933
FXUS10 KWNH 130648
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
247 AM EDT SUN OCT 13 2019
VALID OCT 13/0000 UTC THRU OCT 16/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z FINAL 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 GRADUALLY WEAKEN AS IT LIFTS NORTHEASTWARD ACROSS ONTARIO,
CANADA OVER THE NEXT COUPLE OF DAYS. THE INITIAL COLD FRONT FROM
THIS LOW HAS REACHED THE EAST COAST BUT IS FORECAST TO STALL
ACROSS THE SOUTHEAST ON SUNDAY AND GOING INTO MONDAY, AND A
SECONDARY COLD FRONT CROSSES THE GREAT LAKES AND OHIO VALLEY
THROUGH SUNDAY NIGHT. THE MODELS REMAIN WELL CLUSTERED WITH THIS
SYSTEM AND THEREFORE A DETERMINISTIC MODEL BLEND IS PREFERRED.
PACIFIC NORTHWEST TO THE GREAT LAKES THROUGH TUESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM CONSENSUS
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
THE NEXT FEATURE OF INTEREST TO AFFECT THE WESTERN U.S. WILL BE A
PROGRESSIVE UPPER-LEVEL TROUGH AND ASSOCIATED COLD FRONT THAT
SHOULD REACH THE WEST COAST BY EARLY SUNDAY, AND THEN ADVANCE
INLAND ACROSS THE NORTHERN ROCKIES ON MONDAY. BY MONDAY NIGHT,
THE HEIGHT FALLS START ARRIVING ACROSS THE HIGH PLAINS AND INDUCES
LEE-SIDE CYCLOGENESIS OVER THE CENTRAL PLAINS TO UPPER MIDWEST.
THE GFS AND ECMWF GLOBAL MODELS ARE FAIRLY ALIGNED WITH THEIR
ENSEMBLE MEANS. HOWEVER, THE NAM BECOMES TOO AMPLIFIED OVER THE
NORTHERN PLAINS BY TUESDAY MORNING AND EVEN MORE SO BY WEDNESDAY
MORNING, SO A GFS/ECMWF COMPROMISE IS A GOOD STARTING POINT.
SOUTHWESTERN U.S. TO SOUTHERN PLAINS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: EC MEAN/GFS/UKMET
CONFIDENCE: AVERAGE
TROUGHING MOVING THROUGH THE WESTERN US WILL EVENTUALLY PINCH OFF
A SOUTHERN STREAM SHORTWAVE ACROSS SOUTHERN CALIFORNIA EARLY
MONDAY. IT REMAINS THE CASE THAT THE CMC AND NOW THE 00Z ECMWF
ARE MORE AMPLIFIED ALOFT ACROSS THE SOUTHWEST EARLY IN THE WEEK
COMPARED TO THE OTHER GUIDANCE. BY TUESDAY MORNING, THE GFS IS
MORE PROGRESSIVE ACROSS THE WESTERN HIGH PLAINS AND THE AMPLIFIED
CMC AND ECMWF ARE SLOWER. AT THE SURFACE, THE 00Z UKMET HAS
TRENDED CLOSER TO THE CONSENSUS WITH THE SURFACE LOW OVER THE
CENTRAL PLAINS COMPARED TO ITS 12Z RUN. TAKING THESE FACTORS INTO
ACCOUNT, A BLEND OF THE EC MEAN/GFS/UKMET SHOULD SUFFICE FOR NOW.
PACIFIC NORTHWEST BY MIDWEEK
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: DETERMINISTIC MODEL BLEND
CONFIDENCE: ABOVE 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
HAMRICK
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page