Series of Storms to affect the West with more Snow/rain/win

Winter Weather Discussion

Moderator: S2k Moderators

Forum rules

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K.

Help Support Storm2K
Message
Author
Metalicwx220

#121 Postby Metalicwx220 » Sat Feb 19, 2011 10:05 pm

AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 300 PM PST SAT FEB 19 2011 .SYNOPSIS...DRY NORTHERLY FLOW WILL KEEP SKIES CLEAR ACROSS WESTERN TONIGHT. A RIDGE WILL PASS OVERHEAD ON SUNDAY THEN WEAKEN AS AN UPPER LEVEL LOW MOVES BY TO THE WEST. ANOTHER SYSTEM WILL MOVE INTO THE AREA ON TUESDAY. A COLD UPPER LEVEL LOW WILL SETTLE OVER THE REGION FOR THE MIDDLE PART OF NEXT WEEK. && .SHORT TERM...SEVERE CLEAR ACROSS WESTERN WA TODAY...THANKS TO DRY NORTHERLY FLOW ACROSS THE REGION. STILL QUITE BRISK ACROSS THE AREA BUT WINDS WILL DIE DOWN TONIGHT. WILL SEE OVERNIGHT LOWS DIP INTO THE 20S ACROSS MOST AREAS. SUNDAY STILL LOOKS MAINLY DRY AS OUR NEXT SYSTEMS PASSES OFFSHORE. KNOCKED POPS DOWN AND KEPT THE AREA DRY ONCE AGAIN. MAY SEE A LITTLE CIRRUS IN THE AFTERNOON BUT WILL STICK WITH SUNNY WORDING. OTHERWISE...TEMPS STILL COOL WITH HIGHS IN THE LOWER TO MID 40S. THE SURFACE LOW TRACKS FARTHER SOUTH AND AWAY FROM THE CWA SUNDAY NIGHT...AND REALLY DOES NOT LOOK LIKE WE WILL SEE MUCH PRECIP. ALL MODELS ARE DRY FOR THE INTERIOR SO REMOVED POPS. HOWEVER...I DID KEEP A SLIGHT CHANCE ALONG THE COAST AND SOUTH PORTION OF THE CWA AS THE EURO DOES SHOW A LITTLE MOISTURE GLANCING THE REGION. CONFIDENCE IS LOW THOUGH. THERE ARE BETTER CHANCES OF SEEING SHOWERS MON AND TUE AS A BROAD TROUGH ROUNDS OUT ACROSS B.C. AND WA. MODELS SHOW A NWLY 110KT JET NOSING IN WITH INCREASING LOW LEVEL ONSHORE FLOW. BOOSTED POPS A LITTLE...ESPECIALLY FOR THE COAST AND MOUNTAINS. MAY NOT SEE MUCH IN THE PUGET SOUND AREA WITH SHADOWING OFF THE OLYMPICS. THUS HELD BACK ON POPS A BIT THERE. 33 .LONG TERM...A COOL UPPER LEVEL TROUGH WILL DESCEND INTO W WA OVER THE LONG TERM PERIOD...MAINTAINING BELOW NORMAL TEMPERATURES AND A CHANCE OF LOWLAND SNOW SHOWERS. KEPT A MENTION OF SHOW SHOWERS IN THE FORECAST FROM TUESDAY NIGHT ONWARD AS SNOW LEVELS WILL HOVER ONLY A FEW HUNDRED FEET AGL. HOWEVER...EXACT SNOW AMOUNTS ARE STILL TOUGH TO PINPOINT AT THIS MOMENT. MODELS SHOW SPOTTY...LIGHT COVERAGE AND SNOW SHOWERS WILL LIKELY BE TIED TO HEAVIER BANDS OR CONVERGENCE ZONES. BUT WITH SNOW LEVELS AS LOW AS THEY ARE CANNOT RULE OUT A FEW FLAKES ACROSS THE AREA. THE BEST CHANCE FOR SEEING SNOW MAY BE WED NIGHT OR THU AS THE SURFACE FRONT DROPS FARTHER DOWN. THE GFS IS MUCH COOLER AND FASTER THAN THE EURO THOUGH. WILL WANT TO SEE A FEW MORE RUNS AND BETTER CONSISTENCY. VERY LOW CONFIDENCE IN THE FORECAST...BASICALLY THURSDAY ONWARD. BOTH THE GFS AND EURO ADVERTISING COMPLETELY DIFFERENT SOLUTIONS. IN FACT THE GFS IS DRY...WHEREAS THE EURO IS EXTREMELY WET. WILL STICK WITH PERSISTENCE BEFORE MAKING ANY DRASTIC CHANGES. 33
0 likes   

Metalicwx220

#122 Postby Metalicwx220 » Sat Feb 19, 2011 10:07 pm

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
210 PM PST SAT FEB 19 2011

.SYNOPSIS...A LOW PRESSURE SYSTEM MOVING INLAND ACROSS THE INTERIOR
WESTERN STATES WILL SHIFT FURTHER E TONIGHT. A WEAK RIDGE OF HIGH
PRESSURE WILL MOVE INLAND ACROSS THE PACIFIC NW SUN...AS A LOW
PRESSURE SYSTEM DROPS S OFF THE COAST SUN AND SUN NIGHT. A STRONG NW
FLOW ALOFT WILL DEVELOP OVER THE PACIFIC NW LATE MON AND MON
NIGHT...USHERING IN A MOIST AND COLDER AIR MASS AGAIN THAT WILL
LINGER THROUGH THE WEEK.
&&

.SHORT TERM...CLOUDS ASSOCIATED WITH THE LOW MOVING UP FROM THE SW
TO THE INTERIOR WESTERN STATES CONTINUED TO SPREAD INTO THE SE HALF
OF THE FORECAST AREA SUN AFTERNOON...WITH SOME SNOW SHOWERS LIKELY
CONTINUING ALONG THE CREST OF THE OREGON CASCADES. EXPECT THE CLOUDS
AND SNOW SHOWERS TO RETREAT E OVERNIGHT AS THE LOW MOVES E. WILL ADD
IN SOME PATCHY RADIATIONAL FOG TO THE VALLEYS FOR TONIGHT AND SUN
MORNING AS WINDS GO LIGHT AND SKIES CLEAR OFF.

MODELS REMAIN SIMILAR WITH THE NEXT CLOSED LOW DIGGING S OFF THE
COAST SUN AND SUN NIGHT. SYSTEM TRACKS ALONG ROUGHLY 130W...SIMILAR
TO THE PREVIOUS SYSTEM ON FRI...WITH THE MAIN DIFFERENCE BEING THE
COLD FRONT WRAPPING AROUND THE LOW DOES NOT APPEAR LIKELY TO MAKE IT
FAR ENOUGH E TO REACH THE COAST. SO...WILL KEEP POPS WITH THIS
SYSTEM CONSERVATIVE...MAINLY LIMITED TO CHANCE OR LESS...WITH BEST
CHANCES ALONG THE COAST.

MON NIGHT AND TUE MODELS ALSO IN GENERAL AGREEMENT IN A STRONG NW
FLOW ALOFT DEVELOPING BRINGING COOLER AIR DOWN FROM ALASKA. THIS
SHOULD DROP SNOW LEVELS DOWN INTO THE COAST RANGE AND FOOTHILLS BY
TUE. WITH THE NW FLOW...OROGRAPHICS WILL FAVOR MOUNTAIN SNOWS IN THE
N INITIALLY...BUT GRADUALLY POPS WILL SPREAD S DURING THE DAY AS LOW
LEVEL ONSHORE FLOW INCREASES.

.LONG TERM....CURRENT MODEL SOLUTIONS REMAIN SIMILAR TO PREVIOUS
RUNS...WITH GFS AND ECMWF STILL DIVERGING SIGNIFICANTLY AFTER
MIDWEEK. THE UPPER LEVEL TROUGH DROPPING SOUTH FROM CANADA IS STILL
EXPECTED TO IMPACT THE PACIFIC NORTHWEST THROUGH THE REMAINDER OF
THE WEEK...WITH MODELS CONTINUING TO HINT AT BELOW AVERAGE
TEMPERATURES AND POTENTIAL FOR LOW ELEVATION SNOW WED INTO FRI.
BY THE END OF THE WEEK THOUGH ECMWF HOLDS THE COLD NORTHERN STREAM
TROUGH FURTHER N ALLOWING A LOW TO COME IN OFF THE PACIFIC WITH
PRECIPITATION OVERRUNNING THE COLD AIR. GFS CONTINUE TO DROP THE
UPPER TROUGH S...ENDING PRECIPITATION CHANCES. AT THIS POINT IN
TIME...PREFER TO LEAN A LITTLE MORE TOWARDS THE DRYING OF THE GFS AS
IT IS SUPPORTED BETTER BY THE CANADIAN...BUT OVERALL WILL KEEP
CHANGES SMALL AS MODELS STRUGGLE WITH THE LATTER PERIODS.
0 likes   

Metalicwx220

#123 Postby Metalicwx220 » Sat Feb 19, 2011 10:10 pm

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
259 PM PST SAT FEB 19 2011

.SYSNOPSIS...A BROAD UPPER LEVEL TROUGH WILL SLOWLY EXIT THE
REGION WITH DECREASING LIGHT SNOW TONIGHT. ANOTHER LOW WILL DIVE
DOWN THE OFFSHORE COASTAL WATERS SUNDAY NIGHT THROUGH
MONDAY...FOLLOWED BY A STRONG COLD FRONT ARRIVAL TUESDAY. MUCH
COLDER THAN NORMAL WEATHER WITH POSSIBLE LOW ELEVATION SNOW IS
EXPECTED FROM MID WEEK ON.

.SHORT TERM...LATEST RADAR AND SATELLITE TRENDS INDICATE
WEAKENING IN THE UPPER LEVEL SYSTEM MOVING THROUGH THE AREA. CLOUD
TOPS HAVE WARMED AND RADAR IS DETECTING VERY LITTLE IN THE WAY OF
SHOWERS. THE NORTHERN LAKE COUNTY AREA HOWEVER APPEARS TO STILL BE
RECEIVING SNOWFALL IN NORTHERLY UPSLOPE FLOW THERE AND CONVERGENCE
ON THE HIGHER TERRAIN SOUTHWEST OF HIGHWAY 31. SOME LOCAL EFFECT
ACCUMULATIONS THERE RESULTED IN ACCUMULATIONS AROUND A FOOT FROM
THE CHRISTMAS VALLEY THROUGH SILVER LAKE FROM LAST NIGHT THROUGH
THROUGH LATE THIS MORNING. OTHERWISE ACCUMULATIONS HAVE BEEN
AROUND 2 TO 4 INCHES. DESPITE THE SYSTEM PULLING OUT AND
WEAKENING...LINGERING ACCUMULATIONS UP TO SEVERAL INCHES ARE STILL
EXPECTED ACROSS 30 AND 31 THROUGH THIS EVENING. ELSEWHERE...SOME
ISOLATED TO SCATTERED LIGHT SHOWER ACTIVITY WILL LINGER THROUGH
THE EVENING AS WELL. IMPROVING AND UNEVENTFUL WEATHER IS ON TAP
SUNDAY UNDER SHORTWAVE RIDGING AND THEN MONDAY AS AN UPPER LOW
DIVES DOWN THE COASTAL WATERS. HAVE HEDGED BETWEEN THE DRIER AND
WETTER SOLUTIONS FOR THE MONDAY FORECAST...BUT FAVOR THE DRIER
COMMON FORECAST OF THE NAM GFS.

.LONG TERM...THE GFS AND ECMWF SOLUTIONS BEGIN TO SIGNIFICANTLY
DIVERGE ON WEDNESDAY. THE COLD UPPER LEVEL TROUGH OVER BRITISH
COLUMBIA IS EXPECTED TO MOVE SOUTH INTO THE PACIFIC NORTHWEST.
BOTH THE GFS AND ECMWF INDICATE A PERIOD OF PRECIPITATION FOR AT
LEAST THE NORTHWEST PORTION OF OUR AREA WEDNESDAY INTO THURSDAY.
THE GFS IS MORE PROGRESSIVE AND MUCH DEEPER/COLDER WITH THE TROUGH
THAN THE ECMWF. THE GFS FORECAST IS FAVORED AS IT SHOWS MORE
CONSISTENCY WITH ITS EARLIER RUNS AND IS CLOSE TO THE ENSEMBLE
MEAN SOLUTION. THE RESULT WOULD BE PRECIPITATION LIKELY IN COOS
AND DOUGLAS COUNTIES BY WEDNESDAY AFTERNOON WITH SNOW LEVELS
AROUND 1500 FEET...THEN THE POTENTIAL FOR SIGNIFICANT SNOW AMOUNTS
WEDNESDAY NIGHT INTO THURSDAY EVENING AND A SNOW LEVEL THAT MAY
DROP BELOW 1000 FEET. THE ECMWF SOLUTION WOULD RESULT IN SNOW
LEVELS GENERALLY BETWEEN 2000 AND 3000 FEET AND LIGHTER AMOUNTS.
BEYOND THURSDAY...THE ECMWF WOULD HAVE THE UPPER TROUGH RETROGRADE
OUT OVER THE EASTERN PACIFIC AND RESULT IN OCCASIONAL LIGHT SHOWERS
AND A SEASONAL WESTERLY LOW AND MID LEVEL FLOW THROUGH THE END OF
THE WEEK. HOWEVER...THE GFS TRACKS THE TROUGH EASTWARD TO THE
ROCKIES WITH A STABILIZING AIR MASS BUT ALSO A VERY COLD NORTHERLY
FLOW ON THE BACKSIDE OF THE TROUGH AIMED AT THE PACIFIC NORTHWEST.
DW
0 likes   

Metalicwx220

#124 Postby Metalicwx220 » Sat Feb 19, 2011 10:13 pm

Funny how they all talk about models diverging. LOL
0 likes   

Metalicwx220

#125 Postby Metalicwx220 » Sun Feb 20, 2011 3:38 pm

LOL... The 360-384 hours always has a gigantic huge west coast storm. Temps will be below freezing so if that were to happen, you would very significant snow. Lol
0 likes   

Metalicwx220

#126 Postby Metalicwx220 » Sun Feb 20, 2011 3:57 pm

It takes up the whole west coast. lol 980 milibars and it collasal. Fantasy land has funny and scary things.lol
0 likes   

Metalicwx220

#127 Postby Metalicwx220 » Sun Feb 20, 2011 6:01 pm

AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 917 AM PST SUN FEB 20 2011 .SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE OVER THE REGION FOR DRY WEATHER TODAY. AN UPPER LEVEL TROUGH MOVING INTO THE OFFSHORE WATERS WILL BRING A CHANCE OF SHOWERS TO THE COAST AND SOUTHWEST INTERIOR TONIGHT. A DEEPENING UPPER LEVEL TROUGH OVER THE PACIFIC NORTHWEST WILL BRING COLDER AND UNSETTLED CONDITIONS TO THE REGION LATER MONDAY THROUGH THE UPCOMING WEEK. && .SHORT TERM...WEAK RIDGING WILL PROVIDE ANOTHER COOL BUT DRY DAY ACROSS WESTERN WA. THERE IS A BIT OF CIRRUS MOVING INLAND BUT STILL LOOKS MOSTLY SUNNY FOR THE REGION. TEMPS...QUITE CHILLY THIS MORNING WITH OVERNIGHT LOWS IN THE 20S. WILL WARM UP INTO THE LOWER TO MID 40S TODAY...A FEW DEGREES BELOW CLIMO. MODELS DIG A TROUGH OFFSHORE TONIGHT...BRINGING A LITTLE LIGHT PRECIP TO THE COAST. THE INTERIOR STILL LOOKS DRY. TEMPS SHOULD STAY A LITTLE WARMER WITH INCREASING CLOUDS. SHOWERS WILL INCREASE MONDAY AFTERNOON INTO EARLY TUES A BROAD TROUGH DROPS DOWN FROM B.C. MODELS SHOW STRONG W/NW FLOW ALOFT AS A 115 JET NOSES IN...GOOD OROGRAPHICS FOR HEAVY SNOW IN THE CASCADES. HEAVIER SHOWERS MAY ALSO RESULT IN LOWLAND SNOW...ESPECIALLY INSIDE THE CONVERGENCE ZONE. SNOW LEVELS ARE ONLY A FEW HUNDRED FEET AGL MON NIGHT AND MAY SEE AN INCH OR TWO IN THE FOOTHILLS. DOWNSLOPE FLOW OFF THE OLYMPICS MAY KEEP THE PUGET SOUND AREA SHADOWED. THE FORECAST ON TUES STILL LOOKS ACTIVE WITH STRONG W/NW FLOW OVER THE REGION. MODELS KEEP TEMPS IN THE LOWER TO MID 40S AS STRONG ONSHORE FLOW CONTINUES. HOWEVER...AS STATED ABOVE...SNOW LEVELS ARE ONLY A FEW HUNDRED FEET SO COULD SEE A RAIN/SNOW MIX WITH HEAVIER SHOWERS. THIS IS TRUE TUES NIGHT INTO WED AS WELL. 33 .LONG TERM...PREVIOUS DISCUSSION...THE MODELS BRING ANOTHER UPPER LEVEL TROUGH WITH A MORE WESTWARD TRAJECTORY OVER THE AREA AROUND WEDNESDAY NIGHT OR THURSDAY. THIS COULD ACCOMPANY A MODIFIED ARCTIC BOUNDARY PUSHING SOUTHWARD AS A STRONG SURFACE RIDGE BUILDS OVER INTERIOR BRITISH COLUMBIA. CONFIDENCE IN THE DETAILS THURSDAY ONWARD REMAINS LOW AS THE MODELS CONTINUE TO EXHIBIT QUITE A FEW DIFFERENCES. WHILE IT CERTAINLY SEEMS THAT A COLDER AIR MASS WILL BE OVER THE REGION FOR THE LATER HALF OF THE WEEK...THE AMOUNT OF MOISTURE AVAILABLE REMAINS IN QUESTION. THE GFS/CANADIAN CONTINUE TO ADVERTISE A TRANSITION TO A COLDER AND DRIER AIR MASS FRIDAY INTO THE NEXT WEEKEND...WHILE THE ECMWF IS RADICALLY DIFFERENT WITH A RAPIDLY DEEPENING SURFACE LOW MAKING LANDFALL ON THE CENTRAL OREGON COAST ON FRIDAY. NO CHANGES WERE MADE TO THE EXTENDED FORECAST OVERNIGHT. 27
0 likes   

Metalicwx220

#128 Postby Metalicwx220 » Sun Feb 20, 2011 6:09 pm

Image here is that storm the 12z is showing that I was talking about. above. 18z has it but you barely see it beacuse it is at the edge of the screen just entering. Really far out but interesting.
0 likes   

Metalicwx220

#129 Postby Metalicwx220 » Mon Feb 21, 2011 1:06 pm

Seattle Special weather Statement
...SNOW SHOWERS CAN BE EXPECTED ON THE LOWLANDS THIS WEEK...

A COLDER AIR MASS WILL SETTLE OVER THE REGION BY FRIDAY...RESULTING IN LOWERING SNOW LEVELS ACROSS THE AREA. SNOW LEVELS WILL BE NEAR 1000 FEET BY TUESDAY MORNING...HOWEVER HEAVY SHOWERS WILL LIKELY DRAG THE SNOW LEVELS DOWN TO SEA LEVEL. THIS WILL BE THE CASE MONDAY NIGHT WITH THE PUGET SOUND CONVERGENCE ZONE THAT IS EXPECTED TO DEVELOP NEAR THE KING AND SNOHOMISH COUNTY BORDER. BY THURSDAY MORNING...THE SNOW LEVELS WILL BE DOWN TO SEA LEVEL. THUS...ANY PRECIPITATION THAT FALLS WEDNESDAY NIGHT AND THURSDAY WILL BE IN THE FORM OF SNOW.

ACCUMULATING SNOWFALL IS MOST LIKELY TO OCCUR WITH THE PUGET SOUND CONVERGENCE ZONE OR WITH ANY SHOWER BANDS THAT DEVELOP THIS WEEK. IT WAS STILL TOO EARLY TO TELL EXACTLY HOW MUCH SNOW WILL FALL BUT THE POTENTIAL EXISTS FOR A LEAST A FEW INCHES WITH THE HEAVY OR PERSISTENT SHOWER BANDS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

STAY TUNED TO THE LATEST FORECASTS FROM THE NATIONAL WEATHER SERVICE IN SEATTLE.

&&
0 likes   

Metalicwx220

#130 Postby Metalicwx220 » Mon Feb 21, 2011 1:10 pm

Medford Special weather Statment
...ARCTIC AIR OUTBREAK AND LOW ELEVATION SNOWS LATE WEDNESDAY THROUGH FRIDAY...

A COLD WEATHER PATTERN IS SHAPING UP FOR THE REGION. AN ARCTIC AIRMASS AND UPPER LEVEL LOW PRESSURE SYSTEM WILL DIVE SOUTHWARD FROM WASHINGTON AND NORTHERN OREGON STARTING WEDNESDAY NIGHT. THIS WILL LIKELY BRING ACCUMULATING SNOWS DOWN TO VALLEY FLOORS IN SOUTHWEST OREGON LATER WEDNESDAY NIGHT THROUGH THURSDAY. SEVERAL INCHES OF SNOW ARE POSSIBLE...INCLUDING COASTAL AREAS. TRAVEL WILL BE IMPACTED WITH ICY AND SNOW-COVERED ROADS.

THE MOUNTAINS...AREAS EAST OF THE CASCADES...AND NORTHERN CALIFORNIA SHOULD ALSO RECEIVE UP TO SEVERAL INCHES OF SNOW WITH THIS SYSTEM THURSDAY THROUGH THURSDAY EVENING.

THE BROAD UPPER LOW WILL PROGRESS SOUTHWARD OVER THE REGION WITH LOW ELEVATION SNOW SHOWERS REMAINING POSSIBLE THROUGH FRIDAY. UNUSUALLY COLD AIR WILL ENTRENCH OVER THE REGION WITH RECORD OR NEAR RECORD COLD TEMPERATURES RANGING FROM 15 TO 20 DEGREES BELOW NORMAL.

STAY TUNED TO NATIONAL WEATHER SERVICE FORECASTS AND STATEMENTS FOR UPDATES ON THIS DEVELOPING WINTER STORM.
0 likes   

Metalicwx220

NWS Seattle

#131 Postby Metalicwx220 » Mon Feb 21, 2011 1:35 pm

AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 913 AM PST MON FEB 21 2011 .SYNOPSIS...AN UPPER LOW OFF THE NORTHERN CALIFORNIA COAST WILL CONTINUE MOVING SOUTH TODAY. AN UPPER LEVEL TROUGH WILL DEVELOP OVER THE AREA BEGINNING LATE THIS AFTERNOON AND CONTINUE THROUGH TUESDAY BRINGING UNSETTLED AND SHOWERY WEATHER. A COLDER AIR MASS WILL MOVE INTO THE REGION FROM THE NORTH ON WEDNESDAY AND THURSDAY...FOR THE POSSIBILITY OF SOME LOWLAND SNOW. DRY AND COLD WEATHER COULD RETURN ON FRIDAY. && .SHORT TERM...MODELS TODAY ARE SHOWING RATHER GOOD CONSISTENCY AND CONTINUITY...ESPECIALLY CONSIDERING THAT THE CURRENT UPPER LEVEL CONFIGURATION IS A RIDGE AROUND 150W AND A MEAN TROUGH AROUND 115-120W. IT DOES LOOK INCREASINGLY LIKELY THAT A LATE SEASON ARCTIC OUTBREAK WILL IMPACT AT LEAST THE NORTHERN HALF OF WESTERN WASHINGTON BEGINNING LATER WED AND CONTINUING THROUGH EARLY IN THE UPCOMING WEEKEND. IN THE SHORT TERM...THE CUTOFF UPPER LOW THAT GAVE SOME SPOTTY LIGHT SHOWERS TO THE COAST EARLY THIS MORNING IS NOW PULLING SOUTH THROUGH THE NORTHERN CALIFORNIA OFFSHORE WATERS. A 160 KT NWLY JET STREAK AT 300 MB CENTERED JUST TO THE NW OF JUNEAU IS PLOWING SE. WHILE THIS FEATURE WILL WEAKEN AS IT MOVES SE...IT WILL BRING QUICK CHANGES TO THE WEATHER BEGINNING THIS AFTERNOON AS 500 MB HEIGHTS FALL AND FRONTOGENESIS BEGINS FROM ABOUT THE NW INTERIOR OF WESTERN WASHINGTON NORTHWESTWARD. THE MAIN IMPACTS OF THIS INCOMING NWLY FLOW WILL BE TO DEEPEN THE TROUGH OVER THE PACIFIC NW...USHER IN COOL MARITIME AIR...COOL CONDITIONS ALOFT...AND GIVE INCREASING SHOWERS BEGINNING LATE THIS AFTERNOON. LATER TONIGHT THE MOUNTAINS WILL LIKELY SEE INCREASING SNOWFALL...OF A FLUFFY 12 OR 15 TO 1 RATIO...THAT COULD RESULT IN UP TO 18 INCHES OF SNOW BETWEEN THIS EVENING AND TUE EVENING. THIS WARRANTS THE ISSUANCE OF A WINTER STORM WATCH LATER THIS MORNING FOR TONIGHT INTO TUE NIGHT FOR THE CASCADES...THAT MAY NEED TO BE UPGRADED TO A WARNING LATER THIS AFTERNOON. STRONGER NW WINDS WITH THE INCOMING TROUGH AND JET SHOULD REMAIN OFF THE COAST...BUT THE RESULTANT W TO NW FLOW THROUGH THE STRAIT WILL LIKELY RESULT IN THE QUICK FORMATION TONIGHT OF A CONVERGENCE ZONE THAT HANGS UP SOMEWHERE FROM N KING COUNTY TO SOMEWHERE OVER SNOHOMISH COUNTY. WITH ALL THE ONSHORE FLOW...TEMPERATURES IN THE BOUNDARY LAYER WILL BE MARGINAL FOR WET SNOW WITH THE CONVERGENCE ZONE. BUT THE UW WRF MODELS DRIVEN BY THE GFS AND THE NAM...AS WELL AS THE OPERATIONAL RUNS...ALL SHOW SOME POSSIBILITY OF SNOW OR MIXED RAIN AND SNOW WITH THE CONVERGENCE ZONE VERY LATE TONIGHT AND TUE MORNING. CURRENT FORECASTS ARE ALREADY WORDED THIS WAY...BUT INDICATE NO ACCUMULATION. WILL REASSESS THE WORDING THIS AFTERNOON OVER THE HIGHER TERRAIN OF SNOHOMISH COUNTY AND IN THE EAST PUGET SOUND LOWLANDS.
0 likes   

Metalicwx220

NWS seattle

#132 Postby Metalicwx220 » Mon Feb 21, 2011 1:39 pm

THE POTENTIAL FOR BIGGER PROBLEMS BEGIN ON WED AS A 515-520 DAM 500 MB LOW DEVELOPS OVER VANCOUVER ISLAND AND SLIDES SLOWLY S ALONG THE COAST BY THU MORNING. IN THE MEANTIME A 1050-1055 MB SURFACE HIGH DEVELOPS OVER THE NORTH CENTRAL PORTION OF BC AND SLIDES S. THE PRES GRADIENT BETWEEN THE ARCTIC HIGH AND THE LOW PRES DEVELOPING IN THE COASTAL WATERS WILL SET UP IMPRESSIVE OUTFLOW OVER THE NORTH INTERIOR STARTING WED AND CONTINUING THROUGH AT LEAST THU. THE 12Z NAM...WRFGFS...00Z ECMWF AND 12Z GFS ALL HINT AT THE DEVELOPMENT OF AN ARCTIC BOUNDARY THAT COULD RESULT IN LOCALLY HEAVY SNOWFALL OVER THE N INTERIOR WED AND POSSIBLY INTO THE CENTRAL AND SOUTH SOUND AREAS WED NIGHT OR THU. POSSIBLY DAMAGING WIND WITH THE OUTFLOW OVER THE SAN JUANS AND WESTERN WHATCOM COUNTY CANNOT BE RULED OUT...AND FREEZING SPRAY AND STORM FORCE CONDITIONS COULD IMPACT THE WATERS. WILL TAKE A FINAL LOOK AT THE 12Z ECMWF ...BUT IT IS LIKELY THAT SOME WATCHES WILL BE ISSUED FOR THE NORTH INTERIOR AREAS THIS AFTERNOON FOR WED AND WED NIGHT.
This is all Important.
0 likes   

Metalicwx220

Nws Seattle

#133 Postby Metalicwx220 » Mon Feb 21, 2011 1:41 pm

.LONG TERM...PREVIOUS LONG TERM DISCUSSION FOLLOWS...A MODIFIED ARCTIC BOUNDARY IS EXPECTED TO PUSH SOUTHWARD ACROSS WESTERN WASHINGTON WEDNESDAY NIGHT AND THURSDAY...AS FRASER RIVER OUTFLOW INCREASES IN RESPONSE TO STRONG SURFACE RIDGING BUILDING SOUTHWARD OVER INTERIOR BRITISH COLUMBIA. EXACTLY HOW MUCH MOISTURE WILL BE AVAILABLE BY THIS POINT IN TIME OR HOW THIS SYSTEM WILL EVOLVE IS STILL IN QUESTION. WITH THAT SAID...WEDNESDAY NIGHT OR EARLY THURSDAY COULD BE THE BEST PERIOD FOR ACCUMULATING LOWLAND SNOWFALL...BUT ITS STILL FAR TOO EARLY TO PUT ANY CONFIDENCE IN DETAILS. BY THURSDAY NIGHT AND FRIDAY...COLDER DRIER AIR WILL BE FILTERING INTO THE AREA AS THE UPPER LEVEL TROUGH SHIFTS SOUTH OF THE REGION. THE 00Z ECMWF STILL DIFFERS FROM THE GFS SOMEWHAT BY THE WEEKEND...BUT IT IS NOT AS RADICALLY DIFFERENT AS IT WAS 24 HOURS AGO. THE GFS/CANADIAN/ECMWF ARE IN GENERAL AGREEMENT FOR DRY AND RATHER COLD WEATHER FRIDAY INTO THE FIRST PART OF WEEKEND. TEMPERATURES WILL START TO MODERATE BY SUNDAY AS COLD NORTHERLY FLOW GIVES WAY TO INCREASING ONSHORE FLOW. ANOTHER SYSTEM COULD SLIP DOWN THE BRITISH COLUMBIA COAST TOWARD THE REGION BY LATE IN THE WEEKEND. NO CHANGES MADE TO THE EXTENDED FORECAST OVERNIGHT.
0 likes   

Metalicwx220

#134 Postby Metalicwx220 » Mon Feb 21, 2011 1:50 pm

Image LOL an 1058 high wow
0 likes   

Metalicwx220

#135 Postby Metalicwx220 » Mon Feb 21, 2011 1:53 pm

Image Storm+ Arctic Outbreak = Snowstorm
0 likes   

Metalicwx220

#136 Postby Metalicwx220 » Mon Feb 21, 2011 2:21 pm

--------------------------------------------------------------------------------

Issued by The National Weather Service
Portland, OR
... COLD AIR LIKELY TO MOVE INTO THE PACIFIC NORTHWEST THIS COMING WEEK...

A COLD LOW PRESSURE SYSTEM IS EXPECTED TO MOVE SOUTH INTO THE PACIFIC NORTHWEST THIS COMING WEEK... BRINGING COLDER THAN NORMAL TEMPERATURES AND THE POSSIBILITY FOR LOW ELEVATION SNOW.

SHOWERS ARE EXPECTED TO INCREASE MONDAY NIGHT THROUGH WEDNESDAY... WITH SNOW LEVELS EXPECTED TO DROP TO NEAR THE VALLEY FLOORS WEDNESDAY. THERE APPEARS TO BE A GOOD CHANCE FOR HEAVY SNOWFALL IN THE MOUNTAINS DURING THE WEEK... BUT AT LOWER ELEVATIONS THE PROSPECTS FOR SNOW ARE CONSIDERABLY MORE UNCERTAIN.

UNCERTAINTY REMAINS AS TO HOW FAST THE COLD AIR MOVES IN... AS WELL AS WHEN AND HOW MUCH PRECIPITATION CAN BE EXPECTED. IT IS POSSIBLE THAT THE INTERIOR VALLEY FLOORS WILL SEE A SIGNIFICANT SNOWFALL IN THE LATTER HALF OF THE WORK WEEK. ON THE OTHER HAND... IT IS ALSO POSSIBLE THAT LITTLE IF ANY ACCUMULATING SNOW WILL OCCUR.
0 likes   

Metalicwx220

#137 Postby Metalicwx220 » Mon Feb 21, 2011 2:28 pm

This series of storms that will affect the Northwest could give seattle and portland a repeat of the December 2009 snowy month. Naw I don't think so. :lol: :roll: :roll: :roll:
0 likes   

Metalicwx220

#138 Postby Metalicwx220 » Mon Feb 21, 2011 6:37 pm

Image Here it goes again in the real long range with one of these I don't know storms. LOL that is huge and powerful somewhat at 976mb!
0 likes   

Metalicwx220

#139 Postby Metalicwx220 » Mon Feb 21, 2011 10:41 pm

AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 350 PM PST MON FEB 21 2011 .SYNOPSIS...AN UPPER LEVEL TROUGH WILL DEVELOP OVER THE AREA TONIGHT AND CONTINUE THROUGH TUESDAY NIGHT BRINGING UNSETTLED AND SHOWERY WEATHER. A COLDER AIR MASS WILL MOVE INTO THE REGION FROM THE NORTH ON WEDNESDAY AND THURSDAY...FOR THE POSSIBILITY OF SOME LOWLAND SNOW. DRY AND COLD WEATHER IS EXPECTED FRIDAY AND SATURDAY. && .SHORT TERM...12Z AND 18Z MODELS SHOW GOOD CONSISTENCY AND CONTINUITY TODAY. THEY ALL ADVERTISE A COOL AND SHOWERY REGIME THROUGH TUESDAY NIGHT WITH SNOW LEVELS GRADUALLY FALLING TO AROUND 500 FEET LATER TONIGHT AND TO AROUND 300 FEET TUESDAY NIGHT. WITH STRONG NORTHWESTERLY FLOW ALOFT AND THE COLD EXIT REGION OF A 120 KT 300 MB JET MOVING OVER THE AREA OVER THE NEXT 24 TO 36 HOURS...EXPECT A PERIOD OF HEAVIER SNOWFALL OVER THE CASCADES. WHILE LIQUID EQUIVALENT PRECIPITATION AMOUNTS ARE MARGINAL IN THE MOUNTAINS...COOLING ALOFT SUPPORTS 12 TO 15:1 SNOW RATIOS...AND THAT SUPPORTS THE ISSUANCE OF A WINTER STORM WARNING IN THE CASCADES LATER TONIGHT THROUGH TUESDAY NIGHT. AMOUNTS REMAIN IN THE ADVISORY CATEGORY FOR THE OLYMPICS. IN THE LOWLANDS EXPECT LOW TEMPERATURES THROUGH WED MORNING GENERALLY IN THE LOWER 30S WITH HIGHS 40 TO 45. THIS AMOUNTS TO BRIEF AND SPOTTY HILLTOP ACCUMULATIONS OF SNOW DURING THE LATE NIGHT AND MORNING HOURS...ESPECIALLY WHERE THERE ARE HEAVIER SHOWERS SUCH AS IN CONVERGENCE ZONES AND IN THE EAST PUGET SOUND LOWLANDS NEAR THE CASCADES.
0 likes   

Metalicwx220

#140 Postby Metalicwx220 » Mon Feb 21, 2011 10:42 pm

Here is the best part!!!!!!!!!!! LOL
NOW TO THE MORE INTERESTING PERIOD...WHICH IS WEDNESDAY THROUGH THURSDAY. ALL MODELS REALLY COME TO STRONG AGREEMENT NOW THAT AN ARCTIC BLAST WILL COME IN FROM THE NORTH DURING THE DAY WEDNESDAY...WITH ARCTIC AIR SPREADING THROUGHOUT THE AREA WEDNESDAY NIGHT. A 1005-1010 MB LOW DEVELOPS ON THE LEE SIDE OF VANCOUVER ISLAND LATE TUE NIGHT THEN SHIFTS SLOWLY S TO AROUND HOQUIAM THU MORNING. THE GFS IS SLIGHTLY FARTHER OFFSHORE WITH THE TRACK OF THE LOW THAN THE NAM/CANADIAN/ECMWF...BUT DIFFERENCES ARE RELATIVELY SMALL. THE NAM12/CANADIAN/ECMWF WOULD HINT AT HEAVY SNOW IN THE NORTH INTERIOR WITH THE ARCTIC FRONT BEGINNING WED MORNING...SPREADING TO THE SEATTLE AREA IN TIME FOR WED AFTERNOON COMMUTE...AND INTO THE S INTERIOR WED EVENING. THE GFS IS ONLY A BIT DRIER. BELLINGHAM TO WILLIAMS LAKE PRES GRADIENTS DROP TO -16 TO -22 MB. THIS SUPPORTS VERY WINDY CONDITIONS SAN JUANS AND WESTERN WHATCOM COUNTY...GALE AND POSSIBLE STORM FORCE WINDS OVER THE NORTHERN WATERS WITH POSSIBLE FREEZING SPRAY...IN ADDITION TO 4-6 INCH SNOWFALL AMOUNTS WITH THE ARCTIC FRONT. ALL MODELS SPREAD THE ARCTIC AIR THROUGHOUT THE AREA WED NIGHT. WITH THAT WILL ISSUE A WINTER STORM WATCH FROM EVERETT TO THE CANADIAN BORDER AS WELL AS FOR THE EAST PUGET SOUND LOWLANDS WED. LATER SHIFTS WILL LIKELY NEED TO EXPAND THE WATCH SOUTHWARD FOR LATER WED OR WED NIGHT INTO THU AS MOIST AIR OVERRUNS THE ARCTIC AIR. TEMPERATURES WED WILL FALL INTO THE 20S OVER THE N INTERIOR DURING THE DAY WITH 20S OVER THE ENTIRE AREA WED NIGHT. THU WILL STRUGGLE TO GET ABOVE FREEZING. CONDITIONS WOULD AMOUNT TO RECORD COLD FOR LATE FEB. ALBRECHT .LONG TERM...LONG WAVE PATTERN OF A RIDGE AROUND 150W AND TROUGHING IN THE WEST CONTINUES IN THE EXTENDED. COLD CONTINUES ON FRI WITH SLOW MODERATION SAT. LOWS 15-25 AND HIGHS IN THE 30S. IT WILL BE DRY WITH ARCTIC HIGH PRES IN PLACE. FURTHER MODERATION WITH SHOWER CHANCES SUN-MON AND LOW SNOW LEVELS AROUND 1000 FT APPEARS TO BE A GOOD BET. LATEST GFS AND ECMWF SOLUTIONS HINT AT A RELOAD OF ARCTIC AIR FOR NEXT WEEK...BUT LOW CONFIDENCE AT THIS RANGE. ALBRECHT
0 likes   


Return to “Winter Weather”

Who is online

Users browsing this forum: No registered users and 203 guests