486
FXUS10 KWNH 251708
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
108 PM EDT FRI OCT 25 2019
VALID OCT 25/1200 UTC THRU OCT 29/0000 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z NAM/GFS EVALUATION WITH PRELIMINARY PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..TROPICAL DEPRESSION SEVENTEEN
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND WEIGHTED MORE TO 12Z NAM/GFS
CONFIDENCE: REFER TO NHC PRODUCTS
T.D. SEVENTEEN IS MAINLY A SHORT TERM CONCERN BEFORE IT IS
ABSORBED INTO A FRONTAL BOUNDARY APPROACHING FROM THE WEST. THE
MODELS ARE GENERALLY GOOD AGREEMENT WITH T.D. SEVENTEEN, BUT THE
00Z ECMWF/UKMET/CMC ARE SLIGHTLY SLOWER IN THE FIRST 12-24 HOURS
COMPARED TO THE 15Z NHC ADVISORY AND THE 12Z NAM/GFS.
..SHORTWAVE TROUGH OVER THE UPPER MIDWEST/GREAT LAKES ON FRI
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
A SHORTWAVE TROUGH CLIPPING THE GREAT LAKES TODAY WILL ADVANCE
EAST TO THE NORTHEAST EARLY SATURDAY MORNING. ANY MODEL
DIFFERENCES WITH THIS SYSTEM ARE MINOR AND THEREFORE A GENERAL
MODEL BLEND WILL BE PREFERRED.
..AMPLIFYING TROUGH/CLOSED LOW OVER THE SOUTHERN PLAINS
..ENERGY LIFTING NORTHEAST TOWARD THE OH VALLEY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z CMC, 00Z ECMWF AND 12Z GFS
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
THE 12Z GFS HAS TRENDED MORE AMPLIFIED AND SLOWER WITH THE
MID-LEVEL TROUGH COMPARED TO PREVIOUS RUNS AND IS NOW ONLY
SLIGHTLY AHEAD OF THE PREVIOUS PREFERENCE WHICH INCLUDED THE 00Z
CMC/ECMWF AND ECMWF MEAN. THE 00Z UKMET IS SLOWER AND 12Z NAM
FASTER/WEAKER WITH THE UPPER LEVEL REFLECTION OF THIS SYSTEM AS IT
APPROACHES ONTARIO AND QUEBEC. AT THE SURFACE, ENSEMBLE SCATTER
LOW PLOTS AND THE LATEST ENSEMBLE MEANS SUPPORT A BLEND OF THE 12Z
GFS, 00Z ECMWF AND 00Z CMC WITH ONLY SMALL TIMING DIFFERENCES
BETWEEN THEM. THIS THINKING ALSO HOLDS TRUE FOR A SECONDARY
SURFACE LOW FORECAST TO ORGANIZE NEAR THE NEW ENGLAND COAST SUNDAY
NIGHT.
..UPPER TROUGH DIGGING ACROSS THE INTERMOUNTAIN WEST BY SAT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z ECMWF, 12Z NAM, 00Z UKMET
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
A LARGE TROUGH, FORECAST TO AMPLIFY INTO THE WEST THIS WEEKEND,
WILL HAVE A SOUTHERN STREAM COMPONENT WHICH SHOULD REACH THE
SOUTHERN PLAINS MONDAY EVENING. THE GFS HAS BEEN TRENDING SLOWER
BUT THE 12Z RUN REMAINS THE FASTEST OF THE DETERMINISTIC SUITE.
ENSEMBLE SPAGHETTI PLOTS ARE COMING INTO BETTER AGREEMENT OVER
THEIR PAST 4 12Z/00Z CYCLES BUT TIMING DIFFERENCES REMAIN. A
FAVORABLE MIDDLE GROUND AND CONSENSUS APPROACH FAVORS A BLEND OF
THE 00Z ECMWF, 12Z NAM AND 00Z UKMET WITH THE 00Z CMC A TAD SLOWER
THAN EVERYTHING ELSE.
..SHORTWAVE/CLIPPER LOW OVER MT/ND BY MONDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
ONLY MINOR DIFFERENCES EXIST WITH THIS SYSTEM AND SO A GENERAL
MODEL BLEND APPEARS SUFFICIENT AT THIS TIME TO USE FOR THE
PREFERENCE.
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML
OTTO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page