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Meteorological Winter Pattern Discussion II


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00z/14th Ensemble Comparison 1/14-1/29. Normal 850mb temp around  -4C. 

Kick The Can Into February.

We are living witness on how the ensembles just carpet bomb the cold and miss an event that looks like it will turn out to be too warm for most.  This from just four days ago.  So take that into consideration with the blanket nothing but cold in week 2.  I agree with the general premise.  The Pacific teleconnections are primarily cold.  The +NAO outlook suggests exits for 50/50 lows and cold cores.  Doesn't matter they are lined up.  As far as sensible weather, snow threats I'd look around the weekend of the 22nd and then maybe (ha, ha, ha  - - - > ) if the pattern switch is occurring at end of month.  Speaking of pattern switches, yes there looks like a retrogression (didn't I type this four days ago?) of the Bering closed low and our NOAM version near Hudson's Bay.  I don't see any MJO support (well it's been a mess) and the SPV continues chugging along.  Maybe the Wave 1,2 hits become weaker and this causes a change, but for now the can has been kicked.

Teleconnection Fcst Skill Starts At:  NAO Day 10.5;  PNA Day 11.5; AO Day 10

Recent Verification Tendency:  More Positive For All

GEFS: (missed the coastal track) Below normal 850mb temp anomalies into Jan 16th, (new) above normal anomalies later Jan 16th into Jan 17th, below normal anomalies later Jan 17th into Jan 18th, (warmer) above normal anomalies Jan 19th into Jan 20th, below normal anomalies later Jan 20th thru Jan 29th barneyesque thermal trof Jan 25th (end of run).

GEPS: (missed the coastal track) Below normal 850mb temp anomalies into Jan 16th, (new) above normal anomalies later Jan 16th into Jan 17th, below normal anomalies later Jan 17th thru Jan 18th, (moved up) above normal anomalies Jan 19th into Jan 20th, (lost one day warmth) below normal anomalies Jan 20th into (thermal trof 1/25) Jan 27th, above normal anomalies later Jan 27th thru Jan 29th (end of run).

EPS: (missed the coastal track hat trick) Below normal 850mb temp anomalies into Jan 16th, (new) above normal anomalies later Jan 16th into Jan 17th, below normal anomalies later Jan 17th thru Jan 18th (new, total miss?), above normal anomalies Jan 19th into Jan 20th, below normal anomalies later Jan 20th (thermal trof night of 24th) thru Jan 28th. (end of run).    

NAEFS Week 2: Period of Jan 22nd-Jan 29th. High confidence of below normal temperatures, first time this winter.       

 

Teleconnections: 

GEFS:       -EPO

                 +PNA (week longer) thru 1/25; neg 1/26-1/29

                +NAO (big changes/flip) thru 1/23; neg 1/24-1/29

GEPS:      -EPO (trended more neg) thru 1/26; neut 1/27-1/29  

                +PNA (more positive, longer) thru 1/16; (can kick) neg 1/27-1/29

                +NAO (lost neg)

EPS:         -EPO 

                +PNA thru 1/16; (can kick) neg 1/27

                +NAO (most consistent)

 
WPO:       Negative, less negative after 1/24 GEPS & EPS

 

 

MJO:    (WH Sectors) Strongest Convection/Vel Potential Phase 1

GEFS   n/a;  EPS Phase 8 to Phase 7 COD (runs ends 1/28). 

MVentrice Phase 2 & Phase 8 bifurcation;  bifurcated Phase 5 & Phase 8 at end.

 

                  

Strat: NASA Wave 1 70th percentile peak (1100 gpm) mid month before dropping below normal; Wave 2 hit peaked at 80th percentile (600 gpm), falling off cliff, recovering to near normal at end.   EC similar.   

SPV/NAM:  (GFS) remains between normal and 1 SD above. SPV ensembles end above normal 45-50 kts.  EC closer to 60kts. back to non strat hit 1/19; another 1/29?   https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/DJF/combined_image.png

 
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4 minutes ago, Allsnow said:

Signs of the -pna returning now on the ensembles. Looks like the start of February as now pattern lasts forever 

Yea, I'm not sure it goes to December levels but the big closed low that is responsible for the pumping the ridge into Alaska pulls back towards Japan which will pull the ridge back and the trough in the east a bit further west. Will make for a stormier pattern but will also see a se ridge response assuming ens are right that far out. I see 0 help from the strat, that looks strong for the forseeable future. So ssw chances of helping pattern look shot. MJO still looks decent for most of january but by the end and to start feb looks like it tries to push towards phase 3 and onward which would resemble the typical nina pattern for feb. But thats far out there and convection is tough to forecast. In near term, still looks conducive for cold, just have to see if we can get precip into it. 

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2 minutes ago, tombo82685 said:

Yea, I'm not sure it goes to December levels but the big closed low that is responsible for the pumping the ridge into Alaska pulls back towards Japan which will pull the ridge back and the trough in the east a bit further west. Will make for a stormier pattern but will also see a se ridge response assuming ens are right that far out. I see 0 help from the strat, that looks strong for the forseeable future. So ssw chances of helping pattern look shot. MJO still looks decent for most of january but by the end and to start feb looks like it tries to push towards phase 3 and onward which would resemble the typical nina pattern for feb. But thats far out there and convection is tough to forecast. In near term, still looks conducive for cold, just have to see if we can get precip into it. 

Unfortunately, the fear of a good pna is always cold dry. Hopefully something works for us down here before it gets hostile again 

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8 minutes ago, Allsnow said:

Unfortunately, the fear of a good pna is always cold dry. Hopefully something works for us down here before it gets hostile again 

We need another 2013-2014 -epo...

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14 minutes ago, tombo82685 said:

Yea, I'm not sure it goes to December levels but the big closed low that is responsible for the pumping the ridge into Alaska pulls back towards Japan which will pull the ridge back and the trough in the east a bit further west. Will make for a stormier pattern but will also see a se ridge response assuming ens are right that far out. I see 0 help from the strat, that looks strong for the forseeable future. So ssw chances of helping pattern look shot. MJO still looks decent for most of january but by the end and to start feb looks like it tries to push towards phase 3 and onward which would resemble the typical nina pattern for feb. But thats far out there and convection is tough to forecast. In near term, still looks conducive for cold, just have to see if we can get precip into it. 

That overall timing would maintain our alternating warm/cool month pattern that started in October.

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3 hours ago, tombo82685 said:

Yea, I'm not sure it goes to December levels but the big closed low that is responsible for the pumping the ridge into Alaska pulls back towards Japan which will pull the ridge back and the trough in the east a bit further west. Will make for a stormier pattern but will also see a se ridge response assuming ens are right that far out. I see 0 help from the strat, that looks strong for the forseeable future. So ssw chances of helping pattern look shot. MJO still looks decent for most of january but by the end and to start feb looks like it tries to push towards phase 3 and onward which would resemble the typical nina pattern for feb. But thats far out there and convection is tough to forecast. In near term, still looks conducive for cold, just have to see if we can get precip into it. 

What’s amazing is that the seasonal multi-models (NMME/IMME) have been hinting at this for awhile now and it just so happens that it arrives around Feb 1 right on schedule 

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00z/17th Ensemble Comparison 1/14-2/1. Normal 850mb temp around  -4C. 

A Partial Can Kick.

The predicted PNA switch around January 26th-27th is entering modeling skill time, so we will have to see if this holds going forward.  There was a net push back of about a day from the previous posting. For the weekend system, the GEFS & GEPS (above is not necessarily rain in January) is more to one's liking than the EPS.  The EPS has missed these one day warm ups this season.  With the EPO & WPO being outlooked to remain negative there will be cold air intrusions, just if the pattern is truly retrograding, this will start dumping more to the west.  So beside the weekend, the teleconnection transitional switch in the middle of the ensuing week (1/26-1/27) may be another weather system opportunity.  Pretty good to be this cold with a positive AO.  MJO remaining a total mess is not hurting as the Stratospheric Vortex continues to remain stronger than average.  This is one of those occasions where the cold is outperforming. Thank-you(?) PNA.

Teleconnection Fcst Skill Starts At:  NAO Day 10.5;  PNA Day 11.5; AO Day 9.5

Recent Verification Tendency:  More Positive For All

GEFS: (same) Below normal 850mb temp anomalies thru Jan 18th, (same) above normal anomalies Jan 19th into Jan 20th, below normal anomalies later Jan 20th thru Jan 22nd, (new split) above normal anomalies Jan 23rd, below normal anomalies Jan 24th thru Feb 1st (barneyesque thermal trof now Jan 27th (end of run).

GEPS: (same) Below normal 850mb temp anomalies thru Jan 18th, (moved up) above normal anomalies Jan 19th into Jan 20th, below normal anomalies later Jan 20th into Jan 22nd, (new split) above normal anomalies later Jan 22nd into Jan 23rd, below normal anomalies later Jan 23rd into Jan 29th (barney thermal trof still 25th), (total can kick)  above normal anomalies Jan 30th thru Feb 1st (end of run).

EPS: (same) Below normal 850mb temp anomalies thru Jan 18th (same), above normal anomalies Jan 19th into Jan 20th, below normal anomalies later Jan 20th (barney thermal trof still night of 24th) into Jan 30th, near normal anomalies Jan 31st. (end of run).    

NAEFS Week 2: Period of Jan 25th-Feb 1st. Moderate confidence of below normal temperatures, decreasing confidence from previous days.       

 

Teleconnections: 

GEFS:       -EPO

                 +PNA thru 1/26; (day later) neg 1/27-2/1

                +NAO thru 1/23;  (shorter) neg 1/24-1/26; pos 1/27-2/1

GEPS:      -EPO thru 1/27; (day later) neut 1/28-2/1  

                +PNA thru 1/27; (day later) neg 1/28-2/1

                +NAO thru 1/23 (back again) neg 1/24-1/25; pos 1/26-2/1

EPS:         -EPO 

                +PNA thru 1/26; (same) neg 1/27-1/31.

                +NAO (neut 1/25)

 
WPO:       Negative, less negative or briefly positive around 1/24

 

MJO:    (WH Sectors) Strongest Convection/Vel Potential Phase 4

GEFS   COD;  EPS COD emerges Phase 6 (runs ends 1/31). 

MVentrice Phase 2 & Phase 3 thru week 1, then a bifurcated mess week 2.

 

                  

Strat: NASA Wave 1 70th percentile peak (1100 gpm) now before dropping to normal; Wave 2 30th-50th percentile of normal.   EC bigger Wave 1 trof ends rising to around normal (1000 gpm).   

SPV/NAM:  (GFS) remains between normal and 1 SD above. SPV ensembles end above normal 40-47 kts.  EC closer to 40kts. Non strat hit 1/27; another 2/1?  

 

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/DJF/combined_image.png

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4 hours ago, PRINCETON ANGLER said:

PNA switch to minus coincides with the NAO going positive around 1/27. We could be ripe for a storm as part of the reset. Models seem to be hinting at the possibility.

The start of February starting to look torchy.

Yea. Kind of seems to be what’s being modeled. We lose the favorable pac set up as ridge retro’s back west. This allows the TPV to retreat northwards. Could get torchy if that happens. 

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49 minutes ago, irishbri74 said:


 

once the trop and strat couple, it’s gonna be a warm February for someone. Odds are it’s is. 

Meh. Why is strat going to all of a sudden take charge? Not saying it won't happen, but needs more meat on the bone than a few days of modeled AO+.

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16 minutes ago, Chubbs said:

Meh. Why is strat going to all of a sudden take charge? Not saying it won't happen, but needs more meat on the bone than a few days of modeled AO+.

Agreed, I mean we have had a strong vortex this whole month so far. I haven’t looked at it recently but if it hasn’t coupled with trop and it does going forward that could tilt things towards uglier. But the mjo has been controlling this pattern 

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Would it be fair to say that our storm threats have been driven primarily by northern stream short waves diving south and maybe phasing before sliding NE?
 

If so, and IIRC, there used to be an accepted belief that the GFS did better with northern stream systems. I’m fishing for a reason that the GFS has been smoking the Euro like a cheap cigar this month. Thoughts?

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8 hours ago, daniel said:

Just an FYI not sure if people on here know this but Eric Fisher is a well known warminista so that tweet make sense coming from him.

well it also is a valid point. The stratosphere is not going to help

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Newbie question, but in Jan/Feb 2019 we had a bad pacific and still snowed. In fact, most of my snow fell in those two months that year and I got 81” which was better than the last 2 years. What is stopping us from snowing in the upcoming pattern change and how is it different than 2019? 

0684FF81-7374-400F-B46D-D7F30D79B7BF.gif

B3D9FF01-3BE7-4DA3-8295-D698A46FDC1D.gif

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2 hours ago, ErieWX said:

Newbie question, but in Jan/Feb 2019 we had a bad pacific and still snowed. In fact, most of my snow fell in those two months that year and I got 81” which was better than the last 2 years. What is stopping us from snowing in the upcoming pattern change and how is it different than 2019? 

0684FF81-7374-400F-B46D-D7F30D79B7BF.gif

B3D9FF01-3BE7-4DA3-8295-D698A46FDC1D.gif

tpv is sitting over northern hudson bay and you have a ridge bridge over the top forcing cold air south into mid latitudes and you had a strong ssw. Stratosphere right now is completely different, actually a 180 from that 

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