Prognostic Meteorological Discussion
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617
FXUS10 KWNH 240632
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
231 AM EDT SAT SEP 24 2016

VALID SEP 24/0000 UTC THRU SEP 27/1200 UTC

...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...

00Z MODEL EVALUATION WITH MODEL PREFERENCES/CONFIDENCE INTERVALS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT
RANGE FORECASTS.


DEEP CYCLONE MOVING NEAR THE US/CANADIAN BORDER
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/ECMWF COMPROMISE
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE 00Z NAM IS THE MOST SOUTHERLY WITH THIS SYSTEM`S TRACK WHILE
THE 00Z UKMET IS THE SLOWEST.  SINCE THE UKMET`S UPPER PATTERN
ACROSS EASTERN AND NORTHWEST CANADA STRAYS SIGNIFICANTLY FROM THE
OTHER GUIDANCE, BELIEVE ITS HANDLING OF THIS FEATURE IS IN DOUBT.
A STRONG POSITIVE MID-LEVEL ANOMALY MIGRATING NORTH FROM HUDSON
BAY INTO NUNAVUT SHOULD ALLOW A DEEP CYCLONE TO TRACK UNDER ITS
BASE IN THE 40S LATITUDES, WHICH RESEMBLES THE GUIDANCE.  WITH THE
SUPPORT OF THE ENSEMBLE MEAN SOLUTIONS, WILL FAVOR A SOLUTION
CLOSEST TO A 00Z GFS/00Z ECMWF COMPROMISE WITH SLIGHTLY ABOVE
AVERAGE CONFIDENCE.


UPPER TROUGH/FRONT MOVING INTO THE NORTHWEST EARLY TUE
NM CLOSED LOW SHIFTING INTO NORTHWEST MEXICO
TROUGHING LEAVING THE NORTHEAST SUNDAY
LINGERING MID-LEVEL LOW NEAR THE SOUTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
THE GUIDANCE SHOWS GOOD AGREEMENT WITH THESE SYSTEMS, SO PREFER A
COMPROMISE OF THE AVAILABLE GUIDANCE HERE TO IRON OUT ANY DETAIL
ISSUES WITH ABOVE AVERAGE CONFIDENCE.


...MODEL TREND GRAPHICS AT
www.wpc.ncep.noaa.gov/html/model2.shtml...

...500 MB FORECASTS AT
www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...

ROTH
$$





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