596
FXUS10 KWNH 291853
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
253 PM EDT WED JUL 29 2020
VALID JUL 29/1200 UTC THRU AUG 02/0000 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION INCLUDING FINAL PREFERENCES AND FORECAST
CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..MID-UPPER LEVEL TROUGHING OVER THE GREAT LAKES AND NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
ONLY MINOR TIMING DIFFERENCES WERE NOTED WITH THIS SYSTEM, SUCH
THAT A GENERAL MODEL BLEND CAN BE USED THROUGH SATURDAY.
..ENERGY ADVANCING ACROSS THE PLAINS THROUGH THURSDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON 12Z CMC BLEND
CONFIDENCE: SLIGHTLY BELOW AVERAGE
MID-LEVEL ENERGY COMING OUT OF THE ROCKIES INTO THE CENTRAL PLAINS
SLOWLY SAGS SOUTHEASTWARD TOWARD THE OZARKS ON FRIDAY AND
ELONGATES WITH BROADER, LARGER SCALE TROUGHING ALONG THE MS RIVER
THROUGH THE GREAT LAKES REGION BY SATURDAY MORNING. THE 12Z
NON-NCEP GUIDANCE HAS COME INTO BETTER AGREEMENT WITH A MID-LEVEL
VORTICITY MAX LOCATED NEAR THE BASE OF THE TROUGH LATE FRIDAY BUT
THE 12Z CMC IS FLATTER AND FASTER WITH THE TROUGH AXIS. WHILE
THERE ARE NO MODEL OUTLIERS, THE 12Z CMC APPEARS TOO FAST,
ESPECIALLY GIVEN THE 12Z ECMWF/UKMET HAVE TRENDED TOWARD THE
PREVIOUS PREFERENCE OF 12Z NAM/GFS. TIMING-WISE, THE MIDDLE OF THE
GUIDANCE IS FAVORED, WITH A NON 12Z CMC BLEND OF GUIDANCE CLOSEST
TO THE MIDDLE OF THE SPREAD.
..UPPER LOW/TROUGH APPROACHING THE PACIFIC NORTHWEST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
THERE ARE NO SIGNIFICANT DIFFERENCES NOTED WITH THIS SYSTEM.
...POTENTIAL TROPICAL CYCLONE NINE APPROACHING SOUTHERN FLORIDA
AROUND SATURDAY...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z CMC CLOSEST TO 15Z NHC ADVISORY
CONFIDENCE: REFER TO NHC PRODUCTS
POTENTIAL TROPICAL CYCLONE (PTC) NINE WILL TRACK FROM NEAR THE
U.S. VIRGIN ISLANDS WESTWARD TOWARD CUBA AND SOUTHERN FLORIDA
THROUGH SATURDAY. MODEL SPREAD VARIES CONSIDERABLY WITH THIS
FEATURE WITH A SOMEWHAT SOUTHWESTERN TREND WAS NOTED IN THE LAST
FEW CYCLES OF ENSEMBLE LOW PLOTS. THE 12Z DETERMINISTIC MODELS
EITHER STAYED SIMILAR OR TRENDED "RIGHT" OF THE PREVIOUS TRACK
COMPARED TO THEIR 00Z CYCLES. THE BEST MODEL PROXY TO THE OFFICIAL
NHC FORECAST FROM 15Z IS NEAR THE 12Z CMC. THE 12Z UKMET REMAINS
SIMILAR AND SLOW REGARDING THE TRACK OF THE POTENTIAL TROPICAL
CYCLONE. FOR THE LATEST INFORMATION ON PTC NINE, PLEASE SEE THE
UPDATED NHC ADVISORY.
...COLD FRONT MOVING THROUGH THE NORTH-CENTRAL U.S. FRIDAY AND
SATURDAY...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
THERE IS RELATIVELY GOOD AGREEMENT FOR THE TROUGH AXIS AND RELATED
COLD FRONT IMPACTING THE NORTH-CENTRAL U.S. THROUGH SATURDAY.
WHILE MINOR TIMING DIFFERENCES ARE EVIDENT, SUCH AS THE 12Z GFS
AND 12Z CMC BEING SLOWER, THE DIFFERENCES ARE SMALL ENOUGH FOR A
60 TO 84 HOUR FORECAST TO ALLOW FOR A GENERAL MODEL BLEND AT THIS
TIME.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
THIS PRODUCT WILL TERMINATE AUGUST 15, 2020:
WWW.WEATHER.GOV/MEDIA/NOTIFICATION/PDF2/SCN20-58PMDHMD_TERMINATION.
OTTO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page