GaWx

One year ago today, this was the coldest Euro Weeklies map (for mid Jan): it’s always going to be hard to match something like this in the SE as a whole in the general sense. This was near the time of the first major snowstorm (that hit ATL among other places). And there was also a second very cold week around the time of the Gulf coast storm. But one doesn’t need historic periods like this to still have a great period of winter at least in more localized areas:

Today’s Euro Weeklies came in colder in mid to late Jan: 1/12-18 a week ago: 1/12-18 today 1/19-25 today:

Today’s Euro Weeklies’ SPV at 10 mb is even weaker based on mean zonal 60N winds: One week ago: Today: note Jan 12th dip to only 22 vs it being way up at 47 a week ago:

The historic January of 2025 looking better isn’t surprising as it had nearly wall to wall intense cold along with major winter storms in the SE and thus is always going to be hard to match in a general sense. The Euro Weeklies were much colder in the SE US for Jan at this point. Edit: But otherwise: 12Z ensemble means update for late week 2: good news overall for E US cold and also snow lovers: 1. GEFS H5 improved somewhat vs 0Z/6Z with a slightly higher PNA though it’s still a -PNA. The best news is that it’s significantly colder with BN temps and it’s snowier in much of the region. 2. EPS is very similar to the 0Z, which makes that good news because it’s chilly along with a nice +PNA. No caving whatsoever to the ugly 0Z/6Z GEFS.

12Z ensemble means update for late week 2: good news overall for E US cold and also snow lovers: 1. GEFS H5 improved somewhat vs 0Z/6Z with a slightly higher PNA though it’s still a -PNA. The best news is that it’s significantly colder with BN temps and it’s snowier in much of the region. 2. EPS is very similar to the 0Z, which makes that good news. No caving whatsoever to the ugly 0Z/6Z GEFS.

Thanks for your reply. I agree it is a risk, unfortunately. But my supported hopes (GEFS 2nd week on avg has been awful and much too warm) are that today’s 0Z EPS’ moderate +PNA, which starts Jan 7th, will prevail: Today’s 12Z ens runs will be extra interesting due to this major disagreement in week 2!

The 0Z EPS (another run with a transition to a +PNA and a chilly E US) and the 0Z/6Z GEFS (staying -PNA and a warm E US) are in different worlds for mid Jan. The CPC GEFS forecasts of yesterday vs today show a bad 24 hour trend if you want it cold in the E US in mid-Jan: Yesterday’s GEFS PNA forecast was heading up/nice trend vs earlier runs: Today’s 0Z GEFS said never mind, I’ll stay -PNA through the end of the run: yuck GEFS 0Z 360 hour 2m temps: mild in E US with the cold way out to the NW….yuck But the good news is that the GEFS has had a persistent -PNA and warm E US bias over the 90 day period for this map: And the EPS, a better performing and recently steadier ensemble, still has a +PNA and a chilly E US:

Carver/Met, I happen to already be knowledgeable about what BAMwx is trying to say. I don’t know why BAMwx is calling it 43 “points” gained for the GEFS. That throws off this tweet and makes it confusing. It’s actually 43 heating degree days gained for the period 12/28-1/3 vs what the run had 7 days ago (12/21 run). This means that the 12/21 run was much warmer for that period than the 12/28 run mainly because it largely was still missing the oncoming E US cold period. OTOH, the 12/21 EPS wasn’t nearly as far off because it was significantly colder than the GEFS in the E US due to already figuring it out much earlier than the GEFS. So, it only needed to gain 12 HDDs to fully see the light. The blues represent colder changes since 12/21 while the red/yellow means warmer changes.

Jax, The OHC has orange for the first time since early July:

CAD doing its magic in NC! I’m jealous of you caddies. Consider that here it is still 70.8 here (with overcast). But even this is better than high 70s with sunny 24 hours ago and better than earlier this afternoon. This contrast between GA and NC was forecasted quite well. Yesterday’s high at KSAV was a sweaty record tying 80.

Well, check this out: Look at how much weaker the SPV forecast is at 10 mb based on the 60N mean zonal wind on the Euro Weeklies! One week ago (12/21 run): quite strong just about all Jan through Feb 4th with no end in sight (mean 40-47 m/s): Today (12/28 run): near normal Jan 10th-Feb 11th (mean only 25-35):

I looked at the NYC snowfall for the 17 -ENSO winters for which Dec was cold and had snowfall of 6”+ (from @donsutherland1updated list): Year (Dec)..Total Season..Jan+ 1872….60.2….29.9 1874….56.4….46.3 1886….31.9….21.6 1893….39.2….30.9 1903….32.4….26.0 1909….27.2….17.4 1915….50.7….42.6 1916….50.7….36.2 1917….34.5….20.1 1922….60.4….51.4 1926….22.3….10.6 1933….52.0….36.6 1942….29.5….21.0 1944….27.1….20.4 1995….75.6….61.2 2000….35.0….21.6 2010….61.9….41.8 ———————— Analysis: -AVG of these Jan+: 31.5” vs 22.1” full 156 year record mean or 143% of mean for Jan+ (median was 29.9”) -41% (7 of 17) had 35”+ for Jan+ vs only 12% of the other 139 (17 of 139) -These 17, which are only 11% of the total 156 on record, had: 1. Highest Jan of the 156 on record (2011’s 36.0”) and 3 of top 5 Jans (2011, 1996, 1923) 2. 3rd highest Feb of the 156 (1934’s 27.9”) 3. 2nd highest Mar of the 156 (2016’s 25.5”) 4. Highest Apr of the 156 (1875’s 13.5”) and tie for 5th (1917’s 6.5”) ————————— My NYC total 2025-6 snow prediction based on these stats: 40” (most likely range 30-50”) This compares to 156 year and 35 year means of 28”.

I looked at the NYC snowfall for the 17 -ENSO winters for which Dec was cold and had snowfall of 6”+ (from @donsutherland1updated list): Year (Dec)..Total Season..Jan+ 1872….60.2….29.9 1874….56.4….46.3 1886….31.9….21.6 1893….39.2….30.9 1903….32.4….26.0 1909….27.2….17.4 1915….50.7….42.6 1916….50.7….36.2 1917….34.5….20.1 1922….60.4….51.4 1926….22.3….10.6 1933….52.0….36.6 1942….29.5….21.0 1944….27.1….20.4 1995….75.6….61.2 2000….35.0….21.6 2010….61.9….41.8 ———————— Analysis: -AVG of these Jan+: 31.5” vs 22.1” full 156 year record mean or 143% of mean for Jan+ (median was 29.9”) -41% (7 of 17) had 35”+ for Jan+ vs only 12% of the other 139 (17 of 139) -These 17, which are only 11% of the total 156 on record, had: 1. Highest Jan of the 156 on record (2011’s 36.0”) and 3 of top 5 Jans (2011, 1996, 1923) 2. 3rd highest Feb of the 156 (1934’s 27.9”) 3. 2nd highest Mar of the 156 (2016’s 25.5”) 4. Highest Apr of the 156 (1875’s 13.5”) and tie for 5th (1917’s 6.5”) ————————— My NYC total 2025-6 snow prediction based on these stats: 40” (most likely range 30-50”) This compares to 156 year and 35 year means of 28”.

Our area had a sweaty 80 high today.

When you consider that both the EPS and GEFS have had a notable -PNA bias/notable warm bias from your area eastward and that all -ENSO -PNA Decs have transitioned to +PNA Jans, these consistently much better pattern maps for mid-Jan are quite encouraging. Just 5 days ago, the EW had this ugly -PNA for 1/12-18: