Mitchel Volk Posted November 3, 2012 Share Posted November 3, 2012 Looks like the ECMWF and GFS are predicting a moderate size Nor-Easter on Wednesday. A strong pressure gradient. excellent upper level support, lots of moisture and winds gusting to 40mph or so. This is the last thing the mid Atlantic needs. Another phase up as the NAO stays negative, so I am sure that this is going to happen. Link to comment Share on other sites More sharing options...
Cheeznado Posted November 3, 2012 Share Posted November 3, 2012 The NAM begs to differ...... Link to comment Share on other sites More sharing options...
Mitchel Volk Posted November 3, 2012 Author Share Posted November 3, 2012 The NAM is useless after 60 hours most of the time. Especially when the ECMWF and GFS are is reasonable agreement. Link to comment Share on other sites More sharing options...
Cheeznado Posted November 3, 2012 Share Posted November 3, 2012 I realize that, but it trended in the wrong direction. Just a small sliver of doubt being injected into the scenario. Link to comment Share on other sites More sharing options...
WeatherNC Posted November 3, 2012 Share Posted November 3, 2012 This is from the 12z Big 3 ens means at 120hrs, EC, GGEMm and GFS respectively, H5 anoms... http://raleighwx.americanwx.com/models/ecmwfens/12zECMWFENS500mbHeightAnomalyNA120.gif http://raleighwx.americanwx.com/models/cmcensemble/12zGGEMEnsembles500mbHeightAnomalyNA120.gif http://raleighwx.americanwx.com/models/gfsensemble/12zgfsensembles500mbHeightAnomalyNA120.gif On the iPad, can't link images directly, sorry. Going to have to use the right click, summation, sig EC storm is a go. ECMWF op and ens leading the way no surprise. Link to comment Share on other sites More sharing options...
andyhb Posted November 3, 2012 Share Posted November 3, 2012 That is a pretty strong negative height anomaly across the ensembles for a conventional nor'easter. Link to comment Share on other sites More sharing options...
Cheeznado Posted November 3, 2012 Share Posted November 3, 2012 Wow, look at the latest GGEM...I do not think the folks in New England (outside of geeks) want to see that. The GFS has a 1 foot snow storm in western New England. Euro also a slow moving system with lots of precip, but warmer. Link to comment Share on other sites More sharing options...
andyhb Posted November 3, 2012 Share Posted November 3, 2012 Wow, look at the latest GGEM...I do not think the folks in New England (outside of geeks) want to see that. The GFS has a 1 foot snow storm in western New England. Euro also a slow moving system with lots of precip, but warmer. And a strong LLJ feeding right into the Jersey Shore/LI Sound. Link to comment Share on other sites More sharing options...
MJO812 Posted November 3, 2012 Share Posted November 3, 2012 6z GFS shows a 978 low off the coast. Seems like the models are trending stronger. Link to comment Share on other sites More sharing options...
dan11295 Posted November 3, 2012 Share Posted November 3, 2012 Even a moderate storm with fetch into NJ/LI would be bad right now. Virtually all the protection is gone and coastline is very vulnerable to additional erosion at the moment. Link to comment Share on other sites More sharing options...
Srain Posted November 3, 2012 Share Posted November 3, 2012 PRELIMINARY EXTENDED FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD 956 AM EDT SAT NOV 03 2012 VALID 12Z WED NOV 07 2012 - 12Z SAT NOV 10 2012 ...CHANCES INCREASING FOR A SLOW-MOVING NOR'EASTER ALONG THE ATLANTIC COAST... ...ARCTIC OUTBREAK WITH UPSLOPE SNOWS SLATED FOR THE NORTHERN HIGH PLAINS... USED AN EVEN BLEND OF THE 00Z/03 DETERMINISTIC ECMWF AND EUROPEAN CENTRE ENSEMBLE MEAN TO UPDATE THE PRELIMINARY FRONTS AND PRESSURES FOR DAYS 3 THROUGH 7. THE GLOBAL NUMERICAL GUIDANCE IS CLUSTERING MORE TIGHTLY ALONG THE ATLANTIC SEABOARD, INDICATING THAT THE VOID IN THE ATMOSPHERE LEFT BEHIND SANDY AND ITS POST-TROPICAL VORTEX WILL BE REENERGIZED NEXT WEEK- THIS TIME IN THE FORM OF A MORE TYPICAL NOR'EASTER. THE BLOCKING PATTERN- WHERE THE NORMAL WEST-TO-EAST FLOW BREAKS UP INTO QUASISTATIONARY CYCLONIC AND ANTICYCLONIC CIRCULATIONS- IS RESPONSIBLE FOR THE EXTENDED PERIOD OF UNSETTLED WEATHER ACROSS CENTRAL NORTH AMERICA AND THE ADJACENT OCEANS. AS A WHOLE, THE EUROPEAN CENTRE GUIDANCE, PARTICULARLY THE ENSEMBLE PRODUCTS, WAS RELIABLE WITH THE HANDLING OF SANDY AND ITS INTERACTION WITH THE COLD VORTEX THAT DUG INTO THE SOUTHEASTERN UNITED STATES, SO HAVE LEANED TOWARD IT FOR THIS SEPARATE, BUT NOT ENTIRELY UNRELATED EVENT. ALL THE MODELS, INCLUDING THE GFS, GEM GLOBAL, AND UKMET, INDICATE A LARGE CYCLONE OVER THE WESTERN ATLANTIC THIS PERIOD, WITH THE DIFFERENCES IN WHERE AND HOW DEEP THE SYSTEM MATERIALIZES. THE BIGGEST DIFFERENCE BETWEEN THIS UPCOMING EVENT AND SANDY'S INCORPORATION INTO THE BLOCKING PATTERN WILL BE UPSTREAM OVER THE WESTERN UNITED STATES, WHERE AN ARCTIC HIGH IS EXPECTED TO BUILD INTO THE NORTHERN ROCKIES AND ADJACENT HIGH PLAINS DAYS 6 AND 7. WITH A POWERFUL PACIFIC JET IMPINGING ON THE WEST, THE STAGE WILL BE SET FOR SNOWS BOTH IN THE MOUNTAINS OF THE COASTAL STATES AND IN THE NORTHERN ROCKIES AND UPSLOPE AREAS OF MONTANA. Link to comment Share on other sites More sharing options...
Amped Posted November 3, 2012 Share Posted November 3, 2012 Model agreement was much better with Sandy compared to this. Link to comment Share on other sites More sharing options...
Srain Posted November 3, 2012 Share Posted November 3, 2012 Link to comment Share on other sites More sharing options...
Herb@MAWS Posted November 3, 2012 Share Posted November 3, 2012 Hmmmm ...... EXTENDED FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD 137 PM EDT SAT NOV 03 2012 VALID 12Z TUE NOV 06 2012 - 12Z SAT NOV 10 2012 ...CHANCES INCREASING FOR A SLOW-MOVING NOR'EASTER ALONG THE ATLANTIC COAST... ...ARCTIC OUTBREAK WITH UPSLOPE SNOWS SLATED FOR THE NORTHERN HIGH PLAINS... USED AN EVEN BLEND OF THE 00Z/03 DETERMINISTIC ECMWF AND EUROPEAN CENTRE ENSEMBLE MEAN FOR THE FRONTS AND PRESSURES FOR DAYS 3 THROUGH 7. THE GLOBAL NUMERICAL GUIDANCE IS CLUSTERING MORE TIGHTLY ALONG THE ATLANTIC SEABOARD, INDICATING THAT THE VOID IN THE ATMOSPHERE LEFT BEHIND SANDY AND ITS POST-TROPICAL VORTEX WILL BE REENERGIZED NEXT WEEK- THIS TIME IN THE FORM OF A MORE TYPICAL NOR'EASTER. THE BLOCKING PATTERN- WHERE THE NORMAL WEST-TO-EAST FLOW BREAKS UP INTO QUASISTATIONARY CYCLONIC AND ANTICYCLONIC CIRCULATIONS- IS RESPONSIBLE FOR THE EXTENDED PERIOD OF UNSETTLED WEATHER ACROSS CENTRAL NORTH AMERICA AND THE ADJACENT OCEANS. AS A WHOLE, THE EUROPEAN CENTRE GUIDANCE, PARTICULARLY THE ENSEMBLE PRODUCTS, WAS RELIABLE WITH THE HANDLING OF SANDY AND ITS INTERACTION WITH THE COLD VORTEX THAT DUG INTO THE SOUTHEASTERN UNITED STATES, SO HAVE LEANED TOWARD IT FOR THIS SEPARATE, BUT NOT ENTIRELY UNRELATED EVENT. ALL THE MODELS, INCLUDING THE GFS, GEM GLOBAL, AND UKMET, INDICATE A LARGE CYCLONE OVER THE WESTERN ATLANTIC THIS PERIOD, WITH THE DIFFERENCES IN WHERE AND HOW DEEP THE SYSTEM MATERIALIZES. IF THE STORM TRACKS CLOSE ENOUGH TO THE COAST, IT APPEARS THE AIRMASS MAY BE SUFFICIENTLY COLD FOR SNOW TO FALL, EVEN IN THE LOWER ELEVATIONS. THIS TYPE OF SYNOPTIC DETAIL WILL HAVE TO BE REFINED WITH FUTURE MODEL RUNS. THE BIGGEST DIFFERENCE BETWEEN THIS UPCOMING EVENT AND SANDY'S INCORPORATION INTO THE BLOCKING PATTERN WILL BE UPSTREAM OVER THE WESTERN UNITED STATES, WHERE AN ARCTIC HIGH IS EXPECTED TO BUILD INTO THE NORTHERN ROCKIES AND ADJACENT HIGH PLAINS DAYS 6 AND 7. WITH A POWERFUL PACIFIC JET IMPINGING ON THE WEST, THE STAGE WILL BE SET FOR SNOWS BOTH IN THE MOUNTAINS OF THE COASTAL STATES AND IN THE NORTHERN ROCKIES AND UPSLOPE AREAS OF MONTANA. CISCO Link to comment Share on other sites More sharing options...
Srain Posted November 3, 2012 Share Posted November 3, 2012 Link to comment Share on other sites More sharing options...
dan88 Posted November 3, 2012 Share Posted November 3, 2012 At the very least, there is a signal for a relatively low pressure with the potential system GGEM - 962mb at 118 hours GFS - 981mb at 105hours Euro - <980mb at 117 hours Link to comment Share on other sites More sharing options...
Amped Posted November 3, 2012 Share Posted November 3, 2012 Just a perfectly timed phase on the GGEM and the Euro. Where's this setup a month from now? Link to comment Share on other sites More sharing options...
thewxmann Posted November 4, 2012 Share Posted November 4, 2012 At least there's not another hurricane coming up from the Caribbean, lol. That would be absolutely nuts. Link to comment Share on other sites More sharing options...
Sunny and Warm Posted November 4, 2012 Share Posted November 4, 2012 Nice discussion on the potential nor'easter in Mount Holly's disco this morning. Goes into the differences in the model solutions and why they've selected the blend they did: LONG TERM /MONDAY THROUGH SATURDAY/... CHANGES MADE TO THE BUSINESS PART OF THE LONG TERM WERE SUBTLE. THEY REFLECT A VERY MINOR SLOWING DOWN OF THE SYSTEM FROM CONTINUITY. IF WE TOOK THE NAM SERIOUSLY WITH ITS LATEST RUN, WE WOULD BE RATHER PLEASED WITH THE PROSPECT OF ONLY A 1002 MB LOW ABOUT 250 MILES OFF VIRGINIA BEACH AT 12Z WEDNESDAY. IT IS QUITE THE ODD MAN OUT WITH THIS SOLUTION. OF THE NOR`EASTER TRACKS OF THE FOUR REMAINING MAJOR MODELS, ALL ARE WITHIN ABOUT 75 MILES OF EACH OTHER REGARDING DISTANCE FROM OUR COASTLINE DURING PASSAGE (FOR THIS RUN, OF COURSE). THE GFS IS THE FASTEST AND THE ECMWF THE SLOWEST. WE TOOK A FAIRLY CLOSE LOOK AT THE GFS (THE FASTEST MODEL) OVER ITS 03/12Z, 03/18Z AND 04/00Z RUNS AND THE ECMWF (THE SLOWEST MODEL) OVER ITS 03/00Z, 03/12Z AND 04/00Z RUNS. THE GFS HAS BEEN DOING A DRUNKARD`S WALK TOWARD WHAT WE CAN HOPE IS THE RIGHT SOLUTION. IT SHIFTED MODESTLY WEST FROM 03/12Z TO 03/18Z, AND THEN IT SHIFTED SIGNIFICANTLY EAST FROM 03/18Z TO 04/00Z. REGARDING ITS SPEED, IT IS SLOWER IN ITS 04/00Z APPROACH AND FASTER IN ITS 04/00Z ESCAPE FROM THE WATERS OFF DELAWARE AND NEW JERSEY THAN THE PREVIOUS TWO RUNS. THE 04/00Z ECMWF IS SUBTLY FURTHER EAST IN ITS APPROACH, AND THEN IT LIES WITHIN THE RELATIVELY NARROW RANGE OF ITS TWO PREVIOUS RUNS. THE SAME IS TRUE FOR ITS TIMING IF YOU SUBSTITUTE "SUBTLY SLOWER" (THAT`S NOT A MIDNIGHT SHIFT MISTAKE) FOR "SUBTLY FURTHER EAST." THE 04/00Z CANADIAN TRACK LIES WITHIN THE RANGE ESTABLISHED BY THE GFS AND ECMWF, FAVORING THE FASTER GFS IN ITS APPROACH AND THEN FAVORING THE ECMWF. IT IS, HOPEFULLY, AN OUTLIER REGARDING THE DEPTH OF THE LOW. IT DEEPENS IT TO 964 MB WHILE OFF NEW JERSEY. WHEN WE PLOT THE MEAN TRACKS FROM THE LAST THREE RUNS OF THE GFS AND THE ECMWF, WE FIND THAT THE 00Z UKMET IS A VERY CLOSE APPROXIMATION. IT WOULD PUT THE SYSTEM ABOUT 75 MILES OFF HAT AT 12Z WEDNESDAY, ABOUT 175 MILES OFF WAL AT 00Z THURSDAY, ABOUT 100 MILES OFF ACY AT 12Z THURSDAY, AND NEAR MVY AT 00Z FRIDAY. DISCARDING THE CENTRAL PRESSURES OF THE CANADIAN AND THE NAM, WE WOULD BE LOOKING AT ABOUT A 980 MB LOW OFF OUR COAST. THEREFORE, USING THE UKMET TIMING AND TRACK AS A BASIS, WE MADE SOME SUBTLE CHANGES TO THE FORECAST. WE ARE VERY MUCH AWARE THAT TOO MUCH RELIANCE ON WHAT WE ARE SEEING NOW COULD LEAD US TO HARM RATHER THAN IMPROVE THE FORECAST, WHICH IS WHY WE MAINTAIN A GOOD DEAL OF CONTINUITY THIS FAR OUT WHILE NUDGING THINGS IN THE INDICATED WAY. THE STACKED LOW IS GOING TO BE PUSHING AGAINST A STUBBORN AND STACKED HIGH TO THE NORTH (ALMOST A REX BLOCK ORIENTATION). THIS WOULD TEND TO FAVOR A SLOWER SOLUTION, BUT IT ALSO FAVORS A STRONG GRADIENT THAT KEEPS STRONG WINDS IN PLAY. THAT IN TURN KEEPS TIDAL FLOODING IN PLAY, EVEN THOUGH WE NEED ALMOST TWO FEET TO START MINOR TIDAL FLOODING AND ALMOST THREE FEET TO TRIGGER A COASTAL FLOOD WARNING. HEAVIER PRECIPITATION WOULD FAVOR COASTAL REGIONS, BUT SOME SNOW STILL IS A REAL POSSIBILITY NORTHWEST GIVEN THE PRESENT TRACK. THE THINGS THAT MAY NOT FAVOR A LOT OF SNOW ARE THE TIME OF YEAR, THE TEMPERATURE OF THE OCEAN WATERS AND THE FACT THAT THE HIGH TO THE NORTH IS NOT THAT COLD. HIGH PRESSURE PRECEDES AND FOLLOWS THIS EVENT. TEMPERATURES THROUGH MOST OF THE PERIOD ARE FORECAST TO BE BELOW NORMAL. Link to comment Share on other sites More sharing options...
Ginx snewx Posted November 4, 2012 Share Posted November 4, 2012 Surge values in the damage areas are initially projected to be 2-4ft http://www.nws.noaa.gov/mdl/etsurge/index.php?page=text&list=ec Link to comment Share on other sites More sharing options...
am19psu Posted November 5, 2012 Share Posted November 5, 2012 The GFS and Euro continue to be at odds, with the Euro showing the heaviest snow axis from RIC-DCA-MDT and the GFS barely showing anything outside the Poconos and the Berkshires. Obviously, much of the difference comes with the Euro being 2-4C colder in the lower levels than the GFS - though the GFS track is east of the Euro, as well. These differences obviously have something to do with either initialization schemes or model physics, since the GEFS is close to the op GFS and the Euro ENS is close to the op Euro. Then throw in the UKMET, which is way east with the low and you've got a very low confidence solution for a 2-3 day forecast. My gut would be to weigh the models with 2 parts GFS, 1 part Euro. I just don't see where the cold air in the Euro is coming from, but you have to weigh it somewhat given the overall strength of the model. My guess would be heaviest snow in the Poconos and Berkshires - maybe up to a foot. I-95 stays mostly rain, but the western suburbs would pick up 2-4", especially with latitude. Best non-elevation snows go from MDT-AVP-ORH. That forecast couldn't be lower confidence though. Link to comment Share on other sites More sharing options...
Mallow Posted November 5, 2012 Share Posted November 5, 2012 Euro all the way, baby. Link to comment Share on other sites More sharing options...
am19psu Posted November 5, 2012 Share Posted November 5, 2012 Models really came together at 12z, thankfully. Hopefully, that continues through the overnight runs and we can start getting into details of who is getting def bands, etc. Here is my first guess. Link to comment Share on other sites More sharing options...
Ed Lizard Posted November 5, 2012 Share Posted November 5, 2012 Winds near hurricane force near the base of the inversion, I think Long Island may get a gust or two 50 to 60 knots, Link to comment Share on other sites More sharing options...
Coach McGuirk Posted November 6, 2012 Share Posted November 6, 2012 Models really came together at 12z, thankfully. Hopefully, that continues through the overnight runs and we can start getting into details of who is getting def bands, etc. Here is my first guess. Nice. NO TAKE BACKS! Link to comment Share on other sites More sharing options...
am19psu Posted November 6, 2012 Share Posted November 6, 2012 I'm still going to ride with it, at least through 12z. I'm not going to try to get every single detail of the storm right, either. This is a macro forecast, not an IMBY forecast. Link to comment Share on other sites More sharing options...
phil882 Posted November 6, 2012 Share Posted November 6, 2012 I'm still going to ride with it, at least through 12z. I'm not going to try to get every single detail of the storm right, either. This is a macro forecast, not an IMBY forecast. Yea, there is still a lot of waffling back and forth with the deterministic model solutions. The ensembles from both the GFES and ECMWF still show there is plenty of potential for a moderate snowstorm for the outlined areas on Adam's map. A good illustration of this is the noticeable amount of "waffling" that is taking place with the deterministic GFS solutions. Looking at the dprog/dt of the 500 hPa model solutions at 00z 8 Nov show that the model has not locked in on a specific solution. The degree of phasing is still adjusting from run to run, and it appears that the "fully phased" solutions we saw 2-3 days ago are not looking as likely, but its still possible a later phase will occur. http://www.atmos.albany.edu/student/kgriffin/maps/dprog/F048/500vort/namer/500vort_namer_dprog.html Link to comment Share on other sites More sharing options...
am19psu Posted November 6, 2012 Share Posted November 6, 2012 Models really came together at 12z, thankfully. Hopefully, that continues through the overnight runs and we can start getting into details of who is getting def bands, etc. Here is my first guess. Today's guess: Link to comment Share on other sites More sharing options...
bobbutts Posted November 6, 2012 Share Posted November 6, 2012 HPC track Link to comment Share on other sites More sharing options...
jconsor Posted November 7, 2012 Share Posted November 7, 2012 I'd bet on the nor'easter getting at least 10 mb deeper than HPC forecasts - i.e. around 980 mb. HPC track Link to comment Share on other sites More sharing options...
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