bluewave

Yeah, we are similar to BHO which has had 52 top 10 warmest months to only top 10 coldest since 2010.

I enjoy getting outdoors in the winter also. The Great Lakes region is one of most beautiful in winter if you like cold and snow. It’s one area that is really positioned well next few decades for potentially increasing Lake effect snowfall as the warmer lakes stay ice free longer. While winter surfing in my original hometown of Long Beach was very popular, this guy closer to your part of the country takes it to a whole new level.

I don’t like using whole month analogs for a snapshot of a 5 day forecast to start February, the warmth being forecast across Canada is more significant than at the peak of the February 1998 warmth. While the cold over the last 10 days was impressive, its magnitude and aerial coverage was weaker vs cold past extremes than the warm extremes in December. The CONUS finished with one of the warmest Decembers on record. The cold was too short and not extensive enough to rank very high for monthly January cold extremes for the CONUS. But it was impressive for cold on a regional level even if the duration was much shorter than the December warmth.

It’s going to take further research from a team that has access to university computer modeling. I have read numerous studies in the last 5 years on how important tropical convection is in either strengthening or weakening the polar vortex.

Let me give it a try. Back in December 2022 during a La Niña we saw one of the most negative monthly -AOs on record. Our previous 4 La Ninas with such a strong -AOs were 2010,2005,2000, and 1995. Those Decembers all produced 6” events around NYC. Last year we didn’t. Expectations were for a great frontloaded start to winter last year before the period finished. But the Pacific found a way to spoil the party. Now we are entering the typically backloaded part of an El Niño and the Pacific again is too overpowering at least onto the early part of February. So at this point I would say It’s still too early to write off mid to late February for the potential to produce snowfall in NYC. But if we get to February 10th and prospects still aren’t looking good, then NYC would have a shot at its first back to back under 10” seasons. But since it only takes one, it’s too early to call with certainty now. But all we can say for sure the typically backloaded January 15 to probably around February 7th probably won’t live up to past great El Niño periods.

But the +EAMT leading to the Jet extension is also related to the MJO propagating eastward. https://usclivar.org/working-groups/mjo/science/mjo-atmospheric-angular-momentum-length-of-day#:~:text=MJO and Torques,Ocean (Madden%2C 1988). MJO and Torques Frictional and mountain torques induced by the MJO circulation anomalies are responsible for the angular momentum exchange between the atmosphere and the solid earth. Positive frictional torques start the upward trend in AAM when convection increases over the central Indian Ocean (Madden, 1988). As convection moves to the west Pacific, positive mountain torques from east Asian and South American topography provide for a continued increase in AAM. AAM reaches a maximum as convection weakens near the dateline. The relative roles of a direct forcing by the convection versus eddy transport processes induced by the convection remain to be determined. Real time monitoring of the zonal and global AAM budget provides a convenient monitoring and diagnostic tool of the MJO.

The Arctic region shifts with the anomalous +3 AO following the SSW will probably take further research. It is also a very warm signal for us while working in concert with the tropical convection pattern. Several years back there were papers showing a possible link between the Indian Ocean convection and +AO. So it will be interesting to see if such a strong +AO following this SSW is in any related to the recent record Indian Ocean forcing. We usually don’t see such strong forcing there at the time of SSWs. Would probably be a great project for a research paper.

It’s a combination of the record SSTs in the WPAC for such a strong El Niño and the El Niño itself. So we get MJO action which when combined with El Niño is very warm. As these MJOs progress eastward they excite the +EAMT leading to the Pacific Jet extensions. So just looking at one specific MJO phase composite probably won’t be adequate. This most recent Jet extension will take a few weeks to play out. Hoping we can see some improvements by mid-February relative to the start.

Even in this new era of warmth extremes, what is showing up to start February is way beyond what we have ever seen during an El Niño February. The highly amplified MJO over the WPAC is flipping the script. This would be extreme for December let alone in February when El Niño’s are supposed to be cold. Ridiculous how far into Canada the above freezing line gets pushed.

These Pacific Jet extensions through the highly amplified MJO and +EAMT will continue to run the table at least into early February. So this pretty much guarantees that we’ll see a record breaking 9 warm to record warm winters in a row since the 15-16 super El Niño.

We’ll consider it a January thaw even through the colder period was short.

We know we can easily get a ton of 90° days with a very high dewpoint summer. Plus we can even get a run of 100° days like we saw in 2022. But the extreme 2010 and 2011 all-time absolute highs around 105 to 108 generally require a significant drought nearby. Droughts have been tough to come by with how wet our climate has become.

Reminds me a bit of the big Arctic outbreak to our west in 2021. But with warmer temperatures for us and less snow.

Mostly due to all the excess heat being absorbed by the oceans providing more heat to be released to the atmosphere during El Niño’s. Following the first spike in 97-98, we had all the record winter warmth in the late 90s and our new warmest summer up to that time in 2005 with the hyperactive hurricane season. The next El Niño in 09-10 added more heat leading to the record warm summers in 2010 and 2011. Record blocking accompanied this pattern for several winters. Also Sandy occurred during this period. Then the ridiculous +13 December 15 with that El Niño followed by 9 warmer to record warm winters in a row. So now the global temperature spike in 2023 was higher than any of the previous El Niño’s. So we wait and see what is in store with this new even higher baseline world temperatures.

My guess is that the background pattern was colder for 15-16 once winter got going in January coming off the 09-10 to 14-15 colder winter period. Plus the Pacific actually cooperated wit the -AO back then through Valentines Day. That 15-16 heat release from the oceans rose the baseline temperatures. Now the heat release from this El Niño is even more record breaking than the last one. So it will be interesting to see what two big temperature jumps within 10 years does.

Didn’t have time for the pieces to line up correctly for a big snow for us since the Pacific flow has been so fast with frequent kickers coming into the West Coast.

It’s easier for areas to our south with lower snowfall averages to get to normal snowfall for a set date. All it takes is one storm.

Most of the time in late January when we have a 1040mb high to our north, it’s a good wintry threat pattern. But this time it’s being countered by an almost equally strong Bermuda high. Just goes to show how many challenges our recent winter patterns have been dealing with.

15-16 may have been an exception. Some spots had nearly 40” of snow from late January into early February. Then the first below zero reading in NYC on Valentines Day since 94. We would always find ways to score KU events from 09-10 to 17-18.

That’s what I was commenting on a few weeks back. We were discussing the window, but I was concerned it would be too short to put together more than a 1-3 or 2-4 type event. 16-17 was a really unique winter which was very warm and we seemed to get short term pattern changes which produced blizzards. But ever since 18-19, we needed more time to put together bigger events. Like we saw in December 2020 with the decent pattern becoming established early on leading to the great event around the 17th.

I wasn’t primarily using it to make the forecast for this cold period. The models actually did a decent job. But someone asked about the pattern and how lags worked out. So it was to explain what input it had to the overall pattern. The edge for MJO forecasting usually further out in time say 10-15 days to a month and beyond. The models generally handle short term transitions day 1-5 and 6-10 pretty well . But there are systemic biases at play longer range that once corrected lead to better long range forecast outcomes.

Phase 2 is a very warm phase for us during an El Niño and the convection was focused there for much of early January so not much in the way of a lag there. But the lag this month was with the cold this week was through 3 enhanced by the multiple wave breaks but only lagged by about 3-7 days. The moderation coming up after the weekend has elements of 4 and beyond. Plus we have the interaction with what has happened with the dramatic reversal closer to the Arctic.

The VP anomaly charts are probably closer to the truth with the strongest convection in region 7 during December which was displaced further west than was typical for a canonical El Niño response. The actual convection was off the charts near Australia with all time record rainfall and dewpoints. The previous records were established during La Ninas. This is why the records were so noteworthy for a strong El Niño. But not surprising given the nearly warmest SSTs there on record for this time of year. So it’s also no surprise that the forcing was more prominent in those regions and weaker through some of the other MJO phases on the transit. This is why the RMM charts don’t always tell the whole story. But there are times that they do also. Even in the met community there have been papers written on the strengths and weaknesses of the various approaches at different times. The convection shifted over to phase 2 in early January creating the big pattern shift from strong ridge near the Upper Midwest in December to deep trough near the four corners states. Very predictable shifts given the change in the location of the primary convective forcing.

That isn’t the case. The MJO didn't go into 8 but weakened after the warm 4-7 phases. Then the convection fired in 2 which lead to the very strong trough out West with continuing warmth into mid-January. Another reason you are missing the understanding of a lagged response at times is the resulting Jet extensions which take time for the pattern to fully manifest. So it’s an unreasonable expectation for the MJO to always behave in an instantaneous manner. But there are times when the other factors align to give a more instantaneous response.

I think the big PAC Jet extension kept the pattern too progressive so the storm went more ENE to our south than NE. Another case of the Pacific pattern leading to less snowfall than usual in recent years.