Forecast Discussions mentioning ACARS, received at FSL on 06/11/99

.OVERVIEW...THE WEA PAT ACRS ERN/CNTRL PAC CONTS TRSN TO LONG WV TROF NR 140W AND RDG OVR WRN US. MAIN QN OF THE DAY FOR WRN WA IS HOW FAR E THE ASSOCD FNTL BAND GETS AS ENERGY SWINGS NE ARND THE BASE OF THE OFSHR TROF OVR THE WKEND. A 50-100 MILE ERROR CAN MAKE THE DIFFERENCE OVER THE WRN WA VLYS AS TO WHETHER OR NOT IT IS SUNNY AND NR 80...OR CLDY WITH -RA AND TEMPS IN THE 50S/60S. AIRCRAFT RPRTS IN THE E CNTRL PAC SHOW THAT A VRY STG 150-170 KT H3 JET 46N/160W TO 50N/180 DIVING ESE INTO NEW LONG WV TROF PSN 140W IS 20-50 KT TOO WK IN THE US OPERATIONAL MODELS. THE CNDN GLOBAL SPECTRAL MODEL MAY HAVE THE BEST IDEA IN SWINGING ENERGY A BIT FTHR E THAN THE AVN WOULD SUGGEST AS ADDNL ENERGY DIGS INTO OFSHR TROF AND RETROGRADES IT WWD TO 150W SUN/MON. NGM/AVN MOS PREDICTORS...WHILE WM WITH MAX TEMPS FOR SAT...HINT AT CHC POPS INLD WITH APCHG FNT. FOR NOW WILL LEAN TWD BLEND OF AVN/CNDN MODELS...THEN MRF IN EXTDD THAT SLOLY IPVS CONDS LATE SUN THEN PRVDS SHRT WV RDGG MON FOR DRYING/WRMG BFR PSBL MARINE PUSH LATE TUE. .SHRT TERM...WITH VRY LGT GRADIENTS AND MARINE AIR IN PLACE WL ADD PTCHY MORNING FG OR LOW CLDS TO FRI AM FCST. OTHERWISE DRY/STBL CONDS ON TAP FRI WITH ASSOCD WRMG. MID/HI LVL CLDS SPRD INLD SAT WITH CHC RA MAINLY CST. WL UNDERCUT HI MOS TEMPS SAT DUE TO CLDS/MSTR... ALTHOUGH IF A STGR FNT STALLS JUST OFF CST...OFSHR PRES GRADIENTS COULD RESULT IN QUITE WRM MAX TEMPS SAT AFTN. .EXTDD...WL APPEND SAT NGHT PD ONTO EXTDD FCST GIVEN PCPN ASSOCD WITH ENERGY SWINGING INLD...AND WL SLO IPVMT SUN AS FNT STALLS CSCDS OR NEARBY. MON STILL LOOKS NICE WITH SHRT WV RDGG. SFC ONSHR PRES GRADIENTS INCR TUE AS SFC HI PRES BLDS WELL OFF CA CST AND THERMAL TROF MOVS INTO ERN OR/WA.

UIL 1126 SEA ---2 OLM ---2 ALBRECHT

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

.SEW...SCA STRAIT OF JUAN DE FUCA.

SLUGGISH SUMMER LIKE SITUATION CONTG NEXT DAY OR TWO WITH THREAT OF CONVECTION THE MAIN CONCERN. AS ALWAYS ONE CAN SPLIT HAIRS WITH MODELS ON ANY GIVEN DAY AND ONE MUST BE ALERT TO PREVIOUS OLD BOUNDARIES SITTING AROUND AS FOCUS MECHANISMS.

IN THIS CASE BROAD MOSIT SLY FLOW APPEARS TO HAVE WEAK BNDRY ACRS CNTRL IL FM ABT CMI TO UIN WITH MOISTURE POOLED JUST S OF THERE. ANY CONVECTION BLOWING UP IN THIS ZONE TDA MAY AFFECT SRN PTN OF CWA. SFC FNT ACRS NRN AND CTRL WIS SWWD THRU IOWA SPORTS A WEAK SFC LO NW OF DSM. AXIS OF BEST INSTABILITY...READ THETA- E...APPEARS TO LINGER IN AN AXIS FM ERN IA N AND NE INTO ECNTRL WISC TDA. ALSO...LINGERING UPR JET FM LK SUPERIOR INTO MINN HOLDS POCKET OF DIVERGENCE ACRS CNTRL WISC. WITH ONLY SLOW IF ANY MOVMT OF SFC FNT NXT 12-18HRS..ANY SIG THRT OF THUNDERSTORMS IS LKLY TO BE HELD JUST TO W AND N OF NE IL.

ACARS WIND FIELD THIS MRNG SEEMS A BIT STGR THAN FCST WITH 25KTS SEVERLY ZONES AT RFD. MSTR FM ACARS PLANE ALSO SHOWS DRY POCKET IN AND JUST ABV THE BNDRY LYR WHICH SUG GSTY WINDS AIDED BY LOWER THETA-E ZONE MAY BE A PLAYER AGN TDA WITH STRG STORMS. OF COURSE HAVING AN APPARENT LWR THRT OF THUNDERSTORMS IN NE IL MAY ALSO IMPLY MORE SUN WHICH WOULD ADD TO INSTABILITY. CAN'T WIN.

OVERALL UPPER AIR PATTERN SUG SLOW DEVLPMT OF TROF INVOF WRN US/CAN BDR WHICH WILL IN TIME SLIDE SFC FNT EWD. THIS PROCESS SHUD BEGIN ON SAT AS UPR JET OVER NRN LKS IS REENFORCED. THIS COMBINED WITH BETTER THETA-E AXIS PROGGED AT LOWER LVLS AND LKLY AN INCREASE IN WNDS ALOFT SHUD GIVE HIER POPS FOR NRN IL ON SAT AND SAT NIGHT. THIS GOES AGAINST MOS TREND.

FCST WIL TRIM BACK POPS A BIT IN NRN IL TDA/TNGT BUT CONT WITH LKLY WORDING FOR SAT. TEMPS CONTG WARM TDA THEN DRIFTING BACK ON HIGHS FRO SAT WITH MORE CLDS. KML

.CHI...NONE

LIGHT OFFSHORE FLOW AND ABUNDANT SUNSHINE WITH WARMING ALOFT WILL COMBINE TO GIVE A VERY NICE DAY TO WRN WA TODAY. LOCAL STUDY BASED ON KSEA-KSMP 15Z SURFACE TEMPERATURE PROVIDES 75 DEG AT KSEA TODAY. FORECAST CHALLENGES CONTINUE FOR SAT AFTN THRU SUN AS ENERGY ROTATES AROUND DEEP UPPER LOW OFFSHORE. WHILE THE 12Z AVN IS STILL NOT IN...NGM/ETA NOT WELL INITIALIZED CONCERNING STRENGTH OR POSITION OF ELONGATED 984MB SURFACE LOW EXTENDING FROM 41N/140W THRU 46N/149W. AIRCRAFT REPORTS OF 140KT NWLY JET AT 300 MB SUPPORT NW PORTION OF SURFACE LOW WHILE STRONG VORTICITY ASSOCIATED WITH 120KT WLY JET 40N/140W SUPPORTS SERN EXTENSION OF LOW. NGM/ETA INITIAL COMBINES TWO FEATURES. SATELLITE IMAGERY SHOWS GOOD CLOUD TOP COOLING ALONG FRONT NEAR 40N/135W PREPARING TO TURN NEWD. IT APPEARS TO ME THAT THIS FEATURE WILL SWIPE WRN WA LATE SAT AFTN THRU SUN MORNING. WITH INCREASE IN CLOUDS SAT AFTN WILL LOWER MAX TEMPS SAT A COUPLE OF DEGREES...THEN WILL UPDATE STATE FORECAST TO REINTRODUCE SAT NIGHT PERIOD THAT CALLS FOR RA ACROSS MUCH OF WRN WA. WHILE CONDITIONS IMPROVE SUN...SUN AM STILL IN DOUBT...BUT WILL AWAIT NEW AVN AND AFTERNOON PACKAGE FOR UPDATE OF LATTER HALF OF WEEKEND.

UIL 016 SEA 002 OLM 002

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

.SEW...SCA W ENTRANCE TO STRAIT.