465
FXUS10 KWNH 301915
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
315 PM EDT SAT MAY 30 2020
VALID MAY 30/1200 UTC THRU JUN 03/0000 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION INCLUDING PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
UPPER LEVEL TROUGH AND COLD FRONT ACROSS THE EASTERN U.S.
SATURDAY-MONDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND THROUGH 00Z TUESDAY
CONFIDENCE: ABOVE AVERAGE
THROUGH 00Z TUESDAY - AS THE UPPER TROUGH MOVES EAST FROM GREAT
LAKES/OHIO VALLEY THROUGH THE EASTERN U.S. - THE DETERMINISTIC
MODEL RUNS AND ENSEMBLE MEANS ARE IN GENERALLY GOOD AGREEMENT WITH
THE LARGER SCALE FEATURES.
UPPER LEVEL LOW SLOWLY LIFTING FROM NORTHERN MEXICO INTO THE
SOUTHERN PLAINS SATURDAY-TUESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
WHILE THERE ARE DIFFERENCE WITH RESPECT TO SOME OF ITS ASSOCIATED
SMALLER SCALE FEATURES, (WHICH FALL BEYOND THE SCOPE OF THIS
DISCUSSION), MODELS ARE IN GENERALLY GOOD AGREEMENT SHOWING A
BROAD UPPER LOW LIFTING NORTH FROM NORTHERN MEXICO INTO WEST TEXAS
ON MONDAY, BEFORE CONTINUING NORTHEAST INTO NORTHERN TEXAS AND
OKLAHOMA ON TUESDAY.
WEAKENING UPPER LOW LIFTING FROM NORTHERN CALIFORNIA THROUGH THE
PACIFIC NORTHWEST SATURDAY AND SUNDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND THROUGH 12Z TUESDAY,
NON-UKMET BLEND 12Z TUESDAY-00Z WEDNESDAY
CONFIDENCE: AVERAGE
OVERALL, MODELS ARE IN GOOD AGREEMENT SHOWING AN UPPER LOW
CURRENTLY CENTERED ALONG THE NORTHERN CALIFORNIA COAST
TRANSITIONING TO AN OPEN WAVE AS IT LIFTS ACROSS OREGON AND
WASHINGTON LATE SATURDAY AND SUNDAY. MODELS REMAIN IN GOOD
AGREEMENT INTO EARLY MONDAY AS THE SYSTEM CONTINUES FARTHER
NORTHEAST ACROSS THE CANADIAN ROCKIES INTO CENTRAL CANADA.
SIGNIFICANT MODEL DIFFERENCES DO NOT EVOLVE UNTIL EARLY TUESDAY AS
SYSTEM BEGINS TO MOVE SOUTH OF HUDSON BAY. AS THE SYSTEM BEGINS
TO ROUND THE TOP OF THE UPPER RIDGE, THE UKMET BECOMES A NOTED
OUTLIER - WITH A CLOSED SYSTEM DEVELOPING SOUTH OF HUDSON BAY.
UPPER LEVEL TROUGH MOVING FROM THE PACIFIC NORTHWEST TO THE
NORTHERN PLAINS AND UPPER MIDWEST MONDAY-TUESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND THROUGH 12Z MONDAY THEN,
GFS/ECMWF COMPROMISE 12Z MONDAY-00Z WEDNESDAY
CONFIDENCE: AVERAGE
WITH RESPECT TO TIMING, THE MODELS ARE IN GENERALLY GOOD AGREEMENT
THROUGH EARLY MONDAY AS THE SYSTEM MOVES EAST FROM THE EASTERN
PACIFIC INTO THE PACIFIC NORTHWEST. HOWEVER, DIFFERENCES QUICKLY
DEVELOP AS THE SYSTEM MOVES DOWNSTREAM, WITH THE UKMET, ECMWF AND
THE 00Z EC ENSEMBLE MEAN BECOMING NOTABLY FASTER THAN THE NCEP
GUIDANCE THROUGH THE NORTHERN ROCKIES INTO THE PLAINS AND UPPER
MIDWEST. WHILE THE GFS IS STILL AMONG THE SLOWER SOLUTIONS, IT
HAS TRENDED FASTER COMPARED TO ITS 00Z AND PREVIOUS 12Z SOLUTIONS.
AND WHILE STILL FASTER THAN THE GFS, THE 12Z ECMWF IS SLOWER THAN
ITS 00Z RUN - SUGGESTING THE TWO MODELS MAY BE MOVING TOWARD A
CONSENSUS.
CUTOFF LOW DEVELOPING WEST OF SOUTHERN CALIFORNIA AND NORTHERN
BAJA MONDAY-TUESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: UKMET/ECMWF/00Z EC ENSEMBLE MEAN
CONFIDENCE: AVERAGE
ENERGY DROPPING SOUTHEAST ACROSS THE EASTERN PACIFIC IS EXPECTED
TO DEVELOP A CLOSED LOW OFF OF THE SOUTHERN CALIFORNIA AND
NORTHERN BAJA COASTS EARLY NEXT WEEK. LATEST GUIDANCE SHOWS SOME
DIFFERENCES WITH RESPECT TO THE POSITION OF THE LOW'S CENTER, WITH
THE NCEP GUIDANCE GENERALLY EAST OF THE UKMET, ECMWF AND THE 00Z
EC ENSEMBLE MEAN. TRENDS IN THE GFS SUPPORT LEANING TOWARD THE
UKMET, ECMWF AND 00Z EC ENSEMBLE MEAN.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
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