302
FXUS10 KWNH 060646
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
145 AM EST THU FEB 06 2020
VALID FEB 06/0000 UTC THRU FEB 09/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION WITH LATEST MODEL PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..FULL LATITUDE TROUGH IMPACTING THE CENTRAL/EASTERN U.S
..EMBEDDED VIGOROUS SHORTWAVE TROUGH LIFTING NORTHEAST
..CONSOLIDATING LOWS FROM THE TN VALLEY TO THE NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-GFS BLEND
CONFIDENCE: ABOVE AVERAGE
A STRONG FULL LATITUDE TROUGH WILL CONTINUE TO ADVANCE EAST
THROUGH THE CENTRAL AND EASTERN U.S. GOING THROUGH THE END OF THE
WEEK. THIS WILL BE FACILITATED BY A VIGOROUS SHORTWAVE LIFTING OUT
OF THE BASE OF THE TROUGH WHICH THE LATEST MODEL GUIDANCE AGREES
WILL LIFT ACROSS THE LOWER MS VALLEY ON THURSDAY, CROSS THE TN
VALLEY AND SOUTHERN APPALACHIANS THURSDAY NIGHT, AND THEN EJECT
NORTHEAST ACROSS THE MID-ATLANTIC AND NORTHEAST ON FRIDAY. THIS
WILL DRIVE MULTIPLE WAVES OF SURFACE LOW PRESSURE ALONG A STRONG
COLD FRONT INITIALLY DRAPED FROM THE TN VALLEY DOWN TO THE CENTRAL
GULF COAST. THE GUIDANCE STRONGLY AGREES IN LOW PRESSURE
CONSOLIDATING AND DEEPENING OVER THE CENTRAL MID-ATLANTIC REGION
BY EARLY FRIDAY AND THEN LIFTING NORTHEAST THROUGH SOUTHERN AND
EASTERN NEW ENGLAND BY FRIDAY EVENING AS A TRAILING COLD FRONT
THEN SWEEPS OFF THE EAST COAST. THE 00Z GFS IS SEEN AS BEING A TAD
FASTER AND FARTHER NORTH WITH THIS CONSOLIDATING SURFACE LOW
PRESSURE AND RELATED TRACK. THE NON-GFS DETERMINISTIC SUITE OF
GUIDANCE AND MOST OF THE 00Z HREF SUITE OF GUIDANCE (NAM CONEST,
ARW2, AND NMMB) ALL FAVOR A MODESTLY SLOWER AND FARTHER SOUTH
TRACK BY COMPARISON WITH RATHER GOOD CLUSTERING. THE 00Z ARW
THOUGH DOES TEND TO FAVOR THE GFS TRACK A BIT MORE, BUT NOT TO
QUITE THE SAME EXTENT. BASED ON THE MAJORITY CONSENSUS, AND
ENSEMBLE CLUSTERING, A NON-GFS BLEND WILL BE PREFERRED FOR THE
SMALLER AND LARGER SCALE DETAILS OF THIS SYSTEM.
..SHORTWAVE CROSSING THE PLAINS AND OH VALLEY BY SATURDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM BLEND
CONFIDENCE: ABOVE AVERAGE
STRONG FLOW WILL CONTINUE TO OVER-TOP A BROAD BUT DOMINANT EASTERN
PACIFIC/WEST COAST RIDGE AXIS THROUGH THE REMAINDER OF THE WEEK.
THIS WILL ALLOW SUBTLE SHORTWAVE ENERGY CRESTING THE RIDGE TO DIVE
SOUTHEAST ACROSS THE CENTRAL/NORTHERN PLAINS ON FRIDAY AND THEN
TOWARD THE OH VALLEY ON SATURDAY. A WEAK AREA OF SURFACE LOW
PRESSURE AND A FRONT WILL BE ASSOCIATED WITH THIS ENERGY. THE 00Z
NAM APPEARS TO BE SOMEWHAT OF A SLOWER AND DEEPER OUTLIER WITH
THIS SYSTEM, SO WILL PREFER A NON-NAM BLEND WITH THIS SYSTEM.
..DEEP TROUGH/CYCLONE CROSSING THE PACIFIC NORTHWEST SATURDAY
..SEPARATING ENERGY OVER THE GREAT BASIN BY SUNDAY
..DOWNSTREAM TROUGHING OVER THE NORTHERN PLAINS BY SUNDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS/CMC/ECMWF
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
A STRONG CLOSED LOW WILL ADVANCE THROUGH THE ALEUTIAN ISLANDS AND
AK PENINSULA BY FRIDAY, WITH STRONG SHORTWAVE ENERGY DIGGING INTO
THE WESTERN GULF OF AK. THIS ENERGY WILL THEN DIVE SOUTHEAST
TOWARD BRITISH COLUMBIA AND THEN ACROSS THE PACIFIC NORTHWEST ON
SATURDAY. BY EARLY SUNDAY, A PORTION OF THIS ORIGINAL ENERGY WILL
QUICKLY EJECT DOWNSTREAM ACROSS THE NORTHERN ROCKIES AND OVER THE
NORTHERN PLAINS. MEANWHILE, A SPLIT IN THE UPPER FLOW WILL ALLOW
FOR A SUBSTANTIAL AMOUNT OF ENERGY TO THEN DIG SOUTHWARD OVER THE
GREAT BASIN AROUND THE EASTERN SIDE OF A REORGANIZING AND
STRENGTHENING RIDGE OFFSHORE THE WEST COAST.
THE MODELS ARE IN RATHER GOOD AGREEMENT AS THE SYSTEM CROSSES
THROUGH THE GULF OF AK THROUGH FRIDAY, BUT THE 00Z NAM TENDS TO BE
PERHAPS JUST A TAD SLOWER THAN THE GLOBAL MODEL CONSENSUS AS THE
SYSTEM SWEEPS THROUGH THE PACIFIC NORTHWEST. THE 00Z NAM ALSO
BECOMES A DEEPER OUTLIER WITH THE ENERGY BY EARLY SUNDAY THAT
CROSSES THROUGH THE NORTHERN PLAINS, AND BY BEING DEEPER, IT ENDS
UP WITH A CORRESPONDING SURFACE LOW TRACK NORTH OF ALL OF THE
GLOBAL MODELS. MEANWHILE, WITH THE ENERGY LAGGING BACK OVER THE
GREAT BASIN, THE 00Z UKMET IS A BIT OF A PROGRESSIVE OUTLIER WITH
THE REMAINING MODELS RATHER WELL CLUSTERED. THEREFORE, WILL FAVOR
A BLEND OF THE 00Z GFS, 00Z CMC AND 00Z ECMWF TO COMPREHENSIVELY
ACCOUNT FOR BOTH STREAMS LATE IN THE PERIOD WHICH IS WELL
SUPPORTED BY THE LATEST ENSEMBLE MEANS.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
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