jconsor

Detailed thread about recent trends in the Indian Ocean and ENSO regions, and indicators as to which seasonal models are more likely to have the right idea on ENSO situation during peak hurricane season: https://x.com/yconsor/status/1922643952135557481

Thanks for posting the S&P outlook, Barry. Very interesting! One of the few *data-driven* (not totally qualitative) landfall risk outlooks I have seen. Their maps seem to suggest higher than usual activity in the central Atlantic portion of the MDR (around 40-60W) and the Bahamas area (off FL coast) as well as the Caribbean and GOM.

Early indications from seasonal models favor an active Atlantic hurricane season, perhaps even hyperactive. https://x.com/yconsor/status/1901982720378425715

While I agree that extratropical (non-MJO) forcing played a significant role in the cold Jan 2025 outcome across the eastern/central US, we need to be careful using VP averaged across an entire month. Subseasonal variability clearly played a role here. In addition, the NCEP reanalysis has some notable biases in VP - it tends to show overly positive VP anomalies near C/S. America and Africa. See Stanfield et. al 2024, A Climatological Analysis of Upper-Level Velocity Potential Using Global Weather Reanalysis, 1959–2020: https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/joc.8659 The vast majority of the cold anomalies in the eastern/central US occurred in the first two-thirds of Jan. From around Jan 23 onward it turned warmer than normal. The Jan 1-10 and Jan 11-20 VP anomalies show -VP anomalies migrating from the central/eastern Pacific and W. Atlantic, to the e. Atlantic and w. Africa. The magnitude is not as high as the negative anomalies that developed from the eastern IO to Maritime Continent in the Jan 21-31 period. However, especially in the Jan 11-20 period I would argue the MJO had a significant role, given the coherent wave of -VP (and corresponding +VP across the c/e. Pacific) that developed.

The Jan 22, 1987 snowstorm you are referring to is one of the main events that got me interested in weather. I grew up on the North Shore of LI (Roslyn) and I recall the forecast being for an inch or two, then quickly changing to rain. Instead snow piled up at 1-2" per hour and there was never a change to plain rain, just a little freezing drizzle at the end. As Ed said, it was traffic chaos. I was in second grade at the time and we were stuck at school for about 6 hours! The plows couldn't keep up with the snow and the hills on the roads in/around Roslyn made things even worse.

Some additional context to the unusual nature of this cold outbreak stratosphere-troposphere wise: https://bsky.app/profile/drahbutler.bsky.social/post/3lekmlyusmc25

Indeed, as we get closer in the guidance is correcting to a stronger high pressure and CAD wedge for the last week of Dec. https://x.com/yconsor/status/1870772344031268877

https://x.com/yconsor/status/1869457576339136768

https://x.com/yconsor/status/1869457576339136768

MJO phases 5 and 6 are far from a guarantee of warmth in the eastern US. https://x.com/commoditywx/status/1866191470287286392 https://x.com/bamwxcom/status/1866093279948763384

Per Eric Webb, the PDO has limited influence and limited usefulness for subseasonal predictability (especially in a winter like this with a strong Indo-W Pacific warm pool). https://x.com/webberweather/status/1864088518886322455 https://x.com/webberweather/status/1864091992386605400 https://x.com/webberweather/status/1864095069449699705 https://x.com/webberweather/status/1864150597710369022 Also interesting comments on PDO's limited usefulness as a teleconnection here: https://x.com/_WxPhil_/status/1864148237403263157

https://x.com/yconsor/status/1850618329804730523

Some short-term drought relief possible this weekend: https://x.com/yconsor/status/1848326240068837640

Thread on important short-term northward/stronger trends noted regarding Beryl, and how this influences her potential TX/MX impacts: https://x.com/yconsor/status/1808853711629746332

@bluewave Nice model bias charts! Can you please provide the link for them? Thanks.