40/70 Benchmark

March Forecast Offers Mixed Results Low Western heights Temper High Latitude Blocking & Active Storm Track The Eastern Mass Weather forecast for a very active and more wintry month of March had been well advertised dating back to the release of the winter outlook this past fall. The parallels drawn to the analogs of 1956 and 2018 were valid in the sense that there was in fact a second major disruption of the polar vortex. And this did in fact lead to another period of major late season high latitude blocking that ultimately led to a major mid month winter storm that resulted in over 3 feet of snow across the hills of northern Worcester county and the Berkshires. However, as evidenced by the 500mb chart above, the NAO block was largely offset by extremely low and persistent troughing over the western US. While lower western heights attributable to residual cool ENSO influence were anticipated, this was clearly more extreme than forecast. This obviously resulted in lower heights over the western US, and slightly elevated heights over the eastern US relative to the forecast, which may have played a role in the delayed phase of the major mid month winter storm that greatly mitigated snowfall impact over the coastal plane relative to expectation. Eastern Mass Weather Forecast H5 Composite Unsurprisingly, the March 1956 analog was plagued by the same issue greater western heights relative to 2023, which negated the fact that March 2023 featured even greater NAO blocking than 1956. The month or March was never expected to be as cold as March 1956 or 2018 across the eastern US due to the fact that the PV was displaced onto the other side of the globe. But was still milder than forecast over the eastern US due to persistence of very low western heights, which actually encompassed the western half of the AO domain space and also acted to bias the AO positive for the month. March temp forecast near normal for region: Reality was a few degrees above average: The precipitation forecast was decent in reflecting near normal precipitation across the region: But the active subtropical jet that has been pummeling California was missed.

Blocking and major storm window nailed, but deeper than expected western heights threw a wrench in things...probably related to the nipple low/delayed phase IMO. March Forecast Offers Mixed Results | Eastern Mass Weather

It was a tricky season...I can see why some other guys went big given factors that ultimately did lead to major NAO blocking, but I am glad I kept in my pants, so to speak. I remember fielding questions about why my seasonal snow totals weren't larger given the blocking implied. That said, still a lot to learn from others, like Raindance, who really did a good job with the sensible weather outcome. My work definitely left something to be desired...missing the modoki natutre or la nina was big for me....I am usually decent with that, but blew it this year.

I don't recall seeing any seasonal forecaster from the NE predicting well above normal snowfall or well below average temps there last year...can you name any?

You had me at rectal glue...

It was just a light film over the lawn and deck...didn't last too long.

Grass and deck coated...34.0

Snow mixing in.....Boooinnggggg 35.4

Where will it be next week...

Hell of a way to ring in a cold front-

I feel like phasing imperfections like that nipple low can be caused by low western heights, too....because phasing systems are akin to tropical systems in that they are very sensitive to less than ideal permutations in the flow. A bit more ridging out west and lower SE heights could have allowed for a more proficient phase, so I don't want to come off as though its all a product of chance. My forecast definitely wasn't perfect. Very happy with how I handled the artic this year...but what went on out west was just soooo anomalous that it really threw a major wrinkle in things this season.

Main issue I see was a theme all season long....lower western heights than anticipated, even though I did expect lower heights out there.

Not bad call from 4 months out on 11/10.

I will do a full write up next week, but here is a sneak preview....nipple low be damned, I am pretty happy with my forecast.

Moderate to low-end strong, but I don't think it will remain east-based. The uber-strong el nino events are actually the most hostile ENSO state.

Well, its usually over by now...even in a good year.

Yea, I know that...just saying, more often than not our seasonal total would be better in that set up. Coastal plane got porked.

Yea, that was always looking like a mega event.

Must have been some huggers...could have easily ended up like 2002-2003 with 80"+...

BTW, Canadien was the only guidance that nailed the la nina ending up as a modoki event this year.....I ignored it last fall, as everything else was central or east. But it was mild and the la nina really western biased.

Yea, that, 1986, 2002, and 2009 are some progressions that I could see....strong(er) central-west based type of events,.

I guess by "high end", I mean the type of season where I end up with like 90"+...

I guess "high end" is subjective....my snowfall was about average.