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. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... RUBIN-OSTER