152
FXUS10 KWNH 050655
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
154 AM EST SUN JAN 05 2020
VALID JAN 05/0000 UTC THRU JAN 08/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION WITH PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..SHORTWAVE TROUGH EXITING THE NORTHWEST
..ENERGY EJECTING EAST ACROSS THE NORTHERN TIER STATES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS ARE IN GOOD AGREEMENT WITH THE SHORTWAVE EXITING THE
NORTHWEST AND CROSSING THE NORTHERN PLAINS/UPPER MIDWEST THROUGH
SUNDAY. BY SUNDAY NIGHT AND MONDAY, THIS ENERGY WILL CROSS THE
GREAT LAKES AND NEW ENGLAND. THE GLOBAL MODELS ARE NOW IN GOOD
AGREEMENT WITH THIS ENERGY, BUT THE 00Z NAM IS SEEN AS BEING A
LITTLE STRONGER AND SOMEWHAT OUT OF TOLERANCE WITH THE GLOBAL
MODELS AS THE SYSTEM CROSSES THE GREAT LAKES, SOUTHERN QUEBEC AND
NORTHERN NEW ENGLAND. A NON-NAM BLEND WILL BE PREFERRED.
..SPLIT-FLOW TROUGH NEAR THE PACIFIC NORTHWEST ON SUN
..ENERGY REACHING THE GREAT LAKES/NORTHEAST TUES/WED
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS/UKMET/ECMWF
CONFIDENCE: AVERAGE
THE MODELS ARE IN GOOD AGREEMENT WITH THE MID-LEVEL TROUGH AXIS
REACHING THE PACIFIC NORTHWEST ON SUNDAY. THIS ENERGY WILL RAPIDLY
ADVANCE DOWNSTREAM WITH A WEAK LOW CENTER CLIPPING THE NORTHERN
PLAINS AND REACHING THE GREAT LAKES BY
TUESDAY. THERE WILL BE SOME GRADUALLY AMPLIFICATION OF THE SYSTEM
AS IT CROSSES THE GREAT LAKES AND MORE SO AS IT APPROACHES THE
NORTHEAST BY WEDNESDAY. THE 00Z CMC GRADUALLY APPEARS TO BE A TAD
TOO SLOW WITH THIS SYSTEM, AND THE 00Z NAM IS AN OUTRIGHT DEEP
OUTLIER. THE 00Z GFS/UKMET/ECMWF SOLUTIONS ARE NOW WELL CLUSTERED
AND HAVE GOOD ENSEMBLE SUPPORT SO A BLEND OF THESE SOLUTIONS WILL
BE PREFERRED.
..SOUTHERN STREAM TROUGH/LOW NEAR THE TN VALLEY BY TUES
..SURFACE LOW IMPACTING THE MID-ATLANTIC/NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z NAM/GFS AND 12Z ECMWF
CONFIDENCE: AVERAGE
THE MODELS TAKE A SHORTWAVE TROUGH IN THE SOUTHERN STREAM AND
ADVANCE IT ACROSS THE LOWER MS AND TN VALLEYS THROUGH MONDAY AND
TUESDAY ALONG WITH A WEAK WAVE OF LOW PRESSURE. THIS SYSTEM WILL
THEN CROSS THE MID-ATLANTIC BY LATE TUESDAY AND DEEPEN OFFSHORE
SOUTHERN NEW ENGLAND BY EARLY WEDNESDAY. THE 00Z CMC HAS OVERALL
TRENDED TOWARD THE MULTI-MODEL CONSENSUS, BUT MAY BE A TAD TOO
SLOW STILL, AND ESPECIALLY AS THE SYSTEM ADVANCES OFFSHORE THE
EAST COAST. THE 00Z ECMWF FOR ITS PART IS REASONABLY CLOSE TO THE
NAM/GFS CAMP, BUT IN THE LAST 12 HOURS (FORECAST HOUR 72 TO 84) OF
THE SHORT RANGE PERIOD, THE ECMWF BECOMES THE STRONGEST SOLUTION
WITH A DEEPER LOW/MID-LEVEL LOW TRACK AND MORE DIRECT IMPACT IN
ACROSS SOUTHEAST NEW ENGLAND. THE TREND OF THE ECMWF AND EVEN TO A
MODEST EXTENT THE 00Z UKMET ARE SUGGESTIVE OF THERE BEING MORE
INFLUENCE/INTERACTION WITH THE NORTHERN STREAM ENERGY CROSSING THE
GREAT LAKES AND INTERIOR OF THE NORTHEAST IN THE TUESDAY/WEDNESDAY
TIME FRAME. FOR NOW, THE PRIOR PREFERENCE OF BLENDING THE 00Z
NAM/GFS AND YESTERDAY'S 12Z ECMWF WILL BE MAINTAINED.
..SHORTWAVE/FRONTS APPROACHING THE PACIFIC NORTHWEST MON
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
YET ANOTHER IN A SERIES OF SHORTWAVE TROUGHS WILL ARRIVE ACROSS
THE PACIFIC NORTHWEST LATE MONDAY INTO TUESDAY. INITIALLY A WARM
FRONT WILL CROSS THE REGION AHEAD OF THIS ENERGY, WITH THE MAIN
TROUGH CROSSING BY LATE TUESDAY. THERE IS SOME MODEST TIMING
SPREAD, BUT OVERALL THE AGREEMENT APPEARS GOOD ENOUGH THAT A
GENERAL MODEL BLEND CAN BE PREFERRED.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page