Jump to content
Rtd208

January 2019 General Discussion & Observations

Recommended Posts

Good Wednesday morning everyone.  To open, for your  improvement as modeling for January evolves. I probably wont be commenting - just leaving this as ball park assessment from what I've been noticing in modeling trends the past several days. Ensemble long range guidance commonly seen via Tropical tidbits, Weather bell, Weather ok, and other groups,  indicate a potential substantial cool down (to below, or much below normal cold) beginning vicinity Jan 5-6, lasting who knows how long? Certainly the coldest air of the season (so far early this winter) should (in my mind) arrive sometime between Jan 6-11. To get there, ---ie a somewhat stable +PNA, there probably will be a couple of events Jan 1-5...ptype/timing/amount uncertain (since models and associated ensembles are changing daily, trying to figure out the sensitive short wave interactions between Polar and Pacific jets). Also, the ensembles, including the NAEFS, seem to imply reinforcement of the colder trend near or after Jan 8,  via a possible east coast low, for now modeled well offshore but from what I can tell of the overall pattern,  an option close to the coast.  Interpretation of the modeled MJO phase is not considered here. As of cycles through 06z/26, consensus modeling (NAEFS, GEFS, EPS) I think is leading us in this direction... much more wintry here in the ne USA. It's January, so we're probably due. 

 

12/27 833 PM:  I've checked  ensemble guidance from the EC/GFS...  so far,so good on the above.  I think its going to become a more interesting winter weather wise for us Jan 3 onward, though near misses to the south are possible.  Worthy to monitor for  the persistent cold outbreak as well in the Jan 6-11 time frame. If I see this starting to crash and burn (more than a days worth of cycles), I'll give it up and comment here. 

 

12/29 747 AM:  While the pattern is adjusting, its not quite where I thought it would be for modeling ~Jan 6...but more or less still a similar message as originated the 26th. So the following from a daily blog update to a few weather interested friends. It tends to keep me busy in the long indoor winter, and trying to maintain some prior skill.  Again my overview only. You may see it different. For now,  I think we're going to see some interesting developments in the ne US Jan 4-11. 

Good Saturday morning all: Dec 29 623 AM. Daily large scale weather update focused nw NJ/ne PA: Another 1/2-1" of rain mainly 1PM-Midnight on Monday-31st with some drizzle or light showers lingering NY day morning. Yet, another signif precip (rain) event Th-F Jan 3-4 (1/4-1"), BUT may need monitoring for heavy wet snow ~Jan 4. Thereafter, much colder weather arrives M-F Jan 7-11, with certainly January normal cold if not below normal temps for several days that week. Within that, there may be a snow event Jan 8-9. Most certainly, for our snowmobiling friends in upstate NY: substantial snow is ensembled that second week of January. In summary: Seasonable wintry conditions are on the horizon Jan 4-11.

Good Sunday morning: I copied this from a Dec30th  reply.  No substantial change from 12/26, 27, 29 herein: If there is a seed of doubt, its Temp: How much below normal T in the week of Jan 7-11...its still 9 days away and lots can change and prefer to be sure it wont get very cold in that period before I give it up...better to prepare, if its a reasonable option.  GEFS/EPS are very different in solutions so I need to wait.  In the meantime, my guess from model guidance/ensembles, snow cover is probably going to increase roughly 6" northern PA and I-84 northward by Jan 9. It is winter, and the big warmth of the last half of Dec (NAEFS D8-14's were much too cold) seems to me to be completed or greatly reduced by Jan 3. I could be wrong but am relying on non-MJO instinct. 

It's early, lots of sensitive interactions between northern and southern streams. My sense, the EC big warmth next week is wrong (Jan 7-11). Too much downhill flow in Canada, plus southern streamers continue and probably pretty good snow cover from somewhere nrn PA through much of NYS into northern central New England, making it easier maintain shallow cold. (a half foot or more increase possible over that of this Dec 30th morning.) Obvious wait and see but EC is very good at holding onto closed lows southern stream, but i tend to doubt its ensemble outlook week two, whereas GFS i think is reading a correct potential for phasing northern and southern streams around Jan 8-9, s of Nova Scotia.  Should be an interesting period 1/3-11.  Btw,  the 00z/30 EC  ensembles are a little faster than then the 00z EC op. GGEM/NAEFS is slower than the GFS, and am guessing Jan 4 Long duration comma head event, if I'm reading this right. 06z/30 GEFS is coming around big time to an extensive 1/2" or greater w.e. event.  Yes, probably too warm NYC,  but not very far nw of I95...its going to be an interesting week of potential substantial snows Jan 4 and 8ish.  Another event ensemble ~ Jan 12. So, the trough has been in the east since last July.  Means, if it can, it will precip but la/lo northern fringe always in doubt.  Am thinking we're good for 1/2" our more qpf 12/31, 1/4 and 8 ne PA-NNJ north to at least I-90.  Finally: just a comment on FV3. I have checked on this: to my knowledge here in the ne USA, i dont see it as an improvement on the current GFS model.  I am told in 2020, FV3 will be a significant improvement. Meanwhile unsure of FV3 implementation date. wd 8AM

 

12/31 753  AM self reply on original 12/26: see no reason for major changes to previously multi model ensembled  interpretation above. EPS and GEFS both probably not holding onto cool enough 500 pattern (possible intensification of 500 LOW as it crosses NJ 1/5), therefore, probably too warm and too light on the already modeled 1/2" or greater pcpn which should be widespread 0.5-1.5" with deep CCS off NJ. It's possible the column might be too warm for snow on nw edge, but I'll only add, if not snow, then ICE.  Need to ride this out for further model evolution.  A player may be the preceding Thursday short wave/cfp, that spreads a little light snow across much of our area near and nw of ABE-NYC line.  The WPC D4 outlook is similar to its D5 of yesterday, and imo, i think one day too fast. I think this is mostly a 15z Friday-21z Sat event (see slower EPS/GEFS 500MB and UKMET in particular), with I think comma head banding somewhere nrn PA to central or SNE Ptype is uncertain, in my mind. The 1/8-9 event is all over the place but ensembled 1/2" or greater... and in its wake- potentially much colder. Still large diffs between EPS/GEFS tho some sign EPS giving up big warmth all next week while GEFS so far through 06z/31, is intensifying the 1/9-10 phasing off the New England coast. I can see some of the modeled warmth cut off s of NYC Jan 3 onward through the 11th.  

 

1/1/19 Happy New Year!, but not for persistent wintry sub normal cold for a while and I now admit being overall wrong-incorrect on  Jan 7-11 substantial cold outbreak as per other posters here relying more heavily on EPS  and recent posts on AAM/MJO impact, both of which I'm not well schooled.  My only question: is not MJO/AAM at least modestly integrated into the GFS? or is that not possible? It seems many here are very firm on MJO impact upon general upper flow here in the ne USA. Is this is a research to operations (RTO) problem, or my misunderstanding of model physics capability? Thanks!  Posted in this thread only at 741AM 1/1

Verification observations below for

Wantage NJ 4sw = 8 mi s High Point  (will add representative BGMCF6AVP for January on January 12)

12/31 2PM-1 AM 1/1  0.96 rain (all but .04 on the 31st)

1/3 3-4A 0.02 rain.  A trace of of sleet or flurries occurred prior, sometime between 830-midnight/2nd.

1/5 1230AM-230 PM 1.52"  (1.77" in Franford Township). Excellent banding ne PA/nw NJ 14z-17z/5. 

1/6 AVG 5 F colder than 1/5.

1/7 Coldest temps since Dec 19 arrived. Lows were 15-20.  Climat temp was 1-2F below normal and first below normal day since Dec 19, and the coldest day in parts of our NY metro-ne PA region since Dec 8th!  

1/8 ne PA and nw NJ...down to just s of I80. Sleet/freezing rain overnight (0.02 melted) with a few school delays this morning as the modeled snow storm in late Dec is warmer and split, with part two coming Wednesday the 9th and doing its big snow dumps from nw PA through upper NYS-NNE, over the favored lake effect-orographic upslope areas. 0.31 storm pcpn for the calendar day. Will update 1/9-11 to close the verification. non temps-snowfall (and NOHRSC included). 729A 1/8  

1/8 and 9 temp departures ~+8F each day I-80 region.  

1/10 Temp anomaly within 1 degree either side of normal NYC-AVP. Attached 3 day snow fall map from NOHRSC which accounts for obs and automated assessment ending 12z/10. 

1/11 Temp anomaly ~minus 6F CP-I80-AVP.  5 day mean 7th-11th was only +1+2F same area as compared to the first 6 days +10F.  In other words, while modeled in late December a little on the cold side, the GEFS idea of a much colder outbreak in the period of 7-11 was correct.   Image of Jan 11 mean temp departure-finally.  Poorest departures in snow drought region (much below climb normal) near I80 southward. 

 

Summarizing: 1/4 snow potential was wrong...too warm. 1/8 snow potential was far too high for the 8th...storm occurred, but in two segments. Results are posted for 3 day totals below. The modeling overall had the idea. My giving up on cold in the 1/1 comment update for Jan 7-11 was wrong...the AAM/MJO etc probably had little impact on the temp results here and this was a GEFS far superior cold outbreak outlook vs EPS in the outlooked evaluation period of Dec 26-31. Simply stated EPS week 2 was wrong.  I think we need to balance week2 thermal assessments and consider for review GEFS vs EPS. It's just not EC/EPS dominant, at least for this period of Jan 7-11, 2019.  Thanks for having checked the verification. Walt 656A 1/12. 

Screen Shot 2019-01-10 at 7.08.33 PM.png

1262402023_ScreenShot2019-01-12at11_15_22AM.thumb.png.941259759ebc89a6bd9bd3775c1537b5.png

  • Like 6
  • Thanks 2

Share this post


Link to post
Share on other sites

I am going to track the Ball Drop conditions starting today, at 120hrs. out, using the GFS:

120hrs    >>> 52   Light Rain.

114hrs    >>> 56   Rain                 Next 7 days averaging 45degs., or about 10/11degs. AN, through the 3rd.

108hrs    >>> 50   Light Rain

102hrs    >>> 46    Hvy. Rain

   96hrs   >>> 59    Rain

   90hrs   >>> 59    Light Rain       Next 7 days averaging 42degs., or about 7/8degs. AN, through the 4th.

   84hrs   >>> 58    Light Rain

   78hrs   >>> 54    Rain

   72hrs   >>> 56    Light Rain

   66hrs   >>> 53    Light Rain       Next 7 days averaging 44degs., or about 10degs. AN, through the 5th.

   60hrs   >>> 54    Rain

   54hrs   >>> 54    Rain

   48hrs   >>> 56    Rain

   42hrs   >>> 55    Hvy. Rain        Next 7 days averaging 43degs., or about 9degs. AN, through the 6th.   Taken literally, we would have 1 32* day in a 19 day period.

   36hrs   >>> 55    Rain

   30hrs   >>> 54    Rain

   24hrs   >>> 54    Rain

   

  • Like 1

Share this post


Link to post
Share on other sites

The New Year's Day high temp record could be in jeopardy at KNYC. Most of the 2m and MOS guidance currently falls short, but if the WAA regime (50-60KT SWrly jet at 925mb) during the pre-dawn hours overperforms, surface temps could easily reach the lower 60s. Central Park's Jan 1 record high of 62 occurred in 1966. The record high min for the day of 52 is safe given strong cold advection progged during the PM hours.

  • Like 2

Share this post


Link to post
Share on other sites

January snowfalls 6" or more in Central Park......

27.5" 1/22-23/2016
20.2" 1/07-08/1996
19.0" 1/25-26/2011
13.8" 1/22-23/2005
13.6" 1/19-20/1978
13.0" 1/01-02/1877
13.0" 1/15-16/1879
13.0" 1/23-24/1935
12.5" 1/12-13/1964
11.5" 1/02/1925

11.5" 1/21-22/2014
11.0" 1/24-25/1905

10.3" 1/24/2004
10.0" 1/27-28/1897
10.0" 1/23-24/1908
10.0" 1/14-15/1910
9.9" 1/19-20/1961

9.8" 1/26-27/2015

9.8" 1/04/2018
9.1" 1/11-12/2011
9.0" 1/01/1869
9.0" 1/26-27/1871
9.0" 1/03-04/1923
9.0" 1/19/1936
8.8" 1/13-14/1939
8.6" 1/10-12/1954
8.1" 1/22/1987
8.0" 1/03/1882
8.0" 1/25/1891
8.0" 1/02-03/1904
7.8" 1/14/1923
7.0" 1/20/1925
7.0" 1/03-04/1905
6.8" 1/29-30/1966
6.7" 1/15-16/1945
6.5" 1/14/1874
6.5" 1/26-27/1894
6.5" 1/28-29/1922
6.4" 1/01/1971

6.4" 1/2-3/2014
6.3" 1/10/1965

6.0" 1/19/1869
6.0" 1/22/1873
6.0" 1/15/1892
6.0" 1/05-06/1893
6.0" 1/17/19/1907
6.0" 1/21/2001

  • Like 1

Share this post


Link to post
Share on other sites
Just now, hudsonvalley21 said:

 

image.png

Big change from 0z

What was once a weak low along a front is now becoming a bigger storm.

Cmc is mostly rain for the coast and snow well inland.

Share this post


Link to post
Share on other sites
6 hours ago, SnowGoose69 said:

If that unfolds exactly as shown which it obviously won’t it would likely be snow just about everywhere.  You don’t need much cold air with that setup 

Current forecasts are for cloudy and cold conditions Wednesday and Thursday with temps in the 30s with rain on Friday and temps in the 40s.

Share this post


Link to post
Share on other sites

D.P. in NYC is above 32 all the way[06ZGFS] with the Jan. 03-4 event, so no snow for us.   As usual the colder, but dry and sinking air behind the system, cuts all precipitation before it can get cold enough to snow here.

BTW:  Only two BN days are showing in the next 16.     More +20 to +30 in-coming mid-month,  when JB's historic cold is set to start as of now.

  • Like 1

Share this post


Link to post
Share on other sites
1 minute ago, CIK62 said:

D.P. in NYC is above 32 all the way[06ZGFS] with the Jan. 03-4 event, so no snow for us.   As usual the colder, but dry and sinking air behind the system, cuts all precipitation before it can get cold enough to snow here.

Dont tell that to the NAVGEM....SECS all the way.

Share this post


Link to post
Share on other sites

Just a thought on temps:  At this time of year, will "above normal" at night change snow to rain, or above normal in the afternoon - after a morning event has occurred, mean that it rained? We all love the 10-20F 30 MPH 1/hr classic snowstorms, but many big snowstorms occur with marginal temps.  For now, I think its good we have such an active southern stream...  The rest is timing the event with just cold enough thermal column and preferably strong VV in the ideal dendrite growth zone (-12-18C >75% rh).  One other comment: Already the prediction by some of an above normal winter snow wise in the southeastern USA has verified and it's only DEC.  If we can manage near normal temps the next two months (overall),  there should be plenty of snow opportunities-not all snow but at least the option of occurring.  10.5 "seasonal total here in my lower elevation of Wantage NJ (740'MSL), to date. 

  • Like 2

Share this post


Link to post
Share on other sites
Just now, bluewave said:

Both the EPS and GEFS have a strong MJO 6 look for early January.

 

92607861-2DAF-4A8E-9F22-9C4CEE6BC9DA.png.540b88f0f5e75e09c71a0c08202a2c90.png

Hopefully phase 7 mid month. At least we are ahead of the game regarding snowfall when comparing to 2014 2015.

Share this post


Link to post
Share on other sites
15 minutes ago, EastonSN+ said:

Hopefully phase 7 mid month. At least we are ahead of the game regarding snowfall when comparing to 2014 2015.

We normally don’t expect much from El Niño winters during the first half anyway. 2002 and 2009 were 2 of the biggest outliers relative to El Niño climatology. But this year has the very unusual Niña-like December +SOI. It’s  a mixed pattern so far with the Niño ridge over North America and La Niña ridge north of Hawaii. So we have a dueling split flow pattern.

Share this post


Link to post
Share on other sites
4 minutes ago, bluewave said:

We normally don’t expect much from El Niño winters during the first half anyway. 2002 and 2009 were 2 of the biggest outliers relative to El Niño climatology. But this year has the very unusual Niña-like December +SOI. It’s  a mixed pattern so far with the Niño ridge over North America and La Niña ridge north of Hawaii. So we have a dueling split flow pattern with a mild and very active storm track.

Most of the MJO plots go into phase 7 or COD. Only 1 loops back to 6. Do you think they are picking up an SOI drop, or will they correct back to 6 if SOI remains positive?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×