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November 2011 Obs/Forecasting Discussion


WxUSAF

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Looks like this first week of November probably will see average/slightly-below average temps, but then the 12z Euro and 12z GFS are both advertising a big SE ridge forming early next week. In the fantasy range, GFS breaks that down, starts pumping a big -NAO and drops a PV into Canada. Maybe warm start and cold finish for the month?

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Looks like this first week of November probably will see average/slightly-below average temps, but then the 12z Euro and 12z GFS are both advertising a big SE ridge forming early next week. In the fantasy range, GFS breaks that down, starts pumping a big -NAO and drops a PV into Canada. Maybe warm start and cold finish for the month?

Similar thoughts here. End of November's gonna be effin cold.

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Looks like this first week of November probably will see average/slightly-below average temps, but then the 12z Euro and 12z GFS are both advertising a big SE ridge forming early next week. In the fantasy range, GFS breaks that down, starts pumping a big -NAO and drops a PV into Canada. Maybe warm start and cold finish for the month?

As long as we don't hit mid month and the models don't keep showing the flip @ day 10 I'll be cool with that. After what we have seen in the last decade, the I'm a bit paranoid with the se ridge.

Nina isn't and most likely won't be strong enough for the more classic stubborn winter se ridge though. I'm actually looking forward to a nice stretch of seasonable temps. Nov is still a great month to get outside and do stuff.

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I think November will probably be below normal here this year, though no huge signal....I think it will take on more of an el nino look though with the coldest anomalies in the south and warm in the upper midwest and plains...I think this "consensus" forecast of a brutal winter in the upper midwest and plains could be in trouble....I don't see a November anything like 1995

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I think November will probably be below normal here this year, though no huge signal....I think it will take on more of an el nino look though with the coldest anomalies in the south and warm in the upper midwest and plains...I think this "consensus" forecast of a brutal winter in the upper midwest and plains could be in trouble....I don't see a November anything like 1995

East-Based -NAO or a PV over the Maritimes? October certainly turned out Nino-ish with the cold anoms in the Southeast, coastal storm track and a generally wet pattern for us.

I suspect we'll see a +PNA period from later this month through mid december, likeky a -NAO as well?

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East-Based -NAO or a PV over the Maritimes? October certainly turned out Nino-ish with the cold anoms in the Southeast, coastal storm track and a generally wet pattern for us.

I suspect we'll see a +PNA period from later this month through mid december, likeky a -NAO as well?

overall I would lean toward a good PAC and a bad Atlantic for November in the means...but that is a low confidence guess

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The MJO looks to be entering phase 3 with forecasts clearly moving it into phase 4 and maybe 5. Phases 3 and 4 are warm across the middle of the country but the warm come east in phase 3 while phase 4 looks sort of negative nao-ish but with us being slightly above normal. BY phase 5 we're cold again. Of course that all in the mean and there are variations. The gefs ensemble means look on the warm side for the eastern 1/3 of the nation during the 1st 10 days or so of the month but not overwhelmingly warm. As the wavelenghts change towards winter, the mjo signal's ends up being cold during phases 8-2 and warmer than normal during phases 4-6 and even into 7. Of course as the nao goes negative again, that can trump the tropics but the tropics also can push the north atlantic towards a negative nao.

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The MJO looks to be entering phase 3 with forecasts clearly moving it into phase 4 and maybe 5. Phases 3 and 4 are warm across the middle of the country but the warm come east in phase 3 while phase 4 looks sort of negative nao-ish but with us being slightly above normal. BY phase 5 we're cold again. Of course that all in the mean and there are variations. The gefs ensemble means look on the warm side for the eastern 1/3 of the nation during the 1st 10 days or so of the month but not overwhelmingly warm. As the wavelenghts change towards winter, the mjo signal's ends up being cold during phases 8-2 and warmer than normal during phases 4-6 and even into 7. Of course as the nao goes negative again, that can trump the tropics but the tropics also can push the north atlantic towards a negative nao.

looks like we could be in Phases 8-2 for the beginning of December which appears like it would correlate with the cold start that a lot are anticipating...

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looks like we could be in Phases 8-2 for the beginning of December which appears like it would correlate with the cold start that a lot are anticipating...

As long as the MJO keeps moving which is always the rub. Usually in weak enso years, it is more active. I have little faith in monthly forecasts as if you get a little off in timing, it can tilt the month.

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As long as the MJO keeps moving which is always the rub. Usually in weak enso years, it is more active. I have little faith in monthly forecasts as if you get a little off in timing, it can tilt the month.

me either....which is why I am struggling with the anomalies for CWG.....I don't worry about departures too much though I know Howard/KA view them more seriously....over the years I have realized imo that if you call for +1 and a month ends up -1, it is a much superior forecast to going +1 and a month ending up +6....If I go close to normal for a month and it ends up close to normal, I don't care a whole lot on which side of the departure it ends up.....

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12z GFS fairly consistent with previous runs in pumping the SE ridge this weekend through next week, and then sets up a classically cold pattern with -NAO/+PNA way out in fantasy range. Drops the PV into the UP of Michigan! I suspect the GFS is underdoing the warmth next week, it still has temps not that far off of seasonable levels. I bet we see at least a day or two with highs into the 70s. Still looks seasonable this week.

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12z GFS fairly consistent with previous runs in pumping the SE ridge this weekend through next week, and then sets up a classically cold pattern with -NAO/+PNA way out in fantasy range. Drops the PV into the UP of Michigan! I suspect the GFS is underdoing the warmth next week, it still has temps not that far off of seasonable levels. I bet we see at least a day or two with highs into the 70s. Still looks seasonable this week.

I agree on the warmth. Seems to me that when mid-range has a warm look, the temps usually verify at least a few degrees higher than what the model temps are. Just an observation - nothing really to back that up.

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Nice fall days. I had frost this morning.

Would one of the Pro Mets please explain briefly what a REX Block is and how it would affect the east coast? I notice in Weather bell that Joe D)Aleo says a rex block expected to set up in late November. Thanks Brad Chandler CHO

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Indeed it does. And it kept the approximate time of the pattern change the same (i.e., didn't keep it at 300+hrs). Still has temperatures hardly above normal next week...still believe that will get warmer as we get closer to this big (but transient) SE ridge. That cold shot would be frigid if it verified.

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GFS still hanging on to cold in the lr. I know it's total fantasy land but I like the look of 500 height anoms after the big front moves through. Atlantic looks pretty good.

GFS Op. has been liking the idea of suppressing the storm that forms during the middle of next week, which helps set up the pattern change going into the 11-15 day. Unfortunately for the cold lovers (which includes myself this month as that's what my forecast calls for), the GFS Op. has been fairly out of sync with the ensembles and other models. It might be sniffing out the seemingly inevitable pattern change, but more likely than not it's just being silly in the fantasy range.

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Would one of the Pro Mets please explain briefly what a REX Block is and how it would affect the east coast? I notice in Weather bell that Joe D)Aleo says a rex block expected to set up in late November. Thanks Brad Chandler CHO

http://www.theweatherprediction.com/habyhints/178/

http://forecast.weather.gov/glossary.php?word=REX%20BLOCK

An example upper air chart with a Rex Block from wikipedia: http://en.wikipedia.org/wiki/File:NGM_700_MB.PNG

Rex blocks often form over the West Coast and that would leave our area in an upper-level trough. If there is sufficient cold upstream (in Canada), this would keep our area cold/below normal. A "block" in general is a pattern that is hard to budge and the airflow diverts around the block. So a true block should have a bit of staying power rather than being transient.

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Indeed it does. And it kept the approximate time of the pattern change the same (i.e., didn't keep it at 300+hrs). Still has temperatures hardly above normal next week...still believe that will get warmer as we get closer to this big (but transient) SE ridge. That cold shot would be frigid if it verified.

Of course we all know it's overdone in the lr because that is quite a flip and not just a transient flip either. However, it fits right in with just about everyone's winter forcast. Even though its pre-december there is no reason not to consider it as a possible to even likely solution in some fashion or another.

I wouldn't be surprised at all is we did flip to a solid -NAO during the last 10 days of November and having it last through the balance of Dec. 500 has a nice look in the vicinity of Greenland and that combined with a vortex just spinning around in eastern Canada has happened quite a bit the last couple of winters.

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It might be sniffing out the seemingly inevitable pattern change, but more likely than not it's just being silly in the fantasy range.

The ONLY reason that I give it a second thought is that it fits with alot of analysis for the upcoming winter. It might be pre-mature but we are all pretty much expecting that kind of overall setup for Dec.

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http://www.theweathe.../habyhints/178/

http://forecast.weat...ord=REX%20BLOCK

An example upper air chart with a Rex Block from wikipedia: http://en.wikipedia....:NGM_700_MB.PNG

Rex blocks often form over the West Coast and that would leave our area in an upper-level trough. If there is sufficient cold upstream (in Canada), this would keep our area cold/below normal. A "block" in general is a pattern that is hard to budge and the airflow diverts around the block. So a true block should have a bit of staying power rather than being transient.

Thankk you very much

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GFS ensemble mean loosely supports the Op with a pattern change, but has it later than the Op. Looking at the individual members, the Op is not alone in the pattern change, but several members also still have the big SE ridge through the end of the run.

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GFS Op. has been liking the idea of suppressing the storm that forms during the middle of next week, which helps set up the pattern change going into the 11-15 day. Unfortunately for the cold lovers (which includes myself this month as that's what my forecast calls for), the GFS Op. has been fairly out of sync with the ensembles and other models. It might be sniffing out the seemingly inevitable pattern change, but more likely than not it's just being silly in the fantasy range.

12z Euro seems to be doing the same thing (suppressing that storm) and is suggesting a pattern change beyond Day 10.

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