Prognostic Meteorological Discussion
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000
FXUS10 KWNH 150651
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
251 AM EDT MON SEP 15 2014

VALID SEP 15/0000 UTC THRU SEP 18/1200 UTC

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

...AN EVALUATION OF THE 00Z CMC/UKMET/ECMWF ALONG WITH FINAL
PREFERENCES/FORECAST CONFIDENCE...

THERE DID NOT APPEAR TO BE ANY INITIALIZATION ERRORS WITH THE 00Z
NAM/GFS DEEMED SIGNIFICANT ENOUGH TO IMPACT THEIR FORECASTS.


...BROAD LONGWAVE TROF AFFECTING THE NORTHEASTERN SECTOR OF THE
CONTINENT...
...PROGRESSIVE FRONTAL ZONE...

FINAL PREFERENCE: BLEND OF THE 00Z GFS/ECMWF
FORECAST CONFIDENCE: AVERAGE

AN EXPANSIVE NEGATIVE HEIGHT ANOMALY WILL CONTINUE TO DOMINATE THE
NORTHEASTERN PORTION OF NORTH AMERICA. A PRONOUNCED SHORTWAVE IS
FORECAST TO SLIDE EASTWARD FROM THE NORTHERN PLAINS INTO THE GREAT
LAKES AND NORTHEASTERN U.S. ON MONDAY/TUESDAY. BY 16/0600Z...THE
00Z GFS/GEFS MEAN ARE SLIGHTLY QUICKER WITH THIS SHORTWAVE
RELATIVE TO OTHER SOLUTIONS BUT THE DIFFERENCE DOES NOT APPEAR TOO
MEANINGFUL. AS TIME PROCEEDS FORWARD TO MID-WEEK...THE 00Z NAM IS
MORE AGGRESSIVE WITH THE ENERGY DIGGING TOWARD LAKE SUPERIOR. THIS
CREATES A SOLUTION THAT IS SLOWER THAN THE ENSEMBLE MEANS ALTHOUGH
IT IS NOW JOINED BY THE 00Z UKMET. DIFFERENCES GROW TOWARD THE END
OF THE PERIOD BUT THE IMPACTS ARE PRIMARILY WITH THE HEIGHT FIELDS
ACROSS EASTERN CANADA. THE COMBINATION OF THE 00Z GFS/ECMWF AFFORD
A REASONABLE COMPROMISE AND AGREE WITH THE ENSEMBLE MEANS QUITE
WELL.


...WEAK AREA OF LOW PRESSURE CROSSING THE WESTERN GULF OF MEXICO...

FINAL PREFERENCE: GENERAL MODEL COMPROMISE
FORECAST CONFIDENCE: ABOVE AVERAGE

AN AREA OF LOW PRESSURE AND THE ACCOMPANYING ENHANCED MOISTURE
FLUXES WILL ADVANCE WESTWARD REACHING EASTERN MEXICO/SOUTH TX BY
LATE MONDAY NIGHT. SOLUTIONS SLIGHTLY VARY WITH TIMING BUT ALL
SHOW SOME SORT OF DIFFUSE WAVE CROSSING SOUTH TX EARLY TUESDAY
MORNING. FORTUNATELY THE 00Z CMC HAS TRENDED AWAY FROM ITS
PREVIOUS SOLUTION WHICH WAS MORE EXTREME IN NATURE GIVEN THE
AMOUNT OF RAINFALL IT PLACED ALONG THE WESTERN GULF COAST. WPC
WILL NOW RECOMMEND A GENERAL MODEL COMPROMISE.


...SHEARED SHORTWAVES MOVING FROM THE SOUTHERN PLAINS TOWARD THE
LOWER TN VALLEY ON DAY 1...

FINAL PREFERENCE: NON-00Z ECMWF/12Z ECMWF ENSEMBLE MEAN MODEL
CONSENSUS
FORECAST CONFIDENCE: SLIGHTLY ABOVE AVERAGE

WEAKENED ENERGY WHICH LIFTED FROM THE RIO GRANDE WILL TURN TOWARD
THE EAST AS IT BECOMES CAPTURED IN THE WESTERLY FLOW ALOFT. ONLY
18 HOURS INTO THE FORECAST THE 00Z ECMWF/12Z ECMWF ENSEMBLE MEAN
ARE SLOWER IN EJECTING THESE IMPULSES EASTWARD. EVENTUALLY THE
SYSTEM IS HARDER TO IDENTIFY AS IT SHEARS OVER THE LOWER TN
VALLEY. WILL STICK CLOSER TO THE MODEL CONSENSUS AND CONTINUE TO
DISMISS THE ECMWF SUITE.


...MEAN UPPER TROF AFFECTING THE EASTERN PACIFIC/IMMEDIATE WEST
COAST...

FINAL PREFERENCE: BLEND OF THE 00Z GFS/ECMWF THROUGH
18/0000Z...FOLLOWED BY A BLEND OF THE 00Z GEFS/12Z ECMWF ENSEMBLE
MEAN
FORECAST CONFIDENCE: AVERAGE

A LARGE RIDGE INITIALLY OVER THE WEST COAST WILL SLIDE EASTWARD
AHEAD OF AN UPPER TROF ORGANIZING ACROSS THE EASTERN PACIFIC. THE
INITIAL SHORTWAVE IS EXPECTED TO LIFT NORTHEASTWARD AND SHEAR OVER
THE COASTAL PACIFIC NORTHWEST EARLY TUESDAY. THE ORGANIZED AXIS OF
HEIGHT FALLS LURK UPSTREAM WITH THE ENERGY PROGRESSING EASTWARD
TOWARD THE WEST COAST THROUGH EARLY THURSDAY. THE ENSEMBLE MEANS
SHOW MUCH BETTER CLUSTERING THAN IN PREVIOUS DAYS WHICH INCLUDES
THE 00 GEFS/21Z SREF/12Z ECMWF ENSEMBLE MEANS. THE 00Z CMC/UKMET
ARE WEST OF THESE SOLUTIONS WHILE THE 00Z GFS/ECMWF SHOWS GENERAL
AGREEMENT WITH THE MEANS. WILL RECOMMEND THE 00Z GFS/ECMWF THROUGH
72 HOURS BEFORE THE 00Z ECMWF BECOMES SLOWER SO WILL FOCUS ON THE
ENSEMBLE MEANS FOR EARLY THURSDAY.


...HURRICANE ODILE...

FINAL PREFERENCE: THROUGH 17/0000Z: 00Z ECMWF...THEREAFTER...00Z
CMC
FORECAST CONFIDENCE: AVERAGE

THIS TROPICAL SYSTEM AS OF THE 03Z ADVISORY WAS REPORTING A
PRESSURE OF 930 MB WITH MAXIMUM SUSTAINED WINDS OF 110 KNOTS AND A
MOTION TOWARD THE NORTH-NORTHWEST AT 15 KNOTS. THE FORECAST
CARRIES ODILE RIGHT ALONG THE WEST COAST OF BAJA CA AS A HURRICANE
THROUGH TUESDAY MORNING BEFORE WEAKENING AS IT CROSSES INTO THE
GULF OF BAJA CA/SEA OF CORTEZ. THE 00Z NAM GENERALLY GOES EAST OF
THE NHC TRACK WHILE THE 00Z GFS GETS AHEAD OF THEIR SOLUTION. AS
OF RIGHT NOW...THE 00Z ECMWF OFFERS A REASONABLE SOLUTION THROUGH
48 HOURS RELATIVE TO THEIR TRACK BUT TENDS TO GET NORTH OF THEIR
SOLUTION THEREAFTER. THE 00Z CMC SEEMS TO BE MORE REPRESENTATIVE
BEYOND 48 HOURS.



...MODEL TREND GRAPHICS AT
www.wpc.ncep.noaa.gov/html/model2.shtml...
...500 MB FORECASTS AT
www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...

RUBIN-OSTER

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