514
FXUS10 KWNH 061934
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
233 PM EST MON JAN 06 2020
VALID JAN 06/1200 UTC THRU JAN 10/0000 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION WITH PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..SOUTHERN STREAM TROUGH/LOW NEAR THE TN VALLEY BY TUES
..SURFACE LOW IMPACTING THE MID-ATLANTIC/NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
19Z UPDATE: NO SIGNIFICANT UPDATES OR CHANGES NOTED WITH THE REST
OF THE 12Z GUIDANCE. THE GENERAL MODEL BLEND IS STILL PREFERRED.
A COMPACT, PROGRESSIVE SHORTWAVE TROUGH CURRENTLY PUSHING INTO THE
SOUTH-CENTRAL PLAINS WILL RACE TOWARD THE MID-ATLANTIC OVER THE
NEXT 24 HOURS. ITS SURFACE LOW MOVES FROM THE TN VALLEY TO OFF THE
MID-ATLANTIC BY 00Z WEDNESDAY. OVERALL, MODEL AGREEMENT ALOFT AND
AT THE SURFACE SHOW FAIRLY HIGH AGREEMENT RUN TO RUN AND WITHIN
THE VARIOUS DETERMINISTIC GUIDANCE. WITH THAT IN MIND, WILL SIDE
ON A GENERAL MODEL BLEND FOR THIS AREA DURING THE NEXT 3 DAYS.
..PARADE OF SHORTWAVES APPROACHING PACIFIC NORTHWEST THIS WEEK
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND THROUGH 08.12Z; GFS/ECMWF/UKMET
BLEND THEREAFTER
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
19Z UPDATE: FOR THE FIRST SHORTWAVE ARRIVING IN THE PAC NW
TUESDAY/WEDNESDAY, THERE IS FAIRLY GOOD CLUSTERING NOW WITH THE
LOW POSITION/TIMING INTO BRITISH COLUMBIA. WITH THE SECOND WAVE
COMING IN ON THURSDAY, THE GFS REMAINS THE WEAKEST SOLUTION WHILE
NAM IS ON THE SLOWER SIDE OF THE MODEL SPREAD. THE 12Z CMC IS
FASTER AND FURTHER NORTH WHILE THE UKMET LOOKS LIKE A REASONABLE
MIDDLE GROUND, CONSENSUS SOLUTION NOW BOTH IN MAGNITUDE AND
TIMING.
LATE TUESDAY INTO WEDNESDAY ANOTHER SHORTWAVE TROUGH AND FRONT
WILL APPROACH THE PACIFIC NORTHWEST COAST. IN THE LARGE SCALE
SENSE, THE TIMING/STRENGTH APPEAR VERY AGREEABLE BETWEEN THE
VARIOUS DETERMINISTIC MODELS. THE NAM'S EARLIER SLOW BIAS HAS
LESSENED SOME WITH ITS 12Z RUN, BUT STILL LAGS THE OTHER GLOBAL
GUIDANCE SOMEWHAT. THE 12Z GFS IS A BIT AHEAD OF THE GUIDANCE AS
WELL.
ANOTHER FAST MOVING SHORTWAVE PUSHES THROUGH THE REGION THURSDAY
WITHIN THE INCREASINGLY MORE AMPLIFIED PATTERN. TIMING DIFFERENCES
INCREASE WITH THIS SYSTEM WITH THE UKMET/CMC BEING ON THE FASTER
SIDE OF THE MODEL SPREAD AND IS MORE AMPLIFIED WITH THE UPSTREAM
RIDGE OVER THE PACIFIC. THE GFS/NAM/ECMWF OFFER A SLIGHTLY SLOWER
SOLUTION, OF ABOUT THE SAME MAGNITUDE/STRENGTH, THOUGH THE GFS IS
THE WEAKEST SOLUTION. WILL LEAN ON A GFS/ECMWF BLEND BEYOND 08.12Z
TO ACCOUNT FOR THE TIMING DIFFERENCES SEEN IN THE UKMET/CMC.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
TAYLOR
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page