788
FXUS10 KWNH 131643
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1242 PM EDT WED MAY 13 2020
VALID MAY 13/1200 UTC THRU MAY 17/0000 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z NAM/GFS EVALUATION INCLUDING INITIAL PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...CLOSED LOW OVER ALBERTA TRACKING TO THE UPPER GREAT LAKES
THU...THEN ACROSS NORTHERN NEW ENGLAND FRI...
...SURFACE LOW MOVING FROM THE NORTH CENTRAL US TONIGHT INTO
NORTHERN NEW ENGLAND FRI...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z NAM/00Z ECMWF/00Z UKMET BLEND
CONFIDENCE: AVERAGE
THE 12Z NAM/GFS ARE CLOSE TO THE CONSENSUS WITH THE SHORT WAVE
ENERGY SWINGING OUT OF SOUTHERN ALBERTA ACROSS THE UPPER GREAT
LAKES BY 15/12Z. AFTER THAT TIME, THE 12Z GFS BECOMING SLOWER THAN
THE CONSENSUS (AS IT HAS BEEN FOR THE PAST THREE MODEL CYCLES)
WITH THE SHORT WAVE CROSSING NORTHERN NEW ENGLAND AFTER 16/12Z. BY
CONTRAST, THE 12Z NAM MAINTAINS CONTINUITY WITH ITSELF AND THE
CONSENSUS WITH THE TIMING OF THE SHORT WAVE. THE 00Z CMC IS CLOSE
TO THE CONSENSUS TIMING, BUT REMAINS FLAT WITH THE SHORT WAVE AS
IT CROSSES NORTHERN NEW ENGLAND.
THE 12Z GFS ALSO REMAINS SLOWER WITH THE SURFACE WAVE AS IT EXITS
THE ME COAST AFTER 16/12Z, WITH THE REMAINDER OF THE GUIDANCE
FORMING A FAIRLY TIGHT CLUSTER WITH THE SURFACE LOW AS IT PASSES
SOUTH OF NOVA SCOTIA. GIVEN THE SLOWNESS OF THE GFS, AND THE
WEAKNESS OF THE 00Z CMC SHORT WAVE, FORECAST CONFIDENCE IS
CLIMBING, BUT REMAINS AVERAGE THROUGH THIS PERIOD.
....CLOSED MID LEVEL LOW OFF THE PACIFIC NORTHWEST COAST
THU...MOVING TO THE NORTHERN PLAINS SAT...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
BOTH THE 12Z NAM/GFS ARE CLOSE TO THE CONSENSUS TAKING THE CLOSED
MID LEVEL LOW OFF THE PACIFIC NORTHWEST COAST THU AND TRACKING IT
ACROSS THE NORTHERN ROCKIES BEFORE REACHING THE NORTHERN PLAINS BY
17/00Z. IN FACT, THERE IS GENERALLY GOOD CLUSTERING WITH THIS
FEATURE, SO A GENERAL MODEL BLEND IS PREFERRED WITH SLIGHTLY ABOVE
AVERAGE FORECAST CONFIDENCE.
..MID LEVEL TROUGH OVER NORTHERN MEXICO THU
MOVING INTO CENTRAL
TX SAT...
..SURFACE LOW OVER EASTERN NM/WEST TX FRI
CROSSING INTO CENTRAL
TX SAT...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
THE 12Z NAM/GFS ARE CLOSE TO THE MODEL CONSENSUS DEVELOPING A LONG
WAVE TROUGH OVER NORTHERN MEXICO THU...THEN TRACKING IT EASTWARD
ACROSS NM INTO CENTRAL TX SAT. WHILE THERE ARE SOME MINOR
DIFFERENCES IN THE PLACEMENT/STRENGTH OF THE MID LEVEL SYSTEM IN
CENTRAL TX, THERE IS A GOOD CLUSTERING HERE, AS IT THE SURFACE
SYSTEM. THE 00Z ECMWF MAY BE A BIT ON THE WEAK SIDE WITH THE MID
LEVEL SYSTEM, AND A BIT FURTHER NORTHEAST WITH THE SURFACE LOW
SAT, BUT AT THIS POINT THE DIFFERENCES ARE SMALL ENOUGH TO FAVOR A
GENERAL MODEL BLEND WITH SLIGHTLY ABOVE AVERAGE CONFIDENCE.
..LOW PRESSURE DEVELOPING NEAR THE BAHAMAS FRI NIGHT INTO SAT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z GFS/00Z GEFS MEAN/00Z ECMWF MEAN
CONFIDENCE: AVERAGE
THE 12Z GFS HAS BACKED OFF ON ITS WESTWARD DEPICTION OF THE
SURFACE WAVE CLOSER TO THE FL EAST COAST LATE FRI NIGHT, BEFORE
MOVING THE WAVE NORTH OF THE BAHAMAS SAT. THE EASTWARD MOVEMENT
BRINGS IT CLOSER TO THE 00Z GEFS MEAN/00Z ECMWF MEAN WITH THE
PLACEMENT OF THE SURFACE WAVE BY 17/00Z. IN CONTRAST, THE 12Z
NAM/00Z ECMWF LOOK TOO FAR EAST WITH THE SYSTEM FROM FRI NIGHT
INTO SAT, WHILE THE 00Z CMC IS IN BETWEEN THE TWO CAMPS. FROM THIS
VANTAGE POINT, THE CONSENSUS LED BY THE 12Z GFS WAS FAVORED WITH
THIS SYSTEM. HOWEVER, THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY
HERE, FOR FORECAST CONFIDENCE IS AVERAGE AT BEST.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
HAYES
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page