GaWx

Today’s 0Z models update shows a significantly increased chance for a strat wind reversal Jan 15-16 with 12Z 1/16 mins of GEPS at -1, FNMOC at -3, GEOS at 0, GFS at +1, and GEFS at +2.5. Well over half of the non-GEFS ensemble members reverse Jan 15-16 with most of those getting down to -1 to -5 and the lowest getting down to -6. If the reversal actually occurs, I don’t know thar it would actually be called a major SSW due to the lack of warming accompanying it (though fairly modest warming follows it):

Regarding the overall pattern: Latest GEFS MJO forecast is not what most would expect during a cold/wintry SE US period, strong in phases 4 and 5. Actually, the opposite wx tends to occur with this MJO. This illustrates well that it is just one factor and tells us only what often happens rather than anything even close to what always happens.

That would be the first wintry precip down here (looks like sleet in this run) in 6 years. Going 6+ years between wintry precip events this far SE, even if minor, is nothing unusual (and thus not something to bet on) though the last one was anything but minor.

And potentially the second winter in a row with coldest of winter for many when the MJO is strong in the MC.

Models continue to indicate a cold pattern despite the MJO moving through strong phases 4 & 5. Similar to Christmas of 2022. MJO overruled by other factors. MJO only determines what often happens, which is far from what always happens.

1. The ND MEI came in at +1.1. That’s quite a comeback from the mere +0.4 of SO. Actually, this 0.7 rise is the largest on record (back to 1979). I think this bodes well for Feb potential: https://psl.noaa.gov/enso/mei/ 2. The 0Z GFS looks awfully close to a major SSW on 1/17.

With all of the snow predicted, the GFS, Euro, and CMC are suggesting Chicago may have a high below 0F early next week. Though the model assumptions have a tendency to bring down temperatures too much over fresh, generous snowcover, I wouldn’t rule out a high below 0 there with all of the snow predicted. The NWS currently isn’t yet buying it, however. About 15% or ~1 in 7 of their Jans have a high that cold. That’s 22 of them since 1873. The El Niño (along with their strength) Jans with one (10 of them out of ~50 (~20%) El Niño Jans) were: 1888 (weak), 1897 (strong), 1912 (moderate), 1924 (moderate), 1940 (moderate), 1942 (moderate), 1966 (strong), 1977 (weak), 1988 (strong earlier at its peak), and 2019 (weak). 2023 would be at/near strongest per ONI (though not per RONI, which may be the key) with a subzero high there if it were to occur.

Latest GLAAM forecast from CFS says El Niño like pattern returns late Jan til at least mid Feb:

Latest GLAAM forecast from CFS says El Niño like pattern returns late Jan til at least mid Feb:

I was also at Peachnet. So, were several others that are regulars here and were also at Eastern. I remember lookout, highway#, and NE GA, among others. Meanwhile, the current storm means business!

We get it. That storm is likely not going to give you what you want. But the winter/early spring in WNC is likely not hanging on it. There’s still a very long way to go, especially with it being a strong Nino.

When there’s a +1.0 or higher ONI peak in fall/winter going back to late 1800s, Raleigh has had only 29% of their snow on average through Jan 20th. More details below: -31 winters since 1888-9 -Nov avg: 0.2” -Dec avg: 0.9” -Jan 1-20 avg: 1.1” -Jan 21-31 avg: 0.9” -Feb avg: 2.4” -Mar avg: 1.7” -Apr avg: 0.4” -So, Nov-Jan 20 avg: 2.2” -So, Jan 21-Apr avg: 5.4” -So, on average only 29% of SN falls at RDU through Jan 20th & 71% Jan 21st+ -Thus, a very long way to go. -Regarding 6”+ storms for these 31 periods at RDU, median date not til Feb 10-11 -There have been more 6”+ events during these 31 there in Mar (4) than either Feb (3) or Jan (3)!

No, it is the opposite. The daily is still high end strong. That’s a good bit stronger than the average for being almost in mid January. My stats don’t even consider whether or not El Niño weakens quickly.

For RDU El Niños that were moderate or stronger: snowfall: -31 winters since 1888-9 -Nov avg SN: 0.2” -Dec avg SN: 0.9” -Jan 1-20 avg SN: 1.1” -Jan 21-31 avg SN: 0.9” -Feb avg SN: 2.4” -Mar avg SN: 1.7” -Apr avg SN: 0.4” -Nov-Jan 20 avg SN: 2.2” -Jan 21-Apr avg SN: 5.4” -So, only 29% of SN through Jan 20th & 71% Jan 21st+ -Thus, a very long way to go. -Regarding 6”+ storms, median date not til Feb 10-11 -More 6”+ events in Mar than Feb or Jan!

I was a bit slow today lol. Though 0Z GFS just missed it with a +4, it actually had a reversal days 15-16 instead. It looks like the 12Z GEPS is probably close to 0. The 0Z was at -1. Going to be interesting next few days following this. Could be implications for Feb, which already tends to have good climo in El Niño. But if reverses, it doesn’t look to be a strong reversal but probably a rather weak one. Regardless, I’d love to see it. Any reversal is significant and would be a surprise vs recent EPS runs.

Check today’s 0Z EPS out for Jan 17th! Are we going to sneak in an unexpected major SSW in 9 days? The mean has sunk to just +1 m/s (only the 12/25 and 12/26 runs lower and those were for early Jan) with probably 1/3 or so of the members below 0: Compare to yesterday, when mean dipped only to +5: For 1/17 on 0Z runs, GEPS and GEOS were at -1 while the GFS and FNMOC were at +4 and GEFS was at +8.

It is still very early. A significant majority of major SE El Niño snowstorms have occurred after mid January. Even in a snowy El Niño winter, often there’s only one widespread major storm in the SE. So, we have plenty of time for that storm to happen.

Fwiw from the average of the last 48 CFS runs, a cool mid-Feb with a good portion of the E US 1-3 BN 2/11-18, which is during peak snow climo:

1. Even though I replied to your post, I didn’t intend for it to be just for you. Temperatures are an important aspect of winter to monitor on their own, especially during winter. Although I’m not yet expecting super cold, the fact that it’s possible in ~10 days is intriguing. Widespread cold on its own can have at least as much (if not more in some cases) impact as a snowstorm. Plus it could set the table for a followup winter storm in more ways than one though that’s beside the point. 2. Last Dec MJO: I’m pointing out similarities for those who may find it interesting. You don’t care, but others might. There are a lot of members and guests that read these. I love to look at both similarities and differences of various factors when looking back in wx history.

Although likely too cold, the even colder 12Z CMC is somewhat similar with very cold air moving into the SE on 1/17, which would likely lead to the coldest of the winter to this point. Similar to last winter’s coldest around Christmas, this appears like it would be during a moderate to strong MC phase of the MJO interestingly enough. The strong -EPO/-AO/-NAO combo doing its thing.

In my area we quite possibly will have the coldest first half of January since 2018 with right at normal.

The 0Z 1/7/24 EPS mean has maintained the Jan 11-18 period of near or sub -150 (-1.5) EPO that was on this 0Z 1/4/24 run. An 8+ day long period of -150 or lower has occurred about once every two winters on average since 1948 with no winter having more than two of them. The 0Z 1/7/24 EPS run is implying that the low of this period would probably be sub -300. https://downloads.psl.noaa.gov/Public/map/teleconnections/epo.reanalysis.t10trunc.1948-present.txt

Thank you. So, the 0Z 1/7/24 EPS mean has maintained the Jan 11-18 period of near or sub -150 (-1.5) that was on the 0Z 1/4/24 run. An 8+ day long period of -150 or lower has occurred about once every two winters on average since 1948 with no winter having more than two of them. This EPS run is implying that the low of this period would probably be sub -300. https://downloads.psl.noaa.gov/Public/map/teleconnections/epo.reanalysis.t10trunc.1948-present.txt

Does anyone have the latest EPO forecast from the EPS or any model? TIA

Thank you!