GaWx

44 minutes ago, MJO812 said:

Where was this in Janaury?

1) Only 19% of Januaries 1981-2023 had -NAO (sub -0.25). -NAOs were three times more frequent in Jan during 1955-80 (58%)!

2) This 19% of Jans with -NAO 1981-2023 contrasts with 35% of Aprils during the same years.

3) Actually though, the GEFS chart shows a forecasted -NAO in April similar to that of early to mid Jan. Jan 15-21 near the end of that -NAO was the coldest week of the winter along with two snows.

NAO monthlies:

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

Is the 12Z GFS on crack? Inquiring minds want to know.

56 minutes ago, PhiEaglesfan712 said:

List of El Nino to La Nina transition years (bolded are best analog years for 2024-25)

1954: Weak El Nino -> Weak La Nina (followed by Strong La Nina in 1955-56)

1964: Moderate El Nino -> Weak La Nina

1970: Weak El Nino (preceded by Moderate El Nino in 1968-69) -> Moderate La Nina

1973: Super El Nino -> Strong La Nina

1983: Super El Nino -> Weak La Nina (followed by Moderate La Nina in 1984-85)

1988: Strong El Nino -> Strong La Nina

1995: Moderate El Nino -> Moderate La Nina

1998: Super El Nino -> Strong La Nina (repeated in 1999-2000)

2005: Weak El Nino -> Weak La Nina

2007: Weak El Nino -> Strong La Nina

2010: Strong El Nino -> Strong La Nina

2016: Super El Nino -> Weak La Nina (repeated in 2017-18)

2020: Maybe Weak El Nino (preceded by Weak El Nino in 2018-19) -> Moderate La Nina (repeated in 2021-22 and 2022-23)

I love this kind of stuff! Thanks for posting.
 

1) I’ll do the same with pre 1950 using Eric Webb’s table: Nino to Nina

1856: mod Nino to mod Nina

1869: mod Nino to weak Nina 

1886: mod Nino to mod Nina

1889: super Nino to mod Nina

1903: strong Nino to weak Nina

1920: weak Nino to weak Nina

1924: mod Nino to mod Nina

1942: mod Nino to mod Nina

 2) There were nine strong to super Ninos 1850-1950. Of these nine, none transitioned directly to a strong to super Niña, which is very much unlike the four out of the nine strong to super Ninos that you showed did so from 1950-present:

Pre-1950: 1 went to mod Niña, 1 went to weak Niña, 5 went to neutral, 1 went to weak Nino, 1 went to mod El Nino

Webb’s data from here:

https://www.webberweather.com/ensemble-oceanic-nino-index.html

1 hour ago, PhiEaglesfan712 said:

If we get a strong la nina, then I don't see us having another El Nino until at least 2027-28. There were 4 times we have gone from strong el nino to strong la nina, and each time, the next el nino was at least 3 years later.

1973 - Next el nino was 1976-77 (3 years later, moderate repeated following year)

1988 - Next el nino was 1991-92 (3 years later, strong)

1998 - Next el nino was 2002-03 (4 years later)

2010 - Next el nino was 2014-15 (4 years later, following year would be a super el nino)

There have been 8 strong la nina years. Only once, in 1976 (following the 3rd year of a la nina), did we transition to any type of el nino.

 Interesting! With a strong Niña quite possible and even more possible on a RONI basis, I feel your analysis is pertinent. I was just getting ready to post the last times we had a Nino/Niña/Nino progression for any strength of Nino/Nina, which I assume you know at least back to 1950:

1) 2004-5/05-06/06-07 but they were all only weak

2) 1963-4/64-5/65-6 but 1963-4/64-5 were only moderate/weak

3) 1923-4/24-5/25-6 but 1923-4/24-5 were only moderate

4) 1902-3/03-4/04-5: 1902-3 was a strong Nino but 1903-4 was only a weak Nina

5) 1885-6/86-7/87-8 but 1885-6/86-7 were only moderate

 The above list fwiw suggests to me that there might be a better shot if 2024-5 were to end up only a moderate La Niña like 1924-5 and 1886-7. After all, it is still way too early to say that it is a forgone conclusion that 2024-5 will peak as a strong Niña. Also, keep in mind the unusual situation of this massive undersea volcanic eruption. Is it possible that analogs are not as useful as they’d otherwise be?

 CANSIPS has Aleutian high/-PNA/+EPO/+NAO/+AO/-PDO in its latest fcast for next winter: yippee I can’t wait /hope it is wrong. Regardless, winter is still my favorite season since even a mild one would be 25+ colder with way less humidity than the typical miserable summer here (along with no bugs ). Also, even a mild one would be far more interesting than summer with much more day to day volatility.

On 3/22/2024 at 11:21 AM, GaWx said:

 I’ll believe a legit +PDO is coming next winter when I see it.

 Posted below is the latest WCS PDO chart showing -0.37 as of March 20. But keep in mind that a -0.37 WCS is comparable to a much more negative NOAA PDO. The Feb 2024 NOAA PDO was still down at -1.33 despite this WCS chart showing every Feb daily being above -0.75 and Feb averaging -0.45 to -0.50:

https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat

 So, the current NOAA PDO is likely ~~-1.20, still a solid -PDO. Also, the chart below shows that the WCS PDO has been oscillating around this same territory since late Jan (despite how warm most of the E US has been since then). Thus, I still see no indication of a clear move toward a +PDO.

 For there to be just a weak NOAA based +PDO next winter (say +0.25 to +0.50), the WCS dailies would likely need to rise all of the way to near the +1.00 to +1.25 range. With what appears to be a moderate to strong La Niña coming (probably even stronger on RONI basis as it has averaged a whopping 0.4 cooler than ONI for the last year), that’s highly improbable as of now.

 The last La Niña winter with a +0.25+ NOAA PDO was way back in 2005-6 (barely with +0.27) and that one was just a low end moderate Niña at most. The subsequent nine Ninas were either -PDO (7 of the 9) or neutral PDO (2016-7 and 2017-8). Prior to 2005-6, the last +PDO Niña was 1995-6 (moderate Niña). Keep in mind that there’s a good chance for a high end moderate to strong Niña (RONI based) next fall/winter.

 There have been 11 seasons with a sub -1.20 low on a RONI basis since 1949-50, which is very likely where we’re headed next fall/winter. None of those winters had a NOAA based +PDO:

1949-50: -1.6

1955-6: -2.2

1973-4: -1.1

1988-9: -0.9

1998-9: -1.0

1999-0: -1.8

2007-8: -1.3

2010-1: -1.8

2017-8: +0.1 (the only neutral PDO and that was with RONI dip to only -1.25)

2020-1: -0.9

2021-2: -2.3

AVG winter PDO for sub -1.2 RONI: -1.3

 

 Based on the above analysis as well as SSTa progs for next winter that I’ve seen, I’m betting heavily that there will not be a NOAA based +PDO (+0.25+) next winter.

 Supporting the above for a -PDO next winter (CFS is similar) (Note that if this verified it wouldn’t at all be E based Niña/closer to Modoki than E based):

2m vs 1981-2010 climo (would be little cooler vs 1991-2020 but keep in mind the cold bias of most models):

On 3/23/2024 at 4:23 PM, LibertyBell said:

hmm what kind of la nina was 2010-11?

 

https://www.cpc.ncep.noaa.gov/data/indices/ersst5.nino.mth.91-20.ascii

 -What distinguishes 2010-1 was the combo of a record avg -NAO/-AO for DJ for La Niña.

-Feb +NAO/+AO ended that

-Since 1979-80, there have been only 6 -NAO winters (sub -0.25 avg) with all of them occurring during low sunspot #s (sub 35): 1984-5, 1986-7, 1995-6, 2009-10, 2010-1, 2020-1. To compare, the last 2 winters’ sunspots averaged ~120. AGW is quite possibly a factor in limiting -NAO winters while also increasing their frequency during summer.

15 hours ago, raindancewx said:

The PDO continues to reverse from pretty negative despite the El Nino falling apart. That's worth watching. The +PDO La Ninas are an interesting bunch. 

+PDO tends to be cold East, La Nina tends to be cold North. It's the opposite of last winter where -PDO tends to be cold West, and El Nino tends to be cold South. Years like 1995-96 and 2017-18 are +PDO La Ninas. 

I see some indications that the WPO may flip pretty negative in the Fall. That's often accompanied by early Fall snows nationally, but we'll see how that goes.

 I’ll believe a legit +PDO is coming next winter when I see it.

 Posted below is the latest WCS PDO chart showing -0.37 as of March 20. But keep in mind that a -0.37 WCS is comparable to a much more negative NOAA PDO. The Feb 2024 NOAA PDO was still down at -1.33 despite this WCS chart showing every Feb daily being above -0.75 and Feb averaging -0.45 to -0.50:

https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat

 So, the current NOAA PDO is likely ~~-1.20, still a solid -PDO. Also, the chart below shows that the WCS PDO has been oscillating around this same territory since late Jan (despite how warm most of the E US has been since then). Thus, I still see no indication of a clear move toward a +PDO.

 For there to be just a weak NOAA based +PDO next winter (say +0.25 to +0.50), the WCS dailies would likely need to rise all of the way to near the +1.00 to +1.25 range. With what appears to be a moderate to strong La Niña coming (probably even stronger on RONI basis as it has averaged a whopping 0.4 cooler than ONI for the last year), that’s highly improbable as of now.

 The last La Niña winter with a +0.25+ NOAA PDO was way back in 2005-6 (barely with +0.27) and that one was just a low end moderate Niña at most. The subsequent nine Ninas were either -PDO (7 of the 9) or neutral PDO (2016-7 and 2017-8). Prior to 2005-6, the last +PDO Niña was 1995-6 (moderate Niña). Keep in mind that there’s a good chance for a high end moderate to strong Niña (RONI based) next fall/winter.

 There have been 11 seasons with a sub -1.20 low on a RONI basis since 1949-50, which is very likely where we’re headed next fall/winter. None of those winters had a NOAA based +PDO:

1949-50: -1.6

1955-6: -2.2

1973-4: -1.1

1988-9: -0.9

1998-9: -1.0

1999-0: -1.8

2007-8: -1.3

2010-1: -1.8

2017-8: +0.1 (the only neutral PDO and that was with RONI dip to only -1.25)

2020-1: -0.9

2021-2: -2.3

AVG winter PDO for sub -1.2 RONI: -1.3

 Based on the above analysis as well as SSTa progs for next winter that I’ve seen, I’m betting heavily that there will not be a NOAA based +PDO (+0.25+) next winter.

On 3/19/2024 at 12:10 PM, GaWx said:

Indeed, it looks wet for many areas of the SE late week into the weekend. Also, the latest drought map for the SE overall looks good and way better than it looked 2.5 months ago thanks to El Niño. I know N GA could use a break from recent heavy rains with plentiful creek/river flooding (I saw it) and fortunately it doesn’t look too heavy there. My area (SE GA) has averaged near normal though not too far away in Charleston it has been too wet.

 
 This is how bad it was 12/26/23:

Fantastic improvement most areas since then with dry area of E NC in line for heavy rain by weekend:

Drought monitor map from today (as of 3/19/24): far NW GA dry area gone, but E NC area expanded slightly including in the Fayetteville vicinity. Based on most model runs’ precip progs for the next 10 days (i.e., assuming the 6Z GFS won’t verify), there may be no yellow in NC.

On 3/19/2024 at 1:01 PM, NorthHillsWx said:

Yep the drought from last fall has been erased but we haven’t had measurable rain since March 9 and it’s quickly dried out during that time. Friday should be wet but we’ve seen a lot of recent systems fall apart for central NC this spring so hopefully that trend is halted. April and May are typically dry months for us so going into them dry can be a bad thing as we start to really warm up. 

After the late week/weekend expected good rains in a decent portion of the SE, mid to late next week also looks wet for much of the SE on most runs of the various models, including ensembles. However, the 6Z GFS was a good bit less wet for mid to late next week than most prior runs. Then again, its own ensemble mean says the op is a dry outlier.

24 minutes ago, michsnowfreak said:

Assuming that's a typo on the bottom graph (meaning it should be 2020-21) I'd have to say his forecast was dead on here. The "normal" line runs through Detroit and DTW finished the winter +0.1°.

 

Also, am I reading correctly? Did he actually forecast 2013-14 to be a warm winter 

1. Yes, that’s a typo on the bottom graph.

2. He actually did well with his cooler revision for 2020-1. My point in showing that though was to show that he’s not held onto a mild forecast for that region since at least 2013-4 due I assume to having a cold bias/warm winter forecasts are bad for business. There are companies that are more objective and will not be afraid to go warm giving them much more credibility.

3. My bad due to poor wording. I don’t know what he forecasted for 2013-4. The only reason I referred to it is that the furthest back ones I can find only go back to 2014-5.

 Anyone want to bet that Joe Bastardi won’t go 3+ F warmer than normal for the bulk of the Ohio Valley, Mid-Atlantic, and New England for his FINAL winter forecast for 2024-5? I’m not talking about any preliminary forecasts. I actually hope I’m wrong because I’d like to see him do it for a change for his final. I can’t tell you how long it has been since he did just that. One at the very least has to go back to 2013-4 for the final one to possibly be that warm. I actually don’t know what he had for 2013-4 or earlier because I can’t find them. WxBell started ~2010.

 His preliminary winter forecast for 2020-1 was ~+3 to +4 for the bulk of the Mid-Atlantic and much of the Ohio Valley (New England was +2 to +3):

But then he cooled it way down for the final to mainly +0.5 to +1: that’s why I say wait until the final is released

On 3/18/2024 at 6:44 AM, NorthHillsWx said:

Hopefully we get some good rains Friday-Saturday because it looks exceptionally SE-ridgy/dry beyond the weekend and it truly hasn’t rained much here lately. Western areas and South Carolina a different story 

Indeed, it looks wet for many areas of the SE late week into the weekend. Also, the latest drought map for the SE overall looks good and way better than it looked 2.5 months ago thanks to El Niño. I know N GA could use a break from recent heavy rains with plentiful creek/river flooding (I saw it) and fortunately it doesn’t look too heavy there. My area (SE GA) has averaged near normal though not too far away in Charleston it has been too wet.

 
 This is how bad it was 12/26/23:

Fantastic improvement most areas since then with dry area of E NC in line for heavy rain by weekend:

No snakes today and a great walk with mid 60s temp and dewpoints near 38 along with a nice NW breeze.

Cool time lapse of the big mid-March snowstorm in Evergreen, CO, located at 7.2K ft 20 miles WSW of Denver or 10 miles SW of Golden:

https://m.facebook.com/WeatherNation/videos/3-days-worth-of-snow-in-24-seconds/732334295379764/

 On this date in 1892 - A winter storm in southwestern and central Tennessee produced 26 inches of snow at Riddleton, and 18.5 inches at Memphis. It was the deepest snow of record for those areas. (David Ludlum)

 Also on this date in 1892, Nashville got blasted with 17.0” of snow (17" on 3/17)! This was and still is the heaviest calendar day of snowfall on record there by a good margin. And it fell after 4.3” fell the prior two days! Chattanooga got 0.9” on 3/17 and 0.3” on 3/18. Knoxville got 3” though it was recorded on 3/18. Atlanta got 0.3” 3/17-18.

I’ve taken thousands of walks and until yesterday evening I had never seen three snakes in one walk. I don’t know if I’ve even seen two though I may have once or twice. 99% of the time I see none. So, seeing three yesterday was so ridiculously improbable! Two were poisonous and both apparently were Copperheads of different types. I’d post pics of them here but can’t due to attachment limits. 
 Temperatures were in the 70s while dewpoints were in the 50s. The breeze was light.

 There are some model hints that the period around 3/23-5 might include interesting wx in a good portion of the SE. Keep in mind that “interesting wx” and “winter storm” are not one and the same even though a winter storm is obviously interesting.

 The models are near unanimous in showing a sub -20 mean 10 mb (strat.) wind at 60N on March 15th. That would be the 2nd most negative 10 mb wind in March since records started in 1959.

1 hour ago, iluvsnow said:

Was just reading about the "most anomalous" weather month in US history....March 1843. Fascinating reading. It included a huge midmonth snowstorm in Tennessee and 25 degree below normal temperatures for the month of March for much of the central and eastern US. Fort Snelling in St. Paul Minnesota averaged an unbelievable 4 degrees above zero for the month. Snow fell in Tennessee well into April. Just wonder what kind of meteorological setup could have produced such weather.

https://www.researchgate.net/publication/284436645_March_1843_The_Most_Abnormal_Month_Ever

https://www.weather.gov/ohx/18430315

March of 1843 was truly amazing! From David Ludlum:

Confirmation that the cold and snowy regime of March 1843 was widespread across the Southland came from a new observing post in southwestern Arkansas.

In 1840 Nathan D. Smith of Washington; Hempstead County, near Texarkana, commenced a series of very good records which continued at least until the opening of the Civil War. The period from 1840 to 1859 was published in tabular form by the Smithsonian Institution in October 1860, and the record in manuscript is available until April 1861.° March 1843 (35.3°) was the coldest month in Dr. Smith's record save January 1856 (34.0°).

His maximum of 70° came on the 30th, the minimum of +6° on the 16th. There were two 4-inch snowstorms, on the 15th and 24th-the same dates that Natchez received a like covering. On another occasion glaze formed on trees, and on another sleet fell.

Beautiful dry spring wx is expected again the next two days. 

On 2/3/2024 at 3:34 PM, GaWx said:

The unrounded ONI max came in at +1.97. RONI never made strong with another +1.49.

I just noticed that the unrounded ONI peak (NDJ) was revised down slightly from +1.97 to +1.95:

https://www.cpc.ncep.noaa.gov/data/indices/oni.ascii.txt
 

 The RONI peak remained at +1.49 (OND)(border of moderate and strong):

https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

 Yesterday was quite nippy here in the ATL area with 50s and 20 mph winds. Today was beautiful and felt much warmer with 60s highs, much lighter winds, and sunshine. It was a great day for walking at the park I was at. The water was high due to last week’s 4-5” of rainfall. I saw several turtles on the lake’s edge.

17 hours ago, StantonParkHoya said:

RDU never gets below 40 on the 6z GFS through 384

Same with the 18Z GFS it appears. The Euro suites have generally been colder. We’ll see which comes closer.