Portastorm wrote:srainhoutx wrote:Alright folks. I have to run for now, but the 12Z ECMWF as well as the CMC will likely start some conversation back in the thread again.
I'm trying hard not to say much ... but for those who haven't seen those runs yet, the Arctic front around Christmas looks "wetter" -- before AND after -- on these runs than previous runs. But, we gotta keep in mind it is just one run. If these solutions are showing up Sunday and Monday ... then it'll be time to buy those ice scrapers and snowplows. Heh, heh.
I couldn't resist, Portastorm...

Hmmm...

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
150 PM EST FRI DEC 18 2009
VALID 12Z MON DEC 21 2009 - 12Z FRI DEC 25 2009
WE REMAIN IN A QUITE INTERESTING AND STORMY HOLIDAY WEATHER
PATTERN FOR OUR FINE NATION.
SHORT RANGE DIFFERENCES WITH ENERGY DETAILS/INTERACTIONS REACHING
WRN NOAM...SEE OUR PMDHMD DISCUSSION...BECOME MORE ROBUST
DOWNSTREAM MIDWEEK THROUGH CHRISTMAS. WHILE PLAUSIBLE...WE REMAIN
SKEPTICAL OF THE 00Z/18 ECMWF TREND TO SUCH DEEP LOW DEVELOPMENT
FROM THE CENTRAL PLAINS NEWD TO THE GREAT LAKES MIDWEEK TO
CHRISTMAS DESPITE CONTINUED SUPPORT FROM RECENT RUNS OF THE GFS
AND GEM GLOBAL UNDER AMPLIFIED TROUGHING ALOFT. THERE COULD STILL
BE A DECENT PARENT LOW THAT WILL FOCUS QUITE A SWATH OF
WRAP-AROUND HEAVY SNOWS CONSIDERING INFLOW/LIFT...BUT THE 00 UTC
UKMET AND ECMWF ENSEMBLES SHOWED THE BULK OF ENERGY MORE
SUPPRESSED BY A DOMINANT NORTHERN STREAM. THE 12 UTC UKMET/ECMWF
NOW ALSO FAVOR THIS TYPE OF SOLUTION...BUT NOT THE 12 UTC
GFS/CANADIAN. ALL OF THESE 12 UTC MODELS HAVE PRETTY MUCH STAYED
WITH THEIR 00 UTC MODEL SOLUTIONS RESPECTIVELY EXCEPT FOR THE
ECMWF THAT HAS TRENDED SIGNIFICANTLY MORE TOWARD A MORE SRN
EMPHASIS. THIS TREND LEADS TO MORE RAPID ENERGY TRANSFER AND HEAVY
WINTER PCPN POTENTIAL INTO/AROUND A TRIPLE POINT LOW MORE ACROSS
THE SRN US AND THEN ERN US COASTAL SYSTEM AS DID A CLUSTER OF THE
LAST SEVERAL ECMWF ENSEMBLE MEANS AND SOME OLDER DETERMINISTIC
RUNS. THE STRONG BLOCK HELD IN PLACE BY THE NEGATIVE NAO COULD
ACT TO LIMIT POTENTIAL FOR MAJOR CYCLOGENESIS IN THE GREAT LAKES
REGION UNLESS THERE IS A MORE ROBUST PATTERN DESTABILIZATION.
ACCORDINGLY...FINAL HPC PROGS MAINTAIN HPC CONTINUITY AND REMAIN
PRIMARILY DERIVED FROM THE 00 UTC ECMWF DAYS 3/4 BEFORE SWITCHING
TO THE 00 UTC ECMWF ENSEMBLES WED-CHRISTMAS.
CISCO/SCHICHTEL