808
FXUS10 KWNH 131703
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
103 PM EDT SUN OCT 13 2019
VALID OCT 13/1200 UTC THRU OCT 17/0000 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION WITH LATEST PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DEEP PLAINS/UPPER MIDWEST CYCLONE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE ANOMALOUSLY DEEP LAYER CYCLONE OVER THE NORTH-CENTRAL U.S.
WILL CONTINUE TO FILL AND WEAKEN AS IT LIFTS NORTHEAST INTO
ONTARIO, CANADA OVER THE NEXT 24-36 HOURS. THE ASSOCIATED COLD
FRONT SWEPT THROUGH THE EAST COAST, BUT WILL STALL/LINGER ACROSS
THE SOUTHEAST U.S. EARLY NEXT WEEK AND BE THE FOCUS FOR LOCALLY
HEAVY PRECIPITATION. A COUPLE IMPULSES RIDING ALONG THE FRONT WILL
ENHANCE PRECIPITATION TOTALS. OVERALL, THE GLOBAL DETERMINISTIC
MODEL GUIDANCE IS IN ABOVE AVERAGE AGREEMENT WITH THE SYNOPTIC
FEATURES SUCH THAT A GENERAL MODEL BLEND IS PREFERRED.
PACIFIC NORTHWEST TO THE GREAT LAKES THROUGH TUESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
SHORTWAVE ENERGY COMING INTO THE PACIFIC NORTHWEST TONIGHT WILL
PROGRESSIVELY CROSS THROUGH THE NORTHERN ROCKIES AND INTO THE
NORTHERN PLAINS THROUGH MONDAY NIGHT. THE TROUGH WILL DEEPEN AND
CLOSE OFF AS IT APPROACHES THE GREAT LAKES AND GRADUALLY BECOME A
LONGWAVE TROUGH OVER THE EASTERN U.S. WITH A NEGATIVE TILT. THIS
WILL SPAWN A SURFACE LOW OVER THE GREAT LAKES TUESDAY
NIGHT/WEDNESDAY AND ALSO A SECONDARY LOW ACROSS THE SOUTHEAST U.S.
THAT COULD LIFT TOWARD THE NORTHEAST OR NEW ENGLAND AREAS BY
MID/LATE WEEK. IN THE BIG PICTURE, THE GLOBAL MODELS ARE IN DECENT
AGREEMENT. BY 72 TO 84 HOURS, THE ECMWF LOW POSITION OVER THE
GREAT LAKES IS AHEAD OF THE REST OF THE GUIDANCE, BUT ITS
DEPICTION OFF THE EAST COAST IS WELL WITHIN THE MODEL CONSENSUS
SPREAD. THE 00Z UKMET IS A TOUCH SLOWER WITH THE 500 MB TROUGH
AXIS SWINGING THROUGH BY DAY 3, BUT IT IS NOT SIGNIFICANT ENOUGH
TO EXCLUDE AT THIS TIME. SO, A GENERAL MODEL BLEND IS PREFERRED AT
THIS TIME.
SOUTHWESTERN U.S. TO SOUTHERN PLAINS
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PREFERENCE: GENERAL MODEL BLEND (LESS WEIGHT GIVEN TO GFS)
CONFIDENCE: AVERAGE
TROUGHING MOVING THROUGH THE WESTERN US WILL EVENTUALLY PINCH OFF
A SOUTHERN STREAM SHORTWAVE ACROSS SOUTHERN CALIFORNIA EARLY
MONDAY. THE MODELS HAVE COME INTO SLIGHTLY BETTER AGREEMENT WITH
THE AMPLITUDE AND AXIS ORIENTATION AS THE SHORTWAVE PUSHES INTO
THE FOUR CORNERS REGION. THE GFS REMAINS A BIT AHEAD OF THE REST
OF THE MODELS AND PROBABLY COULD BE LIMITED IN THE OVERALL BLEND.
THE EC/ECENS MEAN ALONG WITH THE UKMET/CMC REMAIN THE MOST
CONSISTENT AND AGREEABLE THROUGH THE 3 DAYS.
PACIFIC NORTHWEST BY MIDWEEK
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: DETERMINISTIC MODEL BLEND
CONFIDENCE: AVERAGE
A STRONG STORM SYSTEM ORIGINATING FROM THE GULF OF ALASKA IS
EXPECTED TO BEGIN APPROACHING THE PACIFIC NORTHWEST COAST BY
WEDNESDAY MORNING AFTER A PERIOD OF QUIET WEATHER EARLY IN THE
WEEK. ALTHOUGH THE SURFACE COLD FRONT IS FORECAST TO PASS THROUGH
THE REGION MID-WEEK, THE PARENT SURFACE LOW IS EXPECTED TO REMAIN
WELL TO THE NORTH ACROSS WESTERN CANADA. THERE ARE ONLY MINOR
MODEL DIFFERENCES WITH THE SYNOPTIC SCALE FEATURES AT THIS TIME,
SO A BLEND OF THE DETERMINISTIC GUIDANCE SHOULD WORK WELL.
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML
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