Prognostic Meteorological Discussion
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FXUS10 KWNH 161838
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
237 PM EDT WED APR 16 2014

VALID APR 16/1200 UTC THRU APR 20/0000 UTC

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


12Z MODEL EVALUATION WITH PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT
RANGE FORECASTS.


SYSTEM APPROACHING THE PACIFIC NORTHWEST SAT
SYSTEM MOVING ACROSS SOUTHERN CANADA FRI/SAT
SYSTEM MOVING ACROSS THE SOUTHWEST FRI/SAT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE:  GENERAL MODEL COMPROMISE
CONFIDENCE:  ABOVE AVERAGE

THE GUIDANCE SHOWS MINIMAL ISSUES WITH THE PROGRESSION AND DEPTH
OF THESE SYSTEMS, AT THE SURFACE OR ALOFT.  A GENERAL MODEL
COMPROMISE IS PREFERRED WITH ABOVE AVERAGE CONFIDENCE CONSIDERING
THE GOOD MODEL AGREEMENT.


CLOSED LOW DEVELOPING NEAR FL FRI NIGHT/SAT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE:  CLOSEST TO THE ECMWF
CONFIDENCE:  AVERAGE

THE SYNOPTIC PATTERN FEATURES A NORTHERN STREAM SLOWLY SHIFTING
NORTHWARD IN ADVANCE OF A SYSTEM APPROACHING WESTERN NORTH AMERICA
SATURDAY.  THIS CHANGE IN THE NORTHERN STREAM ALLOWS THE
POSSIBILITY OF CLOSED SYSTEMS ALOFT IN THE SOUTHERN STREAM, AND
THE AVAILABLE GUIDANCE BEARS THIS OUT.  THIS SOUTHEASTERN SYSTEM
HAS A CHANCE TO DIG/AMPLIFY INTO FRIDAY NIGHT BEFORE THE UPSTREAM
SYSTEM IN THE SOUTHWEST WEAKENS.  THE 12Z GUIDANCE IS AGREEABLE ON
THE SYSTEM`S LATITUDE, THOUGH PROGRESSION ISSUES LINGER.  THE 12Z
GFS IS BEING CONTAMINATED BY GRIDSCALE FEEDBACK, AS A PARTICULARLY
STRONG BULL`S EYE MOVES INTO FL`S BIG BEND INTO THE WESTERN
SUBTROPICAL ATLANTIC MIDDAY FRIDAY, WHICH ACTS TO OPEN UP THE GFS
SOLUTION AT THE 500 HPA AND 700 HPA LEVELS FRIDAY AFTERNOON.  THIS
IS LEADING TO A QUICKER SOLUTION AND MORE DELAYED CLOSURE OF THE
500 HPA AND 700 HPA LOWS.  THE SYSTEM SHOULD MAINTAIN SOME
PROGRESSION DUE TO MOVEMENT UPSTREAM ACROSS SOUTHWEST/SOUTHERN
ROCKIES, BUT THE GFS IS LIKELY TOO QUICK.  THE 12Z CANADIAN/12Z
UKMET ARE THE SLOWEST SOLUTIONS, WITH THE 12Z ECMWF SPLITTING THE
DIFFERENCE.  WE FAVOR A SOLUTION CLOSEST TO THE 12Z ECMWF WITH
SLIGHTLY ABOVE AVERAGE CONSIDERING THE RECENT CONVERGENCE WITHIN
THE GUIDANCE.


SYSTEM MOVING BY NEW ENGLAND FRI NIGHT/SAT MORNING
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE:  GENERAL MODEL COMPROMISE
CONFIDENCE:  AVERAGE

THERE ARE SLIGHT ISSUES ALOFT WITH THE SYSTEM`S PROGRESSION AND
SHARPNESS, BUT FOR THE MOST PART, THE MASS FIELD ISSUES ARE QUITE
SMALL.  A GENERAL MODEL COMPROMISE IS PREFERRED HERE WITH AVERAGE
CONFIDENCE CONSIDERING THE EXISTING MODEL SPREAD AND ITS
PROGRESSIVE NATURE.



...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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