Forecast Discussions mentioning ACARS, received at FSL on 04/09/00

SUNDOWNER TAKING SHAPE ACROSS S SBA COUNTY COAST THIS EVENING. MARIA YGNACIO SENSOR IN SAN MARCOS PASS HAD WINDS UP TO 53 MPH. ISSUED A WIND ADVISORY FOR THE SANTA YNEZ MTNS AND S SBA COUNTY COAST THRU 3 AM. OTHERWISE...WEATHER ACROSS THE DISTRICT THIS EVENING QUIET WITH CLEAR SKIES (EXCEPT SOME LOW CLOUDS IMMEDIATE CENTRAL COAST SBA/SLO COUNTIES). LOW CLOUDS MAINLY ALONG AND OFF CENTRAL COAST EXTENDING TO WESTERN CHANNEL ISLANDS SOUTHWARD. MESO-ETA BOUNDARY LAYER RH SUGGESTS LOW CLOUDS TO DEVELOP TOWARD THE LAX COUNTY COAST LATER TONIGHT. MESO-ETA CROSS SECTIONS ALSO SHOW COASTAL LAX COUNTY SHOULD SEE SOME LOW CLOUDS TOWARD MORNING...THEN CLEAR OFF BY LATE SUN MORNING. NO SIGNS OF AN EDDY YET AS LOW LEVEL WINDS OVER THE SOUTHERN CALIFORNIA BIGHT CONTINUE TO BE GENERALLY NW TO W. AN EDDY MAY FORM LATE TONIGHT...BUT IT SHOULD BE WEAK AND NOT AFFECT THE MARINE LAYER MUCH. LATEST MARINE LAYER DEPTH WAS STILL RATHER SHALLOW NEAR 1000 FEET. GOOD LAX ACARS SOUNDING AT 0220Z SHOWED TWO LOW LEVEL INVERSIONS... A STRONG ONE BEGINNING BELOW 900 FEET..THEN A WEAKER ONE AT 1900 FEET.

00Z ETA/NGM IN GOOD AGREEMENT WITH UPPER TROF OVER NRN CA TO SLIDE OVER THE TOP OF THE LONG WAVE RIDGE AND INTO THE NRN GREAT BASIN SUN...THEN S INTO THE SRN GREAT BASIN FOR MON...WITH A RIDGE ALONG THE CA CST. GOOD ONSHORE GRADIENTS CONTINUE DURING THE DAY SUN AND MON...WITH THICKNESSES LOWER SUN...THEN UP SLIGHTLY FOR MON. TEMPS WILL BE TRICKY THE NEXT COUPLE OF DAYS DEPENDING ON THE MARINE LAYER...BUT AT THIS TIME IT LOOKS LIKE THE MARINE LAYER SHOULD REMAIN RELATIVELY SHALLOW THROUGH THE PERIOD WITH ONLY MINOR FLUCTUATIONS IN DEPTH. TEMPS IN THE VALLEYS WERE MUCH WARMER THAN EXPECTED TODAY...AND EXPECT ONLY A FEW DEGREES COOLING FOR SUN THERE. ANY LOW CLOUDS ALONG THE LAX/VTU COUNTY COASTS LATER TONIGHT AND SUN SHOULD STAY OUT OF THE VALLEYS (DEWPOINTS AT BUR/VNY DROPPED INTO THE UPPER 30S TO LOW 40S THIS EVENING). WILL UPDATE ZONES BY 945 PM MAINLY FOR LAX/VTU COUNTY COASTS AND VALLEYS FOR FEWER LOW CLOUDS AND WARMER DAYTIME TEMPS SUN.

IN THE EXTENDED...UPPER RIDGE WITH FAIR WEATHER TO LINGER OVER SOCAL TUE AND WED AS ANOTHER UPPER LOW PARKS ITSELF WELL OFF THE W COAST... THEN THE UPPER LOW IS FORECAST TO MOVE INTO CENTRAL CA THU WITH SOME CLOUDS MAINLY OVER NORTHERN SECTIONS OF SOCAL. TEMPS WARMEST TUE AND WED...THEN A FEW DEGREES COOLER FOR THU.

LAX 0000. SIRARD

.LAX...WIND ADVISORY (SEE LAXNPWLAX) GALE WARNING/SMALL CRAFT ADVISORY (SEE LAXCWFLAX).



SMALL UPR LOW HAS MOVED TO SRN ORE/NRN CA CST AND CIRCULATION ARND LO HAS BROUGHT SM CONVECTION INTO SRN ORE PER LIGHTNING STRIKE DATA AND RADAR RETURNS. CIRCULATION HAS TURNED E TO SELY FLOW ALF INTO SRN PART OF WA WITH DEFORMATION DUE TO UPR RDG RMNG OVR WA AND ALG BC CST. WK THERMAL SFC TROF HAS NOW MOVD WITH 03Z PRES TENDENCIES SHOWG FALLG PRES E OF CASCDS AND RISING ALG CST AND WRN INTERIOR. THIS CONTS TRND FOR MARINE PUSH WHICH IS HAMPERED BY ELY WINDS AT HIGHR ELEVATIONS. SO BELIEVE THIS WL BE A WK PUSH...ALTHO ENUF OF ONE TO BRING SCA TO STRAIT AND BLANKET MOST SECTIONS OF WRN WA WITH LO MARINE ST BFR SUNRISE SUN. CURRNT FCSTS FLW THIS TRND. NEW ETA SHOWS UPR RDG REESTABLISHED BY MON WITH TRND TWD OFSHR FLO AGAIN. NO SGFNT UPDATES ATTM. ...NOTED BIRD SIGNATURE ON KATX COMPOSITE REFLECTIVITY AND VWP WHICH SHOWS SLY WNDS ALL THE WAY UP DUE TO BIRDS HEADING TWD THE N. ACARS WINDS OUT OF SEATAC SHOW N WINDS OF 3 TO 8 KTS FM SFC TO 4 THSD FT. ART

UIL 1111 SEA 1111 OLM 1111

.KATX...VCP32/CSR32...OPERATIONAL.

.SEW...SCA FOR STRAIT JDF. N 

...A PLETHORA OF WEATHER TO DEAL WITH...

SYNOPSIS...A SERIES OF SHORT WAVES IS PIN-WHEELING THROUGH THE EAST COAST LONG WAVE. ELONGATED SURFACE LOW PRESSURE OVER SOUTHWESTERN CONNECTICUT DEEPENS AS IT MOVES NORTH THROUGH NEW ENGLAND THIS AFTERNOON. NEXT WAVE TO MOVE IN WITH WARM ADVECTION ON TUESDAY.

SHORT TERM...FRONTAL BOUNDARY CURRENTLY OVER THE EASTERN PORTION OF THE REGION WITH COLD AIR WRAPPING IN BEHIND. TEMPS HAVE DROPPED TO FREEZING JUST WEST OF THE FCST AREA WITH SNOW NOW REPORTED AS FAR SOUTH AS IAD IN NORTHERN VA. TSTMS CONTINUE FLOW NORTH AHEAD OF THE FRONTAL BOUNDARY AND HAVE ISSUED MARINE WARNING FOR THESE. FOG AS WELL.

NEGATIVE TILT OF THE UPPER TROF WILL MEAN A SLOW EASTWARD MOVEMENT OF THE FRONTAL BOUNDARY AND THE DEFORMATION PCPN ON THE BACK SIDE OF THE SYSTEM.

EXPECT PCPN TO CHANGE OVER TO SNOW AND ACCUMULATE TO 2 TO 4 INCHES OVER NW ZONES. HAVE PROPOSED AN ADVISORY FOR THIS REGION BUT MAINLY FOR THE HIGHER ELEVATION ON THE GRASSY SURFACES. MODEL PROFILES SUPPORTING LARGE DENDRITES WITH VVEL MAXED AT 600 MB LEVEL ALONG WITH GOOD AGGREGATION AND RIMING IN THE THE DEEP 0 TO -10 LAYER. THUS...BIG WET SNOW FLAKES! WINDS COULD MAKE IT LOOK RATHER AMAZING CONSIDERING IT WAS NEAR 80 ONLY 18 HOURS EARLIER.

MODELS...INCLUDING SUNY STONY BROOK MM5...IN GOOD AGREEMENT ON THE SYNOPTIC SCALE. IN DETAIL...ETA P-TYPE FCSTS SN FOR STEWARD (SWF) BY 12Z AND 15Z FOR LGA BASED ON CANADIAN BOURGOUIN TECHNIQUE WITHIN BUFKIT. MM5 THOUGH SWITCHES NYC OVER BY 12Z. WILL HAVE TO NOWCAST THIS ONE AND CHECK THE ACARS AS WE GET TOWARDS 12Z. WILL PROBABLY HAVE TO UPDATE NO MATTER WHICH WAY I GO.

WILL NOT MIX SNOW IN OVER SUFFOLK COUNTY AND EASTERN CT AS TEMPS ARE TOO WARM...OR AT LEAST THAT WHAT I THINK IS TH CASE.

TEMPS...EXPECT 30S IN THE PCPN WILL WARM TO JUST BELOW FWC NUMBERS. LATEST 05Z LAMP DATA LOOKS GOOD.

WINDS...WILL KEEP ADVISORY AS THINKING IS THAT MOMENTUM WILL TRANSFER DOWNWARD TO PRODUCE A FEW GUSTS NEAR 40 KT.

WILL UP TUESDAY TO LIKELY BASED ON LATEST AVN WARM ADVECTION PCPN.

MARINE...KEEPING THE GALE. NO OTHER SIGNIFICANT CHANGES.

.OKX...WND ADVSRY NYZ067>081...NJZ002>006-011...CTZ005>012 GALE WARNING FOR ALL CSTL WTRS (ANZ355-353-350-338-335-330) SNOW ADVIORY NYZ067...NJZ002 $$

TONGUE



...SYNOPSIS... AN UPPER LEVEL LOW PRESSURE SYSTEM OVER NORTHERN CALIFORNIA WILL MOVE TO SOUTHERN NEVADA TONIGHT AND ARIZONA MONDAY BRINGING GUSTY WINDS TO THE MOUNTAINS AND DESERTS OF SOUTHWEST CALIFORNIA THROUGH MONDAY...COOLER TEMPERATURES FOR MONDAY...AND AN INCREASE IN COASTAL LOW CLOUDS AND FOG TONIGHT AND MONDAY.

...DISCUSSION... WK CSTL EDDY BEGINNING TO DEVELOP WITH STRATUS SLOWLY FORMING AND EXPANDING ALG THE SAN COUNTY CST NORTHWARD INTO ORANGE COUNTY. THE 00Z SOUNDING FM NKX SHOWED THE BASE OF THE MARINE INVERSION NR 1000 FT WITH THE TOP OF THE INVERSION AROUND 2500 FT...LTL CHANGE FM 24 HOURS AGO. TO THE N...THE INVERSION LOWERED DURG THE DAY SATURDAY WITH A 02Z HIGH RESOLUTION ACARS SOUNDING FM LAX SHOWING THE BASE OF THE MARINE INVERSION BLO 500 FT. WITH THE DEVELOPMENT OF THE CSTL EDDY...STRATUS SHOULD EXPAND IN COVERAGE ALG THE CST THRU SUNRISE...BUT THE STRENGTH AND SHALLOWNESS OF THE INVERSION SHOULD LIMIT THE INLAND PENETRATION THIS MORNING. THE CURRENT INVERSION HEIGHT WOULD SUGGEST THE POTENTIAL FOR AREAS OF DENSE FOG ON THE ORANGE COUNTY COASTAL PLAIN THIS MORNING AND NR THE MESAS IN SAN COUNTY.

AS THE UPR LOW OVR NRN CA MOVES SOUTHEASTWARD TONIGHT ALG THE SPINE OF THE SIERRA INTO SRN NV PER THE AVN...MDT-STG NW-N FLOW ALG THE CNTRL CA CST AND A STRENGTHENING OF THE ONSHR FLOW ALG THE S CST OF SRN CA SHOULD PROVIDE STRONGER SUPPORT FOR A CSTL EDDY LATE TONIGHT INTO MON MORNING. THIS SHOULD ALLOW FOR EXPANSION OF THE STRATUS FIELD LATE TONIGHT INTO MON MORNING WITH DEEPENING OF THE MARINE LYR POSSIBLY SUFFICIENT TO ALLOW STRATUS TO REACH THE INLAND EMPIRE BY MON MORNING. HAVE INCRD WINDS MON BEHIND THIS SHORTWAVE FOR THE MTNS AND NRN DESERTS. INLAND HIGH TEMPERATURES TODAY SHOULD BE LTL CHANGED FM SAT LVLS...THEN COOL MON AS THE EQUIVALENT OF A BACK DOOR COLD FRONT MOVES ACROSS SRN CA LATE TONIGHT AND MON ASSOCD WITH AFFORMENTIONED UPR LOW. THE DEGREE OF COOLING IN THE INLAND VLYS FOR MON WL ALSO DEPEND UPON HOW MUCH THE MARINE LYR DEEPENS TONIGHT INTO MON MORNING. FOR NOW...HAVE A MODEST AMOUNT OF COOLING FOR MON FOR THE INLAND EMPIRE.

EXTENDED...LATEST MRF EJECTS DEVELOPING CLOSED LOW OVR THE ERN PAC NORTHEAST INTO NRN CA MID TO LATE WEEK...VERY SIMILAR TO THE SCENARIO YESTERDAY. WITH THE LATEST MRF...THE WARMEST DAY WOULD BE TUE...FOLLOWED BY A COOLING TREND SPREADING INLAND FM THE CST AS THE MARINE LYR GRADUALLY DEEPENS.

SAN 000

.SAN...NONE.

MARTIN