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Winter 2015-16 Medium-Long Range Discussion


OHweather

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Watch this one in the coming days

gfs_mslp_pcpn_frzn_us_38.png

12z Euro ensembles looked interesting in that range at 500mb...the strong blocking should prevent it from tracking too far NW but could see it track into the Ohio Valley if it phases early enough.

Notice how this all happens on the models after I made a negative post the other day :P

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12z Euro ensembles looked interesting in that range at 500mb...the strong blocking should prevent it from tracking too far NW but could see it track into the Ohio Valley if it phases early enough.

Notice how this all happens on the models after I made a negative post the other day :P

 

According to Cohen, at AER in his latest blog, the stretched polar vortex pushed well off the pole towards Asia has been responsible for delivering Siberian cold to North America  the past three winters.I think it is his faith in this that has made for his cold Jan Feb March forecast for the eastern two thirds of the US.

 

SSW may be better but the stretched vortex of late seems to be doing the job.Wave flux of heat into the strat. at higher latitudes around Dec.20 may have been the key to this turn around from Dec.

 

Nice that medium range forecasting is so full of surprises!

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right, but the stretched vortex is likely done and tough to maintain with the nino this size. it triggers some type, form of greenland block, but that is so far out to take seriously. It won't last either once the forcing ends. You need a ssw to bring the real deal blocking.

 

Cohen also says we need the the SSW for an extended -AO but seems confident that his model predicting another strong wave flux period is going to give SSW before the month is out.Given the failure of that to take place the past two years you have to be skeptical but we did not have the predicted -NAO those years nor the kind of GOA low in the Pacific we now have.Both are supposedly ideal  conditions for pumping heat into the polar strat polar vortex.

 

  So is a kind of wait and see thing but has been my experience that change to strong -AO at the beginning of Dec or Jan. tends to repeat itself later and be neutral in its off periods.

 

   This kind of El Nino,however, makes for uncharted waters so best not to be too sure about anything.

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12z euro is a snooze fest.   The clipper next week is weak.  Then everything that tries to come out of the sw after day 7 gets crushed to oblivion.

 

Here is the 10 day snow totals.  Beyond that the HP settles in like a fat chick in a waterbed with a leak.

Looks eventful in Michigan.

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lol @ the arctic, wtf is going on up there

 

test8.gif

 

AAM near the equater is like 3 maybe 4 standard deviations above the average.This sets up a northward wave train of positive 500mb anomalies at 20 degrees north, negative at 45 degrees north and positive again at 70 degrees north.If this were your ordinary El Nino the neg anomalies would be around 30 degrees north and the positive at 55 degrees north.Suspect the extreme of the average angular momentum has something to do with this jump northward in the  northern hemispheric anomalies.

 

 Models failure to predict this kind of AAM is going to make your typical cold temps southern US warm temps northern US bomb!

 

Details of how out if sight the AAM is right now can be found at @antmasiello  on twitter. NCAR used to post this data but they have discontinued it.

 

It might be noted that this kind of AAM will be impossible to maintain so atmosphere will have to make adjustments as it comes back to more recognizable levels.

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If this forecast of the 250 mb chart  at 189 hours verifys Ohio should have received a nice snow fall.

 

Note how Pacific jet maintains its strength and takes up all the energy after its split west of CA so that the northern jet is weak. Weakness of northern jet makes for high lat. blocking and the  mid lat. neg anomalies over the US.

 

  Jet that extends from central Asia to the mid Atlantic at low latitudes is what gives the incredibly high AAM mentioned in previous post.

 

El Nino is delivering here big time as convection in the subtropical eastern Pacific powers the Pacific jet going over the southern US.

 

   Is good thing I think. If the northern jet that goes up towards the GOA ever gets its share of the energy back we will loose the high lat. blocking

 

[post-13877-0-80654200-1452334492_thumb.g 

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Next weekend could end up interesting:

 

WHERE IT GETS INTERESTING IS OVER THE WEEKEND. AT THAT POINT THE
NORTHERN STREAM WAVE IS DIGGING SOUTH WHILE THE SOUTHERN STREAM WAVE
IS TRYING TO EJECT ITSELF OUT INTO THE CENTRAL PLAINS. IF THIS
PHASES AND THE LATEST ECMWF HINTS AT THAT... WE COULD BE LOOKING AT
ANOTHER MAJOR WINTER STORM.

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Next weekend could end up interesting:

 

WHERE IT GETS INTERESTING IS OVER THE WEEKEND. AT THAT POINT THE

NORTHERN STREAM WAVE IS DIGGING SOUTH WHILE THE SOUTHERN STREAM WAVE

IS TRYING TO EJECT ITSELF OUT INTO THE CENTRAL PLAINS. IF THIS

PHASES AND THE LATEST ECMWF HINTS AT THAT... WE COULD BE LOOKING AT

ANOTHER MAJOR WINTER STORM.

 

Replay of this weekend?

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