Forecast Discussions mentioning ACARS, received at FSL on 05/05/00

QUIET NIGHT ACROSS THE FORECAST AREA WITH NOT MUCH WIND OVER THE MOUNTAINS AND LESS WIND ACROSS THE COASTAL WATERS THAN ON PREVIOUS NIGHTS. STRATUS PATTERN APPEARS QUITE SIMILAR TO 24 HOURS AGO ACROSS SRN CA...BUT CLEARING HAS OCCURRED ALONG THE CENTRAL COAST AND EXPECT ONLY PATCHY FOG AT MOST THERE THIS MORNING. BASE OF THE MARINE INVERSION CONTINUES AT AROUND 2000-2500 FEET ACROSS SRN CA BASED ON RECENT ACARS DATA...BUT DOWN BLO 1000 FEET ON THE 00Z VBG SOUNDING. EDDY APPEARS TO BE QUITE WEAK AND FAR OFFSHORE TONIGHT...SO EXPECT DECENT CLEARING DURING THE MORNING FOR MOST PLACES TODAY. STUBBORN LOCATIONS SUCH AS THE VTU COAST COULD TAKE A BIT LONGER...BUT WITH WEAKER EDDY AND LIKELY HIGH CLOUD DISRUPTION DO NOT EXPECT A REPEAT OF YESTERDAY WHEN SOME STATIONS TOOK MOST OF THE AFTERNOON TO SCATTER OUT.

MODELS IN GENERAL AGREEMENT THROUGH 48 HOURS. BROAD TROFFING SWINGS THRU TODAY...WITH FLAT ZONAL FLOW TONIGHT AND ANOTHER MINOR TROF APPROACHING NRN CA BY LATE SATURDAY. COMPLICATING FACTORS ARE STRENGTH AND LOCATION OF EDDY...HIGH CLOUDS AND POSSIBLE STRATUS SURGES DOWN THE CENTRAL COAST. EDDY IS FAVORED BY BROAD TROF WITH ATTENDANT PVA...BUT WEAKER NW WINDS AROUND PT CONCEPTION ARE A NEGATIVE. WILL ASSUME INTERMITTENT WEAK EDDY WILL CONTINUE THRU SATURDAY. ABUNDANT HIGH CLOUDS WHICH ARE LINED UP OFFSHORE FOR SEVERAL HUNDRED MILES COULD ALSO COMPLICATE THINGS...WITH SIGNIFICANT MARINE LAYER DISRUPTION POSSIBLE. FOR THE FORECAST...WILL CUT BACK LOW CLOUDS A BIT FOR MOST AREAS TONIGHT AND SATURDAY...AND ADD VARIABLE HIGH CLOUDS FOR ALL PERIODS. WILL ALSO REMOVE LOW CLOUDS FROM THE LOWER COASTAL SLOPES. TEMPS... EXPECT GREATEST COOLING TODAY FOR MOUNTAINS AND DESERTS AS HEIGHTS AND THICKNESSES DROP...WITH SLIGHT COOLING FOR COASTS AND VALLEYS. LITTLE CHANGE THEREAFTER FOR SATURDAY.

EXTENDED...NEW MRF IS SIMILAR TO PREVIOUS THINKING...WITH ONE MORE SHORTWAVE BRUSHING THE NRN PARTS OF THE DISTRICT SUNDAY...THEN A FLAT BUT FAIRLY STRONG UPPER RIDGE BUILDING IN FROM THE SW FOR MONDAY AND TUESDAY. CANADIAN AND UKMET CONCUR WITH THIS. WILL MAKE ONLY MINOR ADJUSTMENTS TO THE PREVIOUS FORECAST FOR THE EXTENDED TIMEFRAMES. MRF IS RATHER INTERESTING IN THE 6 TO 10 DAY PERIOD...WITH DEEP CUTOFF LOW DEVELOPING OFF THE NRN CA COAST...AND RAIN ACROSS THE ENTIRE FORECAST AREA BY NEXT WEEKEND. WILL HAVE TO WAIT AND SEE.

LAX 000. JACOBSON

.LAX...SMALL CRAFT ADVISORY (SEE LAXCWFLAX).



GULF OF ALASKA LOW WAS CENTERED NEAR 52N/138W EARLY THIS MORNING WITH ASSOCIATED TROUGH EXTENDING SE INTO CENTRAL CA. SHORTWAVE THAT MOVED ACROSS NORCAL THURS EVE WAS LIFTING NE INTO THE GREAT BASIN AT THIS TIME AND WILL HELP SHIFT TROF AXIS EAST OF THE FA LATER THIS MORNING. NEVERTHELESS...CWA WILL REMAIN UNDER A SWIFT ZONAL FLOW ALOFT THROUGH AT LEAST SAT NIGHT WITH EMBEDDED SHORTWAVES SUSTAINING AN ONSHORE FLOW ALONG THE COAST. PRIMARY IMPACTS ON THE FA WILL BE CONTD MODERATE P-GRADS ACROSS THE CENTRAL INTERIOR WITH BREEZY TO WINDY CONDITIONS CONTG THROUGH SAT. ONSHORE FLOW AND DEEPENED MARINE LAYER WILL ALSO PROVIDE A REINFORCING SHOT OF COOLER MARINE AIR INTO THE SJ VALLEY THIS EVE TO ENHANCE COOLING IN LOWER LEVELS.

MOISTURE FETCH WITH WESTERLY FLOW OVER CENTRAL/EASTERN PAC EXTENDS WEST TO 160E AND VARYING AMOUNTS OF MAINLY HIGH CLOUD COVER WILL AFFECT THE CWA AS WAVES PUSH INLAND OVER THE PAC NW AND NORCAL. ALTHOUGH 00Z PROGS SHOW INCREASING LOW-MID LEVEL MOISTURE OVER NORTHERN PORTIONS OF THE DISTRICT SAT AFTN...TIMING OF WAVES WILL BE DIFFICULT AT BEST AND WESTERLY FLOW WILL KEEP THE FA UNDER RELATIVELY HIGH HEIGHTS WITH DYNAMICS REMAINING OVER NORCAL. WILL THEREFORE INCREASE CLOUDS BUT REFRAIN FROM INTRODUCING POPS AT THIS TIME. ALTHOUGH INLAND SHIFT IN TROUGH TODAY WILL DECREASE THICKNESSES ENOUGH TO LOWER MAX TEMPS SEVERAL DEGREES... WESTERLY FLOW WILL PREVENT ANY SIGNIFICANT CHANGES ON SAT.

ALTHOUGH MEDIUM RANGE GUIDANCE IS SIMILAR SHOWING INCREASED RIDGING OVER THE ERN PAC EARLY NEXT WEEK...NOTED DIFFERENCES ARE EVIDENT IN DEPICTIONS OF WHERE AMPLIFICATION WILL OCCUR WITH CANADIAN/MRF SOLUTIONS ABOUT 10DEG WEST OF NOGAPS. DIFFERENCES WILL AFFECT DOWNSTREAM TROUGH LOCATION WITH MAINLY TEMP IMPACTS ON THE CWA.

.HNX...NONE.

FAT AB 080/051 079/055 080 88000 BFL AB 081/050 079/053 082 88000 YNP AB 068/046 068/049 072 88000

JSN



AN UPDATE NEEDED THIS EVENING TO ADD A CHANCE OF THUNDER ACROSS THE LASSEN AREA TONIGHT AND TO ALSO DIMINISH THE PRECIPITATION THREAT THROUGHOUT THE VALLEY AND ADJACENT HILLS TONIGHT AS WELL AS TOMORROW. SAT PIX SHOWING MAINLY HIGH CLOUDS STREAMING OVER CWA. ASOS INDICATING MOST BASES ABOVE 12K WITH 00Z OAK SOUNDING VERIFYING THIS WITH BEST MOISTURE ABOVE 600 MB. SURFACE OBS ARE PICKING UP MINIMAL LIGHT PRECIPITATION THOUGH ACROSS THE NERN CWA. MANZINITA LAKE SHOWING /.03/ AT THIS TIME WITH LIGHTNING DATA SHOWING POSITIVE STRIKES JUST SOUTH OF THIS AREA. A WEAK SHORT WAVE...CYCLONIC FLOW...AND OROGRAPHIC LIFT ARE RESPONSIBLE FOR THESE LIGHT RETURNS. JUST WEST OF THIS POINT ACROSS THE VALLEY AND NORTHERN COASTAL RANGE...SKIES ARE BEGINNING TO CLEAR. NEW 00Z ETA AND AVN NOT SHOWING MUCH IN THE WAY OF LOW LEVEL MOISTURE TOMORROW. WITH AREA BETWEEN SHORT WAVES AT THIS TIME HAVE TAKEN OUT SMALL POPS ACROSS THE CWA. AS FOR FRIDAY AFTERNOON TEMPERATURES...WITH LITTLE SYNOPTIC TEMPERATURE CHANGE AND LESS CLOUD COVER ACROSS THE NORTH...LOCALES SUCH AS REDDING AND RED BLUFF ARE LIKELY TO BE A FEW DEGREES WARMER. FURTHER SOUTH TEMPS SHOULD BE PRETTY MUCH STATIC COMPARED TO TODAY.

.STO...NONE.

KRUZDLO



MARINE LAYER IS ABOUT 3000 FEET DEEP THIS EVENING AND PUSH OF MARINE AIR HAS GENERATED LOCAL WINDS 15-20 MPH OVER THE CENTRAL SAN JOAQUIN VALLEY. SURFACE OBSERVATIONS AT 04Z PLACE THE SOUTHERN EXTENT OF THE MARINE PUSH BETWEEN FRESNO AND HANFORD AND EXPECT THE MARINE AIR WILL REACH THE SOUTH END OF THE VALLEY AFTER MIDNIGHT.

THE UPPER-LEVEL LOW IS CENTERED NEAR 52N/137W WITH THE UPPER-LEVEL TROUGH MOVING ONTO THE COAST. NEXT SHORT-WAVE EXTENDS DOWN TO 43N/ 132W...FOLLOWED BY ANOTHER VORTICITY LOBE AT 57N/143W. THESE IMPULSES WILL KEEP A BROAD TROUGH OVER THE WESTERN STATES THROUGH FRIDAY NIGHT FOR COOLER TEMPERATURES AND A CONTINUING ONSHORE FLOW PATTERN. THE SHORT-WAVES WILL REINFORCE THE SURFACE PRESSURE GRADIENTS AS THEY ROTATE THROUGH CENTRAL CALIFORNIA...SO WILL SEE BREEZY TO LOCALLY WINDY CONDITIONS REDEVELOP FRIDAY AFTERNOON... ESPECIALLY OVER THE KERN COUNTY MOUNTAINS AND DESERTS WHERE THE MESO-ETA FORECASTS THE PRESSURE GRADIENT TO TIGHTEN AGAIN BY 21Z FRIDAY. INCREASED VALLEY WINDS WILL BRING ANOTHER MARINE PUSH FOR FRIDAY AFTERNOON THAT WILL KEEP HIGH TEMPERATURES ONLY IN THE UPPER 70S TO LOWER 80S. LITTLE CHANGE IN VALLEY TEMPERATURES SATURDAY WITH POOLED MARINE AIR...THEN A SLOW WARMING TREND AS AN UPPER-LEVEL RIDGE BUILDS INTO CALIFORNIA DURING THE FIRST HALF OF THE WEEK.

MINOR TWEAKS TO THE DESERT ZONE FORECAST THIS EVENING...OTHERWISE NO CHANGES PLANNED TO THE FORECAST PACKAGE.

ALL POPS ZERO. SANGER

.HNX...NONE.



MARINE LAYER RUNNING ABOUT 1200 FT AT VBG AND 1800 FT OVER LAX THIS EVENING. LARGE AREA OF LOW CLOUDS EXTENDING FROM L.A. COUNTY COAST SOUTHWARD...WITH A PATCH OF LOW CLOUDS OVER VTU COUNTY COAST AS OF 9 PM. LOW CLOUDS EXPANDING INTO L.A. COUNTY VALLEYS...AND INTO VTU COUNTY INTERIOR VALLEYS AS SHOWN ON LATEST FOG PRODUCT IMAGES. EXPECT ANOTHER WEAK EDDY FO DEVELOP OVERNIGHT AS NW WINDS IN THE OUTER WATERS REMAIN RATHER STRONG...COMBINED WITH GOOD ONSHORE GRADIENTS AND LOWER PRESSURE NEAR LAS VEGAS. LOW CLOUDS SHOULD CONTINUE TO EXPAND INLAND OVERNIGHT AND REACH THE LOWER COASTAL SLOPES BY MORNING. FARTHER NORTH...SOME HI CLOUDS ASSOCIATED WITH AN UPPER TROF WAS APPROACHING SLO/SBA COUNTIES...BUT NO LOW CLOUDS ANYWHERE NEAR THE CENTRAL COAST THIS EVENING. EXPECT PATCHY LOW CLOUDS MAY STILL DEVELOP THERE LATER TONIGHT. WILL UPDATE ZONES TO SCALE BACK ON LOW CLOUD FORECAST FOR CENTRAL COAST...AND EVEN FOR SLO COUNTY INTERIOR VALLEYS.

BROAD UPPER TROF TO MOVE INTO W COAST LATER TONIGHT AND FRI THEN WEAKEN INTO MORE OF A ZONAL FLOW FRI NITE AND SAT. SOME HI CLOUDS AT TIMES POSSIBLE...OTHERWISE FAIR SKIES WITH MORE NIGHT AND MORNING LOW CLOUDS AND FOG EXPECTED ALONG THE COAST AND INTO THE VALLEYS FRI THRU SAT. WITH LOWERING HEIGHTS AND THICKNESSES...ALONG WITH ONSHORE FLOW CONTINUING OVER THE DISTRICT...TEMPS ARE LOOKING AT LEAST SLIGHTLY COOLER FROM TODAY FOR FRI THEN ABOUT THE SAME FOR SAT.

IN THE EXTENDED...ZONAL FLOW CONTINUES SUN...THEN AN UPPER RIDGE IS EXPECTED TO BUILD INTO SOCAL FOR MON AND TUE. DRY WEATHER TO CONTINUE SUN THRU TUE...WITH SOME NIGHT AND MORNING LOW CLOUDS AND FOG ALONG THE COAST. A WARMING TREND IS EXPECTED WITH ABOVE NORMAL TEMPS...ESPECIALLY MON AND TUE WITH THE VALLEYS REACHING INTO THE 90S.

LAX 0000. SIRARD

.LAX...SMALL CRAFT ADVISORY (SEE LAXCWFLAX).



...SYNOPSIS...

ONSHORE FLOW AND THE MARINE LAYER WILL CONTINUE NIGHT AND MORNING LOW CLOUDS AND FOG WEST OF THE MOUNTAINS WITH ONLY PARTIAL AFTERNOON CLEARING NEAR THE BEACHES. OTHERWISE...DRY WESTERLY FLOW ALOFT WILL KEEP THE WEATHER FAIR THROUGH SATURDAY WITH LITTLE TEMPERATURE CHANGE. BUILDING HIGH PRESSURE WILL RESULT IN A DECREASING MARINE LAYER AND WARMING TREND EARLY NEXT WEEK.

...DISCUSSION...

COASTAL LOW CLOUDS SPREADING INLAND THIS EVE WITH MODERATELY STRONG NW WINDS AROUND PT CONCEPTION AND EDDY OFFSHORE. 00Z NKX SOUNDING SHOWED THE INVERSION BASED NEAR 2000 FT. MODERATELY STRONG ONSHORE GRADIENTS WITH OVER 7 MB SAN-IPL.

MODEL TRENDS LOOK SIMILAR TO PREVIOUS RUNS WITH TROUGH JUST OFF COAST ROTATING PAST TO N WITH WEAK SHORT WAVE ALSO MOVING PAST TO N LATE SAT/ EARLY SUN. THIS WILL CONTINUE ONSHORE FLOW WITH INTERMITTENT EDDY INTO SAT. LITTLE CHANGE IN LOCAL HEIGHTS/THICKNESS/850 MB TEMPS FOR ONLY MINOR TEMP CHANGES NEXT COUPLE DAYS. LOW CLOUDS SHOULD CONTINUE TO BE SLOW TO CLEAR FROM IMMEDIATE COAST EACH DAY...OTHERWISE HAZY AFTERNOON SUNSHINE W OF MOUNTAINS AND CLEAR IN MOUNTAINS/DESERTS.

LONGER RANGE PROGS INDICATE UPPER HI BUILDING OFF COAST AND SLOWING SHIFTING OVER SW EARLY NEXT WEEK. THIS SHOULD RESULT IN DECREASING MARINE LAYER AND WARMING TREND.

SAN 0000

.SAN...NONE.

ATKIN

WE HAVE PLENTY OF HIGH CLOUDS OVER OUR FORECAST AREA THIS EVENING IN A CONTINUING BRISK...SLIGHTLY CYCLONIC WSW FLOW ALOFT...BUT NO LOW CLOUDS. THE OAKLAND SOUNDING REVEALS LITTLE MOISTURE BELOW 600 MB ...EVEN DOWN NEAR SEA LEVEL. AND...THE MARINE INVERSION IS WEAK AND DEEP AS INDICATED BY THE SOUNDING AND ALSO BY THE FT ORD PROFILER. THIS ALL MEANS THAT WE WILL PROBABLY NOT SEE MANY LOW CLOUDS FORM TNGT...IF ANY. THE SFO-SAC GRADIENT IS STILL FAVORABLE AT 2.5 MB ONSHORE AS OF 8 PM...BUT THE OTHER PARAMETERS ARE NOT. THUS WILL UPDATE ZONES AND DROP CRUD COVERAGE BACK TO PATCHY FOR TNGT AND FRI MRNG...AND EVEN THATS A HEDGE.

THE FAST CYCLONIC WLY FLOW WILL CONTINUE THRU SAT...WITH SHORT WAVES RACING THRU OUR DISTRICT FROM TIME TO TIME. THE FIRST ONE WILL GO THRU OVERNIGHT TNGT BUT CURRENTLY HAS ONLY HIGH CLOUDS ASSOCIATED WITH IT. THE NEW ETA BRINGS ANOTHER RIPPLE THRU FRI NIGHT...WHICH SHOULDNT BRING US SIGNIFICANT WEATHER EITHER. TEMPS WILL REMAIN SEASONAL ON THE COAST AND A LITTLE COOLER THAN NORMAL INLAND DUE TO THE RELATIVELY LOW 500 MB HEIGHTS. THE NEW ETAS FORECAST HEIGHTS ARE SLIGHTLY LOWER THAN THE MRNG AVN VALUES.

THE MRNG AVN RUN BROUGHT LIGHT RAIN AS FAR S AS SJC SAT NIGHT...WITH 500 MB HEIGHTS 570 DM OR HIGHER. ONE OF THOSE TWO FORECASTS IS WRONG. EITHER WE WONT GET ANY RAIN AT ALL...OR THE HEIGHTS WILL TURN OUT TO BE CONSIDERABLY LOWER THAN FORECAST. BUT...WE WONT GET RAIN OUT OF WLY FLOW IN MAY WITH HEIGHTS OF 570 DM. THE AFTN PACKAGE FORECAST A CHANCE OF RAIN IN THE N BAY SAT NGT AND WILL LEAVE THAT ALONE. IF THE NEW ETA IS ON THE RIGHT TRACK THE 500 MB HEIGHTS MAY INDEED WIND UP LOWER THAN THE MRNG AVN FORECAST VALUES...SO CANT RULE OUT THE SHOWER CHANCE.

THE MRF AND EURO BOTH FORECAST RIDGING TO DEVELOP SUN/MON...BUT BREAK DOWN AGAIN STARTING TUE. IN FACT...THE MRF HAS AN UNSEASONABLY COLD TROF DROPPING INTO CA BY NEXT THU...BUT AS THIS IS 7 DAYS OUT ITS STRICTLY CONJECTURE RIGHT NOW. IT COULD HAPPEN...ABOUT THIS TIME OF YEAR IN 1977 WE HAD A VERY COLD...DEEP TROF DROP INTO CNTRL/SRN CA THAT PRODUCED HEAVY RAIN AT LOW ELEVATIONS AND SNOW ON THE GRAPEVINE. POPS ZERO. MARKKANEN

.SFO...TNGT...SCA...PT ARENA TO PT PIEDRAS BLANCAS AND SFO BAY.

N 

NUMERICAL MODELS...AND SFC FRONT...STILL HAVING TROUBLE KEEPING UP WITH SHORT WAVE CURRENTLY CROSSING NW CA. ITS EFFECTS ON AREA WEATHER HAVE BEEN FAIRLY MINIMAL THOUGH...AS IT ONLY SPREAD A THICK SHIELD OF CIRRUS OVER THE AREA THIS AFTERNOON. IN ITS WAKE THE HIGH CLOUDS ARE THINNING...BUT THE LOW LEVEL MOISTURE ASSOCIATED WITH THE WEAK FRONT REMAINS JUST OFFSHORE OF NW CA. MODELS SEEM TO HAVE A DECENT HANDLE ON THE OVERALL PROFILE OF MOISTURE WITH THIS SYSTEM. THEY INDICATE SIGNIFICANT DRYING AT MID AND UPPER LEVELS OVERNIGHT AS LOW LEVEL MOISTURE BUMPS UP AGAINST THE COAST NORTH OF CAPE MENDOCINO...BUT DISSIPATES SOUTH OF THE CAPE IN THE SUBSIDENCE. ALTHOUGH SATELLITE SHOWS MAIN PLUME OF TPW TO THE SOUTH OF THE AREA...IR IMAGES SHOW CLOUD TOP TEMPS IN THE -5 TO -7 DEG C RANGE NORTH OF THE CAPE...BUT ONLY -1 TO -2 SOUTH OF THE CAPE. SO LOCAL DRIZZLE OR A CHANCE OF LIGHT SHOWERS TONIGHT ACROSS ZONES 1 AND 3...AND PARTS OF ZONE 4... STILL LOOKS GOOD. MODELS SHOW COLD AIR ALOFT AND DECENT JET DYNAMICS ACROSS THE NORTH COAST AS NEXT SHORT WAVE MOVES THROUGH FRI MORNING. BUT SFC HIGH SHOULD BUILD DURING THE AFTERNOON AS THE WAVE MOVES OUT OF THE AREA AND MID AND UPPER LEVEL TEMPS BEGIN TO RECOVER. NO UPDATES TO CURRENT ZONE FORECAST PACKAGE. TJADEN

POPS CEC 3303 EKA 3303 UKI 0000. .EKA...NONE.



PRESSURE GRADIENTS INCREASING AGAIN THIS AFTERNOON...CURRENTLY AT 3.6 MB FROM SFO-SAC. THIS WILL GENERATE ANOTHER DECENT DELTA BREEZE THROUGH EARLY EVENING. UPPER TROF CONTINUES TO SLOWLY DEEPEN OVER THE REGION. TIMING OF SHORT WAVES WILL CONTINUE TO BE THE TRICKY PART...SINCE EACH WAVE WILL BE ASSOCIATED WITH MOST OF THE CLOUDINESS FOR THE REGION AND ANY CHANCE OF PRECIP OR SPRINKLES. CURRENTLY ONE SHORT WAVE IS JUST OFF THE NORTHERN CALIFORNIA COAST. NOT A LOT OF MOISTURE ASSOCIATED WITH IT BUT THERE MAY BE JUST ENOUGH INSTABILITY TO PRODUCE A FEW LIGHT SHOWERS OVER THE NORTHERN ZONES AND SOME SPRINKLES IN THE SOUTH AS IT PASSES THROUGH TONIGHT.

MODELS INDICATE ANOTHER SHORT WAVE ROTATING THROUGH DURING THE DAY ON FRIDAY. AS UPPER VORT MOVES THROUGH REGION ONLY MARGINAL INSTABILITY ASSOCIATED WITH IT...AND MAINLY OVER THE NORTH END OF THE SAC VLY. HAVE JUST LEFT IN SLIGHT CHANCE OF AFTERNOON SHOWERS FOR NOW. MODERATE ONSHORE FLOW ON FRIDAY SHOULD CONTINUE TO PRODUCE A DECENT DELTA BREEZE. TEMPS SHOULD COOL SLIGHTLY AS WELL OVER TODAYS HIGHS.

A BETTER SHORT WAVE WILL APPROACH THE REGION LATE SATURDAY OVER THE NORTHERN AND WESTERN ZONES...BUT THE PRIMARY CHANCE OF ANY PRECIP WILL BE SATURDAY NIGHT AND SUNDAY FOR THE REGION.

.STO...NONE.

BLU EE 042/056 042/056 043 75122 RBL BE 053/077 051/077 053 7522- SAC BE 052/077 051/077 053 75--0



NW CALIFORNIA REMAINS IN A BROAD TROUGH THROUGH THE PERIOD WITH WEAK SHORTWAVES MOVING THROUGH THE FLOW. NEXT WEAK WAVE IS AROUND 40N 140W AND WILL BE MOVING ONSHORE LATE THIS AFTERNOON AND INTO TONIGHT AND ANOTHER WAVE FOR TOMORROW MORNING. THESE WEAK WAVES WILL KICK OFF EITHER SOME VERY LIGHT RAIN SHOWERS AT THE COAST OR DEEPEN AND AGITATE THE MARINE LAYER ENOUGH TO SQUEEZE OUT SOME DRIZZLE ALONG THE COAST ESPECIALLY NORTH OF CAPE MENDOCINO. THIS IS SUPPORTED IN THE 1000...950...900 AND 850 OMEGA FIELDS WHICH HAVE NEGATIVE OMEGA VALUES TONIGHT NORTH OF THE CAPE AND HIGHER RH IN THE SAME AREA. SINCE THERE IS NO STRATUS ON THE SATELLITE AT THIS TIME AND WITH THE WEAK WAVES COMING THROUGH...FEEL MARINE LAYER WILL NOT BE VERY DEEP AND WILL GO WITH A SHOWERY SCENARIO INSTEAD OF THE DRIZZLE AND CLOUDS SCENARIO. THIS COULD CHANGE HOWEVER AT THIS POINT AS SOME OF THESE WEAK WAVES MOVING THROUGH MIGHT DEEPEN THE MARINE LAYER. SOUTH OF THE CAPE...THE OMEGA VALUES ARE POSITIVE AND MOISTURE IS LESS IN THAT AREA. NOT EXPECTING MORE THAN .10 INCH OF QPF ALONG THE COAST. UPPER LEVEL FLOW BY THE END OF THE PERIOD BECOMES ZONAL WITH A STRONGER SHORTWAVE JUST BRUSHING THE AREA NORTH OF CAPE MENDOCINO WITH BETTER DYNAMICS STAYING WELL NORTH OF THE AREA ON SATURDAY AND SUNDAY. WITH THE ZONAL FLOW...TIMING OF THESE WEAH SHORTWAVES IS TOUGH AND WILL BROADBRUSH THE FORECAST AT THIS POINT.

IN THE EXTENDED...NW CA STAYS IN A BROAD TROUGH AND IT IS HARD TO GO COMPLETELY DRY AT THE COAST ESPECIALLY NORTH OF CAPE MENDOCINO AS THIS AREA WILL BE CLOSER TO THE DYNAMICS AND STORM TRACK. WILL BROADBRUSH EXTENDED AT THIS POINT AND GO WITH CHANCE OF RAIN NORTH OF THE CAPE AND DRY SOUTH OF THE CAPE EXCEPT FOR SATURDAY NIGHT AND SUNDAY.

POPS CEC 3303 EKA 3303 UKI 0000. .EKA...NONE.

MICHELS



...SYNOPSIS... A CATALINA EDDY AND A DEEPENING MARINE LAYER WILL BRING GRADUAL COOLING THROUGH SATURDAY...ALONG WITH SLOWER AFTERNOON CLEARING. SUNDAY THROUGH TUESDAY WILL BE FAIR WITH A WARMING TREND.

...DISCUSSION... THE COOLING TREND CONTINUED TODAY WITH TEMPERATURES SEVERAL DEGREES LOWER THAN YESTERDAY. COASTAL EDDY AND STRONG ONSHORE FLOW CONTINUED TO DEEPEN THE MARINE LAYER...AND AS A RESULT THE CLOUDS BURNED OFF MORE SLOWLY THIS AFTERNOON...LEAVING BEHIND HAZY SUN IN THE INLAND VALLEYS. STUBBORN CLOUDS REMAINED ALONG COASTAL SAN DIEGO AND ORANGE COUNTIES THIS AFTERNOON...AND WITH LITTLE CHANGE IN THE OVERALL PATTERN THE NEXT TWO DAYS...FRIDAY AND SATURDAY WILL NOT LIKELY BE MUCH DIFFERENT.

THE UPPER LEVEL TROF RESPONSIBLE FOR THE DEEP MARINE LAYER AND STRONG ONSHORE FLOW WILL MOVE EAST SATURDAY NIGHT. HEIGHTS BEGIN TO RECOVER SUNDAY AS BROAD UPPER RIDGE BUILDS WEST OF BAJA. ON MONDAY AND TUESDAY...A SHALLOWER MARINE LAYER WILL PROMOTE A FASTER CLOUD BURNOFF AND BRING WARMER WEATHER FOR EARLY NEXT WEEK.

SAN 000

.SAN...NONE.

MOEDE

ST/FG VRY SLO TO CLR SRN CA CST TDA AS CSTL EDDY CRLCTN CONTS AND ONSHR GRADS ALSO INCRG. MARINE LYR WAS ABT 2 THSD FT DP THIS MRNG AND SHUD CONT TO DPN TNGT WITH APPROACHG S/WV. XPC INVRN TO LIFT ENUF TO ALLOW LCL FG TO REACH LWR CSTL SLPS BY FRI MRNG...WITH SLO CLRG XPCD AGN FRI AFTN. NWLY GRADS DCRG ALG CNTRL CST AS UPR TROF APPROACHES AND NW WNDS OMTNS AND CSTL WTRS DCRG RPDLY THIS AFTN. GUD CLRG CNTRL CST ERY TDA BUT STILL XPC ST/FG TO RTN TNGT AS SHLW MARINE LYR DPNS. MDLS MOV S/WV ACRS W CST FRI MRNG AND XPC EDDY TO CONT AND ONSHR GRADS TO INCR TILL THEN. SO MARINE LYR DPNG SHUD BE OVR FRI MRNG. LCTMP TO SLGHTLY COOLR MOST AREAS FRI...WITH INLD VLYS COOLG THE MOST. GUSTY W TO SW AFTN WNDS MTNS/DESERTS. AS S/WV EXITS EWD ONLY SLGT INCR IN TKNS AS NR ZONAL FLO ALF DVLPS OFF CA CST SAT. ALSO GRADS XPCD TO RMN ONSHR THO EDDY CRLCTN WILL PROBABLY END. SO LTL IF ANY DCR IN MARINE LYR SAT AND TEMPS AND WNDS ABT THE SAME AS FRI. LAX 0000. HENDERSON

.LAX...SMALL CRAFT ADVISORY (SEE LAXCWFLAX).



CURRENT FORECAST LOOKS OK...CURRENT TEMPS ACROSS THE SACRAMENTO VALLEY ARE RUNNING 2 TO 3 DEG WARMER THAN 24 HRS AGO. THIS SHOWS UP ON SAC SOUNDING 24 HR COMPARISON...WHICH SHOWS A WARMER PROFILE IN THE 1ST THOUSAND FEET AS COMPARED TO YESTERDAYS....THEN A COOLER PROFILE ABOVE THAT. CURRENTLY THINKING THAT THE COOLER AIR ALOFT WILL MIX DOWN...PRODUCING MAX TEMPS VERY SIMILAR TO YESTERDAY.

MAIN CONCERN ARE WINDS AT SUU...17 GUSTING TO 25 MPH. WILL CHECK UPCOMING OBS...AND MAY CONSIDER BEEFING UP WINDS IN THE FORECAST (CURRENTLY W-NW TO 15 MPH).

OTHERWISE...ETA DATA IS IN...WITH AVN STILL TRICKLING IN. NEW MODELS STILL CONSISTENT WITH YESTERDAYS RUNS...WITH BRINGING IN BEST CHANCE OF SHOWERS...EVEN SRN ZONES...FOR LATE SATURDAY INTO SUNDAY. WILL KNOW MORE AFTER AVN COMES IN.

.BASIL/BARUFFALDI

.STO...NONE.