"MEDIUM RANGE GUIDANCE SHOWS GOOD CONTINUITY WITH RESPECT TO THE
EXPECTED CHANGE IN EMPHASIS OF HIGHER LATITUDE POSITIVE HGT
ANOMALIES FROM ERN/NERN CANADA TO NEAR THE BERING STRAIT. THIS
TRANSITION IS STILL EXPECTED TO LEAVE A MODERATE STRENGTH POSITIVE
ANOMALY CENTER ABOUT HALFWAY BETWEEN HUDSON BAY AND SRN GREENLAND
THOUGH. AS SUPPORTED BY TELECONNECTIONS... STRONGEST NEGATIVE HGT
ANOMALIES NEAR THE EAST COAST EARLY IN THE PERIOD SHOULD WEAKEN
WHILE HGTS DECREASE OVER SRN/SWRN CANADA... WITH AN INCREASE IN
PACIFIC ENERGY FLOWING INTO THE WEST.

OVER THE CENTRAL/ERN STATES THE FCST WILL BE DOMINATED BY A
POTENTIAL STORM TRACKING ALONG THE GULF COAST AND INTO THE WRN
ATLC... TRAILED BY COLD HIGH PRESSURE SINKING INTO THE PLAINS.
DURING DAYS 3-4 SUN-MON THE 00Z GFS/ECMWF AND 00Z GEFS/12Z ECMWF
ENSEMBLE MEANS AS A WHOLE PROVIDE A REASONABLE FCST ALONG THE GULF
COAST WITH CONFIRMATION FROM LATEST ENSEMBLE MEANS. THE UKMET/CMC
ARE SLIGHTLY FASTER WITH THE SRN STREAM SHRTWV SUPPORTING THE GULF
COAST SFC LOW... AND ARE NOT PARTICULARLY FAVORED IN LIGHT OF
MULTI-DAY TRENDS/CONTINUITY THAT HAVE GENERALLY FAVORED SLOWER
PROGRESSION. GUIDANCE DIVERGES FROM DAY 5 TUE ONWARD. DUE TO THE
00Z ECMWF TRENDING SLOWER THAN CONSENSUS WITH ENERGY CROSSING THE
CONUS DURING THE PERIOD... THAT MODEL EJECTS THE INITIAL WAVE EWD
INTO THE ATLC AND THEN TAKES ANOTHER 1-2 DAYS TO DEVELOP ITS
STRONGER WRN ATLC SFC LOW THAT ENDS UP ON THE SRN FRINGE OF THE
MODEL/ENSEMBLE ENVELOPE. 00Z GEFS/12Z ECMWF ENSEMBLES SHOW BEST
CLUSTERING A LITTLE EWD OF THE 00Z GFS BUT THE GFS IS WITHIN THE
SOLN ENVELOPE AND THE UKMET/CMC TRACKS ALSO FALL IN THE MIDDLE TO
WRN HALF OF THE SPREAD. WITH ENSEMBLE MEANS OFFERING THE BEST
CONTINUITY AMONG GUIDANCE SO FAR... PREFER TO LEAN MORE TOWARD THE
00Z GEFS/12Z ECMWF MEANS WITH ABOUT 1/3 WEIGHTING OF THE GFS TO
PROVIDE SOME ADDED STRENGTH FROM DAY 5 TUE ONWARD. IT IS HOPED
THAT WITH A LARGER PROPORTION OF THE SUPPORTING ENERGY CROSSING A
MAJORITY OF THE CONUS VERSUS ENTERING THE CONUS FROM CANADA WHERE
MDLS HAVE MORE DIFFICULTY RESOLVING SHRTWV FEATURES... THAT THIS
SYSTEM WILL ULTIMATELY HAVE SOMEWHAT BETTER PREDICTABILITY THAN
PRECEDING SYSTEMS AFFECTING THE EAST COAST".

With the Sunday-Tuesday winter storm still in the poorly sampled Pacific Ocean West of CA it's too early to get into specifics on amounts and type of precip or location as a lot variation
still exisits in model output with the system still about 4 days away. The NOAA consensus surface low track is as of this morning, starting on the TX Southeast coast Sunday morning on to just South of the AL/FL Pan Handle Monday morning heading NE to just Southeast of Cape Hatteras NC Tuesday morning. Obviously the various numerical simulation equations differ on the track and thermal profiles and if it's a miller A, B, or hybrid of some kind will make a world of difference in precip type and amount for everyone. I almost never try to get specific until a system in question gets well into the USA mainland where better atmosphere sampling can occur.