GaWx

I never noticed there was a different Euro Weeklies chart for surface! I always look at 2m. For determining frost on ground, I’d think surface would be more important than 2m. On good radiational cooling nights, you may already realize that surface is sometimes couple of degrees colder than 2m due to colder air being heavier. But 2m is official. And thus I’ll continue to use those. On nights after a cold front has just come through and the cold winds are advecting colder air, I’d think sfc would tend to be slightly warmer. When sun is out, the ground should be warmer than 2m, especially in summer.

-I thought 2m and surface were the same. -Please show me where they’re different. -Shades of red: anomalies in degrees C 1st: 0 to +1 2nd: +1 to +3 3rd: +3 to +6 4th: +6 to +10 5th: +10+

Unfortunately for cold lovers like myself, today’s Euro Weeklies for 2/17-23 & 2/24-3/2 totally reversed yesterday’s much colder runs for those two weeks and are back to a solid mild signal: 2/17-23: The other 5 weeks of the run through 3/16 are about as warm or warmer. The implied prog for Feb as a whole is for ~6F AN in much of the SE. The good news is that there’s still plenty of time for especially late Feb to reverse. But the overall signal for a mild SE in Feb has been persistent with a dominant SE ridge and +AO/+NAO (canonical La Niña Feb). And for those worried about cold rains in early Mar, this run says “no worries” like it did yesterday.

Unfortunately for cold lovers like myself, today’s Euro Weeklies for 2/17-23 & 2/24-3/2 totally reversed yesterday’s much colder runs for those two weeks and are back to a solid mild signal: 2/17-23: All 6 weeks of today’s run are this warm or warmer in the E US. The implied Feb avg is ~4F AN NYC and ~5-6F DC south. Would be very close to March normals in SE. Many places in the area DC south would have a Feb ~13-15 warmer than Jan. Be that as it may, there still appears to be a good shot at a 2-3 day long cold period starting Feb 8-9.

I don’t disagree for the most part. But I was responding to CWG’s tweet saying this: “MJO approach to phase 7 could flip pattern back to cold side for U.S. by 2nd week of February, similar to super-warm late December to cold early January flip from this winter.” So, the tweet was referring explicitly to temperatures and said nothing about snow. Thus, my response was referring to just temperatures based on what 0Z/6Z model consensus was showing. I wasn’t at all addressing snow, which is much more unpredictable, especially 11+ days out, since it is so dependent on precise storm track and actually having a storm at the right time. Also, some do care about temps on their own.

Even in a mild (cold) month, a short period or two of cold (mild) isn’t uncommon. 0Z/6Z ens means are suggesting a 2-3 day long cold period is quite possible in the E US starting ~Feb 9th-10th but otherwise they’re mainly on the mild side NYC south and restrengthen the SE ridge immediately afterward. So, the means for the first half of Feb would still easily be AN NYC south. Will keep watching ens mean trends for Feb 9th+ to see how they trend going forward. Phases 6-7, especially 6, lean toward the AN temp side in Feb fwiw. Phases that are BN on avg in Feb are 8, 1, 2, and 3, especially if amplitude isn’t strong.

Even in a mild (cold) month, a short period or two of cold (mild) isn’t uncommon. 0Z/6Z ens means are suggesting a 2-3 day long cold period is quite possible in the E US starting ~Feb 9th-10th but otherwise they’re mainly on the mild side NYC south and restrengthen the SE ridge immediately afterward. So, the means for the first half of Feb would still easily be AN NYC south. Will keep watching ens mean trends for Feb 9th+ to see how they trend going forward. Phases 6-7, especially 6, lean toward the AN temp side in Feb fwiw. Phases that are BN in Feb on avg are 8, 1, 2, and 3, especially if amplitude isn’t strong.

Yeah, I fully realize that it takes on average a couple of weeks to translate vertically. But about all of Jan has been much stronger than average with high 50s to 60 also 1/7-14 (see image below) and it was pretty high before that. Yes, I realize you didn’t say significantly colder.

Even a weak SPV isn’t anywhere close to being a reliable indicator for a cold E US. Consider that the SPV mean wind was actually peaking near a record high upper 50s on the days that the Deep South had an historic snow/sleetstorm (1/21-2)!

However, the latest Euro Weeklies and extended GEFS still show no strong signal for a major SSW in Feb like they did for the several that occurred in 2023 and 2024. But Joe D’Aleo did find a connection with high solar and +QBO that says to be on guard for that possibility: EPS (1/29): shows 60N 10 mb zonal winds dropping 2/6-15, but mean drops only to a little above climo with most members at 15-40: GEFS (1/28): mean drops to 40 on Feb 11th, but that’s still well above 20 climo (**edited for correction): *Edited for correction

Good news for you as of now. There’s no indication for a cold first 1/3 of March on today’s Euro Weeklies. Though it could of course change drastically since it is over a month away, this map shows the opposite of cold in the E US: This is for Mar 3-9:

Both the CFS and the Euro Weeklies this winter have had the E (including the SE) with far BN temps several weeks in advance (and the coldest anomalies on the globe) and they remained consistent with the cold thereafter. These are just 3 examples of the many times they did with strong signals for cold in the E US: Issued 12/28/24 for 1/13-19: CFS 48 forecast mean (4 members, 12 runs 12/25-28) for 1/11-17: CFS 48 forecast mean (4 members, 12 runs 12/29-1/1) for 1/15-22): In contrast, today’s significantly colder Euro map vs yesterday for 2/17-23 is at least as of yet nowhere near as cold: Latest CFS 48 forecast mean for 2/20-7: still mild in E US

Well Mr. Moles, I wouldn’t say in bank but 3”+ storms in Feb in GA have tended to occur mid to late Feb to Mar 2nd as well as in late Jan. For an unknown reason early Feb has been quiet. Could be merely randomness.

Though still not showing anywhere near BN cold and still mild through 2/16 in the SE, the new Euro Weeklies have cooled off from AN to only slightly above to NN in N portions 2/17-3/2 in the SE US. We’ll see whether or not that is a one run aberration. 2/17-23: (2/24-3/2 looks similar in SE)

There’s been no measurable snow/sleet in ATL during Feb since 2014. In the late 1800s, Feb was the snowiest month.

The Euro Weeklies have been amazingly accurate this winter several weeks out! This 500 mb map below was released on Dec 15th for Jan 6-12, which was at the release time 22-28 days in the future. One can see that the coldest anomalies on the entire globe were targeting the E US even 3-4 weeks out, which verified well. The cold on these and the 2m maps intensified as the period got closer. The Euro did similarly well for the subsequent two weeks (Jan 13-19 and Jan 20-26) well in advance concentrating the coldest on the planet in the E US. For Feb they’ve been harping on a much milder pattern in the E US especially south of New England (canonical La Niña Feb pattern) thanks to a -PNA/+AO/+NAO (near opposite of Jan). Based on the Euro’s impressive accuracy weeks in advance and La Niña climo, I see no reason to bet against a much warmer pattern, especially MidAtlantic/Ohio Valley south. This Euro 2m temp map is for Feb 3-9: much warmer than Jan especially most of E US and much colder SW Canada and NE Canada/Greenland: This one is for Feb 10-16: similar

850 mb temperatures for the airmass a week ago were as cold as -37C in the upper Midwest! That’s not seen too often.

Today’s Euro Weeklies for Feb are ~5F AN vs yesterday’s ~+4F. More like a normal March than Feb. But cheer up as that would still be 2-3F cooler than Febs 2023, 2018, and 2017. So, it could always be worse.

We finally lost the last remnants of the very stubborn mainly sleet-cover yesterday (started from 3”). So, it lasted just over 5 days mainly in some shaded spots. Impressive staying power but that’s the nature of sleet combined with some ZR on bottom and some snow mixed in top layer. It took some rain to help lose it.

Yes: 4/2/1965 had 1.2” at NYC. Other metro stations were similar.

Agreed as of now. The following La Niña Feb/Mar had a late Feb/early Mar -AO/-NAO; all but one had a major SSW preceding it: 2023: Feb 16th 2018: Feb 12th 2006: Jan 21st (also had -AO/-NAO a month earlier) 2001: Feb 11th 1971 in early to mid Mar: Jan 17th 1965: the exception of these 6 as there was no SSWE til Mar 23rd Whereas the models (extended EPS/GEFS) continue to show nothing, the combo of current high solar and +QBO suggests per Joe D’Aleo and confirmed by my own analysis that the chance for one is actually good. So, we’ll need to monitor. Of course if it occurs and it isn’t til, say, Mar, it would be unimportant for late Feb/early Mar due to lag.

The latest Euro Weeklies are dominated in Feb by AN in the Ohio Valley and MidAtlantic south to the SE. Feb 10-16 warmed from NN to AN. But New England remains mainly only slightly AN to NN. Favoring E warmth is a SE ridge/-PNA/Aleutian ridge in combo with a +AO/+NAO. The tricky thing though is a pretty strong -EPO for the 1st half of the month, which could allow for some cold (probably well modified) to reach these otherwise mild areas and especially NE/Ohio Valley. The Euro Weeklies have been magnificent so far this winter and is why I like to post about them whether cold or mild.

The new Euro Weeklies for the SE are AN every week of Feb. Overall, this run is even warmer than yesterday’s as a result of a warmer Feb 10-16, which is AN vs the NN of the prior two runs. This run has much of the SE at an anomaly of ~+4F, which would equate to in the absolutes about a 11-14F warmer month than Jan. The SE ridge/-PNA/Aleutian ridge as well as +AO/+NAO are dominant through the month. The main fly in the ointment is a pretty strong -EPO for the 1st half of the month, which may allow for some cold air sneaking in at times although the weeklong 2m maps don’t explicitly show any. The Euro Weeklies have been magnificent weeks in advance for this winter so far. That’s why I feel they’re worthy of posts and is why I’ve been regularly posting about them throughout this winter whether cold or mild.

Don’t forget that even a mild winter month can and often does have a short cold period. They’re far from mutually exclusive. Just like a cold month often has a short mild period.

I’m projecting Jan of 2025 to end up with a mean temp of 44.8F (~6F BN) in Savannah. That would make it the coldest Jan since 1981 and tied with 1918 for the 8th coldest Jan back to 1874 behind only: 1893, 1940, 1958, 1970, 1977, 1978, and 1981 For non-El Nino only, 2025 would with 1918 be tied for 3rd coldest Jan behind only 1893 (La Niña) and 1981 (cold neutral)! Here are the only 6 La Niña Jans that were 46 or colder at KSAV: 1887 (46.0) 1893 (44.3) 1918 (44.8) 1976 (45.9) 1985 (45.3) 2011 (45.1) Average of these 6: 45.2 (MB) How were the subsequent Febs along with their anomalies using 53.6 as normal? 1887: 59.9 (MA) 1893: 56.8 (A) 1918: 58.9 (MA) 1976: 56.3 (A) 1985: 52.9 (N) 2011: 55.4 (slightly A) Average of these 6: 56.7 (A) -So, for these very cold (46 or colder/MB) Nina Jans, the following Febs averaged a whopping 11.5 warmer! -None were BN. -All but 1985 were 10+ warmer than the prior Jan. The Euro Weeklies are suggesting Feb of 2025 will be 10+ warmer than Jan of 2025 at KSAV thanks to a dominant solid SE ridge. Based on the above analysis, I have no reason to doubt that this will actually occur as of now. Historical data: https://www.weather.gov/wrh/Climate?wfo=chs