780
FXUS10 KWNH 040727
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
327 AM EDT THU JUN 04 2020
VALID JUN 04/0000 UTC THRU JUN 07/1200 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION INCLUDING FINAL PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...MID-LEVEL SHORTWAVE MOVING THROUGH ONTARIO/QUEBEC AND THE
NORTHEAST THROUGH THE WEEKEND...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
THE MODELS SHOW SIMILARLY TO ONE ANOTHER CONCERNING THE TIMING AND
STRENGTH OF A MID-LEVEL TROUGH ADVANCING EAST THROUGH SOUTHERN
CANADA AND THE NORTHEAST ALONG WITH THE RELATED SURFACE LOW. THERE
ARE SOME MINOR DIFFERENCES, BUT OVERALL, A GENERAL MODEL BLEND
WORKS HERE GIVEN THE DIFFERENCES ALL FALL WITHIN THE FAIRLY
TIGHTLY CLUSTERED ENSEMBLE GUIDANCE.
...INITIAL CUT-OFF LOW OFFSHORE SOUTHERN CALIFORNIA, MOVING
ONSHORE FRIDAY AND INTO GREAT BASIN SATURDAY WITH WEAKENING
AMPLITUDE...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 50/50 BLEND OF THE 00Z ECMWF/00Z GFS
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
A CUT OFF UPPER LOW WILL MOVE SLOWLY NORTHEAST FRIDAY AND MOVE
ONSHORE INTO SOUTHERN CALIFORNIA. THE LOW OPENS UP AS IT MOVES
INLAND WITHIN CONFLUENT FLOW AND THIS IS WHERE TIMING DIFFERENCES
SHOW UP IN THE MODEL GUIDANCE. THE GFS HAS TRENDED SLOWER WHICH
LEAVES THE 00Z NAM AS THE FASTEST/FARTHEST EAST WITH THE SHORTWAVE
AS IT CROSSES THE ROCKY MOUNTAINS. THE 00Z ECMWF/UKMET/CMC ARE
FAIRLY SIMILAR TO ONE ANOTHER AND SLOWER THAN THE 00Z NAM/GFS.
LITTLE CHANGE WAS NOTED BETWEEN THE 00Z ECMWF/UKMET/CMC AND THEIR
PRIOR 12Z CYCLES. THE ENSEMBLE MEANS SEEM TO SPLIT THE DIFFERENCE
BETWEEN THE SLOWER NON-NCEP CAMP AND THE 00Z GFS, SO A 00Z GFS/00Z
ECMWF BLEND WILL BE PREFERRED FOR THIS SYSTEM.
THE 00Z UKMET AND 00Z CMC ARE SIMILAR TO THE 00Z ECMWF WITH THEIR
TIMING AND MAY ALSO BE USED AS WELL ALONG WITH THE 00Z ECMWF.
...CLOSED LOW OFF BRITISH COLUMBIA DRIFTING SOUTH THROUGH FRIDAY
NIGHT AND THEN OFF WASHINGTON/OREGON SATURDAY...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z GFS/ECMWF/UKMET BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
ONLY THE 00Z NAM, WHICH IS FASTER TO TAKE MID-LEVEL HEIGHT FALLS
EASTWARD ACROSS THE NORTHWESTERN U.S. SATURDAY NIGHT INTO SUNDAY,
DIFFERS SIGNIFICANTLY FROM THE REMAINING GOOD MODEL CLUSTERING.
HOWEVER, THE 00Z/12Z CMC IS DISPLACED A BIT NORTH WITH THE CLOSED
LOW AND DOES NOT HAVE A RATHER POWERFUL 110-130 KT UPPER LEVEL JET
AXIS AS FAR SOUTH AS THE WELL CLUSTERED 00Z ECMWF, 00Z GFS AND 00Z
UKMET ON SUNDAY. THEREFORE, THE PREFERENCE IS TOWARD A BLEND OF
THE 00Z GFS/ECMWF/UKMET. ONLY VERY MINOR CHANGES WERE NOTED WITH
THE 00Z ECMWF/UKMET/CMC COMPARED TO THEIR PRIOR 12Z CYCLES.
..TROPICAL CYCLONE CRISTOBAL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z NAM, 00Z ECMWF CLOSEST TO 03Z NHC ADVISORY
CONFIDENCE: REFER TO NHC PRODUCTS
THE 00Z NAM AND 00Z ECMWF AIR FAIRLY SIMILAR WITH THE TRACK FOR
T.S. CRISTOBAL WHILE ALSO SHOWING FAIRLY SIMILAR STRENGTH TO ONE
ANOTHER. THE 12Z CMC DIFFERS THE GREATEST COMPARED TO THE 03Z NHC
ADVISORY FOR THE TRACK OF CRISTOBAL, WITH A FASTER TIMING. WHILE
THE 00Z CMC SLOWED DOWN COMPARED TO ITS 12Z CYCLE, THE CMC REMAINS
FASTER. THE 00Z GFS IS ALSO FASTER THAN NHC AND A BIT TO THE EAST
OF THE NHC TRACK, BUT NOT AS SIGNIFICANT AS THE 00Z UKMET WHICH
FALLS ON THE VERY EASTERN EDGE OF THE LATEST ENSEMBLE SCATTER LOW
PLOTS. THE 00Z ECMWF/UKMET REMAINED SIMILAR TO THEIR PRIOR 12Z
CYCLES.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
OTTO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page