am19psu Posted January 30, 2012 Share Posted January 30, 2012 All winter, I've been about 2-4 days too quick in making adjustments to the longwave pattern. The upcoming cold period seems to be similar. Instead of starting around the 5th, which was the original forecast from 19th, it looks like it will be closer to the 8th. In any case, there appears to be a 7-10 day window of winter on the way through the 15th-18th (leaning later based on my biases from most of the season). Beyond that period, tropical forcing looks to head back to the Maritime Continent, and we'll be back in the warm phases of the MJO. At least the last 1/3 of February should see above to maybe much above normal temperature departures here in Philly. Link to comment Share on other sites More sharing options...
Rainshadow Posted January 30, 2012 Share Posted January 30, 2012 All winter, I've been about 2-4 days too quick in making adjustments to the longwave pattern. The upcoming cold period seems to be similar. Instead of starting around the 5th, which was the original forecast from 19th, it looks like it will be closer to the 8th. In any case, there appears to be a 7-10 day window of winter on the way through the 15th-18th (leaning later based on my biases from most of the season). Beyond that period, tropical forcing looks to head back to the Maritime Continent, and we'll be back in the warm phases of the MJO. At least the last 1/3 of February should see above to maybe much above normal temperature departures here in Philly. Whoops I was going to take a WAG that week 3 on the Euro weeklies was going to trend colder because the northern half of noam flow still looked too blocky. It is interesting (first those GFS MJO outlooks ) on how the MJO met less resistance last winter getting to the dateline with a stronger thermally speaking nina than it has this winter. Link to comment Share on other sites More sharing options...
am19psu Posted January 30, 2012 Share Posted January 30, 2012 Whoops I was going to take a WAG that week 3 on the Euro weeklies was going to trend colder because the northern half of noam flow still looked too blocky. It is interesting (first those GFS MJO outlooks ) on how the MJO met less resistance last winter getting to the dateline with a stronger thermally speaking nina than it has this winter. I'm not really basing my forecast on the weeklies... in fact, verbatim, my forecast is a lot colder than the weeklies in Week 3. Week 2 only goes to Feb 12, and I'm below normal for at least the first half of Week 3, if not most of Week 3 (like I said, I've been too quick to rush these "pattern changes"). I honestly have no idea how or why the MJO propagates as far as it does from a seasonal perspective. I'm sure some it has to do with the QBO and the height of the tropopause. The deeper the troposphere, the more latent heat that can be released, and the stronger the MJO. It has something to do with the trades, too, since stronger easterlies make it harder for the MJO to force convergence at the surface and drive convection. I honestly don't remember what the trades were doing last Dec/Jan near the dateline or what really forces them to be stronger or weaker. This season, though, they've definitely been stronger than normal and that's what has kept the MJO from propagating across the Pacific (at least until this shot). Link to comment Share on other sites More sharing options...
Rainshadow Posted January 30, 2012 Share Posted January 30, 2012 I'm not really basing my forecast on the weeklies... in fact, verbatim, my forecast is a lot colder than the weeklies in Week 3. Week 2 only goes to Feb 12, and I'm below normal for at least the first half of Week 3, if not most of Week 3 (like I said, I've been too quick to rush these "pattern changes"). I honestly have no idea how or why the MJO propagates as far as it does from a seasonal perspective. I'm sure some it has to do with the QBO and the height of the tropopause. The deeper the troposphere, the more latent heat that can be released, and the stronger the MJO. It has something to do with the trades, too, since stronger easterlies make it harder for the MJO to force convergence at the surface and drive convection. I honestly don't remember what the trades were doing last Dec/Jan near the dateline or what really forces them to be stronger or weaker. This season, though, they've definitely been stronger than normal and that's what has kept the MJO from propagating across the Pacific (at least until this shot). Adam, Whoops I didn't mean to infer that you were, was postulating more about the weeklies themselves. It is strange that the higher trades have not caused a greater ssta. I just checked the mei and to date it was stronger last winter than this also. I miss the aussie site outlook, they haven't updated it since last June although other parts of that same page are being updated. http://cawcr.gov.au/staff/mwheeler/maproom/RMM/ At anyrate having to put out a deterministic forecast for thu-sun of this week has increased the level of my personal frustration pretty high. I'm guessing they'll be going through with the dropsonde missions and hopefully add more clarity to the end of this week. Link to comment Share on other sites More sharing options...
am19psu Posted January 30, 2012 Share Posted January 30, 2012 I miss the aussie site outlook, they haven't updated it since last June although other parts of that same page are being updated. http://cawcr.gov.au/...er/maproom/RMM/ Which Aussie site outlook? Have you seen this site? I like it better than just looking at the phase space diagrams. http://cawcr.gov.au/staff/mwheeler/maproom/OLR_modes/ Link to comment Share on other sites More sharing options...
Rainshadow Posted January 30, 2012 Share Posted January 30, 2012 Which Aussie site outlook? Have you seen this site? I like it better than just looking at the phase space diagrams. http://cawcr.gov.au/...room/OLR_modes/ Oh, they moved that part. If you scroll down on the link I posted, the outlooks have not been updated on that page since the end of June. Thanks! Link to comment Share on other sites More sharing options...
Harbourton Posted January 30, 2012 Share Posted January 30, 2012 Interesting blurb from the HPC this morning. USED THE 00Z/30 DETERMINISTIC ECMWF TO UPDATE THE PRELIMINARY FRONTS AND PRESSURES FOR DAYS 3 AND 4...THEN SWITCHED TO THE 00Z/30 ECENS MEAN FOR DAYS 5 THROUGH 7. FORECAST CONFIDENCE DROPS PRECIPITOUSLY AFTER DAY 4...WITH A DIZZYING ARRAY OF MODEL SOLUTIONS FOR THE FLOW ACROSS CENTRAL NORTH AMERICA AT THAT RANGE. THE CULPRIT...A FAMILIAR ONE THIS COLD SEASON...IS A PRONOUNCED SPLIT IN THE JET...WITH THE DOMINANCE OF ONE STREAM VERSUS ANOTHER RENDERING THE SORTING OF INDIVIDUAL SHORTWAVES AND THEIR POTENTIAL INTERACTIONS MOOT. ELECTED TO RELY ON THE ECENS MEAN OVER THE GEFS MEAN FOR THE MOST UNCERTAIN TIME FRAME...WITH A GLIMMER OF HOPE LYING IN THE CROSS-MODEL SUPPORT WITH THAT MEAN FROM THE 00Z/30 DETERMINISTIC GFS. THE ECMWF LOOKED FINE FOR THE FIRST TWO DAYS...CLOSELY CORRELATED WITH THE ECENS MEAN. Link to comment Share on other sites More sharing options...
atownwxwatcher Posted January 30, 2012 Share Posted January 30, 2012 Adam new ECM weeklies colder? Link to comment Share on other sites More sharing options...
am19psu Posted January 30, 2012 Share Posted January 30, 2012 Adam new ECM weeklies colder? Wow. Holy -NAO block on the weeklies. Holds strong from Week 2 through Week 4. I don't have the temp anomalies, only H5 this week, but would be a much more conducive pattern if it verifies. Standby until Thursday to see if this is hiccup or not. Link to comment Share on other sites More sharing options...
am19psu Posted January 30, 2012 Share Posted January 30, 2012 Anyway, Week 2 is a +PNA with an east based -NAO, Week 3 is a -EPO/-NAO, and Week 4 is -PNA/-NAO Link to comment Share on other sites More sharing options...
famartin Posted January 30, 2012 Share Posted January 30, 2012 Anyway, Week 2 is a +PNA with an east based -NAO, Week 3 is a -EPO/-NAO, and Week 4 is -PNA/-NAO Some hope for me at least... Link to comment Share on other sites More sharing options...
Rainshadow Posted January 31, 2012 Share Posted January 31, 2012 Wow. Holy -NAO block on the weeklies. Holds strong from Week 2 through Week 4. I don't have the temp anomalies, only H5 this week, but would be a much more conducive pattern if it verifies. Standby until Thursday to see if this is hiccup or not. Well I missed my calling in life, I can predict which way the weeklies will go. What that has to do with the actual outcome may be slim at best. Link to comment Share on other sites More sharing options...
Rainshadow Posted January 31, 2012 Share Posted January 31, 2012 Joking aside, the NAEFS have been holding steady for a few days with their week 2 outlooks starting on or about 2/5 to 2/12 to be around normal with temps, its only the second stretch this winter I've seen that. The other one was around Mid January. Link to comment Share on other sites More sharing options...
am19psu Posted January 31, 2012 Share Posted January 31, 2012 I'm pretty interested in the disconnect between last night's model runs and some of the longer range guidance. I'm not jumping off the call for cooler/stormier just yet based on the 0z guidance Link to comment Share on other sites More sharing options...
cast4 Posted January 31, 2012 Share Posted January 31, 2012 I'm pretty interested in the disconnect between last night's model runs and some of the longer range guidance. I'm not jumping off the call for cooler/stormier just yet based on the 0z guidance Yeah, when the models show different solutions every run it's hard to put trust in them. 12Z GFS now has the weekend storm as a southern slider FWIW. Link to comment Share on other sites More sharing options...
tombo82685 Posted January 31, 2012 Author Share Posted January 31, 2012 Yeah, when the models show different solutions every run it's hard to put trust in them. 12Z GFS now has the weekend storm as a southern slider FWIW. yea its been trending stronger with the confluence as well as the euro with a slightly -nao for the period. 12z gfs actually dumps 1-3 from dc to central del Link to comment Share on other sites More sharing options...
Harbourton Posted January 31, 2012 Share Posted January 31, 2012 12Z GFS is a disaster right through the end. Hope the Euro weeklies are right otherwise a rockin February is in jepoardy. Link to comment Share on other sites More sharing options...
CoastalWx Posted January 31, 2012 Share Posted January 31, 2012 I'm pretty interested in the disconnect between last night's model runs and some of the longer range guidance. I'm not jumping off the call for cooler/stormier just yet based on the 0z guidance I still don't quite comprehend, why the EC breaks it down so quick, but it's probably no surprise that the GEFS...the model showing the most robust MJO wave, looks the best. I am concerned a bit for the longevity of the change, but lets see what the 12z guidance does. Link to comment Share on other sites More sharing options...
MGorse Posted January 31, 2012 Share Posted January 31, 2012 I'm pretty interested in the disconnect between last night's model runs and some of the longer range guidance. I'm not jumping off the call for cooler/stormier just yet based on the 0z guidance It must be tied to the split flow as the models are having a tough time resolving the energy within this flow regime. This appears to be causing quite a stir in much of the model guidance. Link to comment Share on other sites More sharing options...
am19psu Posted January 31, 2012 Share Posted January 31, 2012 It must be tied to the split flow as the models are having a tough time resolving the energy within this flow regime. This appears to be causing quite a stir in much of the model guidance. I guess my questions are more along the lines of: does having a coupled ocean in days 11-15 make a big difference in the Euro operational ensemble versus the Euro ensemble used for the weeklies. Their atmospheres are the same, but they couple an ocean model to the weeklies after Day 10. My assumption is yes, since coupling an ocean makes predicting the MJO more skillful. But, it's also not my area of expertise. Link to comment Share on other sites More sharing options...
MGorse Posted January 31, 2012 Share Posted January 31, 2012 I guess my questions are more along the lines of: does having a coupled ocean in days 11-15 make a big difference in the Euro operational ensemble versus the Euro ensemble used for the weeklies. Their atmospheres are the same, but they couple an ocean model to the weeklies after Day 10. My assumption is yes, since coupling an ocean makes predicting the MJO more skillful. But, it's also not my area of expertise. I would have to assume yes, but my knowledge with this is not up there. I was referring to the operational models as they are showing quite the variation from run to run, which has to be tied to the split flow. Link to comment Share on other sites More sharing options...
am19psu Posted January 31, 2012 Share Posted January 31, 2012 I guess my questions are more along the lines of: does having a coupled ocean in days 11-15 make a big difference in the Euro operational ensemble versus the Euro ensemble used for the weeklies. Their atmospheres are the same, but they couple an ocean model to the weeklies after Day 10. My assumption is yes, since coupling an ocean makes predicting the MJO more skillful. But, it's also not my area of expertise. Note also that the CFSv2 is a lot closer to the Euro weeklies, too, and it too has a coupled ocean Link to comment Share on other sites More sharing options...
am19psu Posted January 31, 2012 Share Posted January 31, 2012 I would have to assume yes, but my knowledge with this is not up there. I was referring to the operational models as they are showing quite the variation from run to run, which has to be tied to the split flow. Yeah, clearly the split flow is really screwing with the forecast this weekend and even into next week. It's amazing to me how far off the LW patterns are on some of these runs. Link to comment Share on other sites More sharing options...
Rainshadow Posted January 31, 2012 Share Posted January 31, 2012 I guess my questions are more along the lines of: does having a coupled ocean in days 11-15 make a big difference in the Euro operational ensemble versus the Euro ensemble used for the weeklies. Their atmospheres are the same, but they couple an ocean model to the weeklies after Day 10. My assumption is yes, since coupling an ocean makes predicting the MJO more skillful. But, it's also not my area of expertise. The Cfs/2 was not as cold this morning, but I suppose like the strato warming site, you can drive yourself off the cliff following every burp on every run. CPC didn't update the Euro's weekly MJO yet, but the op looked robust through the colder phases. Its hard to buy the GFS's large amplitude given its been wrong before, but phase 7 is "not as warm" and given the whole 500mb nh outlooked flow it would seem hard to not average "near normal" at least after this week. Only thing maybe if the mjo takes a dive in phase 7, it may be that "the angle of the cold" hits the midwest harder and we end up closer to normal. Link to comment Share on other sites More sharing options...
am19psu Posted January 31, 2012 Share Posted January 31, 2012 The Cfs/2 was not as cold this morning, but I suppose like the strato warming site, you can drive yourself off the cliff following every burp on every run. CPC didn't update the Euro's weekly MJO yet, but the op looked more robust. Its hard to buy the GFS's large amplitude given its been wrong before, but phase 7 is "not as warm" and given the whole 500mb flow it would seem hard to not average "near normal" at least after this week. Only thing may be if the mjo takes a dive in phase 7, it may be that "the angle of the cold" hits the midwest harder and we end up closer to normal. The Phase Spaces didn't update, but here is the Hovmoller of convection. You can see how it pumps P8-type convection Feb 5-11, then shifts the dominant mode back to the IO afterwards (meaning back to flat flow across the Pac again). Link to comment Share on other sites More sharing options...
Rainshadow Posted January 31, 2012 Share Posted January 31, 2012 The Phase Spaces didn't update, but here is the Hovmoller of convection. You can see how it pumps P8-type convection Feb 5-11, then shifts the dominant mode back to the IO afterwards (meaning back to flat flow across the Pac again). I don't know. To me it would seem the breakdown would be too fast. Regardless CPC's list of analog years doesn't ring any sexy bells for me for February. Link to comment Share on other sites More sharing options...
usedtobe Posted January 31, 2012 Share Posted January 31, 2012 I don't know. To me it would seem the breakdown would be too fast. Regardless CPC's list of analog years doesn't ring any sexy bells for me for February. For us it has been showing mostly nickle and dime events. BB looks to be in trouble as here still is not much southern stream to work with and right now, nothing seems to want to dig far enough south to help us. Make me worried about my yesterday's post. Link to comment Share on other sites More sharing options...
am19psu Posted February 1, 2012 Share Posted February 1, 2012 The week long period of favoribility is trending much shorter in both the model guidance and the MJO forecasts. The Euro ENS for D11-15 is downright ugly. Link to comment Share on other sites More sharing options...
iceman56 Posted February 1, 2012 Share Posted February 1, 2012 It would be pretty ironic to finally get a decent snow after March 20 to complement the October snow and have the actual winter season nearly snowless. February is looking more and more like a continuation of the pattern that brung us. Link to comment Share on other sites More sharing options...
Rainshadow Posted February 1, 2012 Share Posted February 1, 2012 It would be pretty ironic to finally get a decent snow after March 20 to complement the October snow and have the actual winter season nearly snowless. February is looking more and more like a continuation of the pattern that brung us. March 3rd is the snow day. Our senior service hydrologist has worked the short term desk the Friday before our two biggest snows this season. His next one is on 3/2. When I was living up in New York, we moved from Yonkers to Yorktown Heights during the winter of 1989-90. While it snowed that December, I don't recall any big snow events in Yonkers. We closed and or moved to our Yorktown house (its about 35 miles north of the NYC line and at 500 feet) around the first day of spring and the crab apple tree in front was in full bloom. On the first Saturday in April, we had 6 inches of snow when I woke up that morning. I went to work, the sun came out. When I got back home that late afternoon, the only snow that was left was on the north side of the house. Link to comment Share on other sites More sharing options...
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