3000-4000 FT
MSL THIS AFTERNOON. BKN-OVC CIGS WILL FILL BACK IN THIS EVENING,
GENERALLY MORE EXTENSIVE IN COVERAGE, WITH BASES 1500-2500 FT MSL.
LOW CLOUDS SCATTERING OUT BETWEEN 16-18Z MONDAY MORNING.

MOUNTAINS/DESERTS...SCT-BKN CLOUDS OVER AND NEAR THE MOUNTAINS WITH
BASES 8000-12000 FT MSL, CHANCE OF AFTERNOON SHOWERS OR AN ISOLATED
THUNDERSTORM OVER THE MOUNTAINS AND HIGH DESERT AND LESS WINDY
OVERALL.

&&

.MARINE...
100 PM...THROUGH WEDNESDAY...LIGHT WINDS EACH NIGHT AND MORNING,
FOLLOWED BY ONSHORE NORTHWEST WINDS 10-15 KT EACH AFTERNOON. FOR
THURSDAY AND FRIDAY, A DEEP PACIFIC TROUGH WILL BRING STRONGER AND
MORE CONSISTENT NORTHWEST WINDS AND A CHANCE OF RAIN.

&&

.BEACHES...
100 PM...A LONG-PERIOD SOUTHERLY SWELL WILL BRING ELEVATED SURF TO
SOUTHWEST FACING BEACHES TODAY AND MONDAY WITH STRONG RIP AND
LONGSHORE CURRENTS. A BEACH HAZARDS STATEMENT IS IN EFFECT THROUGH 9
PM THIS EVENING. SEE LAXCFWSGX FOR DETAILS.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR ORANGE COUNTY
     COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.

PZ...NONE.
&&

$$

PUBLIC...JAD
AVIATION/MARINE/BEACHES...TS




000
FXUS66 KLOX 011839
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1139 AM PDT SUN MAY 1 2016

.SYNOPSIS...
A departing low pressure system will bring the slight chance of
showers and thunderstorms today across the mountains, foothills,
and antelope valley. A high pressure system will briefly build
into the region through Tuesday, supporting a gradual warming
trend. A slow moving low pressure system will likely bring a cool
down to the area with showers also possible Thursday through the
weekend.

&&

.SHORT TERM...(TDY-TUE)

Satellite imagery showing partly to mostly cloudy skies across the
Los Angeles basin this morning...otherwise mostly clear skies
across the district. Latest ACARS sounding and pilot reports
showing marine layer depth between 2000 and 2500 feet across
LA county this morning. Look for another mild day across the
region, with most inland areas climbing into the 70s.

Main upper level low pressure is spinning across Arizona this
morning, but a secondary weak upper level trough and associated
vorticity energy is forming on the back side of the low
pressure system across central and southern California. This
feature will likely generate some weak cyclonic flow over
the forecast area today. Some residual moisture across the
region today, with precipitable water values of around .7-.8
inches. With ample early May sunshine and still some cold air
aloft (500 mb temperatures as low as -18 degrees celsius across
interior sections), there will likely be enough instability and
moisture to generate some showers over the mountains this
afternoon. With lifted index values ranging between -2 and -4, and
CAPE values between 300-500 J/kg, the convective parameters do
indicate a slight chance for thunderstorms this afternoon across
the mountains. With the upper level wind flow from the northwest
and mid level flow from the north-northeast, could see some storms
drift off the mountains into the adjacent foothill portions of the
valleys, as well as the Santa Clarita and Antelope Valleys. If any
thunderstorms do develop today, they could be slow moving, capable
of producing a brief heavy downpour, gusty winds, and small hail.

*** From previous discussion ***

Another night and another mdl fcst of an eddy and a significant
marine layer stratus deck. Again this is not a high confidence
fcst and could easily see less clouds. The upper low will be much
further east and the only convection will be limited some
afternoon cu over the mtns driven only by afternoon heating.

By Tuesday a large upper low begins to approach the west coast.
The increase in cyclonic turning associated with this low will
help the overnight marine layer stratus deck to form and move into
the vlys. Otherwise skies will be partly cloudy and max temps will
be several degrees above normal.


.LONG TERM...(WED-SAT)

A cooling trend should begin by Wednesday with an upper-level
trough approaching from the northwest. Models are in good synoptic
agreement that a cutoff low will develop over the area Thursday
night through Friday, then slowly drift east on Saturday. There
will be a chance for hit and miss showers in most places late
Wednesday night through Saturday. At this time, it looks like late
Thursday through Friday would be the best chance for any showers.
Thunderstorms are not in the forecast at the moment, but they may
need to be added at a later time, as 500 mb temps are as low as
-25 deg C when the center of the upper low moves overhead.

&&

.AVIATION...01/1800Z

AT 1737Z at KLAX, the marine layer depth was 3300 feet. The top
of the inversion was around 3900 feet with a temperature of 13
degrees C.

a newly reinvigorated eddy was causing some ceiling issues in
southern la county. klax remains on the north edge of the cloud
shield. the clouds over coastal la county are expected to slowly
push to the east this afternoon as the sea breeze clears the skies
for a time. elsewhere...skies will be mostly clear this afternoon
except in the mountains and deserts where a stray thunderstorm is
possible during the afternoon.

tonight...there is moderate confidence in the development of
marine clouds across the coastal and valley sections for later
this evening and overnight. there is less confidence for the
central coast.

KLAX and kbur...moderate confidence in the 18z taf. mvfr
conditions are expected for the overnight hours extending into
monday morning.


&&

.MARINE...01/900 AM...

Winds have diminished across the coastal waters. There is rather
high confidence that conds will remain below SCA levels across the
entire waters through at least Tue.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 9 PM PDT this evening
      For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Gomberg
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Munroe

weather.gov/losangeles




000
FXUS66 KMTR 011729
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1029 AM PDT SUN MAY 1 2016

.SYNOPSIS....OFFSHORE WINDS WILL CONTINUE TODAY...RESULTING IN
SUNNY AND WARM CONDITIONS IN MOST AREAS. COASTAL FOG AND LOW
CLOUDS WILL LIKELY RETURN BY LATE TODAY OR TONIGHT. SEASONABLE
AND DRY WEATHER IS FORECAST MONDAY AND TUESDAY. A WEATHER SYSTEM
WILL APPROACH CALIFORNIA BY THE MIDDLE OF THE WEEK...BRINGING A
CHANCE OF SHOWERS FROM LATE WEDNESDAY THROUGH THE END OF THE
WEEK...ALONG WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 8:45 AM PDT SUNDAY...CLEAR START TO THE DAY
WITH A MODERATE OFFSHORE FLOW IN PLACE. N-TO-S GRADIENT RIGHT NOW
IS OVER 2 MB WHILE W-TO-E FLOW IS SLIGHTLY FROM THE EAST. AS THE
PREVIOUS DISCUSSION MENTIONED, MODELS ARE INDICATING A SOUTHERLY
PUSH UP THE COAST TODAY ALTHOUGH CURRENT SATELLITE DOES NOT SHOW
ANY CLOUDS EVEN UP TO SLO COUNTY. 14Z RUN OF THE HRRR DOES
INDICATE SOUTHERLY WINDS WILL SET UP OVER THE NEXT FEW HOURS, SO
WILL KEEP A CLOSE EYE ON THE SATELLITE TO SEE IF IT DOES
MATERIALIZE.

CURRENT FORECAST ON TRACK SO NO UPDATES PLANNED AT THE MOMENT.

.PREVIOUS DISCUSSION...SKIES ARE CLEAR ACROSS OUR ENTIRE FORECAST
AREA EARLY THIS MORNING AS LIGHT OFFSHORE FLOW CONTINUES. CURRENT
TEMPERATURES ARE GENERALLY WARMER THAN 24 HOURS AGO AND IN SOME
CASES SEVERAL DEGREES WARMER. FORECAST GUIDANCE INDICATES HIGH
TEMPERATURES TODAY WILL BE ABOUT FIVE DEGREES WARMER THAN
YESTERDAY. HOWEVER...MODELS FORECAST AN END TO OFFSHORE FLOW TODAY
ALONG WITH THE DEVELOPMENT OF SOUTHERLY FLOW ALONG THE COAST. THIS
DOES NOT LOOK LIKE A CLASSIC "SOUTHERLY SURGE" SCENARIO...SINCE
LOW CLOUDS DO NOT ALREADY EXIST TO OUR SOUTH NEAR POINT
CONCEPTION. WHAT`S MORE LIKELY TO HAPPEN IS THAT LOW CLOUDS AND
FOG WILL FORM IN COASTAL AREAS FROM MONTEREY BAY SOUTH BY EARLY
AFTERNOON...AND THEN MOVE NORTH UP ALONG THE REST OF OUR COAST
LATE THIS AFTERNOON AND EVENING. THIS MAKES FOR A DIFFICULT
TEMPERATURE FORECAST TODAY FOR COASTAL AREAS SINCE THE TIMING OF
THE SOUTHERLY WIND ONSET AND COASTAL FOG DEVELOPMENT WILL HAVE A
BIG IMPACT ON TEMPERATURES. MOST LIKELY SCENARIO IS FOR COOLING TO
OCCUR IN LOCATIONS LIKE BIG SUR AND SANTA CRUZ WHILE OTHER COASTAL
AREAS WILL BE AS WARM OR WARMER THAN YESTERDAY.

ANOTHER ITEM TO WATCH TODAY IS A SHORTWAVE TROUGH CURRENTLY OVER
SOUTHEAST OREGON THAT IS ROTATING AROUND A LONGWAVE TROUGH
CENTERED OVER THE DESERT SW. THIS SHORTWAVE IS FORECAST TO ROTATE
INTO NORTHERN AND CENTRAL CALIFORNIA LATER TODAY. THE ECMWF KEEPS
ALL PRECIP ASSOCIATED WITH THIS SHORTWAVE TO OUR EAST...MAINLY OVER
THE SIERRA NEVADA. HOWEVER...BOTH THE 00Z NAM AND 00Z GFS
FORECAST ISOLATED SHOWERS ALONG THE EASTERN FRINGES OF OUR
FORECAST AREA LATE THIS AFTERNOON AND EARLY THIS EVENING. HAVE
THEREFORE ADDED SLIGHT CHANCE POPS TO FAR EASTERN ALAMEDA...SANTA
CLARA...AND SAN BENITO COUNTIES FOR LATER TODAY.

DRY AND MILD WEATHER IS FORECAST FOR MONDAY AND TUESDAY. ONSHORE
FLOW WILL LIKELY MAINTAIN AT LEAST AREAS OF NIGHT AND MORNING LOW
CLOUDS AND TEMPERATURES WILL BE NEAR NORMAL.

AN UPPER TROUGH CURRENTLY SEEN ON SATELLITE IMAGERY OFFSHORE ALONG
145W IS FORECAST TO GRADUALLY APPROACH THE CALIFORNIA COAST OVER
THE NEXT THREE DAYS AND BEGIN TO GENERATE SHOWER CHANCES ACROSS
OUR AREA BY LATE WEDNESDAY. BOTH THE GFS AND ECMWF FORECAST A
CUTOFF LOW TO DEVELOP NEAR SAN FRANCISCO BY THURSDAY...WITH THAT
LOW THEN PROJECTED TO DROP SOUTHEAST AND TRACK ACROSS SOUTHERN
CALIFORNIA BY LATE FRIDAY AND FRIDAY NIGHT. THUS...SHOWER CHANCES
WILL CONTINUE THROUGH THE END OF THE WEEK AND PROBABLY INTO NEXT
WEEKEND AS WELL. GIVEN THE UNPREDICTABILITY OF CUTOFF LOW
MOVEMENT...IT`S DIFFICULT TO PINPOINT WHERE SHOWER CHANCES WILL BE
GREATEST DURING THE SECOND HALF OF THE WEEK. ISOLATED THUNDERSTORMS
MAY ALSO OCCUR...BUT WILL WAIT TO ADD THUNDERSTORMS TO THE
FORECAST UNTIL CONFIDENCE INCREASES ON THE TIMING AND TRACK OF THE
UPPER LOW. IN ADDITION TO PRECIPITATION CHANCES...THIS UPPER LOW
WILL RESULT IN COOLER THAN NORMAL CONDITIONS ACROSS MOST OF OUR
AREA DURING THE SECOND HALF OF THE WEEK.

&&

.AVIATION...AS OF 10:30 AM PDT SUNDAY...DRY OFFSHORE FLOW KEEPING
VFR TODAY. THE ONE FLY IN THE OINTMENT IN THE FORECAST IS A
POSSIBLE SOUTHERLY SURGE LATER TODAY. LATEST NAM AND WRF SHOW A
SOUTHERLY SURGE IMPACTING KMRY/KSNS...POSS MAKING IT INTO SF BAY
OVERNIGHT. CONF IS MARGINAL.

VICINITY OF KSFO...VFR.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY TERMINALS...VFR BECOMING MVFR LATE THIS EVENING AND
OVERNIGHT.

&&

.MARINE...AS OF 8:45 AM PDT SUNDAY...HIGH PRESSURE OVER THE
EASTERN PACIFIC WILL KEEP NORTHERLY WINDS OVER THE COASTAL WATERS
TODAY. LOCALLY GUSTY WINDS WILL BE POSSIBLE OVER THE OUTER WATERS
NORTH OF POINT REYES. SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT
AND EARLY MONDAY. A MODERATE SWELL WILL MIX WITH A SMALLER LONG
PERIOD SOUTHERLY SWELL THIS WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...NONE.

$$

PUBLIC FORECAST: BELL/DYKEMA
AVIATION: SIMS
MARINE: SIMS


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000
FXUS66 KMTR 011729
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1029 AM PDT SUN MAY 1 2016

.SYNOPSIS....OFFSHORE WINDS WILL CONTINUE TODAY...RESULTING IN
SUNNY AND WARM CONDITIONS IN MOST AREAS. COASTAL FOG AND LOW
CLOUDS WILL LIKELY RETURN BY LATE TODAY OR TONIGHT. SEASONABLE
AND DRY WEATHER IS FORECAST MONDAY AND TUESDAY. A WEATHER SYSTEM
WILL APPROACH CALIFORNIA BY THE MIDDLE OF THE WEEK...BRINGING A
CHANCE OF SHOWERS FROM LATE WEDNESDAY THROUGH THE END OF THE
WEEK...ALONG WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 8:45 AM PDT SUNDAY...CLEAR START TO THE DAY
WITH A MODERATE OFFSHORE FLOW IN PLACE. N-TO-S GRADIENT RIGHT NOW
IS OVER 2 MB WHILE W-TO-E FLOW IS SLIGHTLY FROM THE EAST. AS THE
PREVIOUS DISCUSSION MENTIONED, MODELS ARE INDICATING A SOUTHERLY
PUSH UP THE COAST TODAY ALTHOUGH CURRENT SATELLITE DOES NOT SHOW
ANY CLOUDS EVEN UP TO SLO COUNTY. 14Z RUN OF THE HRRR DOES
INDICATE SOUTHERLY WINDS WILL SET UP OVER THE NEXT FEW HOURS, SO
WILL KEEP A CLOSE EYE ON THE SATELLITE TO SEE IF IT DOES
MATERIALIZE.

CURRENT FORECAST ON TRACK SO NO UPDATES PLANNED AT THE MOMENT.

.PREVIOUS DISCUSSION...SKIES ARE CLEAR ACROSS OUR ENTIRE FORECAST
AREA EARLY THIS MORNING AS LIGHT OFFSHORE FLOW CONTINUES. CURRENT
TEMPERATURES ARE GENERALLY WARMER THAN 24 HOURS AGO AND IN SOME
CASES SEVERAL DEGREES WARMER. FORECAST GUIDANCE INDICATES HIGH
TEMPERATURES TODAY WILL BE ABOUT FIVE DEGREES WARMER THAN
YESTERDAY. HOWEVER...MODELS FORECAST AN END TO OFFSHORE FLOW TODAY
ALONG WITH THE DEVELOPMENT OF SOUTHERLY FLOW ALONG THE COAST. THIS
DOES NOT LOOK LIKE A CLASSIC "SOUTHERLY SURGE" SCENARIO...SINCE
LOW CLOUDS DO NOT ALREADY EXIST TO OUR SOUTH NEAR POINT
CONCEPTION. WHAT`S MORE LIKELY TO HAPPEN IS THAT LOW CLOUDS AND
FOG WILL FORM IN COASTAL AREAS FROM MONTEREY BAY SOUTH BY EARLY
AFTERNOON...AND THEN MOVE NORTH UP ALONG THE REST OF OUR COAST
LATE THIS AFTERNOON AND EVENING. THIS MAKES FOR A DIFFICULT
TEMPERATURE FORECAST TODAY FOR COASTAL AREAS SINCE THE TIMING OF
THE SOUTHERLY WIND ONSET AND COASTAL FOG DEVELOPMENT WILL HAVE A
BIG IMPACT ON TEMPERATURES. MOST LIKELY SCENARIO IS FOR COOLING TO
OCCUR IN LOCATIONS LIKE BIG SUR AND SANTA CRUZ WHILE OTHER COASTAL
AREAS WILL BE AS WARM OR WARMER THAN YESTERDAY.

ANOTHER ITEM TO WATCH TODAY IS A SHORTWAVE TROUGH CURRENTLY OVER
SOUTHEAST OREGON THAT IS ROTATING AROUND A LONGWAVE TROUGH
CENTERED OVER THE DESERT SW. THIS SHORTWAVE IS FORECAST TO ROTATE
INTO NORTHERN AND CENTRAL CALIFORNIA LATER TODAY. THE ECMWF KEEPS
ALL PRECIP ASSOCIATED WITH THIS SHORTWAVE TO OUR EAST...MAINLY OVER
THE SIERRA NEVADA. HOWEVER...BOTH THE 00Z NAM AND 00Z GFS
FORECAST ISOLATED SHOWERS ALONG THE EASTERN FRINGES OF OUR
FORECAST AREA LATE THIS AFTERNOON AND EARLY THIS EVENING. HAVE
THEREFORE ADDED SLIGHT CHANCE POPS TO FAR EASTERN ALAMEDA...SANTA
CLARA...AND SAN BENITO COUNTIES FOR LATER TODAY.

DRY AND MILD WEATHER IS FORECAST FOR MONDAY AND TUESDAY. ONSHORE
FLOW WILL LIKELY MAINTAIN AT LEAST AREAS OF NIGHT AND MORNING LOW
CLOUDS AND TEMPERATURES WILL BE NEAR NORMAL.

AN UPPER TROUGH CURRENTLY SEEN ON SATELLITE IMAGERY OFFSHORE ALONG
145W IS FORECAST TO GRADUALLY APPROACH THE CALIFORNIA COAST OVER
THE NEXT THREE DAYS AND BEGIN TO GENERATE SHOWER CHANCES ACROSS
OUR AREA BY LATE WEDNESDAY. BOTH THE GFS AND ECMWF FORECAST A
CUTOFF LOW TO DEVELOP NEAR SAN FRANCISCO BY THURSDAY...WITH THAT
LOW THEN PROJECTED TO DROP SOUTHEAST AND TRACK ACROSS SOUTHERN
CALIFORNIA BY LATE FRIDAY AND FRIDAY NIGHT. THUS...SHOWER CHANCES
WILL CONTINUE THROUGH THE END OF THE WEEK AND PROBABLY INTO NEXT
WEEKEND AS WELL. GIVEN THE UNPREDICTABILITY OF CUTOFF LOW
MOVEMENT...IT`S DIFFICULT TO PINPOINT WHERE SHOWER CHANCES WILL BE
GREATEST DURING THE SECOND HALF OF THE WEEK. ISOLATED THUNDERSTORMS
MAY ALSO OCCUR...BUT WILL WAIT TO ADD THUNDERSTORMS TO THE
FORECAST UNTIL CONFIDENCE INCREASES ON THE TIMING AND TRACK OF THE
UPPER LOW. IN ADDITION TO PRECIPITATION CHANCES...THIS UPPER LOW
WILL RESULT IN COOLER THAN NORMAL CONDITIONS ACROSS MOST OF OUR
AREA DURING THE SECOND HALF OF THE WEEK.

&&

.AVIATION...AS OF 10:30 AM PDT SUNDAY...DRY OFFSHORE FLOW KEEPING
VFR TODAY. THE ONE FLY IN THE OINTMENT IN THE FORECAST IS A
POSSIBLE SOUTHERLY SURGE LATER TODAY. LATEST NAM AND WRF SHOW A
SOUTHERLY SURGE IMPACTING KMRY/KSNS...POSS MAKING IT INTO SF BAY
OVERNIGHT. CONF IS MARGINAL.

VICINITY OF KSFO...VFR.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY TERMINALS...VFR BECOMING MVFR LATE THIS EVENING AND
OVERNIGHT.

&&

.MARINE...AS OF 8:45 AM PDT SUNDAY...HIGH PRESSURE OVER THE
EASTERN PACIFIC WILL KEEP NORTHERLY WINDS OVER THE COASTAL WATERS
TODAY. LOCALLY GUSTY WINDS WILL BE POSSIBLE OVER THE OUTER WATERS
NORTH OF POINT REYES. SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT
AND EARLY MONDAY. A MODERATE SWELL WILL MIX WITH A SMALLER LONG
PERIOD SOUTHERLY SWELL THIS WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...NONE.

$$

PUBLIC FORECAST: BELL/DYKEMA
AVIATION: SIMS
MARINE: SIMS


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000
FXUS66 KSTO 011637
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
937 AM PDT SUN MAY 1 2016

.Synopsis...
Locally breezy North to East wind today then lighter wind into
early next week. Threat of afternoon showers and thunderstorms
continues over the mountains into Tuesday then a more widespread
chance Wednesday into Friday. Cooling to near normal midweek.

&&

.Discussion...
No changes to the forecast package this morning. Both the HRRR and
HRRRX show that isolated thunderstorms could pop up along the
western Sierra slopes and towards Lassen Park this afternoon.
Convective activity should start around 1 pm and continue into
early evening. Already starting to see breezy winds near the
Redding- Red Bluff vicinity with gusts around 15-20 mph. Breezy
conditions expected along the western side of the Sacramento
Valley today along the I-5 corridor and westward to the coastal
range. Winds will lessen by 4-6 pm this evening. JBB

Previous Discussion...Low level pressure gradient over Interior
NorCal still remains fairly strong this morning at 10 MB between
KMFR and KSAC. Gradient is also becoming more NE-SW oriented and
partial decoupling has occurred overnight. Winds in the Central
Valley are currently below 10 kts. Speeds expected to increase
this morning as momentum aloft mixes down, but then trend down
during the afternoon. Upper meso low currently crossing ORCA
border will drop into NorCal today. Associated synoptic lift
combines with differential heating instability for possible
afternoon showers and thunderstorms over the eastern mountains
from about Lassen Park south. Remainder of Interior NorCal remains
dry today as airmass warms. High temps increase into the mid 80s
in the Central Valley this afternoon.

Meso low weakens over NorCal Monday as deep upper trough in EPAC
approaches into Tuesday. Threat of afternoon mountains showers
and thunderstorms continues Mon/Tue. High temps slowly trend down
into Tuesday as synoptic cooling and onshore flow gradually increase
over Interior NorCal.

Models similar in closing off upper trough into low Wednesday
along the CA coast then gradually dig feature through Friday.
Unsettled weather pattern results due to increased synoptic lift,
moisture, and instability...leading to a more widespread threat
of showers and thunderstorms over Interior NorCal. High temps cool
to near or slightly below normal through midweek.

PCH
&&
.EXTENDED DISCUSSION (Thursday THROUGH Sunday)

Extended models consistent in moving a Pacific low through central
California at the end of the week for a shower and thunderstorm
threat across the CWA. Models then keep the upper low over the
Great Basin bringing continued impacts for the forecast area for
the remainder of the extended period. Forecast models in good
agreement in bringing upper low center onshore somewhere over
Socal late next Thursday. Lift and instability and sufficient
moisture should allow for scattered showers across the area. Upper
level divergence should also aid in isolated thunderstorms just
about anywhere over Norcal. Cloud cover and cooler airmass will
continue to bring down daytime high temperatures with highs
Thursday possibly a little below normal. Upper low moves eastward
very slowly Friday so not all that much change is expected in the
forecast with showers and thunderstorms remaining a possibility.

By next weekend...upper low center should have moved into the
Great Basin but model timing varies some. Upper low remains well
within influence of Norcal however with enough instability and
moisture to warrant a continued threat of showers and afternoon
thunderstorms through next weekend. Once upper low shifts east of
the state...there should be at least some warm up in airmass with
highs next weekend expected to climb back above normal.

&&

.AVIATION...

VFR conditions are expected at the terminals for the next 24
hours. A slight chance of thunderstorms over the Sierra Cascade
range this afternoon and evening. Breezy north winds gusting to 20
mph over the Sacramento valley and foothills decreasing after 20z
today.
&&

.STO Watches/Warnings/Advisories...
None.
&&

$$




000
FXUS66 KSTO 011637
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
937 AM PDT SUN MAY 1 2016

.Synopsis...
Locally breezy North to East wind today then lighter wind into
early next week. Threat of afternoon showers and thunderstorms
continues over the mountains into Tuesday then a more widespread
chance Wednesday into Friday. Cooling to near normal midweek.

&&

.Discussion...
No changes to the forecast package this morning. Both the HRRR and
HRRRX show that isolated thunderstorms could pop up along the
western Sierra slopes and towards Lassen Park this afternoon.
Convective activity should start around 1 pm and continue into
early evening. Already starting to see breezy winds near the
Redding- Red Bluff vicinity with gusts around 15-20 mph. Breezy
conditions expected along the western side of the Sacramento
Valley today along the I-5 corridor and westward to the coastal
range. Winds will lessen by 4-6 pm this evening. JBB

Previous Discussion...Low level pressure gradient over Interior
NorCal still remains fairly strong this morning at 10 MB between
KMFR and KSAC. Gradient is also becoming more NE-SW oriented and
partial decoupling has occurred overnight. Winds in the Central
Valley are currently below 10 kts. Speeds expected to increase
this morning as momentum aloft mixes down, but then trend down
during the afternoon. Upper meso low currently crossing ORCA
border will drop into NorCal today. Associated synoptic lift
combines with differential heating instability for possible
afternoon showers and thunderstorms over the eastern mountains
from about Lassen Park south. Remainder of Interior NorCal remains
dry today as airmass warms. High temps increase into the mid 80s
in the Central Valley this afternoon.

Meso low weakens over NorCal Monday as deep upper trough in EPAC
approaches into Tuesday. Threat of afternoon mountains showers
and thunderstorms continues Mon/Tue. High temps slowly trend down
into Tuesday as synoptic cooling and onshore flow gradually increase
over Interior NorCal.

Models similar in closing off upper trough into low Wednesday
along the CA coast then gradually dig feature through Friday.
Unsettled weather pattern results due to increased synoptic lift,
moisture, and instability...leading to a more widespread threat
of showers and thunderstorms over Interior NorCal. High temps cool
to near or slightly below normal through midweek.

PCH
&&
.EXTENDED DISCUSSION (Thursday THROUGH Sunday)

Extended models consistent in moving a Pacific low through central
California at the end of the week for a shower and thunderstorm
threat across the CWA. Models then keep the upper low over the
Great Basin bringing continued impacts for the forecast area for
the remainder of the extended period. Forecast models in good
agreement in bringing upper low center onshore somewhere over
Socal late next Thursday. Lift and instability and sufficient
moisture should allow for scattered showers across the area. Upper
level divergence should also aid in isolated thunderstorms just
about anywhere over Norcal. Cloud cover and cooler airmass will
continue to bring down daytime high temperatures with highs
Thursday possibly a little below normal. Upper low moves eastward
very slowly Friday so not all that much change is expected in the
forecast with showers and thunderstorms remaining a possibility.

By next weekend...upper low center should have moved into the
Great Basin but model timing varies some. Upper low remains well
within influence of Norcal however with enough instability and
moisture to warrant a continued threat of showers and afternoon
thunderstorms through next weekend. Once upper low shifts east of
the state...there should be at least some warm up in airmass with
highs next weekend expected to climb back above normal.

&&

.AVIATION...

VFR conditions are expected at the terminals for the next 24
hours. A slight chance of thunderstorms over the Sierra Cascade
range this afternoon and evening. Breezy north winds gusting to 20
mph over the Sacramento valley and foothills decreasing after 20z
today.
&&

.STO Watches/Warnings/Advisories...
None.
&&

$$




000
FXUS66 KLOX 011637
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
937 AM PDT SUN MAY 1 2016

.SYNOPSIS...
A departing low pressure system will bring the slight chance of
showers and thunderstorms today across the mountains, foothills,
and antelope valley. A high pressure system will briefly build
into the region through Tuesday, supporting a gradual warming
trend. A slow moving low pressure system will likely bring a cool
down to the area with showers also possible Thursday through the
weekend.

&&

.SHORT TERM...(TDY-TUE)

Satellite imagery showing partly to mostly cloudy skies across the
Los Angeles basin this morning...otherwise mostly clear skies
across the district. Latest ACARS sounding and pilot reports
showing marine layer depth between 2000 and 2500 feet across
LA county this morning. Look for another mild day across the
region, with most inland areas climbing into the 70s.

Main upper level low pressure is spinning across Arizona this
morning, but a secondary weak upper level trough and associated
vorticity energy is forming on the back side of the low
pressure system across central and southern California. This
feature will likely generate some weak cyclonic flow over
the forecast area today. Some residual moisture across the
region today, with precipitable water values of around .7-.8
inches. With ample early May sunshine and still some cold air
aloft (500 mb temperatures as low as -18 degrees celsius across
interior sections), there will likely be enough instability and
moisture to generate some showers over the mountains this
afternoon. With lifted index values ranging between -2 and -4, and
CAPE values between 300-500 J/kg, the convective parameters do
indicate a slight chance for thunderstorms this afternoon across
the mountains. With the upper level wind flow from the northwest
and mid level flow from the north-northeast, could see some storms
drift off the mountains into the adjacent foothill portions of the
valleys, as well as the Santa Clarita and Antelope Valleys. If any
thunderstorms do develop today, they could be slow moving, capable
of producing a brief heavy downpour, gusty winds, and small hail.

*** From previous discussion ***

Another night and another mdl fcst of an eddy and a significant
marine layer stratus deck. Again this is not a high confidence
fcst and could easily see less clouds. The upper low will be much
further east and the only convection will be limited some
afternoon cu over the mtns driven only by afternoon heating.

By Tuesday a large upper low begins to approach the west coast.
The increase in cyclonic turning associated with this low will
help the overnight marine layer stratus deck to form and move into
the vlys. Otherwise skies will be partly cloudy and max temps will
be several degrees above normal.


.LONG TERM...(WED-SAT)

A cooling trend should begin by Wednesday with an upper-level
trough approaching from the northwest. Models are in good synoptic
agreement that a cutoff low will develop over the area Thursday
night through Friday, then slowly drift east on Saturday. There
will be a chance for hit and miss showers in most places late
Wednesday night through Saturday. At this time, it looks like late
Thursday through Friday would be the best chance for any showers.
Thunderstorms are not in the forecast at the moment, but they may
need to be added at a later time, as 500 mb temps are as low as
-25 deg C when the center of the upper low moves overhead.

&&

.AVIATION...01/1145Z

AT 1100Z at KLAX, the marine inversion was around 1800 feet. The
top of the inversion was around 2500 feet with a temperature of
15 degrees C.

Just some patchy low clouds across coastal sections of L.A. County
early this morning, with MVFR conditions. Expect clouds to fill in
a bit more by daybreak, and they could push into the L.A. County
valleys, and into coastal sections of Vtu County. There could be
some showers and even a thunderstorms in the mountains L.A...Vtu
and Sba Counties and the Antelope Valley in the afternoon and
evening. More widespread MVFR cigs expected tonight/Mon morning
across all coastal and many valley locations.

KLAX...Moderate confidence in the 12z TAF. There is a 20 to 30
percent chance that conds will remain VFR this morning. There is
a 20 percent chance that MVFR cigs this evening will arrive as
early as 04Z.

KBUR...Low confidence in the 12z TAF. There is a 40 percent
chance of MVFR cigs between 13Z and 17z. There is a 20 to 30
percent chance that MVFR cigs will arrive as early as 08z tonight.

&&

.MARINE...01/900 AM...

Winds have diminished across the coastal waters. There is rather
high confidence that conds will remain below SCA levels across the
entire waters through at least Tue.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 9 PM PDT this evening
      For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Gomberg
AVIATION...DB
MARINE...Sweet
SYNOPSIS...Munroe

weather.gov/losangeles




000
FXUS65 KPSR 011544
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
845 AM MST SUN MAY 1 2016


.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LINGER OVER THE REGION THROUGH TONIGHT...
PROVIDING BELOW NORMAL TEMPERATURES...AND A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER NORTHERN AND EASTERN ARIZONA. A HIGH PRESSURE
SYSTEM WILL SUBSEQUENTLY REBUILD OVER THE REGION MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM HOWEVER IS FORECAST TO MOVE
INTO THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

A RATHER COOL MORNING...FOR THE 1ST OF MAY ACROSS OUR CWA THIS
MORNING. MOST LOWER DESERT LOCATIONS SAW LOWS IN THE UPPER 50-LOW 60
RANGE...WITH SKY HARBOR SEEING A LOW OF 59...6 DEGREES BELOW THE
NORMAL FOR THE DATE. THE UPPER LOW THAT BROUGHT US THIS COOL
WEATHER...AND THE RAINFALL YESTERDAY/LAST NIGHT IS NOW MOVING
EASTWARD ACROSS EAST-CENTRAL AZ AND IS EXPECTED TO MOVE INTO THE 4-
CORNERS REGION BY THIS EVENING. TO THE SOUTH AND WEST OF THIS LOW
CENTER...TEMPERATURES ALOFT ARE BEGINNING TO WARM...STABILIZING THE
ATMOSPHERE AND ENDING THE SHOWER ACTIVITY ACROSS MOST OF OUR CWA.
HOWEVER...LEFT-OVER MOISTURE ROTATING AROUND THE BACK SIDE OF THE
UPPER LOW CENTER IS STILL TRIGGERING A FEW SHOWERS OVER PINAL AND
SOUTHERN GILA COUNTIES...AS WELL AS EXTREME EASTERN MARICOPA COUNTY
AT THIS HOUR. THE LATEST HRRR HIGH-RES MODEL RUN IS SHOWING THESE
SHOWERS CONTINUING THROUGH ABOUT MIDDAY BEFORE DIMINISHING THIS
AFTERNOON. GIVEN THESE CURRENT TRENDS...IT APPEARS THAT OUR CURRENT
SHORT-TERM FORECASTS ARE HOLDING UP WELL..AND NO UPDATES ARE PLANNED
AT THIS TIME.

&&

.PREVIOUS DISCUSSION...

TODAY AND TONIGHT...

THE COOL LOW PRESSURE SYSTEM OVER AZ WILL LINGER OVER THE STATE
TODAY...ALBEIT MOVE SLOWLY TO THE EAST BY EARLY AFTERNOON. MODELS
FORECAST THE 500 MB CIRCULATION CENTER TO MOVE FROM OVER PHOENIX
EARLY THIS MORNING...TOWARD THE WHITE MOUNTAINS IN EAST CENTRAL AZ
BY AFTERNOON. THEREFORE A FEW LIGHT SHOWERS ARE POSSIBLE OVER THE
DESERTS NEAR PHOENIX THIS MORNING...CHANGING TO A SLIGHT CHANCE OF
SHOWERS DURING THE AFTERNOON WITH INCREASING STABILITY. MOSTLY
CLOUDY SKIES HOWEVER ARE FORECAST OVER MUCH OF SOUTHWEST AND SOUTH
CENTRAL ARIZONA TODAY...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS IN OUR MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY
THROUGH EVENING. CLEARING TO PARTIAL CLEARING SKIES ARE EXPECTED
EARLY THIS EVENING WITH SHOWERS ENDING.

MONDAY THROUGH THURSDAY...

A HIGH PRESSURE SYSTEM WILL SLOWLY BUILD OVER THE REGION THIS PERIOD
PROVIDING MOSTLY CLEAR SKIES AND MUCH WARMER AFTERNOON TEMPERATURES.
BACK MIDDLE 90S ON THE LOWER DESERTS AGAIN...OR ABOUT 5 DEGREES ABOVE
NORMAL.

THURSDAY NIGHT THROUGH SUNDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA AND AZ LATE THURSDAY AND FRIDAY. ENSEMBLE
MEMBER SPREAD APPEARS TO BE CONSOLIDATING MORE...INCREASING OUR
CONFIDENCE THAT THIS NEW WEATHER SYSTEM WILL BODILY MOVE INTO THE
REGION FRIDAY AND THE WEEKEND.  SINCE ENSEMBLE MEMBERS ARE COMING
INTO CLOSER AGREEMENT...WE CAN PLACE SOME VALUE IN THE OPERATION GFS
WHICH SHOWS THIS SYSTEM TO BE INITIALLY DRY FRIDAY AND SATURDAY...
WITH PERHAPS A BETTER CHANCE OF PRECIP SUNDAY. THEREFORE A BROAD
BRUSH FORECAST APPROACH SEEMS TO BE IN ORDER FOR NOW...KEEPING A
SLIGHT CHANCE OF SHOWERS GOING...AND MUCH COOLER TEMPERATURES
DEVELOPING.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
UPPER LOW WILL BEGIN TO WEAKEN AND MAKE A SLOW EXIT TO THE EAST OVER
AZ TODAY. LIGHT RAIN SHOWER ACTIVITY WILL BE POSSIBLE DURING THE
MORNING FROM MARICOPA COUNTY EASTWARD BEFORE PRECIP ACTIVITY FOCUSES
ON THE MOUNTAINS NORTH/EAST OF PHOENIX. SCT TO BKN CLOUDS RANGING 8
TO 12KFT WILL PERSIST THROUGH EARLY AFTERNOON BEFORE DISSIPATING AND
EVENTUALLY CLEARING COMPLETELY AFTER SUNSET. TYPICAL EASTERLY AM
WINDS WILL TRANSITION SOUTH THEN WEST MIDDAY INTO THE
AFTERNOON...WITH GENERALLY LIGHT SPEEDS 6 KTS OR LESS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FOCUS OF ANY LINGERING PRECIP ACTIVITY TODAY WILL BE WELL EAST OF THE
CO RIVER VALLEY. NOTICEABLY LIGHTER WINDS IN STORE TODAY WITH
HEADINGS VARIANT BETWEEN WEST AND NORTHWEST FOR KIPL AND NORTH AND
NORTHEAST FOR KBLH. FEW TO SCT CLOUDS GNLY AOA 10KFT WILL DISSIPATE
DURING THE DAY...WITH CLEAR SKIES POSSIBLE BY THE AFTERNOON AND FOR
THE EVENING.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS QUICKLY WARMING TEMPERATURES TO ABOVE NORMAL READINGS WITH
MANY LOWER ELEVATION SITES HEADING INTO THE MID TO UPPER 90S. DEEP
PACIFIC TROUGH WILL APPROACH THE WEST COAST MIDWEEK SUPPORTING
INCREASING SOUTHERLY WINDS FOR WEDNESDAY AND THURSDAY. THE
COMBINATION OF STRONG WINDS...PARTICULARLY FOR THURSDAY...AND LOW
HUMIDITIES MAY SUPPORT POCKETS OF CRITICAL FIRE WEATHER CONDITIONS
ACROSS THE LOWER AZ DESERTS. CONDITIONS WILL IMPROVE ON FRIDAY AND
SATURDAY WHEN THE NEXT STORM SYSTEM WILL COOL HIGH TEMPERATURES TO
THE LOW TO MID 80S WITH MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20
PERCENT RANGE BY SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA/VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...NOLTE/SAWTELLE




000
FXUS65 KPSR 011544
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
845 AM MST SUN MAY 1 2016


.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LINGER OVER THE REGION THROUGH TONIGHT...
PROVIDING BELOW NORMAL TEMPERATURES...AND A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER NORTHERN AND EASTERN ARIZONA. A HIGH PRESSURE
SYSTEM WILL SUBSEQUENTLY REBUILD OVER THE REGION MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM HOWEVER IS FORECAST TO MOVE
INTO THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

A RATHER COOL MORNING...FOR THE 1ST OF MAY ACROSS OUR CWA THIS
MORNING. MOST LOWER DESERT LOCATIONS SAW LOWS IN THE UPPER 50-LOW 60
RANGE...WITH SKY HARBOR SEEING A LOW OF 59...6 DEGREES BELOW THE
NORMAL FOR THE DATE. THE UPPER LOW THAT BROUGHT US THIS COOL
WEATHER...AND THE RAINFALL YESTERDAY/LAST NIGHT IS NOW MOVING
EASTWARD ACROSS EAST-CENTRAL AZ AND IS EXPECTED TO MOVE INTO THE 4-
CORNERS REGION BY THIS EVENING. TO THE SOUTH AND WEST OF THIS LOW
CENTER...TEMPERATURES ALOFT ARE BEGINNING TO WARM...STABILIZING THE
ATMOSPHERE AND ENDING THE SHOWER ACTIVITY ACROSS MOST OF OUR CWA.
HOWEVER...LEFT-OVER MOISTURE ROTATING AROUND THE BACK SIDE OF THE
UPPER LOW CENTER IS STILL TRIGGERING A FEW SHOWERS OVER PINAL AND
SOUTHERN GILA COUNTIES...AS WELL AS EXTREME EASTERN MARICOPA COUNTY
AT THIS HOUR. THE LATEST HRRR HIGH-RES MODEL RUN IS SHOWING THESE
SHOWERS CONTINUING THROUGH ABOUT MIDDAY BEFORE DIMINISHING THIS
AFTERNOON. GIVEN THESE CURRENT TRENDS...IT APPEARS THAT OUR CURRENT
SHORT-TERM FORECASTS ARE HOLDING UP WELL..AND NO UPDATES ARE PLANNED
AT THIS TIME.

&&

.PREVIOUS DISCUSSION...

TODAY AND TONIGHT...

THE COOL LOW PRESSURE SYSTEM OVER AZ WILL LINGER OVER THE STATE
TODAY...ALBEIT MOVE SLOWLY TO THE EAST BY EARLY AFTERNOON. MODELS
FORECAST THE 500 MB CIRCULATION CENTER TO MOVE FROM OVER PHOENIX
EARLY THIS MORNING...TOWARD THE WHITE MOUNTAINS IN EAST CENTRAL AZ
BY AFTERNOON. THEREFORE A FEW LIGHT SHOWERS ARE POSSIBLE OVER THE
DESERTS NEAR PHOENIX THIS MORNING...CHANGING TO A SLIGHT CHANCE OF
SHOWERS DURING THE AFTERNOON WITH INCREASING STABILITY. MOSTLY
CLOUDY SKIES HOWEVER ARE FORECAST OVER MUCH OF SOUTHWEST AND SOUTH
CENTRAL ARIZONA TODAY...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS IN OUR MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY
THROUGH EVENING. CLEARING TO PARTIAL CLEARING SKIES ARE EXPECTED
EARLY THIS EVENING WITH SHOWERS ENDING.

MONDAY THROUGH THURSDAY...

A HIGH PRESSURE SYSTEM WILL SLOWLY BUILD OVER THE REGION THIS PERIOD
PROVIDING MOSTLY CLEAR SKIES AND MUCH WARMER AFTERNOON TEMPERATURES.
BACK MIDDLE 90S ON THE LOWER DESERTS AGAIN...OR ABOUT 5 DEGREES ABOVE
NORMAL.

THURSDAY NIGHT THROUGH SUNDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA AND AZ LATE THURSDAY AND FRIDAY. ENSEMBLE
MEMBER SPREAD APPEARS TO BE CONSOLIDATING MORE...INCREASING OUR
CONFIDENCE THAT THIS NEW WEATHER SYSTEM WILL BODILY MOVE INTO THE
REGION FRIDAY AND THE WEEKEND.  SINCE ENSEMBLE MEMBERS ARE COMING
INTO CLOSER AGREEMENT...WE CAN PLACE SOME VALUE IN THE OPERATION GFS
WHICH SHOWS THIS SYSTEM TO BE INITIALLY DRY FRIDAY AND SATURDAY...
WITH PERHAPS A BETTER CHANCE OF PRECIP SUNDAY. THEREFORE A BROAD
BRUSH FORECAST APPROACH SEEMS TO BE IN ORDER FOR NOW...KEEPING A
SLIGHT CHANCE OF SHOWERS GOING...AND MUCH COOLER TEMPERATURES
DEVELOPING.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
UPPER LOW WILL BEGIN TO WEAKEN AND MAKE A SLOW EXIT TO THE EAST OVER
AZ TODAY. LIGHT RAIN SHOWER ACTIVITY WILL BE POSSIBLE DURING THE
MORNING FROM MARICOPA COUNTY EASTWARD BEFORE PRECIP ACTIVITY FOCUSES
ON THE MOUNTAINS NORTH/EAST OF PHOENIX. SCT TO BKN CLOUDS RANGING 8
TO 12KFT WILL PERSIST THROUGH EARLY AFTERNOON BEFORE DISSIPATING AND
EVENTUALLY CLEARING COMPLETELY AFTER SUNSET. TYPICAL EASTERLY AM
WINDS WILL TRANSITION SOUTH THEN WEST MIDDAY INTO THE
AFTERNOON...WITH GENERALLY LIGHT SPEEDS 6 KTS OR LESS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FOCUS OF ANY LINGERING PRECIP ACTIVITY TODAY WILL BE WELL EAST OF THE
CO RIVER VALLEY. NOTICEABLY LIGHTER WINDS IN STORE TODAY WITH
HEADINGS VARIANT BETWEEN WEST AND NORTHWEST FOR KIPL AND NORTH AND
NORTHEAST FOR KBLH. FEW TO SCT CLOUDS GNLY AOA 10KFT WILL DISSIPATE
DURING THE DAY...WITH CLEAR SKIES POSSIBLE BY THE AFTERNOON AND FOR
THE EVENING.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS QUICKLY WARMING TEMPERATURES TO ABOVE NORMAL READINGS WITH
MANY LOWER ELEVATION SITES HEADING INTO THE MID TO UPPER 90S. DEEP
PACIFIC TROUGH WILL APPROACH THE WEST COAST MIDWEEK SUPPORTING
INCREASING SOUTHERLY WINDS FOR WEDNESDAY AND THURSDAY. THE
COMBINATION OF STRONG WINDS...PARTICULARLY FOR THURSDAY...AND LOW
HUMIDITIES MAY SUPPORT POCKETS OF CRITICAL FIRE WEATHER CONDITIONS
ACROSS THE LOWER AZ DESERTS. CONDITIONS WILL IMPROVE ON FRIDAY AND
SATURDAY WHEN THE NEXT STORM SYSTEM WILL COOL HIGH TEMPERATURES TO
THE LOW TO MID 80S WITH MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20
PERCENT RANGE BY SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA/VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...NOLTE/SAWTELLE




000
FXUS66 KMTR 011544
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
844 AM PDT SUN MAY 1 2016

.SYNOPSIS....OFFSHORE WINDS WILL CONTINUE TODAY...RESULTING IN
SUNNY AND WARM CONDITIONS IN MOST AREAS. COASTAL FOG AND LOW
CLOUDS WILL LIKELY RETURN BY LATE TODAY OR TONIGHT. SEASONABLE
AND DRY WEATHER IS FORECAST MONDAY AND TUESDAY. A WEATHER SYSTEM
WILL APPROACH CALIFORNIA BY THE MIDDLE OF THE WEEK...BRINGING A
CHANCE OF SHOWERS FROM LATE WEDNESDAY THROUGH THE END OF THE
WEEK...ALONG WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 8:45 AM PDT SUNDAY...CLEAR START TO THE DAY
WITH A MODERATE OFFSHORE FLOW IN PLACE. N-TO-S GRADIENT RIGHT NOW
IS OVER 2 MB WHILE W-TO-E FLOW IS SLIGHTLY FROM THE EAST. AS THE
PREVIOUS DISCUSSION MENTIONED, MODELS ARE INDICATING A SOUTHERLY
PUSH UP THE COAST TODAY ALTHOUGH CURRENT SATELLITE DOES NOT SHOW
ANY CLOUDS EVEN UP TO SLO COUNTY. 14Z RUN OF THE HRRR DOES
INDICATE SOUTHERLY WINDS WILL SET UP OVER THE NEXT FEW HOURS, SO
WILL KEEP A CLOSE EYE ON THE SATELLITE TO SEE IF IT DOES
MATERIALIZE.

CURRENT FORECAST ON TRACK SO NO UPDATES PLANNED AT THE MOMENT.

.PREVIOUS DISCUSSION...SKIES ARE CLEAR ACROSS OUR ENTIRE FORECAST
AREA EARLY THIS MORNING AS LIGHT OFFSHORE FLOW CONTINUES. CURRENT
TEMPERATURES ARE GENERALLY WARMER THAN 24 HOURS AGO AND IN SOME
CASES SEVERAL DEGREES WARMER. FORECAST GUIDANCE INDICATES HIGH
TEMPERATURES TODAY WILL BE ABOUT FIVE DEGREES WARMER THAN
YESTERDAY. HOWEVER...MODELS FORECAST AN END TO OFFSHORE FLOW TODAY
ALONG WITH THE DEVELOPMENT OF SOUTHERLY FLOW ALONG THE COAST. THIS
DOES NOT LOOK LIKE A CLASSIC "SOUTHERLY SURGE" SCENARIO...SINCE
LOW CLOUDS DO NOT ALREADY EXIST TO OUR SOUTH NEAR POINT
CONCEPTION. WHAT`S MORE LIKELY TO HAPPEN IS THAT LOW CLOUDS AND
FOG WILL FORM IN COASTAL AREAS FROM MONTEREY BAY SOUTH BY EARLY
AFTERNOON...AND THEN MOVE NORTH UP ALONG THE REST OF OUR COAST
LATE THIS AFTERNOON AND EVENING. THIS MAKES FOR A DIFFICULT
TEMPERATURE FORECAST TODAY FOR COASTAL AREAS SINCE THE TIMING OF
THE SOUTHERLY WIND ONSET AND COASTAL FOG DEVELOPMENT WILL HAVE A
BIG IMPACT ON TEMPERATURES. MOST LIKELY SCENARIO IS FOR COOLING TO
OCCUR IN LOCATIONS LIKE BIG SUR AND SANTA CRUZ WHILE OTHER COASTAL
AREAS WILL BE AS WARM OR WARMER THAN YESTERDAY.

ANOTHER ITEM TO WATCH TODAY IS A SHORTWAVE TROUGH CURRENTLY OVER
SOUTHEAST OREGON THAT IS ROTATING AROUND A LONGWAVE TROUGH
CENTERED OVER THE DESERT SW. THIS SHORTWAVE IS FORECAST TO ROTATE
INTO NORTHERN AND CENTRAL CALIFORNIA LATER TODAY. THE ECMWF KEEPS
ALL PRECIP ASSOCIATED WITH THIS SHORTWAVE TO OUR EAST...MAINLY OVER
THE SIERRA NEVADA. HOWEVER...BOTH THE 00Z NAM AND 00Z GFS
FORECAST ISOLATED SHOWERS ALONG THE EASTERN FRINGES OF OUR
FORECAST AREA LATE THIS AFTERNOON AND EARLY THIS EVENING. HAVE
THEREFORE ADDED SLIGHT CHANCE POPS TO FAR EASTERN ALAMEDA...SANTA
CLARA...AND SAN BENITO COUNTIES FOR LATER TODAY.

DRY AND MILD WEATHER IS FORECAST FOR MONDAY AND TUESDAY. ONSHORE
FLOW WILL LIKELY MAINTAIN AT LEAST AREAS OF NIGHT AND MORNING LOW
CLOUDS AND TEMPERATURES WILL BE NEAR NORMAL.

AN UPPER TROUGH CURRENTLY SEEN ON SATELLITE IMAGERY OFFSHORE ALONG
145W IS FORECAST TO GRADUALLY APPROACH THE CALIFORNIA COAST OVER
THE NEXT THREE DAYS AND BEGIN TO GENERATE SHOWER CHANCES ACROSS
OUR AREA BY LATE WEDNESDAY. BOTH THE GFS AND ECMWF FORECAST A
CUTOFF LOW TO DEVELOP NEAR SAN FRANCISCO BY THURSDAY...WITH THAT
LOW THEN PROJECTED TO DROP SOUTHEAST AND TRACK ACROSS SOUTHERN
CALIFORNIA BY LATE FRIDAY AND FRIDAY NIGHT. THUS...SHOWER CHANCES
WILL CONTINUE THROUGH THE END OF THE WEEK AND PROBABLY INTO NEXT
WEEKEND AS WELL. GIVEN THE UNPREDICTABILITY OF CUTOFF LOW
MOVEMENT...IT`S DIFFICULT TO PINPOINT WHERE SHOWER CHANCES WILL BE
GREATEST DURING THE SECOND HALF OF THE WEEK. ISOLATED THUNDERSTORMS
MAY ALSO OCCUR...BUT WILL WAIT TO ADD THUNDERSTORMS TO THE
FORECAST UNTIL CONFIDENCE INCREASES ON THE TIMING AND TRACK OF THE
UPPER LOW. IN ADDITION TO PRECIPITATION CHANCES...THIS UPPER LOW
WILL RESULT IN COOLER THAN NORMAL CONDITIONS ACROSS MOST OF OUR
AREA DURING THE SECOND HALF OF THE WEEK.

&&

.AVIATION...AS OF 4:21 AM PDT SUNDAY...DRY OFFSHORE FLOW KEEPING
MAINLY VFR TODAY. THE ONE FLY IN THE OINTMENT IN THE FORECAST
IS A POSSIBLE SOUTHERLY SURGE LATER TODAY. LATEST NAM AND WRF SHOW
A SOUTHERLY SURGE IMPACTING KMRY/KSNS...POSS MAKING IT INTO SF BAY
OVERNIGHT. CONF IS MARGINAL...BUT WILL ADD CIGS TO MONTEREY BAY.

VICINITY OF KSFO...VFR.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY TERMINALS...VFR WITH SOME HAZE IN THE AM. VFR
BECOMING MVFR THIS EVENING AND OVERNIGHT..

&&

.MARINE...AS OF 8:45 AM PDT SUNDAY...HIGH PRESSURE OVER THE
EASTERN PACIFIC WILL KEEP NORTHERLY WINDS OVER THE COASTAL WATERS
TODAY. LOCALLY GUSTY WINDS WILL BE POSSIBLE OVER THE OUTER WATERS
NORTH OF POINT REYES. SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT
AND EARLY MONDAY. A MODERATE SWELL WILL MIX WITH A SMALLER LONG
PERIOD SOUTHERLY SWELL THIS WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 9 AM

&&

$$

PUBLIC FORECAST: BELL/DYKEMA
AVIATION: MM
MARINE: MM


VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA




000
FXUS66 KSGX 011538
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
837 AM PDT SUN MAY 1 2016

.SYNOPSIS...
LOW PRESSURE OVER THE SOUTHWESTERN STATES WILL WEAKEN...WITH A
WARMING TREND THROUGH TUESDAY. RESIDUAL MOISTURE AND INSTABILITY
WILL STILL SUPPORT SCATTERED SHOWERS...AND POSSIBLE THUNDERSTORM
DEVELOPMENT AFTERNOONS AND EVENINGS...MAINLY NEAR THE MOUNTAINS.
COOLER WEDNESDAY AS ONSHORE FLOW BUILDS THE MARINE LAYER AHEAD OF AN
ONCOMING LOW PRESSURE CENTER LATE IN THE WEEK. THIS STORM SYSTEM
WILL BRING COOLER WEATHER...MORE CLOUDS....AND PERIODS OF SHOWERS
AND THUNDERSTORMS INTO THE WEEKEND.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

AT 8 AM PST...AREAS OF MARINE CLOUDS COVERED MUCH OF THE CA BIGHT...
AND THE IMMEDIATE COAST OF SAN DIEGO COUNTY...BUT WERE MORE PATCHY
INLAND. CLOUDS WERE ALSO NOTED ALONG THE HIGHER MOUNTAINS OF
RIVERSIDE AND SAN BERNARDINO COUNTIES. ONSHORE SURFACE PRESSURE
GRADIENTS WERE WEAKENING...AND WINDS GENERALLY LIGHT. THE 12Z
MIRAMAR HAD A VERY WEAK INVERSION BASED NEAR 2700 FT. THE VERTICAL
TEMPERATURE PROFILE WAS STABLE WITH A PW OF 0.83 INCH.

THE FORECAST IS ON TRACK WITH CHANCE POPS IN THE MTNS AND A SLIGHT
CHANCE OF THUNDERSTORMS. MOISTURE IS SUFFICIENT...AND THE 12Z NAM
HAS NEGATIVE LIFTED INDEX VALUES OVER THE MTS. MOST OF THE HI RES
MODELS GENERATE SPOTTY PRECIP THERE AS WELL LATER IN THE DAY.

LINGERING MOISTURE IN THE LOW LEVELS AND CYCLONIC FLOW ALOFT SHOULD
RESULT IN PARTLY CLOUDY SKIES TODAY..AND A BIT WARMER INLAND. LOOK
FOR ADDITIONAL WARMING ON MONDAY AS HEIGHTS SLOWLY RISE. THERE IS
ONE LAST SHORTWAVE THAT IS FORECAST TO SLIP OVER AND EAST OF THE
AREA...ACCOMPANIED BY INCREASING WESTERLY FLOW ALOFT. LINGERING
INSTABILITY WILL CONTINUE A THREAT OF ISOLATED SHOWER DEVELOPMENT
OVER THE MTS...AND THE INCREASING FLOW ALOFT WILL STEER ANY THAT
MANAGE TO FORM...ONTO THE DESERT SLOPES LATE IN THE DAY.

WEDNESDAY WILL BE A TRANSITION DAY AS ONSHORE FLOW INCREASES AHEAD
OF A DEEPENING LONGWAVE TROUGH OVER THE FAR EASTPAC. COOLER MOST
AREAS...BUT FAIR AFTER MORNING MARINE CLOUDS AND FOG DISSIPATE.

&&

FROM PREVIOUS DISCUSSION...

.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
A SLOW MOVING LOW PRESSURE SYSTEM OVER THE EASTERN PACIFIC WILL
BRING COOLING AND INCREASING CLOUDS FOR WEDNESDAY AND THURSDAY.
FOR THURSDAY NIGHT INTO NEXT WEEKEND WEEKEND...THAT LOW PRESSURE
SYSTEM WILL CLOSE OFF AND MOVE SLOWLY INLAND INTO THE SOUTHWEST
STATES. THIS WILL BRING COOLING...MORE CLOUDS...AND PERIODS OF
SHOWERS WITH A SLIGHT CHANCE OF THUNDERSTORMS. THE GFS MOVES THE
COLDEST AIR AT 500 MB ACROSS SOUTHERN CALIFORNIA THURSDAY NIGHT
AND FRIDAY.

&&

.AVIATION...
011530Z...COAST/VALLEYS...SCT-BKN CLOUD LAYERS BETWEEN 2000-3000 FT
MSL AND TOPS TO 4000 FT MSL THROUGH AROUND 18Z, BECOMING FEW-SCT
THIS AFTERNOON. BKN-OVC CIGS OF SIMILAR BASES AND TOPS, WILL REFORM
NEAR THE COAST AND SPREAD INLAND OVERNIGHT, GENERALLY MORE EXTENSIVE
IN COVERAGE. LOW CLOUDS SCATTERING OUT BETWEEN 16-18Z MONDAY MORNING.

MOUNTAINS/DESERTS...SCT-BKN CLOUDS OVER AND NEAR THE MOUNTAINS
WITHBASES 8000-12000 FT MSL, AND A CHANCE OF AFTERNOON/EVENING
SHOWERSOVER THE MOUNTAINS AND HIGH DESERT AND LESS WINDY OVERALL.

&&

.MARINE...
830 AM...THROUGH WEDNESDAY...LIGHT WINDS EACH NIGHT AND MORNING,
FOLLOWED BY ONSHORE NORTHWEST WINDS 10-15 KT EACH AFTERNOON. FOR
THURSDAY AND FRIDAY, A DEEP PACIFIC TROUGH WILL BRING STRONGER AND
MORE CONSISTENT NORTHWEST WINDS AND A CHANCE OF SHOWERS/TSTMS.

&&

.BEACHES...
830 AM...A LONG-PERIOD SOUTHERLY SWELL WILL BRING ELEVATED SURF TO
SOUTHWEST FACING BEACHES TODAY AND MONDAY WITH STRONG RIP AND
LONGSHORE CURRENTS. A BEACH HAZARDS STATEMENT IS IN EFFECT THROUGH 9
PM THIS EVENING. SEE LAXCFWSGX FOR DETAILS.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR ORANGE COUNTY
     COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.

PZ...NONE.
&&

$$

PUBLIC...JAD/17
AVIATION/MARINE/BEACHES...TS




000
FXUS66 KSGX 011538
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
837 AM PDT SUN MAY 1 2016

.SYNOPSIS...
LOW PRESSURE OVER THE SOUTHWESTERN STATES WILL WEAKEN...WITH A
WARMING TREND THROUGH TUESDAY. RESIDUAL MOISTURE AND INSTABILITY
WILL STILL SUPPORT SCATTERED SHOWERS...AND POSSIBLE THUNDERSTORM
DEVELOPMENT AFTERNOONS AND EVENINGS...MAINLY NEAR THE MOUNTAINS.
COOLER WEDNESDAY AS ONSHORE FLOW BUILDS THE MARINE LAYER AHEAD OF AN
ONCOMING LOW PRESSURE CENTER LATE IN THE WEEK. THIS STORM SYSTEM
WILL BRING COOLER WEATHER...MORE CLOUDS....AND PERIODS OF SHOWERS
AND THUNDERSTORMS INTO THE WEEKEND.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

AT 8 AM PST...AREAS OF MARINE CLOUDS COVERED MUCH OF THE CA BIGHT...
AND THE IMMEDIATE COAST OF SAN DIEGO COUNTY...BUT WERE MORE PATCHY
INLAND. CLOUDS WERE ALSO NOTED ALONG THE HIGHER MOUNTAINS OF
RIVERSIDE AND SAN BERNARDINO COUNTIES. ONSHORE SURFACE PRESSURE
GRADIENTS WERE WEAKENING...AND WINDS GENERALLY LIGHT. THE 12Z
MIRAMAR HAD A VERY WEAK INVERSION BASED NEAR 2700 FT. THE VERTICAL
TEMPERATURE PROFILE WAS STABLE WITH A PW OF 0.83 INCH.

THE FORECAST IS ON TRACK WITH CHANCE POPS IN THE MTNS AND A SLIGHT
CHANCE OF THUNDERSTORMS. MOISTURE IS SUFFICIENT...AND THE 12Z NAM
HAS NEGATIVE LIFTED INDEX VALUES OVER THE MTS. MOST OF THE HI RES
MODELS GENERATE SPOTTY PRECIP THERE AS WELL LATER IN THE DAY.

LINGERING MOISTURE IN THE LOW LEVELS AND CYCLONIC FLOW ALOFT SHOULD
RESULT IN PARTLY CLOUDY SKIES TODAY..AND A BIT WARMER INLAND. LOOK
FOR ADDITIONAL WARMING ON MONDAY AS HEIGHTS SLOWLY RISE. THERE IS
ONE LAST SHORTWAVE THAT IS FORECAST TO SLIP OVER AND EAST OF THE
AREA...ACCOMPANIED BY INCREASING WESTERLY FLOW ALOFT. LINGERING
INSTABILITY WILL CONTINUE A THREAT OF ISOLATED SHOWER DEVELOPMENT
OVER THE MTS...AND THE INCREASING FLOW ALOFT WILL STEER ANY THAT
MANAGE TO FORM...ONTO THE DESERT SLOPES LATE IN THE DAY.

WEDNESDAY WILL BE A TRANSITION DAY AS ONSHORE FLOW INCREASES AHEAD
OF A DEEPENING LONGWAVE TROUGH OVER THE FAR EASTPAC. COOLER MOST
AREAS...BUT FAIR AFTER MORNING MARINE CLOUDS AND FOG DISSIPATE.

&&

FROM PREVIOUS DISCUSSION...

.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
A SLOW MOVING LOW PRESSURE SYSTEM OVER THE EASTERN PACIFIC WILL
BRING COOLING AND INCREASING CLOUDS FOR WEDNESDAY AND THURSDAY.
FOR THURSDAY NIGHT INTO NEXT WEEKEND WEEKEND...THAT LOW PRESSURE
SYSTEM WILL CLOSE OFF AND MOVE SLOWLY INLAND INTO THE SOUTHWEST
STATES. THIS WILL BRING COOLING...MORE CLOUDS...AND PERIODS OF
SHOWERS WITH A SLIGHT CHANCE OF THUNDERSTORMS. THE GFS MOVES THE
COLDEST AIR AT 500 MB ACROSS SOUTHERN CALIFORNIA THURSDAY NIGHT
AND FRIDAY.

&&

.AVIATION...
011530Z...COAST/VALLEYS...SCT-BKN CLOUD LAYERS BETWEEN 2000-3000 FT
MSL AND TOPS TO 4000 FT MSL THROUGH AROUND 18Z, BECOMING FEW-SCT
THIS AFTERNOON. BKN-OVC CIGS OF SIMILAR BASES AND TOPS, WILL REFORM
NEAR THE COAST AND SPREAD INLAND OVERNIGHT, GENERALLY MORE EXTENSIVE
IN COVERAGE. LOW CLOUDS SCATTERING OUT BETWEEN 16-18Z MONDAY MORNING.

MOUNTAINS/DESERTS...SCT-BKN CLOUDS OVER AND NEAR THE MOUNTAINS
WITHBASES 8000-12000 FT MSL, AND A CHANCE OF AFTERNOON/EVENING
SHOWERSOVER THE MOUNTAINS AND HIGH DESERT AND LESS WINDY OVERALL.

&&

.MARINE...
830 AM...THROUGH WEDNESDAY...LIGHT WINDS EACH NIGHT AND MORNING,
FOLLOWED BY ONSHORE NORTHWEST WINDS 10-15 KT EACH AFTERNOON. FOR
THURSDAY AND FRIDAY, A DEEP PACIFIC TROUGH WILL BRING STRONGER AND
MORE CONSISTENT NORTHWEST WINDS AND A CHANCE OF SHOWERS/TSTMS.

&&

.BEACHES...
830 AM...A LONG-PERIOD SOUTHERLY SWELL WILL BRING ELEVATED SURF TO
SOUTHWEST FACING BEACHES TODAY AND MONDAY WITH STRONG RIP AND
LONGSHORE CURRENTS. A BEACH HAZARDS STATEMENT IS IN EFFECT THROUGH 9
PM THIS EVENING. SEE LAXCFWSGX FOR DETAILS.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR ORANGE COUNTY
     COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.

PZ...NONE.
&&

$$

PUBLIC...JAD/17
AVIATION/MARINE/BEACHES...TS




000
FXUS65 KPSR 011208
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
508 AM MST SUN MAY 1 2016


.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LINGER OVER THE REGION THROUGH TONIGHT...
PROVIDING BELOW NORMAL TEMPERATURES...AND A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER NORTHERN AND EASTERN ARIZONA. A HIGH PRESSURE
SYSTEM WILL SUBSEQUENTLY REBUILD OVER THE REGION MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM HOWEVER IS FORECAST TO MOVE
INTO THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

TODAY AND TONIGHT...

THE COOL LOW PRESSURE SYSTEM OVER AZ WILL LINGER OVER THE STATE
TODAY...ALBEIT MOVE SLOWLY TO THE EAST BY EARLY AFTERNOON. MODELS
FORECAST THE 500 MB CIRCULATION CENTER TO MOVE FROM OVER PHOENIX
EARLY THIS MORNING...TOWARD THE WHITE MOUNTAINS IN EAST CENTRAL AZ
BY AFTERNOON. THEREFORE A FEW LIGHT SHOWERS ARE POSSIBLE OVER THE
DESERTS NEAR PHOENIX THIS MORNING...CHANGING TO A SLIGHT CHANCE OF
SHOWERS DURING THE AFTERNOON WITH INCREASING STABILITY. MOSTLY
CLOUDY SKIES HOWEVER ARE FORECAST OVER MUCH OF SOUTHWEST AND SOUTH
CENTRAL ARIZONA TODAY...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS IN OUR MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY
THROUGH EVENING. CLEARING TO PARTIAL CLEARING SKIES ARE EXPECTED
EARLY THIS EVENING WITH SHOWERS ENDING.

MONDAY THROUGH THURSDAY...

A HIGH PRESSURE SYSTEM WILL SLOWLY BUILD OVER THE REGION THIS PERIOD
PROVIDING MOSTLY CLEAR SKIES AND MUCH WARMER AFTERNOON TEMPERATURES.
BACK MIDDLE 90S ON THE LOWER DESERTS AGAIN...OR ABOUT 5 DEGREES ABOVE
NORMAL.

THURSDAY NIGHT THROUGH SUNDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA AND AZ LATE THURSDAY AND FRIDAY. ENSEMBLE
MEMBER SPREAD APPEARS TO BE CONSOLIDATING MORE...INCREASING OUR
CONFIDENCE THAT THIS NEW WEATHER SYSTEM WILL BODILY MOVE INTO THE
REGION FRIDAY AND THE WEEKEND.  SINCE ENSEMBLE MEMBERS ARE COMING
INTO CLOSER AGREEMENT...WE CAN PLACE SOME VALUE IN THE OPERATION GFS
WHICH SHOWS THIS SYSTEM TO BE INITIALLY DRY FRIDAY AND SATURDAY...
WITH PERHAPS A BETTER CHANCE OF PRECIP SUNDAY. THEREFORE A BROAD
BRUSH FORECAST APPROACH SEEMS TO BE IN ORDER FOR NOW...KEEPING A
SLIGHT CHANCE OF SHOWERS GOING...AND MUCH COOLER TEMPERATURES
DEVELOPING.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
UPPER LOW WILL BEGIN TO WEAKEN AND MAKE A SLOW EXIT TO THE EAST OVER
AZ TODAY. LIGHT RAIN SHOWER ACTIVITY WILL BE POSSIBLE DURING THE
MORNING FROM MARICOPA COUNTY EASTWARD BEFORE PRECIP ACTIVITY FOCUSES
ON THE MOUNTAINS NORTH/EAST OF PHOENIX. SCT TO BKN CLOUDS RANGING 8
TO 12KFT WILL PERSIST THROUGH EARLY AFTERNOON BEFORE DISSIPATING AND
EVENTUALLY CLEARING COMPLETELY AFTER SUNSET. TYPICAL EASTERLY AM
WINDS WILL TRANSITION SOUTH THEN WEST MIDDAY INTO THE
AFTERNOON...WITH GENERALLY LIGHT SPEEDS 6 KTS OR LESS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FOCUS OF ANY LINGERING PRECIP ACTIVITY TODAY WILL BE WELL EAST OF THE
CO RIVER VALLEY. NOTICEABLY LIGHTER WINDS IN STORE TODAY WITH
HEADINGS VARIANT BETWEEN WEST AND NORTHWEST FOR KIPL AND NORTH AND
NORTHEAST FOR KBLH. FEW TO SCT CLOUDS GNLY AOA 10KFT WILL DISSIPATE
DURING THE DAY...WITH CLEAR SKIES POSSIBLE BY THE AFTERNOON AND FOR
THE EVENING.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS QUICKLY WARMING TEMPERATURES TO ABOVE NORMAL READINGS WITH
MANY LOWER ELEVATION SITES HEADING INTO THE MID TO UPPER 90S. DEEP
PACIFIC TROUGH WILL APPROACH THE WEST COAST MIDWEEK SUPPORTING
INCREASING SOUTHERLY WINDS FOR WEDNESDAY AND THURSDAY. THE
COMBINATION OF STRONG WINDS...PARTICULARLY FOR THURSDAY...AND LOW
HUMIDITIES MAY SUPPORT POCKETS OF CRITICAL FIRE WEATHER CONDITIONS
ACROSS THE LOWER AZ DESERTS. CONDITIONS WILL IMPROVE ON FRIDAY AND
SATURDAY WHEN THE NEXT STORM SYSTEM WILL COOL HIGH TEMPERATURES TO
THE LOW TO MID 80S WITH MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20
PERCENT RANGE BY SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...NOLTE/SAWTELLE




000
FXUS65 KPSR 011208
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
508 AM MST SUN MAY 1 2016


.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LINGER OVER THE REGION THROUGH TONIGHT...
PROVIDING BELOW NORMAL TEMPERATURES...AND A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER NORTHERN AND EASTERN ARIZONA. A HIGH PRESSURE
SYSTEM WILL SUBSEQUENTLY REBUILD OVER THE REGION MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM HOWEVER IS FORECAST TO MOVE
INTO THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

TODAY AND TONIGHT...

THE COOL LOW PRESSURE SYSTEM OVER AZ WILL LINGER OVER THE STATE
TODAY...ALBEIT MOVE SLOWLY TO THE EAST BY EARLY AFTERNOON. MODELS
FORECAST THE 500 MB CIRCULATION CENTER TO MOVE FROM OVER PHOENIX
EARLY THIS MORNING...TOWARD THE WHITE MOUNTAINS IN EAST CENTRAL AZ
BY AFTERNOON. THEREFORE A FEW LIGHT SHOWERS ARE POSSIBLE OVER THE
DESERTS NEAR PHOENIX THIS MORNING...CHANGING TO A SLIGHT CHANCE OF
SHOWERS DURING THE AFTERNOON WITH INCREASING STABILITY. MOSTLY
CLOUDY SKIES HOWEVER ARE FORECAST OVER MUCH OF SOUTHWEST AND SOUTH
CENTRAL ARIZONA TODAY...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS IN OUR MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY
THROUGH EVENING. CLEARING TO PARTIAL CLEARING SKIES ARE EXPECTED
EARLY THIS EVENING WITH SHOWERS ENDING.

MONDAY THROUGH THURSDAY...

A HIGH PRESSURE SYSTEM WILL SLOWLY BUILD OVER THE REGION THIS PERIOD
PROVIDING MOSTLY CLEAR SKIES AND MUCH WARMER AFTERNOON TEMPERATURES.
BACK MIDDLE 90S ON THE LOWER DESERTS AGAIN...OR ABOUT 5 DEGREES ABOVE
NORMAL.

THURSDAY NIGHT THROUGH SUNDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA AND AZ LATE THURSDAY AND FRIDAY. ENSEMBLE
MEMBER SPREAD APPEARS TO BE CONSOLIDATING MORE...INCREASING OUR
CONFIDENCE THAT THIS NEW WEATHER SYSTEM WILL BODILY MOVE INTO THE
REGION FRIDAY AND THE WEEKEND.  SINCE ENSEMBLE MEMBERS ARE COMING
INTO CLOSER AGREEMENT...WE CAN PLACE SOME VALUE IN THE OPERATION GFS
WHICH SHOWS THIS SYSTEM TO BE INITIALLY DRY FRIDAY AND SATURDAY...
WITH PERHAPS A BETTER CHANCE OF PRECIP SUNDAY. THEREFORE A BROAD
BRUSH FORECAST APPROACH SEEMS TO BE IN ORDER FOR NOW...KEEPING A
SLIGHT CHANCE OF SHOWERS GOING...AND MUCH COOLER TEMPERATURES
DEVELOPING.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
UPPER LOW WILL BEGIN TO WEAKEN AND MAKE A SLOW EXIT TO THE EAST OVER
AZ TODAY. LIGHT RAIN SHOWER ACTIVITY WILL BE POSSIBLE DURING THE
MORNING FROM MARICOPA COUNTY EASTWARD BEFORE PRECIP ACTIVITY FOCUSES
ON THE MOUNTAINS NORTH/EAST OF PHOENIX. SCT TO BKN CLOUDS RANGING 8
TO 12KFT WILL PERSIST THROUGH EARLY AFTERNOON BEFORE DISSIPATING AND
EVENTUALLY CLEARING COMPLETELY AFTER SUNSET. TYPICAL EASTERLY AM
WINDS WILL TRANSITION SOUTH THEN WEST MIDDAY INTO THE
AFTERNOON...WITH GENERALLY LIGHT SPEEDS 6 KTS OR LESS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FOCUS OF ANY LINGERING PRECIP ACTIVITY TODAY WILL BE WELL EAST OF THE
CO RIVER VALLEY. NOTICEABLY LIGHTER WINDS IN STORE TODAY WITH
HEADINGS VARIANT BETWEEN WEST AND NORTHWEST FOR KIPL AND NORTH AND
NORTHEAST FOR KBLH. FEW TO SCT CLOUDS GNLY AOA 10KFT WILL DISSIPATE
DURING THE DAY...WITH CLEAR SKIES POSSIBLE BY THE AFTERNOON AND FOR
THE EVENING.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS QUICKLY WARMING TEMPERATURES TO ABOVE NORMAL READINGS WITH
MANY LOWER ELEVATION SITES HEADING INTO THE MID TO UPPER 90S. DEEP
PACIFIC TROUGH WILL APPROACH THE WEST COAST MIDWEEK SUPPORTING
INCREASING SOUTHERLY WINDS FOR WEDNESDAY AND THURSDAY. THE
COMBINATION OF STRONG WINDS...PARTICULARLY FOR THURSDAY...AND LOW
HUMIDITIES MAY SUPPORT POCKETS OF CRITICAL FIRE WEATHER CONDITIONS
ACROSS THE LOWER AZ DESERTS. CONDITIONS WILL IMPROVE ON FRIDAY AND
SATURDAY WHEN THE NEXT STORM SYSTEM WILL COOL HIGH TEMPERATURES TO
THE LOW TO MID 80S WITH MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20
PERCENT RANGE BY SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...NOLTE/SAWTELLE




000
FXUS66 KLOX 011203
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
503 AM PDT SUN MAY 1 2016

.SYNOPSIS...
Expect fair to partly cloudy skies today, with a slight chance
of showers or thunderstorms across the local mountains in the
afternoon and evening hours. Warmer weather is expected early
next week as weak high pressure builds over the region, but
another trough of low pressure could bring showers and cooler
conditions to the area late next week.

&&

.SHORT TERM...(TDY-TUE)

The marine layer has not formed as forecast mostly because the
eddy did not form as forecast. Scaled back the stratus forecast to
include just the L.A. coast and a little of the Ventura coast.
This is not a slam dunk forecast and there is a chance that a more
robust marine layer stratus deck will explode around dawn. Aside
from the stratus the other problem of day - afternoon convection.
The upper low over AZ will spin a vort lobe over the area this
afternoon. There is more instability and a little more moisture to
work with this afternoon and there should be a more robust shower
and thunderstorm outbreak this afternoon. Max instability is over
nrn VTA county and thats where the best convection should set up.
There is not that much steering level winds and the showers and
TSTMs will be slow moving. The slow movement does increase the
risk for flash flooding but this is more that offset by the low PW
values.

Another night and another mdl fcst of an eddy and a significant
marine layer stratus deck. Again this is not a high confidence
fcst and could easily see less clouds. The upper low will be much
further east and the only convection will be limited some
afternoon cu over the mtns driven only by afternoon heating.

By Tuesday a large upper low begins to approach the west coast.
The increase in cyclonic turning associated with this low will
help the overnight marine layer stratus deck to form and move into
the vlys. Otherwise skies will be partly cloudy and max temps will
be several degrees above normal.

.LONG TERM...(WED-SAT)

A cooling trend should begin by Wednesday with an upper-level
trough approaching from the northwest. Models are in good synoptic
agreement that a cutoff low will develop over the area Thursday
night through Friday, then slowly drift east on Saturday. There
will be a chance for hit and miss showers in most places late
Wednesday night through Saturday. At this time, it looks like late
Thursday through Friday would be the best chance for any showers.
Thunderstorms are not in the forecast at the moment, but they may
need to be added at a later time, as 500 mb temps are as low as
-25 deg C when the center of the upper low moves overhead.

&&

.AVIATION...01/1145Z

AT 1100Z at KLAX, the marine inversion was around 1800 feet. The
top of the inversion was around 2500 feet with a temperature of
15 degrees C.

Just some patchy low clouds across coastal sections of L.A. County
early this morning, with MVFR conditions. Expect clouds to fill in
a bit more by daybreak, and they could push into the L.A. County
valleys, and into coastal sections of Vtu County. There could be
some showers and even a thunderstorms in the mountains L.A...Vtu
and Sba Counties and the Antelope Valley in the afternoon and
evening. More widespread MVFR cigs expected tonight/Mon morning
across all coastal and many valley locations.

KLAX...Moderate confidence in the 12z TAF. There is a 20 to 30
percent chance that conds will remain VFR this morning. There is
a 20 percent chance that MVFR cigs this evening will arrive as
early as 04Z.

KBUR...Low confidence in the 12z TAF. There is a 40 percent
chance of MVFR cigs between 13Z and 17z. There is a 20 to 30
percent chance that MVFR cigs will arrive as early as 08z tonight.

&&

.MARINE...01/300 AM...

Winds have diminished across the coastal waters. There is rather
high confidence that conds will remain below SCA levels across the
entire waters through at least Tue.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through this evening For
      zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...DB
MARINE...DB
SYNOPSIS...CK

weather.gov/losangeles




000
FXUS66 KLOX 011203
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
503 AM PDT SUN MAY 1 2016

.SYNOPSIS...
Expect fair to partly cloudy skies today, with a slight chance
of showers or thunderstorms across the local mountains in the
afternoon and evening hours. Warmer weather is expected early
next week as weak high pressure builds over the region, but
another trough of low pressure could bring showers and cooler
conditions to the area late next week.

&&

.SHORT TERM...(TDY-TUE)

The marine layer has not formed as forecast mostly because the
eddy did not form as forecast. Scaled back the stratus forecast to
include just the L.A. coast and a little of the Ventura coast.
This is not a slam dunk forecast and there is a chance that a more
robust marine layer stratus deck will explode around dawn. Aside
from the stratus the other problem of day - afternoon convection.
The upper low over AZ will spin a vort lobe over the area this
afternoon. There is more instability and a little more moisture to
work with this afternoon and there should be a more robust shower
and thunderstorm outbreak this afternoon. Max instability is over
nrn VTA county and thats where the best convection should set up.
There is not that much steering level winds and the showers and
TSTMs will be slow moving. The slow movement does increase the
risk for flash flooding but this is more that offset by the low PW
values.

Another night and another mdl fcst of an eddy and a significant
marine layer stratus deck. Again this is not a high confidence
fcst and could easily see less clouds. The upper low will be much
further east and the only convection will be limited some
afternoon cu over the mtns driven only by afternoon heating.

By Tuesday a large upper low begins to approach the west coast.
The increase in cyclonic turning associated with this low will
help the overnight marine layer stratus deck to form and move into
the vlys. Otherwise skies will be partly cloudy and max temps will
be several degrees above normal.

.LONG TERM...(WED-SAT)

A cooling trend should begin by Wednesday with an upper-level
trough approaching from the northwest. Models are in good synoptic
agreement that a cutoff low will develop over the area Thursday
night through Friday, then slowly drift east on Saturday. There
will be a chance for hit and miss showers in most places late
Wednesday night through Saturday. At this time, it looks like late
Thursday through Friday would be the best chance for any showers.
Thunderstorms are not in the forecast at the moment, but they may
need to be added at a later time, as 500 mb temps are as low as
-25 deg C when the center of the upper low moves overhead.

&&

.AVIATION...01/1145Z

AT 1100Z at KLAX, the marine inversion was around 1800 feet. The
top of the inversion was around 2500 feet with a temperature of
15 degrees C.

Just some patchy low clouds across coastal sections of L.A. County
early this morning, with MVFR conditions. Expect clouds to fill in
a bit more by daybreak, and they could push into the L.A. County
valleys, and into coastal sections of Vtu County. There could be
some showers and even a thunderstorms in the mountains L.A...Vtu
and Sba Counties and the Antelope Valley in the afternoon and
evening. More widespread MVFR cigs expected tonight/Mon morning
across all coastal and many valley locations.

KLAX...Moderate confidence in the 12z TAF. There is a 20 to 30
percent chance that conds will remain VFR this morning. There is
a 20 percent chance that MVFR cigs this evening will arrive as
early as 04Z.

KBUR...Low confidence in the 12z TAF. There is a 40 percent
chance of MVFR cigs between 13Z and 17z. There is a 20 to 30
percent chance that MVFR cigs will arrive as early as 08z tonight.

&&

.MARINE...01/300 AM...

Winds have diminished across the coastal waters. There is rather
high confidence that conds will remain below SCA levels across the
entire waters through at least Tue.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through this evening For
      zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...DB
MARINE...DB
SYNOPSIS...CK

weather.gov/losangeles




000
FXUS66 KSGX 011128
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
428 AM PDT SUN MAY 1 2016

.SYNOPSIS...
LOW PRESSURE OVER THE SOUTHWESTERN STATES WILL WEAKEN WITH A
WARMING TREND THROUGH TUESDAY. RESIDUAL MOISTURE AND WEAK
INSTABILITY WILL BRING A SLIGHT CHANCE OF AFTERNOON AND EARLY
EVENING SHOWERS...MAINLY NEAR THE MOUNTAINS OF SAN BERNARDINO AND
RIVERSIDE COUNTIES. COOLING AND INCREASING CLOUDS FOR WEDNESDAY
AND THURSDAY AS A LOW PRESSURE SYSTEM MOVES SLOWLY ACROSS THE
EASTERN PACIFIC. FOR THURSDAY NIGHT INTO NEXT WEEKEND...A SLOW
MOVING LOW PRESSURE SYSTEM MOVING INTO THE SOUTHWESTERN STATES
WILL BRING MORE CLOUDS...PERIODS OF SHOWERS...AND A SLIGHT CHANCE
OF THUNDERSTORMS.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

.SHORT TERM (TODAY THROUGH TUESDAY)...
A CLOSED LOW PRESSURE SYSTEM OVER ARIZONA WILL WEAKEN THROUGH
MONDAY WITH WEAK HIGH PRESSURE FOR TUESDAY. RESIDUAL MOISTURE AND
WEAK INSTABILITY WILL BRING A SLIGHT CHANCE OF AFTERNOON AND EARLY
EVENING SHOWERS FOR TODAY AND MONDAY...MAINLY NEAR THE MOUNTAINS
OF SAN BERNARDINO AND RIVERSIDE COUNTIES. THERE WILL BE AN INLAND
WARMING TREND FOR TODAY THROUGH TUESDAY. THE MARINE LAYER WILL
BRING AREAS OF NIGHT AND MORNING LOW CLOUDS AND FOG FOR COASTAL
AREAS AND PORTIONS OF THE VALLEYS THE MARINE LAYER A LITTLE LESS
DEEP FOR TUESDAY.

&&

.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
A SLOW MOVING LOW PRESSURE SYSTEM OVER THE EASTERN PACIFIC WILL
BRING COOLING AND INCREASING CLOUDS FOR WEDNESDAY AND THURSDAY.
FOR THURSDAY NIGHT INTO NEXT WEEKEND WEEKEND...THAT LOW PRESSURE
SYSTEM WILL CLOSE OFF AND MOVE SLOWLY INLAND INTO THE SOUTHWEST
STATES. THIS WILL BRING COOLING...MORE CLOUDS...AND PERIODS OF
SHOWERS WITH A SLIGHT CHANCE OF THUNDERSTORMS. THE GFS MOVES THE
COLDEST AIR AT 500 MB ACROSS SOUTHERN CALIFORNIA THURSDAY NIGHT
AND FRIDAY.

&&

.AVIATION...
010900Z...COAST/VALLEYS...SCT-BKN015-025 TOPS 040 THROUGH 17Z. AFT
17Z...SCT020-030. AFT 03Z...BKN-OVC020-030 REFORMING NEAR THE COAST
AND SPREADING INLAND THROUGH 14Z MONDAY.

MOUNTAINS/DESERTS...SCT-BKN080-120 WITH A SLIGHT CHANCE OF AFTERNOON
SHOWERS OVER THE MTNS AND HIGH DESERTS.

&&

.MARINE...

200 AM...SUNDAY THROUGH WEDNESDAY...LIGHT WINDS EACH NIGHT AND
MORNING FOLLOWED BY ONSHORE NORTHWEST WINDS 10-15 KT EACH AFTERNOON.
THURSDAY AND FRIDAY: A DEEP PACIFIC TROUGH WILL BRING STRONGER AND
MORE CONSISTENT WINDS AND A CHANCE FOR RAIN.

&&

.BEACHES...

200 AM...A LONG PERIOD SOUTHERLY SWELL WILL BRING ELEVATED SURF TO
SOUTHWEST FACING BEACHES TODAY AND MONDAY WITH STRONG RIP AND
LONGSHORE CURRENTS. A BEACH HAZARD STATEMENT IS IN EFFECT...SEE
LAXCFWSGX FOR DETAILS.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR ORANGE COUNTY
     COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.

PZ...NONE.
&&

$$

PUBLIC...17
AVIATION/MARINE/BEACHES...MOEDE




000
FXUS66 KMTR 011125
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
425 AM PDT SUN MAY 1 2016

.SYNOPSIS....OFFSHORE WINDS WILL CONTINUE TODAY...RESULTING IN
SUNNY AND WARM CONDITIONS IN MOST AREAS. COASTAL FOG AND LOW
CLOUDS WILL LIKELY RETURN BY LATE TODAY OR TONIGHT. SEASONABLE
AND DRY WEATHER IS FORECAST MONDAY AND TUESDAY. A WEATHER SYSTEM
WILL APPROACH CALIFORNIA BY THE MIDDLE OF THE WEEK...BRINGING A
CHANCE OF SHOWERS FROM LATE WEDNESDAY THROUGH THE END OF THE
WEEK...ALONG WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 3:25 AM PDT SUNDAY...SKIES ARE CLEAR ACROSS
OUR ENTIRE FORECAST AREA EARLY THIS MORNING AS LIGHT OFFSHORE FLOW
CONTINUES. CURRENT TEMPERATURES ARE GENERALLY WARMER THAN 24 HOURS
AGO AND IN SOME CASES SEVERAL DEGREES WARMER. FORECAST GUIDANCE
INDICATES HIGH TEMPERATURES TODAY WILL BE ABOUT FIVE DEGREES
WARMER THAN YESTERDAY. HOWEVER...MODELS FORECAST AN END TO
OFFSHORE FLOW TODAY ALONG WITH THE DEVELOPMENT OF SOUTHERLY FLOW
ALONG THE COAST. THIS DOES NOT LOOK LIKE A CLASSIC "SOUTHERLY
SURGE" SCENARIO...SINCE LOW CLOUDS DO NOT ALREADY EXIST TO OUR
SOUTH NEAR POINT CONCEPTION. WHAT`S MORE LIKELY TO HAPPEN IS THAT
LOW CLOUDS AND FOG WILL FORM IN COASTAL AREAS FROM MONTEREY BAY
SOUTH BY EARLY AFTERNOON...AND THEN MOVE NORTH UP ALONG THE REST
OF OUR COAST LATE THIS AFTERNOON AND EVENING. THIS MAKES FOR A
DIFFICULT TEMPERATURE FORECAST TODAY FOR COASTAL AREAS SINCE THE
TIMING OF THE SOUTHERLY WIND ONSET AND COASTAL FOG DEVELOPMENT
WILL HAVE A BIG IMPACT ON TEMPERATURES. MOST LIKELY SCENARIO IS
FOR COOLING TO OCCUR IN LOCATIONS LIKE BIG SUR AND SANTA CRUZ
WHILE OTHER COASTAL AREAS WILL BE AS WARM OR WARMER THAN
YESTERDAY.

ANOTHER ITEM TO WATCH TODAY IS A SHORTWAVE TROUGH CURRENTLY OVER
SOUTHEAST OREGON THAT IS ROTATING AROUND A LONGWAVE TROUGH
CENTERED OVER THE DESERT SW. THIS SHORTWAVE IS FORECAST TO ROTATE
INTO NORTHERN AND CENTRAL CALIFORNIA LATER TODAY. THE ECMWF KEEPS
ALL PRECIP ASSOCIATED WITH THIS SHORTWAVE TO OUR EAST...MAINLY OVER
THE SIERRA NEVADA. HOWEVER...BOTH THE 00Z NAM AND 00Z GFS
FORECAST ISOLATED SHOWERS ALONG THE EASTERN FRINGES OF OUR
FORECAST AREA LATE THIS AFTERNOON AND EARLY THIS EVENING. HAVE
THEREFORE ADDED SLIGHT CHANCE POPS TO FAR EASTERN ALAMEDA...SANTA
CLARA...AND SAN BENITO COUNTIES FOR LATER TODAY.

DRY AND MILD WEATHER IS FORECAST FOR MONDAY AND TUESDAY. ONSHORE
FLOW WILL LIKELY MAINTAIN AT LEAST AREAS OF NIGHT AND MORNING LOW
CLOUDS AND TEMPERATURES WILL BE NEAR NORMAL.

AN UPPER TROUGH CURRENTLY SEEN ON SATELLITE IMAGERY OFFSHORE ALONG
145W IS FORECAST TO GRADUALLY APPROACH THE CALIFORNIA COAST OVER
THE NEXT THREE DAYS AND BEGIN TO GENERATE SHOWER CHANCES ACROSS
OUR AREA BY LATE WEDNESDAY. BOTH THE GFS AND ECMWF FORECAST A
CUTOFF LOW TO DEVELOP NEAR SAN FRANCISCO BY THURSDAY...WITH THAT
LOW THEN PROJECTED TO DROP SOUTHEAST AND TRACK ACROSS SOUTHERN
CALIFORNIA BY LATE FRIDAY AND FRIDAY NIGHT. THUS...SHOWER CHANCES
WILL CONTINUE THROUGH THE END OF THE WEEK AND PROBABLY INTO NEXT
WEEKEND AS WELL. GIVEN THE UNPREDICTABILITY OF CUTOFF LOW
MOVEMENT...IT`S DIFFICULT TO PINPOINT WHERE SHOWER CHANCES WILL BE
GREATEST DURING THE SECOND HALF OF THE WEEK. ISOLATED THUNDERSTORMS
MAY ALSO OCCUR...BUT WILL WAIT TO ADD THUNDERSTORMS TO THE
FORECAST UNTIL CONFIDENCE INCREASES ON THE TIMING AND TRACK OF THE
UPPER LOW. IN ADDITION TO PRECIPITATION CHANCES...THIS UPPER LOW
WILL RESULT IN COOLER THAN NORMAL CONDITIONS ACROSS MOST OF OUR
AREA DURING THE SECOND HALF OF THE WEEK.

&&

.AVIATION...AS OF 4:21 AM PDT SUNDAY...DRY OFFSHORE FLOW KEEPING
MAINLY VFR TODAY. THE ONE FLY IN THE OINTMENT IN THE FORECAST
IS A POSSIBLE SOUTHERLY SURGE LATER TODAY. LATEST NAM AND WRF SHOW
A SOUTHERLY SURGE IMPACTING KMRY/KSNS...POSS MAKING IT INTO SF BAY
OVERNIGHT. CONF IS MARGINAL...BUT WILL ADD CIGS TO MONTEREY BAY.

VICINITY OF KSFO...VFR.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY TERMINALS...VFR WITH SOME HAZE IN THE AM. VFR
BECOMING MVFR THIS EVENING AND OVERNIGHT..

&&

.MARINE...AS OF 04:19 AM PDT SUNDAY...BUILDING HIGH PRESSURE OVER
THE EASTERN PACIFIC WILL KEEP NORTHERLY WINDS OVER THE COASTAL
WATERS TODAY. LOCALLY GUSTY WINDS WILL BE POSSIBLE OVER THE OUTER
WATERS NORTH OF POINT REYES. SOUTHERLY WINDS WILL DEVELOP LATE
TONIGHT AND EARLY MONDAY. A MODERATE SWELL WILL MIX WITH A SMALLER
LONG PERIOD SOUTHERLY SWELL THIS WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 9 AM

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION: MM
MARINE: MM


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000
FXUS66 KHNX 011052
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
352 AM PDT SUN MAY 1 2016

.SYNOPSIS...
A FEW LINGERING SHOWERS AND THUNDERSTORMS OVER THE REGION
TODAY...THEN CLEARING SKIES AND WARMER TEMPERATURES MONDAY AND
TUESDAY AS WEAK HIGH PRESSURE MOVES OVER THE REGION. ANOTHER
WEATHER SYSTEM WILL MOVE INTO THE REGION WEDNESDAY INCREASING
PRECIPITATION CHANCES FOR THE SECOND PART OF THE WEEK.

&&

.DISCUSSION...
AN UPPER LOW CONTINUES TO BE CENTERED OVER ARIZONA...BUT THE BROAD
LOW CIRCULATION COVERS MUCH OF THE GREAT BASIN. ANOTHER WEAK
SHORTWAVE WILL MOVE SOUTH ALONG THE WEST SIDE OF THE LOW TODAY.
THIS WILL TRIGGER A FEW SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS
AND DESERT THIS AFTERNOON. IT MAY ALSO HELP TO PRODUCE A FEW
SHOWERS ALONG THE COASTAL HILLS THIS AFTERNOON WHICH MAY THEN
DRIFT EAST INTO THE SAN JOAQUIN LATE THIS AFTERNOON AND EARLY
EVENING.

THERE COULD BE A FEW LINGERING SHOWERS IN THE SIERRA NEVADA
MONDAY AFTERNOON AS THE LOW FINALLY MOVES EAST AND A RIDGE OF
HIGH PRESSURE MOVES INLAND. BY TUESDAY AFTERNOON THE RIDGE WILL
SHIFT TO A POSITION NEAR THE ROCKIES...SETTING UP AN OMEGA BLOCK
ACROSS THE U.S WITH A DEEP TROUGH IN THE EASTERN STATES AND
ANOTHER TROUGH OF LOW PRESSURE ALONG THE WEST COAST. THE TROUGH
ALONG THE WEST COAST DEEPENS AND DEVELOPS INTO A CLOSED LOW OFF
THE CALIFORNIA COAST WEDNESDAY. DUE TO THE OMEGA BLOCKING
PATTERN...THE LOW WILL NOT BE ABLE TO MOVE ANYWHERE VERY FAST.
THUS IT WILL REMAIN OVER CALIFORNIA THROUGH FRIDAY BEFORE
BEGINNING TO MOVE EASTWARD NEXT WEEKEND. THIS WILL CREATE AN
UNSETTLED WEATHER PATTERN OVER CENTRAL CALIFORNIA FOR THE LAST
HALF OF THE WEEK. A FEW SHOWERS OR THUNDERSTORMS COULD DEVELOP IN
THE SIERRA WEDNESDAY AFTERNOON. THE CHANCES OF SHOWERS AND
THUNDERSTORMS INCREASES ACROSS THE ENTIRE REGION THURSDAY AND
FRIDAY AND CONTINUES INTO THE WEEKEND.

FOR TEMPERATURES...A WARMING TREND WILL OCCUR TODAY THROUGH
TUESDAY WITH HIGHS AS MUCH AS 5 TO 10 DEGREES ABOVE NORMAL. THEN
TEMPERATURES WILL BEGIN TO COOL ON WEDNESDAY AS THE LOW MOVES IN.
BY THURSDAY AND FRIDAY...TEMPERATURES WILL BE 5 TO 10 DEGREES
BELOW NORMAL FOR EARLY MAY. FOR THE SAN JOAQUIN VALLEY THIS MEANS
THAT TEMPERATURES WILL GO FROM THE MID 80S TO NEAR 90 DEGREES
TUESDAY TO THE 70S ON THURSDAY AND FRIDAY. NORMAL IS NEAR 80
DEGREES FOR THE FIRST WEEK OF MAY.

&&

.AVIATION...
EXPECT AREAS OF MVFR WITH LOCAL IFR POSSIBLE 18Z SUNDAY TO 06Z
MONDAY DUE TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THE
SIERRA NEVADA...AS WELL AS THE KERN COUNTY MOUNTAIN AND DESERT AREAS.
LOCAL MVFR POSSIBLE IN ISOLATED SHOWERS OVER THE SAN JOAQUIN VALLEY
00Z-06Z MONDAY. OTHERWISE VFR CONDITIONS WILL PREVAIL OVER THE
CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS.

&&

.AIR QUALITY ISSUES...
NONE.

&&

.CERTAINTY...

THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.

CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AN/OR TO PROVIDE FEEDBACK.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

PUBLIC...BEAN
AVN/FW...JEB
SYNOPSIS...BEAN

WEATHER.GOV/HANFORD




000
FXUS66 KEKA 011048
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
348 AM PDT SUN MAY 1 2016

.SYNOPSIS...A HIGH PRESSURE RIDGE EXTENDING ACROSS THE REGION WILL
MAINTAIN DRY AND WARMER CONDITIONS ACROSS THE AREA THROUGH MONDAY.
TEMPERATURES WILL DECREASE SLIGHTLY MONDAY AND TUESDAY AS A COLD
FRONT APPROACHES AND MOVES THROUGH THE AREA INCREASING THE CHANCES
FOR A FEW SHOWERS AND INCREASING CLOUDINESS.

&&

.DISCUSSION...CLEAR TO PARTLY CLOUDY SKIES CONTINUE ACROSS THE
REGION AS A HIGH PRESSURE RIDGE PERSIST ACROSS THE AREA. DRY AND
WARM CONDITIONS WILL CONTINUE ACROSS THE AREA THROUGH MONDAY.
A COLD FRONT WILL APPROACH AND MOVE THROUGH THE REGION MONDAY AND
TUESDAY INCREASING CLOUDINESS AND A SLIGHT CHANCE TO CHANCE FOR
SHOWERS MOVING ACROSS PORTIONS OF THE REGION. CLOUDINESS WILL
INCREASE MONDAY AND TUESDAY WHICH WILL COOL TEMPERATURES SLIGHTLY
ACROSS THE REGION. PATCHY FOG MAY DEVELOP ACROSS PORTIONS OF THE
COASTAL AREAS AND INLAND VALLEYS THE NEXT FEW NIGHTS. WINDS WILL
DECREASE ACROSS THE REGION TODAY AND THE NEXT FEW DAYS. LIGHT TO
MODERATE WINDS WILL PREVAIL ACROSS MOST AREAS TODAY AND EARLY
NEXT WEEK. SEASONAL TEMPERATURES WILL PREVAIL ACROSS THE REGION
THE MIDDLE OF THIS WEEK IN THE WAKE OF THE WEAK COLD FRONT. THERE
IS A SLIGHT CHANCE FOR A FEW ISOLATED THUNDERSTORMS ACROSS THE
NORTHEASTER PORTIONS OF DEL NORTE COUNTY WEDNESDAY AND POSSIBLY
THURSDAY AFTERNOONS AND EARLY EVENINGS. TEMPERATURES WILL WARM
SLIGHTLY FRIDAY.

&&

.AVIATION...OTHER THAN SOME BRIEF VISIBILITY RESTRICTIONS ALONG
THE REDWOOD COAST EARLY THIS MORNING DUE TO A COMBINATION OF SEA
SPRAY AND LIGHT GROUND FOG...VFR CONDITIONS ARE EXPECTED. WINDS HAVE
DECOUPLED THIS MORNING...AND BOUNDARY LEVEL WINDS WILL SUBSIDE
FURTHER BEFORE MIXING OCCURS LATER THIS MORNING. AS A RESULT...
GENERALLY LIGHT SURFACE WINDS ARE EXPECTED. /SEC

&&

.MARINE...WINDS AND SEAS ARE ON THEIR WAY DOWN THIS MORNING.
OFFSHORE GALE WARNING HAS BEEN REPLACED BY A HAZARDOUS SEAS WARNING
AND A SMALL CRAFT ADVISORY. BOTH OF THESE HAZARDS SHOULD END BY MID-
MORNING. A FLOW REVERSAL IS EXPECTED BY TONIGHT AS WINDS BECOME
LIGHT AND EVENTUALLY SOUTHERLY. AS OFFSHORE FLOW COMPONENT
WEAKENS...THIS MAY ALLOW FOR SOME SEA FOG TO ADVECT INTO THE AREA
TONIGHT AND MONDAY. HIGH PRESSURE WILL RE-BUILD OFFSHORE BY THE
MIDDLE OF THE COMING WEEK WITH A RETURN TO INCREASED NORTHERLIES. NW
SWELL OF BETWEEN 10 AND 15 SECONDS WILL CONTINUE INTO EARLY NEXT
WEEK. A S BACKGROUND SWELL OF AROUND 2 FT WILL CONTINUE THRU THE
PERIOD. /SEC

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
     SMALL CRAFT ADVISORY UNTIL 9 AM PDT THIS MORNING FOR PZZ470-475.

     HAZARDOUS SEAS WARNING UNTIL 9 AM PDT THIS MORNING FOR
     PZZ470-475.

&&

$$

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