124
FXUS10 KWNH 300707
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
307 AM EDT FRI AUG 30 2019
VALID AUG 30/0000 UTC THRU SEP 02/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z FINAL MODEL EVALUATION, CONFIDENCE, AND PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..OVERALL PATTERN ACROSS THE CONUS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z GFS/CMC/ECMWF WITH SOME UKMET
CONFIDENCE: ABOVE AVERAGE THROUGH 48 HOURS, SLIGHTLY BELOW AVERAGE
DAY 3
07Z UPDATE: OTHER THAN THE NAM, THE GLOBAL SUITE CONTINUES TO BE
IN VERY GOOD AGREEMENT WITH THE EVOLUTION OF THE LARGE SCALE
WESTERN RIDGE/EASTERN TROUGH THROUGH SATURDAY. ON SUNDAY, GUIDANCE
DIVERGES CONSIDERABLY WITH ENERGY ROTATING ONSHORE THE PACNW. THE
GFS/CMC REMAIN VERY WELL CLUSTERED WITH A SLIGHTLY FASTER AND
WEAKER SHORTWAVE MOVING TO THE EAST, WHILE THE ECMWF AND UKMET
HAVE SHIED AWAY FROM THEIR PREVIOUS SLOWER/STRONGER SOLUTIONS TO
SOMETHING CLOSER TO THE GFS/CMC. WHILE THE HIGHEST WEIGHT IN THE
PREFERRED BLEND SHOULD STILL BE PLACED ON THE MORE CONSISTENT
GFS/CMC, THE ECMWF AND UKMET ARE USABLE FOR DAY 3.
PREVIOUS DISCUSSION:
THROUGH THE FIRST 48 HOURS, THE GUIDANCE IS IN VERY GOOD AGREEMENT
THAT A BROAD LONGWAVE TROUGH WILL PERSIST IN THE EAST, WHILE
RIDGING CONTINUES IN THE WEST. SMALL SCALE DISTURBANCES WITHIN THE
FLOW MAY CAUSE PERIODIC ROUNDS OF CONVECTION OF WHICH THE MODELS
DIFFER ON LATITUDINAL PLACEMENT AND QPF, BUT REALLY ONLY THE NAM
IS AN OUTLIER BY BEING TOO DEEP WITH ITS TROUGH. BY DAY 3, THE
GUIDANCE DIFFERS CONSIDERABLY WITH HANDLING OF A MID-LEVEL TROUGH
APPROACHING THE PACNW. THE NAM/UKMET CLOSE OFF THE LOW TO MAINTAIN
A POSITIVELY TILTED TROUGH AXIS WEST OF THE CONUS, THE CMC/GFS
MOVE A WEAKER SHORTWAVE ONSHORE WA/BC, WHILE THE ECMWF IS
SOMEWHERE IN BETWEEN. THE DIFFERENCES SEEM TO ARISE FROM VASTLY
DIFFERENT JET INTENSITIES AND PLACEMENT AS NO FEWER THAN 3 JET
STREAKS INTERACT OVER THE NORTHERN PACIFIC OCEAN. THE GFS/CMC SEEM
TO HANDLE THE CROSS POLAR JET MOST SIMILARLY, BUT CONFIDENCE IS
REDUCED BY DAY 3.
..HURRICANE DORIAN
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PLEASE REFER TO THE OFFICIAL NATIONAL HURRICANE CENTER FORECAST
TRACK
THE GUIDANCE WHICH MOST CLOSELY RESEMBLES THE NHC TRACK FOR
HURRICANE DORIAN IS THE 00Z ECMWF/CMC WHICH ARE NEARLY ON TOP OF
THE 03Z ADVISORY POINTS. THE UKMET IS IN MUCH BETTER AGREEMENT NOW
THAN ITS PREVIOUS RUNS, BUT STILL SLOW COMPARED TO NHC AND THE
PREFERRED BLEND.
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML
WEISS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page