bluewave

Will be interesting to see the Euro seasonal Nino 3.4 forecast on April 5th once it initializes this event. Wouldn’t be surprised if it increases Nino 3.4 temperatures from the March 5th update. If we get these WWBs continuing and not reversing like we saw in June 2014, then this could be our first two events reaching at least +2.0 C on the ONI scale and around 28.57C only three years apart. https://www.cpc.ncep.noaa.gov/data/indices/oni.ascii.txt NDJ 2023 28.57 2.06 NDJ 2015 29.26 2.75 OND 1997 29.02 2.40 NDJ 1982 28.76 2.23 NDJ 1972 28.54 2.12

First back to back Marches with 2+ days reaching 80°. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Mar 80° days Click column heading to sort ascending, click again to sort descending. 1 1998 5 0 - 1945 5 0 2 1910 4 0 3 2026 3 1 4 2025 2 0 - 2016 2 0 - 1990 2 0 - 1977 2 0 - 1938 2 0 - 1921 2 0 5 2021 1 0 - 2020 1 0 - 2011 1 0 - 2007 1 0 - 1989 1 0 - 1986 1 0 - 1985 1 0 - 1962 1 0 - 1946 1 0 - 1908 1 0

Just a wild out of season warm event for the Southwest.

March is becoming too warm for much snow during the 2020s. It will be interesting to see if we can sneak in a snowier bounce back March before the 2020s ends. Even though several spots haven’t seen a 10” event in March since 1993, most would be happy with a nice 1-3” or 2-4” type event.

On track to finish the March 70° day count just behind 2012. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Mar days reaching 70° Click column heading to sort ascending, click again to sort descending. 1 1945 10 0 2 2012 9 0 3 1946 8 0 4 2026 6 1 5 2016 5 0 - 1998 5 0 - 1989 5 0 - 1986 5 0 - 1921 5 0 - 1913 5 0 - 1910 5 0

This could only be the 6th March with a low temperature staying over 60° at a spot like Newark. https://www.weather.gov/wrh/timeseries?site=kewr Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Mar Warmest Minimum Click column heading to sort ascending, click again to sort descending. 1 1998 63 0 2 1985 62 0 - 1910 62 0 3 1949 60 0 - 1945 60 0

I think that it’s still too early to focus in on the exact magnitude of the El Niño which is beginning to emerge . We need to watch the development into June to have a better idea once we get past the spring forecast barrier. The long range climate models have more of a coast to coast ridge look going forward like we saw this March with warmth extending across the country. So this would be a departure from the cold West and Warm East configuration. This may be related to the continuous North Pacific warm pool from Japan to California not really matching any traditional PDO composite. So it’s theoretically possible that we can get a robust Coast to Coast ridge like we saw this March regardless of the exact strength of the coming El Niño. Since the record 500 mb ridge over the West this past winter really wasn’t related to the La Niña magnitude.

The warm spots like New Brunswick have a chance at another 1-2 March days reaching 70° and could get close to 2012. Time Series Summary for New Brunswick Area, NJ (ThreadEx) - Month of Mar Number of 70° days Click column heading to sort ascending, click again to sort descending. 1 1945 11 0 2 2012 8 0 3 1946 7 0 4 2026 6 3 - 1921 6 0 5 2016 5 0 - 1989 5 0 - 1948 5 0 - 1913 5 1 - 1910 5 2 - 1903 5 0

There also seems to be a type of underlying pattern with pairs of winters sharing similar overlapping locations of where their primary ridge and trough locations are found. We can take this back to at least the 09-10 to 10-11 winters. Same story for the 2020s so far. So in a very general sense perhaps the next few winters will find a way to share this similarity also. Obviously, this is all in hindsight and we will need to see how things evolve heading into next winter and beyond. It’s interesting that the models are indicating a potentially robust El Niño development in 26-27 following two winters with strong blocking across the North Pacific into Western North America like we saw following 13-14 and 14-15.

We are currently on track for a very strong event potentially recording an ONI of +2.0 or greater like we recently experienced in 23-24 based on current OHC and WWB intensity unless it’s interrupted by EWBs next few months. The biggest factor will be getting the WWBs to continue through June in order for the subsurface El Niño signal to become fully established at the surface. We can remember the strong EWB in June 2014 which halted the El Niño development when the models had been forecasting +2.0 for 2014-2015. It’s funny how we eventually got the super El Niño a year later. So it was delayed but not denied. That was the last time that the models forecast a +2.0 event that didn’t verify. So unless this process gets derailed by EWBs next few months, there won’t be anything to slow the development going forward. We will need about 3 more months of observations to know if this one can reach its top potential. https://news.yale.edu/2016/02/08/new-insights-stalled-el-ni-o-2014

An historic event to be able to swim in the Pacific this early in the year especially for people that have been on vacation from colder climates and didn’t expect the SSTs to be this warm.

Another March reversion to the new 2020s milder and less snowy mean. March Monthly Mean Avg Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Mean 46.6 46.6 2026 46.2 46.2 2025 48.1 48.1 2024 48.5 48.5 2023 44.9 44.9 2022 45.2 45.2 2021 45.6 45.6 2020 47.9 47.9 March Monthly Total Snowfall for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Mean 0.2 0.2 2026 T T 2025 0.0 0.0 2024 T T 2023 0.6 0.6 2022 0.8 0.8 2021 T T 2020 T T March Monthly Mean Avg Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Mean 42.9 42.9 2019 40.9 40.9 2018 40.4 40.4 2017 39.8 39.8 2016 49.1 49.1 2015 37.7 37.7 2014 37.8 37.8 2013 40.3 40.3 2012 51.3 51.3 2011 43.6 43.6 2010 48.2 48.2 March Monthly Total Snowfall for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Mean 6.2 6.2 2019 9.9 9.9 2018 13.2 13.2 2017 9.4 9.4 2016 1.6 1.6 2015 16.3 16.3 2014 0.2 0.2 2013 8.8 8.8 2012 0.0 0.0 2011 2.2 2.2 2010 T T

Happy one year anniversary of the classic spring in the Northeast pattern.

23-24 was similar in strength for total Nino 1+2 to Nino 4 SST warmth and would have registered a peak ONI around +2.4 C had they not changed the baseline making the departure artificially smaller. This is one of the challenges of measuring the El Niño in a warming world. The winter temperatures in North America and 500 ridge was of super El Niño intensity. But the stronger subtropical ridging didn’t allow for the typical Aleutian Trough strength and the Nino trough we typically see in the Southern and Eastern U.S. This could be a function of the continuing mid-latitude marine heatwaves overlapping wit the ENSO influence like we have frequently seen over the last decade. This effectively means that a super El Niño using the weaker RONI started somewhere near +1.4C with the SST configuration we had in 23-24.