GaWx

Back to 1995-6, lowest SOI plunges -ENSO/lagged NYC wx -52 on 2/17/17: MB 3/10-18 and 9.7” -49 on 12/10/12: B 12/26-1/3 and 0.4” -47 on 12/19/95: MB 1/2-12 and 25” -47 on 2/2/13: B 2/7-10 and 11.4” -44 on 12/4/25 (due to strong compact Tahitian low) ??? -39 on 12/14/01: 12/30-1/2 MB/0” -34 on 1/19/17: 2/9-10 B/9.4” -31 on 11/7/22: 11/14-21 MB/0” The above tells me that IF there’s possibly any partial correlation of a strong -SOI during -ENSO to cold and/or snow at NYC, it’s not until 1-4 weeks afterward. A period of very heavy snow and/or MB temps occurred 1-4 weeks after 6 of the 7 sub -30 cases. This could easily just be random considering the small sample size and that this is pretty spread out (1-4 weeks afterward).

It’s been a semi-raw cloudy day here today with only low 50s most of afternoon and with occasional very light rain. Steadier not as light rain is about to start, which is just the beginning of Mon and off rainy period through Sunday. This should evap cool temps down into the high 40s soon. It’s going to be hard to get walks at the park in but I’ll try my best during any breaks.

Just like yesterday, the GEFS and EPS disagree on how long the MJO will stay in phase 8: GEFS: only 6 days though it returns for rd 2 on 12/18: But the EPS, which recently has been much steadier and has been verifying better than GEFS since phase 7, once again is going with a very long phase 8 (16+ days, longest in 50 years): you can’t place an MJO better than this in Dec for E US cold lovers (and it looks to be cold the next 10 days per models though one must remember that there are always other factors to consider due to the complexity of the atmosphere):

Or will Jan be cold like in 1984, 1985, 2009, 2011, 2014, and 2022? Or will Jan be within a few degrees of normal (in the NE at least) like 1997, 1999, and 2013? So, Jan has had 3 times as many cold vs warm for the analogs since 1983-4 that I’m looking at. OTOH, Feb has a better chance to torch in the NE imho as only 2014 of the analogs I’m looking at was solidly cold there vs 6 being cold in Jan. In Feb, these were mild: 1984, 1997, 1999, 2009, 2017, and 2023. So, in Feb, 6 times as many were mild vs cold. That compares to 3 times as many cold vs mild in Jan. Two very different months on average.

I just took an invigorating walk at the park with middle to low 40s, dewpoints in the high 30s, and no more than a light breeze. This is close to ideal walking wx for me…well except for having the extremely rare snow on the ground to walk on. Nothing beats the soothing feeling of walking on snow!

Thanks, Don. Just to make sure there’s no confusion of the viewers, these ERA-5 values do not match the BoM RMM values. So, they aren’t substitutes for each other as they’re not the same way of tracking the MJO. Examples: - The end of the ERA-5 is on 8/31/2023. Here are the values on 8/25-31/2023 from both the ERA-5 and the BoM RMM: 8/25: ERA-5 is in ph 7 at 1.1 amp 8/25: BoM is in ph 8 at 0.84 amp 8/26: ERA-5 is in ph 7 at 1.06 amp 8/26: BoM is in ph 8 at 0.85 amp 8/27: ERA-5 is in ph 7 at 0.97 amp 8/27: BoM is in ph 1 at 0.64 amp 8/28: ERA-5 is in ph 7 at 0.83 amp 8/28: BoM is in ph 2 at 0.46 amp 8/29: ERA-5 is in ph 7 at 0.66 amp 8/29: BoM is in ph 2 at 0.27 amp 8/30: ERA-5 is in ph 7 at 0.46 amp 8/30: BoM is in ph 3 at 0.28 amp 8/31: ERA-5 is in ph 7 at 0.24 amp 8/31: BoM is in ph 3 at 0.26 amp ERA-5 MJO 1/2/1940-8/31/2023 https://www.psl.noaa.gov/mjo/mjoindex/omi.era5.1x.webpage.4023.txt BoM RMM MJO 6/1/1974-present https://www.bom.gov.au/clim_data/IDCKGEM000/rmm.74toRealtime.txt

I’m assuming this Euro Weeklies H5 has a good chance to verify way off in the E US considering the projected MJO as well as PNA analogs that suggest a +PNA would be likely in Jan and also that the Euro has been correcting for a too strong SER recently:

IF these were to be close to reality, they’d open the door for frigid air to plunge into the US ~12/18-21: MJO phase 8 would be supportive in Dec 12Z EPS: frigid MT/W ND N into SW Canada 12Z EPS: cross polar flow 12Z GEFS: frigid N MT/N Plains/MN northwestward into SW Canada: 12Z GEFS: cross polar flow

The 12Z EPS is hinting at a 3rd NC snow threat on 12/12 with measurable snow from 7 of the 50 members, mainly from lows that move just offshore:

The 12Z Euro has an off the coast low on 12/8 but it’s significantly too warm for snow per 850s/there’s no cold air connection at the surface and it’s actually dry over much of NC outside of far SE part of the state (it would need to get stronger for NC snow per this):

It’s also a matter of perspective. To me that’s a lot of snow in your pic. This area has had that much snow or sleet in the entire winter only 3 times in the last 45 years (1/2025, 1/2018, and 12/1989) and could easily not see that much again for decades.

I’ve never seen any MJO history prior to the BoM’s 6/1/1974.

Natural gas is now near $5, which is the highest in nearly 4 years. NG generally is highest in winter when the E US, especially NE and Midwest, is forecasted to be colder than normal.

For the twelve 6”+ RDU storms since MJO records started, here are the MJO phases with the largest # of these storms:-3: 3.5 28.2” -8: 2.5 16.8” -5: 2 13.2” -1: 1.5 23.7”-7: 1 10.8”-4: 1 5.9”-2: 0.5 9.0”-6: 0 0.0”MJO amplitude:Weak: 63.9” (on or inside circle)Mod 37.8” (1-2 amp)Strong 5.9” (2+ amp)-The MJO is progged to be weak phase 8 Dec 8-9th-All of the 6”+ RDU snows during phases 8, 1, and 2 were when the MJO was inside the circle.-Phase 3 leading may seem counterintuitive but it’s not when considering that 3 of the 3.5 phase 3 storms were during Feb or Mar, when phase 3 is one of the coldest phases:

Regardless, there’s been and looks to continue to be plenty of winter (cold and/or wintry precip) in most of the E US through the first half of Dec at least. Despite the weak -PNA, there’s a very rare combo of a very long moderate amp phase 8 MJO, a -NAO, and a -AO to more than compensate. -NAO: wasn’t seen dominating the 1st 1/2 of Dec as recently as 5 days ago -AO: wasn’t seen dominating the 1st 1/2 of Dec as recently as 5 days ago