Debris Flow in Washington, March 2 to 8, 2014

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PST SUN MAR 2 2014

.SYNOPSIS...A WARM FRONT WILL SPREAD RAIN THROUGH WESTERN WASHINGTON
TODAY WITH SNOW MAINLY OVER WESTERN WHATCOM COUNTY. THE COLD FRONT
WILL THEN SWEEP THROUGH THE REGION TONIGHT. EXPECT HEAVY SNOW IN THE
CASCADES. A WET WEATHER PATTERN WILL PERSIST THROUGH THE END OF THE
WEEK. TEMPERATURES WILL BE CLOSE TO NORMAL.

&&

.SHORT TERM...A WARM FRONT WILL BRING MORE PRECIP TO WESTERN WA
TODAY...WITH A COLD FRONT CUTTING THROUGH THIS EVENING. THE THREAT
OF LOWLAND SNOW STILL EXISTS FOR WESTERN WHATCOM COUNTY WHERE COLD
FRASER OUTFLOW WINDS WILL KEEP THE SNOW LEVEL NEAR THE SURFACE.
RIGHT NOW THERE IS LITTLE PRECIP IN THE NORTH INTERIOR...BUT PRECIP
WILL INCREASE BY THE AFTERNOON AS THE WARM FRONT MOVES IN. THEREFORE
WILL EXTEND THE WINTER WEATHER ADVISORY FOR WESTERN WHATCOM. MODELS
SHOW 1 TO 3 INCHES POSSIBLE BEFORE SWITCHING OVER THE RAIN THIS
EVENING. ELSEWHERE...MAY SEE A RAIN/SNOW MIX IN THE CASCADE
FOOTHILLS THIS MORNING BUT ACCUMULATIONS ARE NOT EXPECTED. THE
SEATTLE SAND POINT PROFILER SHOWS THE FREEZING LEVEL OVER 3000 FT
AND DEW POINTS ARE ABOVE FREEZING. CONFIDENCE IS HIGH THAT PRECIP
FOR THE SEATTLE METRO WILL BE ALL RAIN.

THE CASCADES WILL SEE HEAVY SNOW DURING THIS EVENT AND A WINTER
STORM WARNING IS IN EFFECT THROUGH LATE TONIGHT. MODELS SHOW OVER A
FOOT OF NEW SNOW. THE SNOW LEVEL WILL RISE TO AROUND 3500 THIS
EVENING BUT LINGERING EAST WINDS MAY KEEP SNOQUALMIE PASS AT
FREEZING - FREEZING RAIN IS POSSIBLE THIS EVENING.

MOIST WESTERLY FLOW WILL PREVAIL MONDAY AND TUE FOR MORE SHOWERS
ACROSS THE REGION...AND MORE SNOW IN THE MOUNTAINS. ANOTHER PAC
SYSTEM WILL ARRIVE ON WED FOR ANOTHER WET DAY. TEMPS ARE CLOSE TO
CLIMO. 33

.LONG TERM...A SERIES OF PACIFIC FRONTAL SYSTEMS WILL CLIP THROUGH
WESTERN WA THROUGH NEXT WEEKEND. SO EXPECT MORE WET WEATHER
THROUGHOUT. LITTLE CHANGES WERE MADE TO THE EXTENDED FORECAST. 33

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED THE NEXT 7
DAYS...ALTHOUGH WILL NEED TO MONITOR THE SKOKOMISH RIVER THE MIDDLE
OF THIS UPCOMING WEEK.

&&

.AVIATION...UPPER LEVEL TROUGH OVER CENTRAL BRITISH COLUMBIA MOVING
SOUTHWEST TODAY. NORTHWESTERLY FLOW ALOFT BECOMING WESTERLY THIS
MORNING MORNING AND SOUTHWESTERLY THIS EVENING. WEAK WARM FRONT
MOVING THROUGH THE AREA LATER THIS MORNING INTO THIS AFTERNOON WITH
THE TRAILING COLD FRONT THIS EVENING.

CEILINGS LOWERING ACROSS THE AREA THIS MORNING WITH WARM AIR
ADVECTION AHEAD OF APPROACHING WARM FRONT. CEILINGS BELOW 2000 FEET
COMMON WITH AREAS OF CEILINGS BELOW 1000 FEET AND VISIBILITIES AS
LOW AS A MILE IN LIGHT PRECIPITATION. PRECIPITATION TYPE WILL BE
RAIN EXCEPT NEAR KBLI WHERE A WINTRY MIX WILL OCCUR UNTIL MID TO
LATE AFTERNOON. PRECIPITATION CONTINUING UNTIL THE COLD FRONTAL
PASSAGE THIS EVENING WITH AREAS OF REDUCED VISIBILITIES DECREASING
THIS AFTERNOON BEHIND THE WARM FRONT.

KSEA...SOUTHEASTERLY WINDS 8 TO 12 KNOTS BECOMING SOUTHERLY 10 TO 15
KNOTS WITH AND BEHIND THE COLD FRONT THIS EVENING. CEILINGS BETWEEN
500 AND 2000 FEET WITH VISIBILITIES AROUND 3 SM AT TIMES IN LIGHT
PRECIPITATION THROUGH THE EARLY AFTERNOON HOURS. FELTON

&&

.MARINE...OFFSHORE PRESSURE GRADIENTS WILL CONTINUE TO WEAKEN THIS
MORNING. WARM FRONT MOVING THROUGH THE WATERS LATER THIS MORNING
INTO THIS AFTERNOON WITH THE TRAILING COLD FRONT THIS EVENING. WINDS
PICKING UP JUST AHEAD AND WITH THE COLD FRONT INTO THE SMALL CRAFT
ADVISORY RANGE THIS EVENING OVER ALL THE WATERS. GOOD ONSHORE PUSH
BEHIND THE FRONT WILL KEEP SMALL CRAFT ADVISORIES GOING INTO MONDAY
AFTERNOON FOR THE INLAND WATERS. AFTER A BRIEF BREAK MONDAY NIGHT
INTO TUESDAY THE FIRST IN A SERIES OF SYSTEMS WILL MOVE THROUGH THE
WATERS TUESDAY NIGHT INTO WEDNESDAY FOR ANOTHER ROUND OF SMALL CRAFT
ADVISORIES. ADDITIONAL SYSTEMS MOVING THROUGH THE WATERS INTO THE
WEEKEND WILL KEEP AT LEAST SMALL CRAFT ADVISORY WINDS IN THE
FORECAST. FELTON

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER WEATHER ADVISORY WESTERN WHATCOM COUNTY UNTIL 4 PM PST
     THIS AFTERNOON.
     WINTER STORM WARNING NORTH AND CENTRAL CASCADES UNTIL 4 AM PST
     MONDAY.

PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

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