953
FXUS10 KWNH 011906
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
205 PM 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 12Z GFS/UKMET/ECMWF
CONFIDENCE: AVERAGE...BECOMING BELOW AVERAGE AFTER 60 HOURS
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 PERHAPS A TAD MORE AMPLIFIED WITH THE UPPER TROUGH. 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. HOWEVER, THE 12Z CMC/UKMET
SOLUTIONS HAVE TRENDED IN THIS DIRECTION. THE 12Z ECMWF IS NOW
SLOWER THAN THE MULTI-MODEL CONSENSUS, AND BECOMES THE SLOWEST
SOLUTION ON WEDNESDAY AS SHORTWAVE ENERGY CONSOLIDATES AND DEEPENS
WHILE GOING NEGATIVE TILT OVER PORTIONS OF SOUTHEAST CANADA AND
NEW ENGLAND, ALTHOUGH THERE IS SOME SUPPORT FOR THE ECMWF FROM THE
12Z GEFS MEAN AND 00Z ECENS MEAN. THE GUIDANCE ALL FAVORS
DEEPENING OF THE OH VALLEY LOW CENTER AS IT CROSSES INTERIOR NEW
ENGLAND. THE GFS IS STILL A BIT ON THE STRONG SIDE OF THE GUIDANCE
WITH THE LOW CENTER, BUT THERE AGAIN HAS BEEN A MULTI-MODEL TREND
TOWARD A MORE VIGOROUS TROUGH AMPLIFICATION OVER SOUTHEAST CANADA
AND NORTHERN NEW ENGLAND OVER THE LAST FEW MODEL CYCLES. BASED ON
THE LATEST TRENDS AND CLUSTERING, A BLEND OF THE GFS/UKMET AND
ECMWF WILL BE PREFERRED TO ATTEMPT TO RESOLVE TIMING AND DEPTH
SPREAD. CONFIDENCE IS AVERAGE, BUT BECOMES BELOW AVERAGE AFTER
ABOUT 60 HOURS GIVEN RUN TO RUN, AND MODEL TO MODEL SPREAD WITH
TIMING AND DEPTH OF THE TROUGH/LOW CENTER OVER NORTHERN NEW
ENGLAND/SOUTHEAST CANADA.
..SHORTWAVE APPROACHING BRITISH COLUMBIA ON TUESDAY
..AMPLIFYING DOWN ACROSS THE NORTHERN ROCKIES/HIGH PLAINS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 12Z 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 12Z 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,
ALTHOUGH THE 12Z GEFS MEAN DID TREND MORE AMPLIFIED. A NON-NCEP
BLEND WILL AGAIN BE PREFERRED.
..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
12Z CMC/ECMWF BLEND...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 12Z GEFS MEAN IS JUST A TAD SLOWER THAN THE GFS BY COMPARISON.
OF THE 12Z NON-NCEP MODELS, THE UKMET ENDS UP BEING THE SLOWEST
SOLUTION. THE 12Z CMC TRENDED A TAD FASTER AND IS NOW CLOSE TO THE
12Z GEFS MEAN AND IS JUST A TAD FASTER THAN THE 12Z ECMWF. MODEL
AGREEMENT IS SUCH THAT A GENERAL MODEL BLEND CAN BE PREFERRED
THROUGH 48 HOURS, BUT A SOLUTION MORE STRONGLY TOWARD THE ECMWF
AND CMC IS RECOMMENDED THEREAFTER AS THEY VERY CLOSELY APPROXIMATE
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
ORRISON
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