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February/March Meteorological Pattern Discussion


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00z/13th Ensemble Comparison 1/13-1/28.  Avg normal 850mb temp -4C.  

EPO SWITCH IS NOW WITHIN MODELING SKILL TIME.  CONFIDENT OF PATTERN CHANGE.

GEFS Start Of Teleconnection Forecast Skill:  NAO Day 13; PNA Day 8.5; AO Day 12; Recent Verification Tendency: All More Positive, Especially AO

GEFS:  (same) Above normal 850mb temp anomalies into Jan 16th, (day shorter) below normal anomalies later Jan 16th thru Jan 20th, (0.5 longer) above normal anomalies Jan 21st into Jan 22nd, (dropped the warm night) below normal anomalies Jan 23rd thru Jan 28th.   

GEPS:  (same) Above normal 850mb anomalies into Jan 16th, (day longer) below normal 850mb temp anomalies Jan 16th into Jan 19th, (day shorter) above normal anomalies later Jan 19th thru the 22nd, (colder), below normal anomalies Jan 23rd thru Jan 25th, near to above normal anomalies Jan 26th thru 28th.

EPS:  (same) Above normal 850mb temp anomalies into Jan 16th, (same) below normal anomalies Jan 16th into Jan 19th, (same) near normal anomalies Jan 20th, (same) above normal anomalies Jan 21st into Jan 22nd, below normal anomalies Jan 23rd thru Jan 27th.  Canada starts rolling over colder later on January 20th.

NAEFS Week 2: Week of January 21st-January 28th. Strong confidence of near normal temperatures, alot of I don't knows west of us in CONUS.  This may not be far fetched, warmer at the start, colder at the end.

 

Teleconnections:  

EPS:     +EPO, is negative 1/19-1/26; +PNA, turns negative 1/19 (day later); -NAO

GEPS:  +EPO, is negative 1/19-1/26; +PNA, turns negative 1/18 (same); -NAO 

GEFS:  +EPO, turns negative 1/17; +PNA, turns negative day 1/19; -NAO 

WPO negative switch on 1/24 EPS; 1/21 GEFS/GEPS.

 

MJO:  (WH Sectors) Active convection Phase 3/4.  GEFS Phase 3, Phase 6 at end (1/26) thru COD.  EPS  Phase 6/7 border at end (same COD route).  MVentrice phase 4 (vel potential) stronger look, Phase 7 at end.      

MJO phases in January:  4 thru 7 warm, 8 thru 2 cold, 3 transitional.

Strat: NASA Wave 1 weakening, but still between 50th & 70th Percentile. Wave 2 very weak, undulating and remaining below 10th Percentile. EPS similar.

NAM/SPV:  GFS SPV SSW ongoing rapid re-strengthening (two looks in a row). GEFS recovery pushed back to January 20th (60N); January 23rd (65N). Other models similar on recovery, FNMOC 3 days later. GFS back to no Strat coupling downward; NASA looks similar.

 

I have been chirping three weeks lag since December about this, so might as well go over the ledge with it confidentially.  Colder days ahead.  The EPO switch is within modeling time and yes there is a lag even with it before it arrives here.  The timing looks solid (Jan 22nd-23rdish).  With the -PNA transition the initial dumps should be west (and could it be too west?), but I think this is one time that the -NAO ridge/block will do cold lovers a favor and force it southward.  We will be going thru MJO warmer phases, but all I feel from this is that maybe pre Jan 22nd will average warmer than predicted.  After that (if it progresses), it becomes a win/win (lose/lose for me) as long as the EPO remains negative as we would be progressing through colder phases.  

 

00z/11th Ensemble Comparison 1/11-1/26.  Avg normal 850mb temp -4C.  

GEFS:  (same) Above normal 850mb temp anomalies thru Jan 12th, (colder) below normal anomalies night of Jan 12th, (longer) above normal anomalies Jan 13th into Jan 16th, below normal anomalies Jan 16th thru Jan 21st,  (warmer splits) above normal anomalies Jan 22nd, below normal anomalies Jan 23rd into Jan 25th, above normal anomalies night of Jan 25th, below normal anomalies Jan 26th.   

GEPS:  (shorter) Above normal 850mb anomalies thru the night of Jan 15th, (new, colder) below normal 850mb temp anomalies Jan 16th thru Jan 18th, above normal anomalies Jan 17th thru the 21st, (new, colder), below to near normal anomalies Jan 22nd thru Jan 24th, above normal anomalies Jan 25th, below normal anomalies Jan 26th.

EPS:  (colder split) Above normal 850mb temp anomalies into Jan 12th, below normal 850mb temp anomalies the night of Jan 12th, above normal anomalies Jan 13th into Jan 16th, (longer) below normal anomalies Jan 16th into Jan 19th, near normal anomalies Jan 20th, (same) above normal anomalies Jan 21st & 22nd, below normal anomalies Jan 23rd thru Jan 25th.  Canada starts rolling over colder January 20th.

NAEFS Week 2: Week of January 19th-January 26th. Weak confidence of near normal temperatures, alot of I don't knows across the CONUS.

 

 

 

 
 
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1 hour ago, susqushawn said:

My head hurts trying to follow some of his tweets

Lol. He’s def on another level. 
 

remember the Maps tombo posts with the NAM and the blue dripping down (not model nam, but this NAM refers to the NORTHERN ANNULAR MODE.) if the NAM is negative, that’s usually a -AO/-NAO combination. More alphabet soup for the soul!! 

But yea, we expect to see a certain look to the atmosphere post SSW, and that’s what we’re going to start seeing. (Blocky pattern!).

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3 hours ago, Qtown Snow said:

2021-01-13_11-17-06.jpg

I hope for Tom's sake it trends better than this prog. 

(Open sarcasm) I have never seen the GFS rush a cold pattern change before. (Close sarcasm).  I realize the geps/gefs are nowhere near the Euro at the end of next week. 

5.png

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1 hour ago, Rainshadow5.8 said:

I hope for Tom's sake it trends better than this prog. 

(Open sarcasm) I have never seen the GFS rush a cold pattern change before. (Close sarcasm).  I realize the geps/gefs are nowhere near the Euro at the end of next week. 

5.png

Gfs has been terrible with the cold in mid and long range. I just shrug it off till it’s Backed by eps 

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Temps off the Cfs2 are AN for February and March,  but if we can see this kind of precip anomalies for those months, we've got a shot at decent snows along with other precip types.

On the temp issue,  I  doubt the model has really appreciated the blocking,  but that's a hunch.

usPrecMonInd1 (1).gif

usPrecMonInd2.gif

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We always get into the chicken vs egg discussions about ssta and atmospheric responses.  So far this winter there has been a stability and almost a feedback mechanism continuing with both the NAO and WPO/EPO.  The former's warm pool has made it easier for the -NAO ridge to stay stuck. The latter's tighter ssta thermal gradient has made it easier for enhanced jets to not retract.

cdas-sflux_ssta_global_1.png.450d2143c8e926f30361290c9bbbd55b.png

The EPS has the EPO going positive at the end of this month.  They had it yesterday too.  It is way beyond outlook skill, but were it to happen (and the -PNA also right, also beyond forecast skill) and we'd go back to blocking Pacific Ocean air that would qualify as a SSW bust for us.

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7 minutes ago, Rainshadow5.8 said:

We always get into the chicken vs egg discussions about ssta and atmospheric responses.  So far this winter there has been a stability and almost a feedback mechanism continuing with both the NAO and WPO/EPO.  The former's warm pool has made it easier for the -NAO ridge to stay stuck. The latter's tighter ssta thermal gradient has made it easier for enhanced jets to not retract.

cdas-sflux_ssta_global_1.png.450d2143c8e926f30361290c9bbbd55b.png

The EPS has the EPO going positive at the end of this month.  They had it yesterday too.  It is way beyond outlook skill, but were it to happen (and the -PNA also right, also beyond forecast skill) and we'd go back to blocking Pacific Ocean air that would qualify as a SSW bust for us.

That fits the progression of the weeklies witht hat blob shifting to Alaska again increasing chances of pac air as we get to start of feb

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1 hour ago, tombo82685 said:

That fits the progression of the weeklies witht hat blob shifting to Alaska again increasing chances of pac air as we get to start of feb

My hope is we get the -epo to puke some artic air our way and it gets trapped under the block. That wouldn’t be easy to flush out. 
 

Vortex looks like it will regain strength as the mjo progresses into 5-6-7. First half of February might be a warm risk. 
 

After that, I have little faith the mjo gets into 8-1-2. Perhaps just more of the same with pac puke and -nao fading 

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While you would look at an h5 map like this on the pacific side of things and start to worry about pac air getting into the pattern, not the case here. Trace your hgts lines from where you live. While yes, the flow does go over the pacific but that is a direct discharge of cold air coming right from the north pole. 

ecmwf-ensemble-avg-namer-z500_anom-1921600.png

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This is something to possibly watch for February. The main tropical forcing right now is IO shifting into the maritime continent (phases 4/5) over the next 15 days, all warm phases. Granted there is some weak -OLR out in phase 7, but the main forcing is in the warm phases. Look at the progression here of the -olr. Can see its slowly coming closer towards the dateline. The +olr creeping is in the IO in the 10-15 day looking to push towards the maritime continent. Does this -olr make it through phase 7-8-1-2? For February, 8-1-2-3 are cold phases for the east coast. So I would think we still probably have strat effects ongoing through first week or two of February, then if you combine that with a possible cold loop of the mjo, could cancel out the textbook nina forcing that is so common in february 

 

spatial_olrmap_CA_full.gif.b51c7fb415450dbf561a2386aa060509.gif

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