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Pattern Jarring January

RollTide18 said:
Euro warm bias :cool:
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They made an artificial correction to the Euro's surface parameterization scheme about 15 years ago to partially correct for its decoupling bias between the surface and low-levels in very stable regimes we see in the GFS & CMC but it's cold bias still lingers to an extent especially when there's snowcover
 
This is what the GFS and Euro were predicting 6 days out for this Thursday/Friday potential. GFS had a couple of runs where it wanted to deepen a low in the south west USA but the Euro was not that great either.

ecmwf_6h_precip_noram_144.png

gfs_mslp_pcpn_frzn_us_24.png
 
The GFS and Ensembles were completely disregarded by WPC in the afternoon extended discussion and its all based on how the GFS handles the PAC vs how the EURO and basically everything else handles the PAC region.

UNFORTUNATELY THE GFS/ECMWF ARE AT COMPLETE ODDS WITH ONE ANOTHER
WHICH LEADS TO A RATHER LOW CONFIDENCE FORECAST. THE LARGE ISSUE
REVOLVES AROUND TWO PRIMARY REGIONS OF THE NORTHERN HEMISPHERE. IN
THE VICINITY OF THE NORTH POLE...A LARGE LOBE OF VORTICITY IS
FORECAST TO DESCEND TOWARD CENTRAL CANADA DURING THE NEXT FEW
DAYS. GIVEN THE DEARTH OF UPPER AIR AND SURFACE OBSERVATIONS...IT
MAY INITIALLY BE DIFFICULT TO RESOLVE THIS SYSTEM. DAY 4
DIFFERENCES BETWEEN THE GFS/ECMWF APPEAR MORE LIKE THOSE SEEN AT
DAY 6/7. ELSEWHERE...MODELS ARE STRUGGLING WITH THE HANDLING OF
SPLIT FLOW ACROSS THE EASTERN PACIFIC. IT APPEARS A STRONG
LONGWAVE TROUGH WILL BE MOVING THROUGH THE NORTHEAST PACIFIC WHILE
A SEPARATE ENTITY SHOULD BE EXITING HAWAII. AS NOTED IN THE
ENSEMBLE SPAGHETTI PLOTS...THE GUIDANCE ARE STRUGGLING WITH THE
PROGRESSION OF THESE SYSTEMS. THE 06Z/00Z GFS SHIFT THE SOUTHERN
STREAM SYSTEM BACK TOWARD THE SUBTROPICS WHILE THE 00Z ECMWF/CMC
SHOW MORE EASTWARD PROGRESSION. ON THE OTHER SIDE...THE 00Z UKMET
PHASES THE TWO FEATURES LEADING TO A 973-MB LOW MOVING INTO
COASTAL BRITISH COLUMBIA ON 30/1200Z. SUFFICE TO SAY...THE MODELS
DISPLAY A LOT OF UNCERTAINTY WHICH HAS COMPANY ACROSS THE
CENTRAL/EASTERN U.S. BASED ON EVALUATION OF THE PAST FEW RUNS OF
THE GFS/ECMWF...THE TWO DISPLAY COMPLETELY OPPOSITE SYNOPTIC
EVOLUTIONS. LOOKING AT THE GFS...THESE RUNS FAVOR LIKELY NEAR
RECORD HIGH PRESSURES ACROSS THE GREAT PLAINS AS MSLP FORECASTS
RISE TO ABOVE 1060-MB ON SUNDAY ACROSS THE DAKOTAS. AT THE SAME
TIME...THE 00Z ECMWF/CMC/UKMET SHOW A MUCH WEAKER ANTICYCLONE TO
THE EAST ACROSS THE UPPER GREAT LAKES/MIDDLE MS VALLEY. ALONG THE
WESTERN ATLANTIC...THE 06Z/00Z GFS SPAWN A COASTAL LOW WHICH COULD
AFFECT NOVA SCOTIA ON NEW YEARS DAY IF THE 06Z CYCLE IS TO
BELIEVED. ON THE CONTRARY...THE 00Z ECMWF/CMC/UKMET SUPPORT AN
EARLIER WAVE OF LOW PRESSURE A COUPLE OF DAYS PREVIOUS.
OVERALL...THESE MARKED DIFFERENCES LEAD TO ADDITIONAL
UNCERTAINTIES MOVING INTO THE NEW YEAR. BUT IT DOES APPEAR LOWER
HEIGHTS SHOULD REMAIN EAST OF THE ROCKIES WHILE QUASI-ZONAL FLOW
WITH EMBEDDED SHORTWAVES ARE LIKELY OVER THE WEST.

DECIDED TO DISMISS ANY GFS/GEFS BASED SOLUTION GIVEN SOME OF THE
EXTREMES EARLIER NOTED. THIS ALSO DISCOUNTED THE 00Z NAEFS
ENSEMBLE MEAN HERE. THE FORECAST WAS INITIALLY BASED ON A
COMBINATION OF THE 00Z ECMWF/CMC/UKMET/ECMWF ENSEMBLE MEAN BEFORE
REMOVING THE 00Z UKMET BY DAY 4/SATURDAY GIVEN THE DEEP LOW
APPROACHING BRITISH COLUMBIA. EVENTUALLY REMOVED CONTRIBUTIONS
FROM THE 00Z CMC BEYOND DAY 5/SUNDAY AS IT BEGAN TO DIVERGE FROM
THE 00Z ECMWF/ECMWF ENSEMBLE MEAN. FOR THE NEW YEAR...WENT WITH A
COMPLETELY 00Z ECMWF/ECMWF ENSEMBLE MEAN BASED FORECAST WITH 80
PERCENT DIRECTED TOWARD THE ENSEMBLES.
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olhausen said:
This isn’t 7 days out though for some. It’s only 5 days out for my area and it’s the first storm that has got me excited. Unfortunately it will be the first time I get depressed this winter if it doesn’t work out.
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Yes 5 days out and more snow 4 runs in a row for us. Some model or models are going to be very wrong
 
NWTNWX said:
Yes 5 days out and more snow 4 runs in a row for us. Some model or models are going to be very wrong
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They are all going to be wrong. All you need to look at is upper level patterns, with anything outside of 4-5 days. These models just like teasing everyone with Winter in the South.
 
KBMX says the trend is clear drier for Sunday and Monday . Left a small chance in cause the forecaster was too scared to totally dismiss the gfs


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