Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS66 KSEW 231630
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
830 AM PST MON FEB 23 2015

.SYNOPSIS...AN UPPER RIDGE WILL KEEP THE WEATHER DRY TODAY. A WEAK
UPPER TROUGH WILL BRING A RETURN TO ONSHORE FLOW ON TUESDAY. MOIST
NORTHWEST FLOW ALOFT WILL PREVAIL WEDNESDAY THROUGH FRIDAY. DRIER
NORTHERLY FLOW ALOFT WILL DEVELOP NEXT WEEKEND.

&&

.SHORT TERM...AN UPPER RIDGE AND WEAK LOW LEVEL OFFSHORE FLOW WILL
PRODUCE ONE MORE SUNNY DAY TODAY. A WEAK SHORT WAVE WILL DAMPEN THE
RIDGE ON TUESDAY AND TURN THE FLOW ALOFT WEST TO NORTHWEST. THE MAIN
AFFECT OF THIS FEATURE WILL BE TO SWITCH LOW LEVEL FLOW TO ONSHORE
AND BRING A FEW MORE CLOUDS. SOMEWHAT MOIST NORTHWEST FLOW ALOFT
WILL PREVAIL TUESDAY NIGHT AND WEDNESDAY. A CHANCE OF RAIN CANNOT BE
COMPLETELY RULED OUT BUT THIS WILL LIKELY STILL BE A MAINLY DRY
PERIOD. A BETTER CHANCE OF RAIN STARTS WEDNESDAY EVENING WHEN A MORE
ORGANIZED WEATHER SYSTEM DROPS DOWN FROM THE NORTHWEST. SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...SOME CHANGE IN THE WEATHER
PATTERN IS EXPECTED FOR THE LATTER HALF OF THIS WEEK. A WEAK FRONT
WILL MOVE EAST ACROSS THE AREA WED NIGHT OR EARLY THU. THEN THE
UPPER RIDGE THAT HAS PERSISTED OVER THE AREA FOR MUCH OF THE PAST
FEW WEEKS RETROGRADES BACK TO 145W AND ALLOWS A 542 DAM 500 MB UPPER
LOW TO DROP SE INTO THE COASTAL WATERS EARLY FRI MORNING...THEN INTO
CALIFORNIA SAT MORNING. THIS UPPER TROUGH WILL BRING SOME PERIODS OF
LIGHT RAIN TO THE LOWLANDS AND SNOW TO THE MOUNTAINS DOWN TO
3000-4000 FEET. NOTHING SPECTACULAR IS EXPECTED IN THE WAY OF
MOUNTAIN SNOWFALL...BUT AT LEAST SOME WILL OCCUR. ONCE THE UPPER LOW
DROPS INTO CALIFORNIA FRI NIGHT OR SAT MORNING...DRY NORTHERLY FLOW
WILL TAKE OVER ACROSS WASHINGTON FOR ANOTHER ROUND OF DRY AND
SEASONABLY COOL WEATHER. ALBRECHT

&&

.HYDROLOGY...FLOODING IS UNLIKELY THE NEXT 7 DAYS.

&&

.AVIATION...THERE IS AN UPPER RIDGE OVER THE REGION WITH NLY FLOW
ALOFT. THE AIR IS DRY AND STABLE WITH LIGHT LOW LEVEL OFFSHORE FLOW.
A WEAK WEATHER SYSTEM WILL MOVE THROUGH THE REGION TUESDAY AND
TUESDAY NIGHT.

KSEA...CLEAR WITH A LIGHT NLY OR NE BREEZE. A WEAK WEATHER SYSTEM
SHOULD BRING SCATTERED CLOUDS TO THE AREA ON TUESDAY.

&&

.MARINE...LIGHT OFFSHORE FLOW TODAY WILL TURN ONSHORE TUESDAY. A
WEAK WEATHER SYSTEM WILL MOVE THROUGH THE REGION BY TUESDAY NIGHT.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...NONE.

&&

$$

WWW.WEATHER.GOV/SEATTLE/

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.