MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 144 AM EST THU FEB 13 2014 VALID FEB 13/0000 UTC THRU FEB 16/1200 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. ...UPPER TROF BECOMING NEGATIVELY-TILTED OVER THE COASTAL CAROLINAS BY 13/1800Z... ...STRENGTHENING COASTAL LOW LIFTING ALONG THE EAST COAST... FINAL PREFERENCE: BLEND OF THE 21Z SREF MEAN/12Z ECMWF FORECAST CONFIDENCE: AVERAGE CURRENT WATER VAPOR IMAGERY DEPICTED A STRONG SHORTWAVE CROSSING THE DEEP SOUTH WITH THE IMPULSE GRADUALLY LIFTING NORTHWARD IN RESPONSE TO RIDGING DOWNSTREAM OVER THE WESTERN ATLANTIC. BY 14/0000Z...THE 00Z UKMET/ECMWF AND 12Z ECMWF ENSEMBLE MEAN ALL SHOW A CLOSED 534-DM LOW CROSSING THE DELMARVA PENINSULA. CONTINUAL DEEPENING IS FORECAST ONCE THE SYSTEM MOVES UP INTO LOWER NEW ENGLAND BY THURSDAY NIGHT. WITH REGARD TO TIMING...THE 00Z NAM/ECMWF AND 21Z SREF MEAN/12Z ECMWF ENSEMBLE MEAN ARE A BIT SLOWER WHILE THE 00Z GFS/CMC ARE QUICKER MOVING THE ENERGY NORTHWARD. LOOKING AT THE SURFACE...AS EXPECTED...THE 12Z CMC ENSEMBLE MEMBERS ARE FURTHER TO THE NORTH WITH MORE SCATTER AMONGST THE MEMBERS. THE 12Z ECMWF ENSEMBLE MEMBERS ARE MORE TOWARD THE SOUTH AND WEST WITH MUCH MORE CONSOLIDATION NOTED IN THE PAST 2 PLOTS. DO LIKE THE CONTINUITY IT HAS BEEN SHOWING SO WILL INCORPORATE ITS SOLUTION INTO THE PREFERENCE. THE 21Z SREF MEAN REASONABLY FOLLOWED THE PATH ALOFT SUGGESTED BY THE 12Z ECMWF SO WILL BLEND THE TWO HERE. ...TROF DIGGING THROUGH THE NORTHERN PLAINS/UPPER MIDWEST ON THURSDAY... ...ASSOCIATED SURFACE LOW TRACKING ACROSS THE NORTHERN TIER STATES... FINAL PREFERENCE: BLEND OF THE 00Z NAM/ECMWF FORECAST CONFIDENCE: SLIGHTLY ABOVE AVERAGE A SHARP AREA OF HEIGHT FALLS SLIDING ACROSS THE NORTHERN TIER OF THE CONUS WILL CARRY A SURFACE LOW WHICH IS EXPECTED TO GRADUALLY WEAKEN ACROSS THE UPPER MIDWEST. WITH REGARD TO THE FORECAST TRACK...THE 00Z CMC/ECMWF AND 12Z ECMWF ENSEMBLE MEAN ARE SOUTH OF THE CONSENSUS AS THE LOW TRACKS THROUGH SOUTHERN WI LATE THURSDAY. THE 12Z ECMWF ENSEMBLE LOW PLOT IS PRETTY EMPHATIC ABOUT THIS MORE SOUTHERN TRACK GIVEN ITS SUFFICIENT CLUSTERING. WILL GO AHEAD AND SPLIT THE DIFFERENCE BETWEEN THE MORE SOUTHERN 00Z ECMWF ALONG WITH THE 00Z NAM WHICH SUPPORTS THE NORTHERN CAMP. ...CLIPPER SYSTEM TRACKING ACROSS THE SOUTHERN MID-ATLANTIC BY EARLY SATURDAY... FINAL PREFERENCE: BLEND OF THE 00Z GFS/CMC WITH THE 12Z ECMWF FORECAST CONFIDENCE: AVERAGE WITHIN THE BROAD ZONAL FLOW ANCHORING THE WESTERN STATES...A MYRIAD OF SHORTWAVES WILL TRACK THROUGH UPPER SECTIONS OF THE PACIFIC NORTHWEST EARLY THURSDAY. THE SYSTEM WILL BECOME MORE CONSOLIDATED IN NATURE AS IT DIVES THROUGH THE MIDDLE MS VALLEY BY 14/1200Z WITH THE 00Z NAM BEING THE SLOWEST MODEL DURING THIS EVOLUTION. MOVING FURTHER AHEAD...THE 00Z UKMET IS THE MOST AMPLIFIED BY SATURDAY MORNING ACROSS THE LOWER MID-ATLANTIC/CAROLINAS. THIS SEEMS TOO AMPLIFIED RELATIVE TO THE ENSEMBLE MEANS WITH THE 00Z GFS/CMC AND 12Z ECMWF BEING THE MOST SUPPORTIVE OF THESE MEANS. THE 00Z ECMWF TRENDED SLOWER WITH A TRACK A BIT MORE SIMILAR TO THE 00Z UKMET. NOT READY TO BUY THAT SOLUTION AS IT DIVERGES FROM ITS OWN ENSEMBLE MEAN. OVERALL...WILL RECOMMEND A COMBINATION OF THE 00Z GFS/CMC WITH THE 12Z ECMWF. ...SECONDARY SYSTEM SWINGING THROUGH THE OH VALLEY BY EARLY SUNDAY... FINAL PREFERENCE: BLEND OF THE 00Z GFS/12Z ECMWF FORECAST CONFIDENCE: SLIGHTLY BELOW AVERAGE ON THE HEELS OF THE INITIAL CLIPPER SYSTEM...ANOTHER PROGRESSIVE BATCH OF SHORTWAVE ENERGY WILL TRACK FROM THE NORTHERN PLAINS TOWARD THE OH VALLEY DURING THE UPCOMING HOLIDAY WEEKEND. OVERALL...THE 12Z CMC APPEARS TO BE THE LARGEST OUTLIER HERE BEING FURTHER NORTH WITH THE TRACK OF ITS HEIGHT FALLS. WILL GO AHEAD AND FOLLOW THE LEAD OF THE PRECEDING SYSTEM AND FAVOR THE 00Z GFS/12Z ECMWF FOR THE TRACK OF THIS SYSTEM. ...DEEP UPPER TROF AFFECTING THE NORTHWESTERN U.S. BY LATE IN THE WEEKEND... FINAL PREFERENCE: BLEND OF THE 00Z GEFS/12Z ECMWF ENSEMBLE MEANS FORECAST CONFIDENCE: BELOW AVERAGE PERSISTENT ZONAL FLOW WILL CONTINUE TO CARRY A SERIES OF IMPULSES TOWARD THE PACIFIC NORTHWEST COAST. A STRONG SURFACE LOW IS EXPECTED TO TRACK TOWARD THE BRITISH COLUMBIA COAST BY LATE SATURDAY AS A MORE AMPLIFIED WAVE AFFECTS THE WESTERN SIDE OF THE CONTINENT. THERE IS ENOUGH SPREAD THAT WILL GO AHEAD AND COMBINE ENSEMBLE MEANS INTO THE MIX. www.wpc.ncep.noaa.gov/html/model2.shtml... RUBIN-OSTER