490
FXUS10 KWNH 011701
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1159 AM EST SUN MAR 01 2020
VALID MAR 01/1200 UTC THRU MAR 05/0000 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION WITH LATEST PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..SHORTWAVE CROSSING THE UPPER MIDWEST/GREAT LAKES BY MONDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
A SHORTWAVE AND ASSOCIATED COLD FRONT WILL CROSS THE UPPER MIDWEST
AND GREAT LAKES REGION TONIGHT THROUGH MONDAY. THE GUIDANCE IS IN
VERY GOOD AGREEMENT WITH THIS ENERGY, SO A GENERAL MODEL BLEND
WILL BE PREFERRED.
..SHORTWAVE OVER THE NORTHERN PLAINS/MIDWEST BY TUESDAY
..WEAK SURFACE WAVE/ENERGY LIFTING OVER CROSSING THE OH VALLEY
..DEEPENING LOW CENTER OVER NORTHERN NEW ENGLAND BY WEDNESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z CMC/UKMET/ECMWF SOLUTIONS
CONFIDENCE: AVERAGE
A NEW NORTHERN STREAM SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT
WILL DROP ACROSS SOUTHERN CANADA AND DIG ACROSS THE NORTHERN
PLAINS AND MIDWEST BY TUESDAY. A SURFACE LOW CENTER WITH THIS
SYSTEM WILL CROSS SOUTHERN CANADA THROUGH THE PERIOD. THE 12Z GFS
AGAIN IS GENERALLY A TAD MORE AMPLIFIED WITH THE UPPER TROUGH, AND
ALSO HAS ITS SURFACE LOW PERIODICALLY ON THE SOUTH SIDE OF THE
MODEL SPREAD ON TUESDAY. AFTER ABOUT 60 HOURS, THE GFS TENDS TO
BECOME A BIT MORE PROGRESSIVE WITH THIS ENERGY, ALONG WITH
ENERGY/WAVE ACTIVITY ADVANCING NORTHEAST ACROSS THE OH VALLEY. BY
WEDNESDAY, SHORTWAVE ENERGY WILL BE CONSOLIDATING AND DEEPENING
WHILE GOING NEGATIVE TILT OVER PORTIONS OF SOUTHEAST CANADA AND
NEW ENGLAND. THIS WILL LEAD TO A DEEPENING OF THE OH VALLEY LOW
CENTER AS IT CROSSES INTERIOR NEW ENGLAND. OVERALL, THE GFS IS A
BIT OF A STRONGER AND FASTER OUTLIER SOLUTION RELATIVE TO ALL OF
THE GLOBAL MODELS. THE 12Z NAM ON WEDNESDAY APPEARS TO BE TOO SLOW
WITH ITS EVOLUTION. HOWEVER, THERE HAS BEEN A MULTI-MODEL TREND
TOWARD MORE VIGOROUS TROUGH AMPLIFICATION OVER SOUTHEAST CANADA
AND NORTHERN NEW ENGLAND OVER THE LAST FEW MODEL CYCLES. THE 00Z
NON-NCEP MODELS AS A CONSENSUS TEND TO HAVE A RATHER GOOD
REFLECTION OF THIS WHICH IS NOT QUITE AS EXTREME AS THE GFS. GIVEN
THE VARIETY OF TIMING/DEPTH CONCERNS SEEN WITH THE GFS AND NAM, A
NON-NCEP CONSENSUS WILL BE PREFERRED.
..SHORTWAVE APPROACHING BRITISH COLUMBIA ON TUESDAY
..AMPLIFYING DOWN ACROSS THE NORTHERN ROCKIES/HIGH PLAINS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z CMC/UKMET/ECMWF
CONFIDENCE: AVERAGE
THE GUIDANCE SUGGESTS A SHORTWAVE EMBEDDED WITHIN FAST UPSTREAM
PACIFIC FLOW WILL APPROACHING BRITISH COLUMBIA ON TUESDAY, AND
WILL THEN TEND TO AMPLIFY SOUTHEAST ACROSS THE NORTHERN ROCKIES
AND FAR NORTHERN HIGH PLAINS ON WEDNESDAY. THE GUIDANCE IS IN VERY
GOOD AGREEMENT WITH THE ENERGY THROUGH ABOUT 60 HOURS. THEREAFTER,
THE 12Z GFS EDGES TOWARD THE SLOWER AND DEEPER SIDE OF THE
GUIDANCE. THE 00Z NON-NCEP MODELS PER THE UKMET, CMC AND ECMWF
SOLUTIONS ARE ALL CLUSTERED A BIT WEAKER AND MORE PROGRESSIVE. THE
12Z NAM SPLITS THE DIFFERENCE BETWEEN CAMPS. THERE IS A TREND TO
AMPLIFY THIS ENERGY A BIT MORE, AND IT WOULD APPEAR THAT THE
ENSEMBLE MEANS ARE A TAD TOO FLAT GIVEN THE MULTI-CYCLE TRENDS. A
NON-NCEP BLEND WILL BE PREFERRED FOR NOW, BUT GIVEN THE TRENDS,
THIS CAMP OF SOLUTIONS MAY STILL TREND A TAD STRONGER.
..DEEP TROUGH AMPLIFYING ACROSS CALIFORNIA TODAY
..ENERGY EJECTING EAST ACROSS THE SOUTHERN PLAINS TUESDAY
..ARRIVING TOWARD THE LOWER MS VALLEY ON WEDNESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND...THROUGH 48 HOURS
00Z ECMWF...AFTER 48 HOURS
CONFIDENCE: ABOVE AVERAGE...BECOMING AVERAGE AFTER 48 HOURS
A DIGGING TROUGH ALONG THE WEST COAST WILL YIELD A ROBUST CLOSED
MID-LEVEL LOW CENTER DOWN ACROSS COASTAL AREAS OF CALIFORNIA BY
LATE TODAY. THE ENERGY IS EXPECTED TO ADVANCE EAST ACROSS NORTHERN
MEXICO AND THEN EJECT OUT ACROSS THE RIO GRANDE VALLEY AND
ADJACENT AREAS OF THE SOUTHERN HIGH PLAINS ON TUESDAY. ON
WEDNESDAY, THIS ENERGY WILL ARRIVE ACROSS EASTERN TEXAS AND
ADJACENT AREAS OF THE LOWER MS VALLEY WHICH WILL DRIVE DEEPENING
SURFACE LOW PRESSURE ALONG THE WESTERN GULF COAST AND TOWARD
SOUTHERN LOUISIANA. THE 12Z NAM IS STILL OVERALL SOMEWHAT OF A
STRONGER OUTLIER WITH THIS SYSTEM, AND ESPECIALLY AS IT APPROACHES
AND CROSSES THE RIO GRANDE VALLEY. THE 12Z GFS HAS CONTINUED ITS
SLOWER TREND OVER THE LAST DAY OR SO, BUT STILL ENDS UP A TAD
FASTER THAN THE NON-NCEP MODEL GUIDANCE BY TUESDAY AND WEDNESDAY.
THE 06Z GEFS MEAN IS JUST A LITTLE SLOWER THAN THE GFS BY
COMPARISON. OF THE 00Z NON-NCEP MODELS, THE UKMET ENDS UP BEING
THE SLOWEST SOLUTION AND IS A TAD SLOWER THAN ALL OF THE ENSEMBLE
MEANS, AND THUS PROBABLY A BIT TOO SLOW. MODEL AGREEMENT IS SUCH
THAT A GENERAL MODEL BLEND CAN BE PREFERRED THROUGH 48 HOURS, BUT
A SOLUTION MORE STRONGLY TOWARD THE ECMWF IS RECOMMENDED
THEREAFTER AS IT VERY CLOSELY APPROXIMATES THE MODEL CONSENSUS
TOWARD THE END OF THE PERIOD.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
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