AREA FORECAST DISCUSSION
NWS SEATTLE WA
AFDSEW 215 AM PDT WED JUN 2 1999
.OVERVIEW...SHRT WV ENERGY TOPPING A STG AND PERSISTENT LONG WV RDG
ALG 150W CONTS TO DRIVE SE INTO PAC NW. RATHER DP 5430M H5 LOW FOR
ERY JUN OVR KHQM AT 06Z. THIS FTR PROGGED BY ALL SHRT RANGE MDLS TO
DROP SSE INTO NRN/CTRL CA BY THU BFR EJECTING NE IN RESP TO NXT
UPSTRM SYS THAT APCHS WRN WA FRI NGHT/SAT. WHILE SHRT TERM MDLS APPR
WELL INITIALIZED OVR ERN PAC PER ACARS DATA...THEY ARE HAVING
PROBLEMS HANDLING WRAP ARND MSTR AND DEFORMATION ARND N SIDE OF
SAGGING UPR LOW. WL LEAN HEAVILY ON SAT IMGRY FOR FIRST 2 PDS OF
FCST. IN LONGER RANGE...MDLS APR TO BE HAVING CONSISTENCY AND
CONTINUITY PROBS IN DEALING WITH NEXT SYS PROGGED TO DROP SE INTO THE
PAC NW OVR THE WEEKEND. 00Z AVN SHOWS MORE RDGG ALG 150W AND FASTER
SEWD MOTION OF INCOMING TROF FRI NGHT THAN YDYS MRF. NEW ECMWF SOLN
HAS COME AROUND TO MORE OF AN AMPD SOLN PER MRF. UKMO STILL MORE
ZONAL THAN OTHER MDLS BUT MORE AMPD THAN PREV SOLNS. AVN/MRF MOST
CONSISTENT AND REASONABLE GIVEN RECENT PERFORMANCE AND CURRENT
STRENGTH/PSN OF LONG WV FTRS.
.SHORT TERM...NGM/AVN MOS QUITE DRY AND MILD TDY GIVING NEAR 0 POPS
AND MAX TEMPS IN THE MID 60S. SAT IMGRY AND KATX RADAR SHOWS SHRA
ACTIVITY WITH WRAP ARND BAND SRN BC MOVG SSW. XPC CLOUDS AND CHC -
SHRA THIS MRNG OVR NW WA AS THIS BAND DROPS SWWD...THEN MORE CLOUDS
AND CHC -SHRA THIS AFTN AND EVE AS MSTR OVR ERN AND SERN WA MOVS W/NW
ARND UPR LOW THAT IS SHIFTING S OVER WRN ORE. COOL AMS IN PLACE AND
OCNL CLOUDS WRAPPING ARND UPR LOW SHOULD KEEP MAX TEMPS TDY BLO MOS
GUIDANCE. WHILE FLOW IS ONSHR THU...SHRT WV RDGG BTWN SYSTEMS WL PRVD
DRY/NICE DAY AFT MRNG CLOUDS.
.EXTDD...CLOUDS INCR FRI THEN AREAS OF -RA SPRD INLD FRI NGHT/SAT
WITH APCH OF NXT MAJOR TROF. ENOUGH WLY FLOW AHD OF TROF THAT PTNS OF
INTR WL GET DOWN SLOPE FLOW OFF OLYMPICS AND MTNS OF VRISL. WL KEEP
SHRA CHC SAT AND SUN PER PREV FCST. COOLER THAN NORMAL NEXT SEVERAL
DAYS.
UIL 421 SEA 421 OLM 421 ALBRECHT
.KATX...VCP11/CSR11...OPERATIONAL.
.SEW...NONE...
AREA FORECAST DISCUSSION
NWS SEATTLE WA
AFDSEW 830 PM PDT TUE JUN 1 1999
PREFER 12Z AVN OVR ETA/NGM PER COMPARISON OF IR/ACARS TONIGHT. HUGE
DIFF IN GUIDANCE... AS IN 9 VS 81 PCNT POPS FOR WED. CURRENTLY COLD
UPR LOW OVR UIL MOVG S WITH LAGGING INSTBY FOR WED. TIGHT CYCLONIC
CURVATURE ASSOCD WITH LOW AS WELL AS BROAD AREA OF +3 OMEGA WITH
INCRSG ANTICYLCONIC VORT ADV WED AFTERNOON. HOWEVER NOT ALL FAVORED
INSTBY INGREDIENTS PRESENT WITH 4C WARMING AT 50H AND 70H DURING DAY
WED ALSO. PREFER IDEA OF SHOWERS YET LIMITED BUOYANCY TO PREVENT TS
OR ICE PELLETS. AS LOW DROPS S INTO CA FLOW SPLITS WITH DEFORMATION
AREA RMNG N OVR B.C WED NIGHT...TEASING A BIT...THEN DRIFTING E THU
AS PSEUDO UPR RIDGE PUSHES EWD INTO NRN WA. THUS XPCT DRIER/WARMER PD
THU WITH MORNING CLDS.
.EXTENDED...BIG POLAR LOW AND WITH THE E COAST RIDGE SEEMINGLY THE
TELLING TALES. POLAR LOW APPEARS TO DRIFT S NR THE DATELINE AND
RETAINS A PERSISTENT SPLIT BTWN 45N-55N OVER TIME. THIS PATTERN...IF
CONSISTENT...LOOKS A BIT COOL"ISH" WITH BRIEF BREAKS. HOWEVER BYD
180 HRS A CHUNK OF THAT LOW DIPS S INTO GULF OF AK PUMPING UP A NICE
W COAST RIDGE... HMMM. QUERCIAGROSSA.
UIL 7511 SEA 7521 OLM 7531
.KATX...VCP11/CSR11...OPERATIONAL.
.SEW...NONE...