High Wind in Oregon, October 22, 2001

NORTHWEST OREGON AND SOUTHWEST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
300 PM PDT MON OCT 22 2001

.SYNOPSIS...A STRONG WESTERLY JET STREAM WILL SWEEP A VERY STRONG
PACIFIC FRONTAL SYSTEM ACROSS NORTHWEST OREGON AND SOUTHWEST
WASHINGTON THIS EVENING. HIGH WINDS WILL ACCOMPANY THE
FRONT ALONG THE COAST AND IN THE CASCADES WITH GUSTY WINDS IN THE
INTERIOR VALLEYS. CONDITIONS WILL BE FAVORABLE FOR SIGNIFICANT SNOW
IN THE CASCADES AT AND BELOW PASS LEVELS BEGINNING TONIGHT. LATE ON
WEDNESDAY A WEAKER SYSTEM WILL MOVE INTO WESTERN WASHINGTON FOR
ANOTHER SHOT OF RAIN IN NORTHWEST OREGON AND SOUTHWEST WASHINGTON.
SNOW LEVELS IN THE CASCADES WILL RISE ABOVE PASS LEVELS BY AFTERNOON
TO END THE SNOW EVENT. A TEMPORARY RIDGE OF HIGH PRESSURE WILL BUILD
OVER THE AREA THURSDAY AND FRIDAY FOR A BRIEF DRY PERIOD BEFORE A
RETURN TO WET WEATHER FOR THE WEEKEND.

.DISCUSSION...
.SHORT TERM...THE LATEST RUN OF THE FAVORED AVN MODEL CONTINUES TO
SHOW A 150 KT JET ASSOCIATED WITH THE FRONTAL SYSTEM NOW QUICKLY
APPROACHING THE NORTH OREGON COAST. THE COLD FRONT HAS MOVED INLAND
ON THE SOUTH WASHINGTON COAST AND WILL CONTINUE MOVING SOUTHEASTWARD
TO THE CASCADES BY 00Z. 18Z SURFACE ANALYSIS SUGGESTS LOW CENTER NEAR
975 MB WITH SHIP REPORTED WINDS TO 50 KT JUST TO THE SOUTH OF THE
CENTER. WINDS HAVE INCREASED TO OVER 30 MPH ON THE OREGON AND SOUTH
WASHINGTON COAST THIS AFTERNOON...WITH GUSTS TO 45 MPH REPORTED BY A
SPOTTER NEAR NETARTS. A STRONG NORTH-SOUTH GRADIENT HAS DEVELOPED
ALONG THE OREGON AND SOUTH WASHINGTON COAST...WITH 13 MB FROM ASTORIA
TO MEDFORD AT 21Z. THIS SHOULD BE SUFFICIENT FOR HIGH WIND WARNING
CONDITIONS ON THE COAST EARLY THIS EVENING. SUSTAINED WINDS ON THE
COAST SHOULD REACH 40 MPH WITH GUSTS TO 65 MPH POSSIBLE ALONG THE
COASTAL HEADLANDS. WITH STRONG 850 MB WINDS ACCOMPANYING THE
FRONT...AND SOME INSTABILITY AT MID LEVELS...WILL MAINTAIN 20 TO 30
MPH SUSTAINED WINDS IN THE VALLEY WITH POSSIBLE GUSTS TO 45 MPH EARLY
THIS EVENING. THIS IS SUFFICIENTLY COVERED IN THE LATEST SPECIAL
WEATHER STATEMENT.

GOOD POST FRONTAL OROGRAPHIC WINDS FOR THE CASCADES...UP TO 60 KT AT
850 MB...SHOULD RESULT IN 6 TO 10 INCH SNOW ACCUMULATIONS TONIGHT AND
TUESDAY AT AND BELOW PASS LEVELS. HAVE ISSUED A SNOW ADVISORY TO
COVER THIS. BY TUESDAY A WARM ADVECTION PATTERN SHOULD DEVELOP AS A
WEAKER SYSTEM APPROACHES WESTERN WASHINGTON. THIS WILL END THE SNOW
EVENT IN THE CASCADES AND BRING ANOTHER ROUND OF RAIN TO NORTHWEST
OREGON AND SOUTHWEST WASHINGTON ON WEDNESDAY.

WITH VERY STRONG WINDS NEAR THE LOW CENTER AND A LONG FETCH WAVE
MODELS BRING 30 FOOT SEAS INTO THE COASTAL WATERS BY TUESDAY
AFTERNOON. THIS LOOKS REASONABLE SO A HEAVY SURF ADVISORY HAS BEEN
ISSUED.

.LONG TERM...A RIDGE WILL BUILD OVER THE PACIFIC NORTHWEST THURSDAY
AND FRIDAY FOR A BRIEF DRY PERIOD. A SYSTEM WILL APPROACH THE
NORTHWEST ON SATURDAY FOR A WET WEEKEND.

AST 985752  PDX +84532  SLE +83431  EUG +72221

.PQR...GALE WARNING...FROM CAPE SHOALWATER TO FLORENCE FOR THIS
 EVENING.
       HEAVY SURF ADVISORY...FROM CAPE SHOALWATER TO FLORENCE FOR
       LATE TONIGHT AND TUESDAY.
       HIGH WIND WARNING...FOR THE SOUTH WASHINGTON...AND NORTH AND
       CENTRAL OREGON COASTS FOR THIS EVENING.
       SNOW ADVISORY...FOR THE SOUTH WASHINGTON...AND NORTH AND
       CENTRAL OREGON CASCADES FOR TONIGHT AND TUESDAY