Cheeznado Posted December 27, 2011 Share Posted December 27, 2011 As per a suggestion in the general thread, here is a separate topic for the upcoming system (or not) Link to comment Share on other sites More sharing options...
buckeyefan1 Posted December 27, 2011 Share Posted December 27, 2011 As per a suggestion in the general thread, here is a separate topic for the upcoming system (or not) Link to comment Share on other sites More sharing options...
WeatherNC Posted December 27, 2011 Share Posted December 27, 2011 EXTENDED FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 230 PM EST TUE DEC 27 2011 VALID 12Z FRI DEC 30 2011 - 12Z TUE JAN 03 2012 A QUIET RATHER MILD PATTERN MOST PLACES THRU THE WEEKEND. BUT SIGNIFICANT SNOWFALL IS STILL POSSIBLE FROM THE MID-SOUTH INTO THE CAROLINAS/MID-ATLANTIC/NORTHEASTERN STATES NEXT WEEK. DETAILS QUITE SKETCHY... MODEL CONSENSUS SHOWS THAT THE FLOW PATTERN IS EXPECTED TO BUCKLE THROUGH THIS WEEKEND AS A FULL-LATITUDE TROUGH DIGS FROM ALASKA SOUTHWARD ALONG 140W. THIS IN TURN LEADS TO SIGNIFICANT RIDGING ACROSS WESTERN NORTH AMERICA...CAUSING THE HEAVY PRECIP ACROSS THE PACIFIC NW TO CEASE. A TROF SHOULD DEVELOP SOMEWHERE E OF THE PLAINS STATES...BUT HOW FAR E? HOWEVER...THE GEFS FAMILY OF ENSEMBLE SOLUTIONS IS MUCH FLATTER/DELAYED/FARTHER E AS THEIR TROUGH BEGINS TO DEVELOP SUN DAY 5. WHEN THE 00Z GEFS MEAN FINALLY DOES DEVELOP THE TROUGH...IT IS STILL WEAKER WITH IT MON/TUE THAN THE CORRESPONDING ECMWF FAMILY OF SOLUTIONS. BY SUN...THE 00Z/27 GFS/CANADIAN/GEFS MEAN PROGRESS THE DEVELOPING TROUGH FARTHER EAST THAN THE 00Z/27 UKMET/ECMWF/12Z ECMWF ENSEMBLE MEAN. SINCE THERE IS DECENT MODEL CONSENSUS ON FLOW IN THE ERN PACIFIC BECOMING MORE AMPLIFIED ...A CORRESPONDING SLOW MOVING/AMPLIFIED TROUGH EAST OF THE PLAINS MAKES SENSE...THOUGH NOT AS SLOW/AMPLIFIED AS THE DETERMINISTIC 00Z/27 ECMWF. THE ECMWF HAS A BIAS OF BEING TOO SLOW/STRONG WITH SYSTEMS FARTHER OUT THAN 120 HOURS. LARGE SCALE TELECONNECTIONS ON AN ERN PACIFIC TROUGH AND NEGATIVE HEIGHT ANOMALIES OVER GREENLAND FAVOR A MUCH WEAKER E COAST TROF THAN THE ECMWF OR ITS ENSEMBLE MEAN. THE KEY SEEMS TO BE HOW MUCH AMPLIFICATION OF AN ERN PACIFIC TROUGH ALONG 140W OCCURS AROUND DAY 5...WITH SUBSEQUENT AMPLIFICATION DOWNSTREAM OVER NOAM. THE 00Z/12Z DETERMINISTIC ECMWF SEEMS TO GO TOO FAR IN DEVELOPING A DEEP CLOSED CYCLONE ACROSS THE MID-SOUTH WHICH MOVES INTO THE CENTRAL APPALACHIANS NEXT TUE OR WED. HOWEVER...THERE IS STRONG ECENS ENSEMBLE SPAGHETTI SUPPORT FOR A DEEP...YET LESS DRASTIC...FULL LATITUDE TROUGH TRANSLATING ACROSS THE ERN CONUS MON-WED. THERE IS CONSISTENCY IN RECENT DETERMINISTIC ECMWF RUNS WITH THIS GENERAL AMPLIFYING TREND EARLY NEXT WEEK. THE 00Z/27 ECENS MEAN STILL SEEMS LIKE A GOOD HEDGE AFTER SUN DAY 5...IN VIEW OF ITS GOOD LONG TERM GOOD VERIFICATION. THE 12Z/27 GFS/GEFS MEAN PERSISTED IN A GENERALLY PROGRESSIVE FLAVOR IN ITS FORECASTS. THE GFS SEEMS TO OVERPLAY ONE IMPULSE REACHING THE E COAST SAT DAY 5 GIVEN ITS FAST WESTERLY ENVIRONMENT...WHILE IT SHOWS ONLY MODERATE DEVELOPMENT TO THE NEXT TROUGH REACHING 85W BY SUN. IT HAS EVEN BACKED OFF IN AMPLITUDE HERE FROM ITS 06Z/27 RUN. THE 12Z/27 UKMET WAS IN SNYC WITH THE GFS ON THE MAIN FEATURES ACROSS THE COUNTRY THRU MON DAY 6. THEN COMETH THE 12Z/27 CANADIAN...HANDLING THE PATTERN ACROSS MOST OF THE LOWER 48 FROM DAY 4 ONWARD VERY SIMILAR TO THE 00Z/27 ECMWF WITH SPECTACULAR DIGGING/CLOSING OFF ALOFT NEAR THE LOWER MS VLY EARLY TUE. THE SCORE IS EVEN WITH THE 12Z CANADIAN/00Z AND 12Z ECMWF/00Z/27 ECENS MEAN PITTED AGAINST THE 12Z/27 GFS/GEFS MEAN/UKMET. THE NEW 12Z/27 ECMWF PLAYS UP A DIFFERENT SHORTWAVE IN THE AMPLIFYING CENTRAL/ERN TROF TUE/WED BUT HAS THE SAME IDEA AS PREVIOUSLY...FORECASTING THE A DAY 8 STORM FOR THE E COAST INSTEAD OF DAY 7. WITH THIS MUCH SPREAD AND UNCERTAINTY FINAL GRAPHICS ARE STAYING UNCHANGED...HEAVILY WEIGHTED ON THE BACK END TOWARDS THE ECENS MEAN. FLOOD Link to comment Share on other sites More sharing options...
RaleighWx Posted December 27, 2011 Share Posted December 27, 2011 yeah the op ECMWF is the big outlier much different than almost every member in the spaghetti plots with the trough axis much further west at day 7. As cheeze said, often times the operational can lead the ensemble members since it is the most skilled member. It has actually happened several times this cool season with the cut-offs over the Southern Plains, Deep South. But we need to see several runs in a row of it showing a similar scenario and then I would imagine the ensemble members trend towards it. But with no blocking (+AO/+NAO), no 50/50 low, this is all about timing, so the odds are not great but certainly not impossible. Link to comment Share on other sites More sharing options...
FallsLake Posted December 27, 2011 Share Posted December 27, 2011 RAH long term discussion: .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 240 PM TUESDAY... FORECAST UNCERTAINTY GROWS IN THIS TIME PERIOD. THE AFOREMENTIONED SHORTWAVE TROUGH AND ASSOCIATED SURFACE FRONT PASS THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY MORNING. WITH PRECEDING LOW LEVEL FLOW VEERING AROUND TO MAINLY WESTERLY... MOISTURE RETURN IS ABSENT... THUS EXPECT THE SURFACE FRONT TO PASS THROUGH LARGELY DRY WITH JUST PARTLY CLOUDY SKIES. THICKNESSES REMAIN ABOVE NORMAL AS SHORTWAVE RIDGING MOVES IN ALOFT AND WITH AN INCOMING MODIFIED SURFACE AIR MASS... SO TEMPS SATURDAY/SUNDAY SHOULD REMAIN MILD WITH HIGHS IN THE MID 50S TO LOWER 60S. THEN STARTING LATE IN THE WEEKEND... THE GENERAL TREND OF THE MODELS IS TO A PATTERN FEATURING FULL-LATITUDE LONGWAVE RIDGING IN THE WESTERN US AND TROUGHING IN THE EAST. BUT MAJOR MODEL DIFFERENCES BETWEEN THE DETERMINISTIC GFS AND ECMWF REGARDING PLACEMENT OF THESE LONGWAVE FEATURES INCREASE SIGNIFICANTLY... CULMINATING IN SOLUTIONS THAT ARE 180 DEGREES OUT OF PHASE WITH EACH OTHER BY MONDAY/TUESDAY. THE GFS HAS TRENDED A BIT FARTHER WEST AND DEEPER WITH ITS EASTERN NOAM TROUGH... CLOSER TO THE ECMWF ENSEMBLE MEAN... WHILE THE DETERMINISTIC ECMWF IS MUCH SLOWER AND STRONGER THAN ITS ENSEMBLE MEAN... CLOSING OFF A POTENT VORTEX JUST TO OUR WEST BY TUESDAY. THIS ECMWF SOLUTION INITIALLY APPEARS EXTREME... HOWEVER THIS IS THE SECOND ECMWF RUN SHOWING SUCH AN INTENSE CLOSED LOW. IF THIS COMES TO PASS... WE COULD BE LOOKING AT A SIGNIFICANT STORM FOR NC FOR MONDAY NIGHT THROUGH TUESDAY AND POSSIBLY BEYOND. FOR NOW... AND TO ACCOUNT FOR THE WIDE VARIETY OF MODEL SOLUTIONS... WILL LEAN TOWARD THE MIDDLE-OF-THE-ROAD ECMWF ENSEMBLE MEAN... WHICH SWEEPS A LARGELY DRY COLD FRONT THROUGH THE AREA EARLY MONDAY AND BRINGS IN COOLER AND MORE SEASONABLE AIR FOR LATE MONDAY THROUGH TUESDAY. BUT AGAIN... THE CONFIDENCE IN THE MEDIUM RANGE IS QUITE LOW... SO STAY TUNED. -GIH Link to comment Share on other sites More sharing options...
NavarreDon Posted December 27, 2011 Share Posted December 27, 2011 GSP seems in no rush to promote this in the afternoon long term afd: .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AT 2 PM EST TUESDAY...THE UPPER LEVEL PATTERN IS EXPECTED TO AMPLIFY OVER THE USA OVER THE WEEKEND. THE GFS AND ECMWF GO OUT OF PHASE RATHER QUICKLY. HPC BLENDED ECMWF WITH UKMET AND THE EC ENSEMBLE MEAN...LEADING TO A LOWER PROGRESSION OF UPPER FEATURES. IN THIS SCENARIO...AN UPPER TROUGH CROSSES THE EASTER SEABOARD ON SATURDAY...FOLLOWED BY UPPER RIDGING ON SUNDAY. ANOTHER UPPER TROUGH AMPLIFIES OVER THE MS RIVER VALLEY ON MONDAY...CLOSING OFF AND UPPER LOW OVER THE CENTRAL APPALACHIANS ON TUESDAY. DRY HIGH PRESSURE IS OVER OUR AREA ON FRIDAY NIGHT AND SATURDAY. A COLD FRONT APPROACHES FORM THE NW ON SUNDAY...WITH MODEST GULF INFLOW ONLY DEVELOPING AS IT CROSSES THE TN VALLEY MONDAY NIGHT. THIS WILL MEAN A QUICK SHOT OF PRECIPITATION FOR OUR AREA MONDAY NIGHT...WITH ONLY ENOUGH CONFIDENCE FOR SLIGHT CHANCE POPS AT THIS TIME. THICKNESS FALLS RAPIDLY BEHIND THE FRONT...SUCH THAT SNOW LEVELS FALL TO THE VALLEY FLOORS IN THE NC AND GA MOUNTAINS BY DAYBREAK MONDAY. NW FLOW SHOWERS CONTINUE IN THE NC MOUNTAINS INTO MONDAY... WHILE THE LEE DRIES OUT. SNOW LEVELS RISE TO JUST THE HIGHEST PEAKS BY MIDDAY MONDAY. SNOW LEVELS FALL AGAIN MONDAY NIGHT. THE ECMWF SUGGEST THE POTENTIAL FOR A PROLONGED NW FLOW SNOW IN THE NC MOUNTAINS ASSOCIATED WITH THE COOL POOL BEHIND THE DEVELOPING UPPER LOW. IT ALSO SUGGESTS A COASTAL LOW ON THE FRONT OT OUR EAST. WITH CONFIDENCE QUITE LOW THAT FAR INTO THE FUTURE...THIS FORECAST WILL ALLOW SNOW SHOWERS TO BEGIN TO TAPER OFF MONDAY NIGHT...ENDING EARLY TUESDAY....AND WILL NOT KEEP ANY FRONTAL WAVE PRECIPITATION IN THE INTERSTATE 77 CORRIDOR. NO RAIN OR SNOW ACCUMULATIONS WILL BE FORECAST WITH SLIGHT CHANCE POPS. Link to comment Share on other sites More sharing options...
burgertime Posted December 27, 2011 Share Posted December 27, 2011 Man, we got the skeptic starting this thread...mojo is going to be off the charts! Let's see if the 18z has any changes for us. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted December 27, 2011 Share Posted December 27, 2011 Someone please catch me if EURO later folds on this...I might go cliff diving off the Apps. 18z GFS is rolling... Link to comment Share on other sites More sharing options...
downeastnc Posted December 27, 2011 Share Posted December 27, 2011 Man, we got the skeptic starting this thread...mojo is going to be off the charts! Let's see if the 18z has any changes for us. Well if there is one thing we can gaurantee to for sure happen the next few days it will be for the models to change on timing, LP track etc..heck it wouldnt surprise me to see the models drop it althogether a few runs..be nice to see the GFS go ahead and start getting in line with the Euro. One thing is for sure WeatherNC and Lookout will have their hands full by Sat if this thing is still being forecast to hit..... Link to comment Share on other sites More sharing options...
Poimen Posted December 27, 2011 Share Posted December 27, 2011 If I could choose ONLY one index for a big southeast snow it would be a +PNA. Link to comment Share on other sites More sharing options...
MillzPirate Posted December 27, 2011 Share Posted December 27, 2011 really wish theyd all latch on tonight so it could be like last years Xmas snow where we all tracked in anticipation for days and days Link to comment Share on other sites More sharing options...
NCSNOW Posted December 27, 2011 Share Posted December 27, 2011 Through hr 78 and 18z not quite as flat/zonal as it was at 12z. So far hasn't changed it's tune much. See what t does out west the next few frames. Link to comment Share on other sites More sharing options...
burgertime Posted December 27, 2011 Share Posted December 27, 2011 So far @120 18z is looking more like 12z GFS...nothing like Euro. Link to comment Share on other sites More sharing options...
franklin NCwx Posted December 27, 2011 Share Posted December 27, 2011 Gfs faster and flatter. Link to comment Share on other sites More sharing options...
RaleighWx Posted December 27, 2011 Share Posted December 27, 2011 Main difference seems to be how the models handle a couple of s/w in the eastern Pacific day 3/4 the Euro phases two together and forms a strong trough which pokes up a strong ridge over western Canada and slows and forces the important s/w to amplify around day 4/5. The gfs keeps them separate and allows a more progressive flatter solution. AKA likely no storm this run. Link to comment Share on other sites More sharing options...
burgertime Posted December 27, 2011 Share Posted December 27, 2011 Main difference seems to be how the models handle a couple of s/w in the eastern Pacific day 3/4 the Euro phases two together and forms a strong trough which pokes up a strong ridge over western Canada and slows and forces the important s/w to amplify around day 4/5. The gfs keeps them separate and allows a more progressive flatter solution. AKA likely no storm this run. So it looks like we'll be waiting and watching until around Saturday. FWIW doesn't the 18z run off of 12z data? So it probably would handle those pieces of energy the same? Link to comment Share on other sites More sharing options...
Poimen Posted December 27, 2011 Share Posted December 27, 2011 Link to comment Share on other sites More sharing options...
strongwxnc Posted December 27, 2011 Share Posted December 27, 2011 Good look to it. Link to comment Share on other sites More sharing options...
MillzPirate Posted December 27, 2011 Share Posted December 27, 2011 why does DT even post such things? Just sparks a weenie feeding frenzie Link to comment Share on other sites More sharing options...
WeatherNC Posted December 27, 2011 Share Posted December 27, 2011 12z ECMWF ens mean, 144 & 168 hrs, nowhere near as extreme compared to the op, but much different than the GFS, given run-to-run continuity, a safe bet for the HPC at this range. Deep trough, 540dm heights clipping KY @ day 6, 534dm heights splitting NC day 7, likely a surface reflection in there, possible KU event for the 95 corridor taking shape 1/3. Still a ways out, but given the run-to-run ens mean support from the EC, odds are there is going to be a storm in the period, general picture still a couple days out. Link to comment Share on other sites More sharing options...
Poimen Posted December 27, 2011 Share Posted December 27, 2011 why does DT even post such things? Just sparks a weenie feeding frenzie I'm not sure, other than DT is a bit of a weenie himself, I suppose. Link to comment Share on other sites More sharing options...
Solak Posted December 27, 2011 Share Posted December 27, 2011 Local radio WQDR-Raleigh (Accu affiliated) just tossed out the 'S' word for Tuesday. Link to comment Share on other sites More sharing options...
burgertime Posted December 27, 2011 Share Posted December 27, 2011 18z is a borefest. Nothing to see here if you were hoping for a storm....well I take that back at 276 it looks like we have a HECS fantasy storm for Central and WNC. Link to comment Share on other sites More sharing options...
MillzPirate Posted December 27, 2011 Share Posted December 27, 2011 leave it to the goofus to show the Euro solution a week later... shows almost exact thing for 1/9 instead of 1/3 Link to comment Share on other sites More sharing options...
socar2001 Posted December 27, 2011 Share Posted December 27, 2011 If the euro were to verify, what days would it affect the central carolinas. I am flying from orlando to charlotte to florence january 3rd. Link to comment Share on other sites More sharing options...
Isopycnic Posted December 27, 2011 Share Posted December 27, 2011 ALEET ALEET! CONDITION delTACO!11 Link to comment Share on other sites More sharing options...
Poimen Posted December 27, 2011 Share Posted December 27, 2011 ALEET ALEET! CONDITION delTACO!11 now that's funny right there! lolz! Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 27, 2011 Share Posted December 27, 2011 I think the 18z shows the potential that the pattern holds depending on how each piece of energy is left separated or phased. The way those troughs drop into the East, it doesn't take much imagination to picture a storm riding out of the GOM on one of those frontal boundaries. Link to comment Share on other sites More sharing options...
FallsLake Posted December 27, 2011 Share Posted December 27, 2011 leave it to the goofus to show the Euro solution a week later... shows almost exact thing for 1/9 instead of 1/3 We can be ultimate weenies and hope the euro is right for the 3rd and the GFS is right for the 9th. Link to comment Share on other sites More sharing options...
burgertime Posted December 27, 2011 Share Posted December 27, 2011 ALEET ALEET! CONDITION delTACO!11 lulz you slopeheed. Link to comment Share on other sites More sharing options...
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