September Observations and Discussion

[Tom]

Both 12z GFS/GGEM are showing a pretty potent cold front around October 1st coming down through the Northern Plains.  Let's see if the Euro continues to show the Ridge.  This time of year models flip flop all the time so I wouldn't buy anything till about 5 days out anyway.

[james1976]

GFS is starting to become more consistent with a colder look late month into early Oct. See if it sticks with future runs.

[gosaints]

While the EURO continues the blow torch

[Tom]

GFS is starting to become more consistent with a colder look late month into early Oct. See if it sticks with future runs.

Now the Euro is caving into the GFS and trying to bring a brief sharp cool down for the last day of September and open October kinda chilly across the region.  Seems like the ridge wants to build back into the NE PAC.

[gosaints]

CFSv2 blowtorch on the list as well

[Maxim]

Once again, GFS is overdone with the cold. It has been all year. Could easily change next run too.

[Maxim]

yeah the new 12z run looked more realistic, then we torch again, lol.

[Maxim]

While the EURO continues the blow torch

yep, that GoA trough is going nowhere.

[james1976]

Actually, the GFS has handled things pretty well this summer. And the 12z run has 0 850s into Iowa on the last day of the month.

[Maxim]

Actually, the GFS has handled things pretty well this summer. And the 12z run has 0 850s into Iowa on the last day of the month.

It's extremely brief, and pretty tame. In regards to the GFS, for the most part it has had a cold bias this summer. Can recall many times when it was way too low with 2m temps.

[Tom]

I'm looking forward to some typical Yo-Yo type Autumn weather as we approach October.  Wouldn't be surprised to see these potential cold fronts to pack more punch if that snow cover continues to build up north and build a more pronounce dome of colder air.  We did not see this much snow at this time of year last year.

 

The snow cover that built up last year was more confined in the Archipelago region of the Arctic.  This year it is more concentrated near AK/NW Territories and that is usually where the source region of our cold air is in the lower 48.

[james1976]

12z GFS has another cold shot right after the one around the 30th. Showing a blizzard with a 980mb Low in Canada in long range. That will change with every run but its fun to watch. I'm hoping this continues as the new LRC will begin soon.
What is 12z Euro showing?

[gosaints]

blowtorch

[Maxim]

GFS more in line with EURO now

[james1976]

Neither model is in line with each other. Both have completely flip flopped from yesterday.

[Geos]

Back from the great state of Washington.

Great weather here the past two days. Feels very autumn like and looks to stay that way for the near future here.

 

On a noteworthy side note.

We have a rare event happening this weekend. Late in the evening on the 27th/early on the 28th, a rare supermoon lunar eclipse will happen and it should be visible for most of the U.S.

 

http://www.space.com...ar-eclipse.html

[Tom]

I've been reading Gary's blog on Weather 2020 and he mentioned that last year Day 1 of the LRC was October 7th.  Having said that, he mentioned that the brand new LRC pattern should evolve sometime during the 1st week of October and we may still feel the final influences of the "old' 2014-15 pattern.

 

Here is a short note from him...

 

 

 

The new weather pattern will likely begin with some influence from the old pattern. So, if a big upper low forms north of the Great Lakes, don’t be shocked or surprised, as this is where the old LRC 2014-2015 pattern will be ending, just as the cold phase of the pattern was supposed to begin. It will be quite fascinating to watch evolve.

 

The GFS as of late, has been showing a very chilly pattern right around the 4th-9th.  Is this the start of the new LRC???  It will be interesting to see this evolve.

[james1976]

Yup, GFS continues to show a big Low in southern Canada around that time with a bigtime cold blast hitting the midwest.

[Maxim]

Yup, GFS continues to show a big Low in southern Canada around that time with a bigtime cold blast hitting the midwest.

that's like 324 hours out... just enjoy the warmth while it lasts. So useless to have cold departures in October of all months, lol.

[james1976]

that's like 324 hours out... just enjoy the warmth while it lasts. So useless to have cold departures in October of all months, lol.

That was a reply to Tom's comment about the end of the old LRC. And i like stormy/cold Octobers.

[gosaints]

Awesome fall weather up to this point going to soak it up while it lasts.  Of course we should expect at least a bout or two of below normal temps but the GEFS is above average for about the whole run.  Hoping for a winter without long stretches of cold and dry.  Cold is fine as long of real storms come with it.  

[james1976]

GFS continues to show 2 big systems with colder air behind em in the first part of October. Hopefully this will be the beginning of the new LRC.

[NEJeremy]

wow, where the hell did that come from?! Parts of Omaha/Council Bluffs got nailed last night! From about 4a-8a, the very eastern side of Omaha including the airport and then into Council Bluffs had 5-8" of rain. Eppley measured 5.25". I'm further west about 6-7 miles from the airport and I received about 2". Also the airport had a wind gust of 60 mph. Lots of power outages and pretty substantial flooding especially in Council Bluffs. Rain is supposed to pick back up this afternoon and overnight with 2-3 more inches possible. Was mainly caused by a strong low level jet running up over a boundary in the area combined with some subtropical moisture from the Southwest US. Wasn't supposed to be near this bad though.

[gabel23]

wow, where the hell did that come from?! Parts of Omaha/Council Bluffs got nailed last night! From about 4a-8a, the very eastern side of Omaha including the airport and then into Council Bluffs had 5-8" of rain. Eppley measured 5.25". I'm further west about 6-7 miles from the airport and I received about 2". Also the airport had a wind gust of 60 mph. Lots of power outages and pretty substantial flooding especially in Council Bluffs. Rain is supposed to pick back up this afternoon and overnight with 2-3 more inches possible. Was mainly caused by a strong low level jet running up over a boundary in the area combined with some subtropical moisture from the Southwest US. Wasn't supposed to be near this bad though.

I seen that! A lot of cars where stalled out and schools in the Council Bluffs area were called off because roads were impassable. Quiet the surprise for that area for sure....I'm hoping to see some rain tonight. 

[Tom]

Made it to the top of Camelback Mtn today...it was 95F with a 60F Dewpoint...not the best hiking conditions I'd say but a view that was worth it and you could see for miles...

 

The peak elevation was 2,706ft and about 2.5 miles round trip.

 

[Niko]

What gorgeous weather. Sunny days continue to prevail non-stop. Wow, just magnificent. When the change comes, it will feel a shock to our bodies.

[Tom]

Both the GFS/EURO are trying to develop a major trough near Japan Day 6-8.  This would translate to some troughiness late in the 1st week of October and could be the beginning of a stormier pattern.

 

The waters in the Sea of Japan are colder than normal and surrounding the Island...

 

http://www.ospo.noaa.gov/data/sst/anomaly/2015/anomnight.9.21.2015.gif

[Geos]

I'd probably die if I hiked in that type of heat! 

 

Looks like the water temperature departures came down a bit south of Alaska. Work those negative anomalies over the Aleutians and south and a trough will want to park there.

 

In other news the cirrus clouds were putting on a show late in the day.

 

 

 

Will be posting some pictures from my trip pretty soon. Some include fresh snow that fell over 6500 feet on Rainier.

[th_snow]

1.66" of rainfall today. Still raining.

[Tom]

There has been an explosion of snow/ice coverage in the Arctic.  Eurasia/AK/CA have all seen some pretty big snows over the past couple days.

 

http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow_alaska.gif

 

 

Snow departures have increased substantially and we aren't even into October yet...

 

http://climate.rutgers.edu/snowcover/png/daily_dn/2015266.png

 

 

During the real cold winter of 2013-14, we saw a very large expansion of snow cover in Eurasia around the same time but it was lacking in North America.  I think we are going to see something similar happen in Eurasia BUT much different on this side of the Globe in North America.  It will be interesting to see how this all influences our weather pattern this season.

 

Sept 23, 2013...

http://climate.rutgers.edu/snowcover/png/daily_dn/2013265.png

 

October 3rd, 2013...notice the below normal departures in North America...If I recall correctly, we had a relatively mild Oct that year.  I'm not expecting that to happen this year.

 

http://climate.rutgers.edu/snowcover/png/daily_dn/2013276.png

[Tom]

We have a much different look in the NE PAC today when comparing it to last year's water temperature Anomalies.  Water's have continued to cool adjacent to the shores of AK/NW NAMER where there have been storm systems galore.  This obviously has to do with the seasonal transition in the northern latitudes as the jet intensifies and ushers in colder/stormier weather in the region.  The CFS model continues to pound away in this region over the coming weeks (AK/NW Territories) and dump snow/cold in this region.  Similarly, in Sept/Oct of 2013, the waters near NW NAMER cooled substantially but didn't provide as much snow as I think this season will do up that way.

 

Notice back on Sept 23rd, 2013 how much colder waters were present...

 

http://www.ospo.noaa.gov/data/sst/anomaly/2013/anomnight.9.26.2013.gif

 

Then a month later...

 

http://www.ospo.noaa.gov/data/sst/anomaly/2013/anomnight.10.24.2013.gif

 

 

The waters in the NE PAC are no where near as cold this year compared to 2013, but yet, we are creating a much more present snow pack up there...

 

http://www.ospo.noaa.gov/data/sst/anomaly/2015/anomnight.9.24.2015.gif

 

 

If your a fan of snowy/cold weather, as long as that warm blob of waters stays offshore, I could see a very large dome of cold air brewing next month in AK/Western Canada that will have eyes into the lower 48 soon enough.

[Tom]

12z GFS paints a snowy Canada as we open up the first days of October...would be impressive for early October...

 

http://www.tropicaltidbits.com/analysis/models/gfs/2015092412/gfs_asnow_namer_41.png

[Yerf]

Temp outlook for the beginning of October. Can't remember seeing the lower 48 being all above normal.

[Tom]

I've been watching the Euro & GFS compete with each other over the last 2 years and I'm seeing the same "errors" in the Euro model repeat again this year as we head into the cold season.  It is my opinion, the EURO has a tendency to handle the trough to far "east" when it should be centered farther west.  There seems to be too much feedback with the model pushing the Ridge to far "east", kicking the trough out farther "east" than where it should be.  The NE PAC waters are dictating the pattern.

 

Check out the 850 temps from 2 days ago and compare them to today's run centering it on the 29th @12z...notice how far "west" the model corrects the main trough over Canada...

 

http://www.instantweathermaps.com/ECMWF/2015092212/CAN_TMP_850mb_168.gif

 

 

vs today's run...

http://www.instantweathermaps.com/ECMWF/2015092412/CAN_TMP_850mb_120.gif

 

 

I'm def going to pay attention to this as we move ahead into the Winter months.

[Tom]

12z Euro now with a nasty cold shot near the Lakes Oct 3-4th...LOL...bye bye is the Torch...subzero 850's crash all the way down into the southern Midwest...this will change run to run, but a stark reversal from previous days.

 

Edit: I don't have access to precip maps right now.  Wonder if this run shows any signs of the first flakes of snow during the nocturnal hours.

[james1976]

12z Euro now with a nasty cold shot near the Lakes Oct 3-4th...LOL...bye bye is the Torch...subzero 850's crash all the way down into the southern Midwest...this will change run to run, but a stark reversal from previous days.

 

Edit: I don't have access to precip maps right now.  Wonder if this run shows any signs of the first flakes of snow during the nocturnal hours.

SUBZERO 850s??? wow

[gosaints]

Been a solid stretch of above average.  We are plus 3 degrees celsius or so in the last month.  October will probably prove to be up and down along with november.  Then we will probably get some positive departures in December-February that will some pulling their hair out.

[Tom]

Changes beginning to show up on the GFS/EURO Ensembles Day 8 and beyond.  NW NAMER ridge beginning to show signs of developing as well as the Aleutian Low which will pump the NW NAMER ridge.  It's time to say farewell to the warmer weather.  Coincidentally, it will be perfectly timed when new the 2015-16 LRC begins to develop.

 

GEFS 500mb Day 8...

 

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2015092412/gfs-ens_z500a_sd_namer_33.png

 

Day 10...

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2015092412/gfs-ens_z500a_sd_namer_41.png

 

EPS Day 8,,,

http://www.tropicaltidbits.com/analysis/models/ecmwf-ens/2015092412/ecmwf-ens_z500a_sd_namer_9.png

 

EPS Day 10...

 

http://www.tropicaltidbits.com/analysis/models/ecmwf-ens/2015092412/ecmwf-ens_z500a_sd_namer_11.png

[Tom]

Is there Linkage to the 30mb warming???  I think so...

 

http://www.cpc.ncep.noaa.gov/products/intraseasonal/temp30anim.gif

[gosaints]

hard to find any negative departures on the whole run of the CFSv2