winterymix Posted March 3, 2013 Share Posted March 3, 2013 No one has mentioned yet the glaring differences with the Canadian-NW Atlantic setup. The ECMWF is trying to incorporate another northern wave, which is what the actual storm originally splits from. It has no interaction with the NW Atlantic low either. The GFS does NOT incorporate this Canadian Wave and interacts with the NW Atlantic Low. So, to simply say that the ECMWF has more blocking is actually false. The ECMWF actually lifts the NW Atlantic Low out faster. This is what I meant last week in the Philly Subforum when I said "the northern stream is littered with waves." A lot of players. If the influence of this continues to get incorporated, I could actually see a SE trend in the next 48 hrs. The Intermountain ridge over the Rockies is much more organized at 300 mg on the GFS, with the Euro the ridge is more sloppy and sprawling. Link to comment Share on other sites More sharing options...
yoda Posted March 3, 2013 Share Posted March 3, 2013 Care to share? http://www.hpc.ncep.noaa.gov/pwpf/wwd_accum_probs.php?fpd=24&ptype=snow&amt=1&day=3&ftype=probabilities Link to comment Share on other sites More sharing options...
winterymix Posted March 3, 2013 Share Posted March 3, 2013 how can you use the GFS's 300 mb pattern to make an interpretation of the Euro? Go to wunderground model maps and compare GFS vs. EURO Link to comment Share on other sites More sharing options...
Ian Posted March 3, 2013 Share Posted March 3, 2013 http://www.hpc.ncep.noaa.gov/pwpf/wwd_accum_probs.php?fpd=24&ptype=snow&amt=1&day=3&ftype=probabilities Computer generated Link to comment Share on other sites More sharing options...
CoastalWx Posted March 3, 2013 Share Posted March 3, 2013 HM, are you talking about the s/w at hr 96 on the euro? I think at the point the damage is done and it doesn't matter much. Link to comment Share on other sites More sharing options...
swimmatte Posted March 3, 2013 Share Posted March 3, 2013 Jim Cantore has been dispatched....... Link to comment Share on other sites More sharing options...
EasternUSWX Posted March 3, 2013 Share Posted March 3, 2013 Sure.. Link to comment Share on other sites More sharing options...
asdfk Posted March 3, 2013 Share Posted March 3, 2013 Those HPC probabilities are determined by the GFS. Link to comment Share on other sites More sharing options...
winterymix Posted March 3, 2013 Share Posted March 3, 2013 These processes are dynamical, i.e. over time. The problem is you have yet another northern stream s/w on the ECMWF showing up (what the storm originally splits from and no this isn't the solution from last week where phasing was trying to happen). As this begins to dive SE underneath the block, which the GFS does not do, it adds forward momentum to the southern wave...pushing it SE under the blocking even more. Well, this is the sort of unbiased analysis we need. HM, I think you are discussing an elongated vorticity complex that is vertically oriented just a bit north of the Great Lakes. It appears muted and weak on the GFS and much more intense on the EURO. How soon will we know which is correct? Link to comment Share on other sites More sharing options...
WxMan1 Posted March 3, 2013 Share Posted March 3, 2013 HPC Prob snow graphics are pretty gung-ho for our area in their afternoon update ...and as they should be. Keep in mind the autoensemble probs that come out first are not the final 10/40/70 probs of at least 4/8/12" of snow, and are 3/4 weighted toward the SREF (ensemble of 21 SREF members and 7 operational runs). Bottom line is these are very SREF-heavy. Link to comment Share on other sites More sharing options...
HM Posted March 3, 2013 Share Posted March 3, 2013 HM, are you talking about the s/w at hr 96 on the euro? I think at the point the damage is done and it doesn't matter much. I don't think so. Its influence of adding momentum on the backside is going on long before and it prevents it from going more negatively tilted along the coast. I know it is subtle but it makes a difference for DC-PHL corridor. The differences between the GFS and ECMWF with the Atlantic Low right now are also ridiculous. Link to comment Share on other sites More sharing options...
EasternUSWX Posted March 3, 2013 Share Posted March 3, 2013 Those HPC probabilities are determined by the GFS. Can't be. GFS doesn't give southern PA enough GFS for anywhere close to 18" Link to comment Share on other sites More sharing options...
lester Posted March 3, 2013 Share Posted March 3, 2013 Jim Cantore has been dispatched....... Hopefully it's not in DC, then it'll really go south and east and miss us Link to comment Share on other sites More sharing options...
swimmatte Posted March 3, 2013 Share Posted March 3, 2013 Those HPC probabilities are determined by the GFS. We go over this every time...... it's computer generated based on SREF's plus the rest of the model runs. Link to comment Share on other sites More sharing options...
Ian Posted March 3, 2013 Share Posted March 3, 2013 Jim Cantore has been dispatched....... Where? He mentioned DC last night. Hopefully he means west of town for his sake. Last place id go at this pt is the Mall. Link to comment Share on other sites More sharing options...
BristowWx Posted March 3, 2013 Share Posted March 3, 2013 Jim Cantore has been dispatched....... Oh no...where is he headed? Downtown DC? Link to comment Share on other sites More sharing options...
winter_warlock Posted March 3, 2013 Share Posted March 3, 2013 I don't think so. Its influence of adding momentum on the backside is going on long before and it prevents it from going more negatively tilted along the coast. I know it is subtle but it makes a difference for DC-PHL corridor. The differences between the GFS and ECMWF with the Atlantic Low right now are also ridiculous. SO basically its who do you trust, gfs or euro Link to comment Share on other sites More sharing options...
swimmatte Posted March 3, 2013 Share Posted March 3, 2013 That graphic uses the following: 21 NCEP Short-Range Ensemble Forecast (SREF) members 1 NCEP North American Mesoscale (NAM) 12Z (day) or 00Z (night) operational run1 NCEP Global Forecast System (GFS) 12Z (day) or 00Z (night) operational run1 European Center for Medium-Range Weather Forecasts (ECMWF) latest operational run1 Canadian Model (CMC) latest operational run1 ECMWF latest ensemble mean1 NCEP Global Ensemble Forecast System (GEFS) latest ensemble mean (6-h SLRs)1 GEFS latest ensemble mean (24-h mean SLR) Link to comment Share on other sites More sharing options...
WxMan1 Posted March 3, 2013 Share Posted March 3, 2013 Those HPC probabilities are determined by the GFS. Incorrect. GFS is one out of the 28 members. http://www.hpc.ncep.noaa.gov/pwpf/about_pwpf_products.shtml Link to comment Share on other sites More sharing options...
HM Posted March 3, 2013 Share Posted March 3, 2013 Well, this is the sort of unbiased analysis we need. HM, I think you are discussing an elongated vorticity complex that is vertically oriented just a bit north of the Great Lakes. It appears muted and weak on the GFS and much more intense on the EURO. How soon will we know which is correct? I'm hoping the EURO ensembles shed some light. I think if the ECMWF keeps this up on tonight's run and we see the other data start trending that way, then I would keep expectations in check on the northern edge of this thing. The good news is that these situations are so bad in the modeling (waves underneath blocking...subtle features etc.) that this can easily be taken away on the 00z runs. Link to comment Share on other sites More sharing options...
CoastalWx Posted March 3, 2013 Share Posted March 3, 2013 I don't think so. Its influence of adding momentum on the backside is going on long before and it prevents it from going more negatively tilted along the coast. I know it is subtle but it makes a difference for DC-PHL corridor. The differences between the GFS and ECMWF with the Atlantic Low right now are also ridiculous. I don't know..looks pretty far separated still when the ULL exits off of HSE. I do agree right after it helps give it a boot..but I'm not sure if it's that big of a deal quite yet. Link to comment Share on other sites More sharing options...
mitchnick Posted March 3, 2013 Share Posted March 3, 2013 87 hr from the new SREF looks the same as last run http://mag.ncep.noaa.gov/Image.php?model=sref&area=namer¶m=500_vort_ht&cycle=15ℑ=sref%2F15%2Fsref_namer_087_500_vort_ht.gif Link to comment Share on other sites More sharing options...
CoastalWx Posted March 3, 2013 Share Posted March 3, 2013 Regardless, the euro op just seems to occlude too fast which can happen...it did it in the Feb blizzard we had as well. Link to comment Share on other sites More sharing options...
mitchnick Posted March 3, 2013 Share Posted March 3, 2013 87 hr from the new SREF looks the same as last run http://mag.ncep.noaa.gov/Image.php?model=sref&area=namer¶m=500_vort_ht&cycle=15ℑ=sref%2F15%2Fsref_namer_087_500_vort_ht.gif better actually 24 hr precip at 87 hrs http://mag.ncep.noaa.gov/Image.php?model=sref&area=namer¶m=precip_p24&cycle=15ℑ=sref%2F15%2Fsref_namer_087_precip_p24.gif Link to comment Share on other sites More sharing options...
HM Posted March 3, 2013 Share Posted March 3, 2013 The ECMWF doesn't have a stretched out Atlantic Low setup at Day 3 where the GFS does. This is having an effect on negatively titled timing too. These subtle differences can easily change in the coming days. Link to comment Share on other sites More sharing options...
MN Transplant Posted March 3, 2013 Share Posted March 3, 2013 I don't think so. Its influence of adding momentum on the backside is going on long before and it prevents it from going more negatively tilted along the coast. I know it is subtle but it makes a difference for DC-PHL corridor. The differences between the GFS and ECMWF with the Atlantic Low right now are also ridiculous. Very good point. The Nova Scotia low in the GFS gets dismantled between our storm and the big low dropping from E of Greenland. On the ECMWF it is still acting as its own entity longer, likely affecting the path of our low. Link to comment Share on other sites More sharing options...
EasternUSWX Posted March 3, 2013 Share Posted March 3, 2013 SREF still not budging. If anything it is north this run. Link to comment Share on other sites More sharing options...
PhineasC Posted March 3, 2013 Share Posted March 3, 2013 better actually 24 hr precip at 87 hrs http://mag.ncep.noaa.gov/Image.php?model=sref&area=namer¶m=precip_p24&cycle=15ℑ=sref%2F15%2Fsref_namer_087_precip_p24.gif The SREFs are going total ape mode now. Link to comment Share on other sites More sharing options...
NOVAForecaster Posted March 3, 2013 Share Posted March 3, 2013 I think this is one of the most important maps from the HPC. >50% chance of more than 8" for the northwest suburbs, and 40% chance downtown and just southeast. Th think the number DC hould be focusing on at this point for possible totals is 6"-10". Link to comment Share on other sites More sharing options...
mitchnick Posted March 3, 2013 Share Posted March 3, 2013 The SREFs are going total ape mode now. I saw that 1' qpf during the 24 hrs ending 87 hrs and nearly needed a nitro Link to comment Share on other sites More sharing options...
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