WinstonSalemArlington Posted October 4, 2023 Share Posted October 4, 2023 3 Link to comment Share on other sites More sharing options...
WinstonSalemArlington Posted October 5, 2023 Share Posted October 5, 2023 2 Link to comment Share on other sites More sharing options...
GaWx Posted October 7, 2023 Share Posted October 7, 2023 SN El Niño/-QBO RDU/ATL (excludes ZR): 51-2: 4.7”/3.9” 53-4: 7.1”/0.1” 58-9: 13.5”/2.4” 65-6: 11.8”/0.7” 68-9: 12.0”/2.2” 72-3: 11.3”/1.0” 76-7: 3.6”/1.0” 79-80: 18.3”/4.4” 86-7: 10.8”/4.8” 91-2: T/5.0” 09-10: 8.0”/5.3” 14-15: 7.9”/T AVG RDU Nino/-QBO: 9.1” vs 6.4” norm; so AN avg; median 9.4” AVG ATL Nino/-QBO: 2.6” vs 1.9” norm; so AN avg; median 2.3” 2 2 Link to comment Share on other sites More sharing options...
GaWx Posted October 9, 2023 Share Posted October 9, 2023 I just posted this in the main ENSO thread and feel this is very relevant to prospects for cold in the SE during the upcoming winter. Bottom line: best chances for extended intense cold during El Niño winters are suggested (based on Nino winters since 1976-7) to be when the MJO is weak (including inside the COD), especially when mainly left side weak: 2 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted October 10, 2023 Share Posted October 10, 2023 Excellent work @GaWx. Hope we have a winter to remember. 1 Link to comment Share on other sites More sharing options...
olafminesaw Posted October 11, 2023 Share Posted October 11, 2023 AccuWeather is calling for wintry mix on Christmas Eve and Christmas in the Triad. Lock it in folks. 3 Link to comment Share on other sites More sharing options...
Jebman Posted October 13, 2023 Share Posted October 13, 2023 On 8/7/2023 at 11:22 AM, gman said: We have a Winnah. 1 Link to comment Share on other sites More sharing options...
WinstonSalemArlington Posted October 14, 2023 Share Posted October 14, 2023 TWC’s February outlook 3 Link to comment Share on other sites More sharing options...
GaWx Posted October 17, 2023 Share Posted October 17, 2023 On 9/30/2023 at 5:13 PM, GaWx said: El Niño Oct PNA: Strong +PNA: 53, 65, 79, 15 Mod +PNA: 63, 76, 77, 86, 87, 14 Weak +PNA: 57, 68, 69, 09 Neutral PNA: 51, 58, 94, 18 Weak -PNA: 97 Mod -PNA: 82, 02, 06 Strong -PNA: 72, 91, 04 SE US from coldest to warmest Nino winters 57, 63, 65, 69, 76, 77, 09: cold 68, 86, 87, 02, 14: cool 58, 72, 79, 82, 04: NN 94, 97, 06: mild 51, 53, 91, 15, 18: warm ——————— Correlation of Oct PNA to SE US winter for Nino -25% of the 4 strong +PNA (+1+) in Oct followed by cool to cold SE winter- A whopping 100% of the 10 weak to moderate +PNA (+0.25 to +0.99) in Oct followed by cold to cool SE winters - None of the 4 neutral PNA (-0.24 to +0.24) in Oct followed by cool to cold SE winter - 14% of the 7 -PNA (<-0.24) in Oct followed by cool to cold SE winter - So, only 13% of the 15 Octs that had either strong +PNA, neutral PNA, or -PNA followed by cool to cold SE winters - So, sweet spot by far for best shot at cool to cold SE Nino winters is Oct PNA of +0.25 to +0.99. Needless to say after just today discovering this, I’ll be rooting very hard for a +0.25 to +0.99 PNA in Oct! ** The data I’m basing this on is from the monthly PNA table seen at the 1st link below as opposed to the dailies (2nd link). That’s important to note because the monthlies average ~twice the amplitude of the dailies’ average. ———————— Today’s GEFS PNA prog for Oct 1-14 based on dailies is ~+0.6. However, keep in mind that the absolute value of the corresponding monthly amplitude averages ~twice as high as what the dailies would suggest. So, in this case, the equiv for the first half of Oct could easily be ~+1.2. That bodes very well for the chances of this full Oct’s PNA coming in as a +PNA when the monthly is released. But hopefully it would come in within the +0.25 to +0.99 interval so as to hit the sweet spot for the chances of a cool to cold winter: Monthly PNA (higher amp vs avg of dailies): https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table Daily PNA (lower amp vs monthly): https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii The Oct 1-16, 2023, PNA after doubling the dailies to approximate what the monthly calculation would be is ~+2. However, it is about to fall sharply and is progged to be a -PNA for ~10/22-31. Though it will still easily end up a +PNA for Oct as a whole, this sharp fall will bring down this +2 significantly. How far is the question. For El Niño winters since 1950, here are the Oct PNA along with the nature of the subsequent winter’s temperatures in the SE US: 1953: +1.91 warm 2015: +1.78 warm 1979: +1.53 normal 1965: +1.14 cool 1977: +0.98 cold 1986: +0.92 cool 2014: +0.89 cool 1963: +0.69 cold 1976: +0.68 cold 1987: +0.53 cool 2009: +0.43 cold 1969: +0.35 cold 1957: +0.27 cold 1968: +0.26 cool 1951: +0.24 warm 2018: +0.21 warm 1958: +0.16 normal 1994: -0.23 mild 1997: -0.26 mild 2002: -0.65 cool 2006: -0.84 mild 1982: -0.93 normal 2004: -1.39 normal 1972: -1.50 normal 1991: -2.28 warm Although there’s likely some randomness involved, the fact that all 11 El Niño winters following an Oct with a PNA within the interval +0.26 to +1.14 were cool or cold and 11 of the 12 cool to cold Nino winters (out of a total of 25 Nino winters) followed an Oct with a PNA in that range seems pretty significant. It tells me that if the Oct 2023 PNA were to end up in that range that the chance for a BN SE 2023-4 winter would be higher than the ~45% for an El Niño winter in general and the ~33% chance for all SE winters. 5 Link to comment Share on other sites More sharing options...
olafminesaw Posted October 18, 2023 Share Posted October 18, 2023 Winter is coming. We're about a month away from when according to climo, we might conceivably see some flakes. 4 Link to comment Share on other sites More sharing options...
GaWx Posted October 22, 2023 Share Posted October 22, 2023 On 10/16/2023 at 8:05 PM, GaWx said: The Oct 1-16, 2023, PNA after doubling the dailies to approximate what the monthly calculation would be is ~+2. However, it is about to fall sharply and is progged to be a -PNA for ~10/22-31. Though it will still easily end up a +PNA for Oct as a whole, this sharp fall will bring down this +2 significantly. How far is the question. For El Niño winters since 1950, here are the Oct PNA along with the nature of the subsequent winter’s temperatures in the SE US: 1953: +1.91 warm 2015: +1.78 warm 1979: +1.53 normal 1965: +1.14 cool 1977: +0.98 cold 1986: +0.92 cool 2014: +0.89 cool 1963: +0.69 cold 1976: +0.68 cold 1987: +0.53 cool 2009: +0.43 cold 1969: +0.35 cold 1957: +0.27 cold 1968: +0.26 cool 1951: +0.24 warm 2018: +0.21 warm 1958: +0.16 normal 1994: -0.23 mild 1997: -0.26 mild 2002: -0.65 cool 2006: -0.84 mild 1982: -0.93 normal 2004: -1.39 normal 1972: -1.50 normal 1991: -2.28 warm Although there’s likely some randomness involved, the fact that all 11 El Niño winters following an Oct with a PNA within the interval +0.26 to +1.14 were cool or cold and 11 of the 12 cool to cold Nino winters (out of a total of 25 Nino winters) followed an Oct with a PNA in that range seems pretty significant. It tells me that if the Oct 2023 PNA were to end up in that range that the chance for a BN SE 2023-4 winter would be higher than the ~45% for an El Niño winter in general and the ~33% chance for all SE winters. Preliminary indications are that the Oct PNA will likely end up within the +0.85 to +1.15 range. If so, that would put it in the upper part of the most common range of past El Niño Oct PNAs preceding cool to cold SE winters: 1965: +1.14 cool 1977: +0.98 cold 1986: +0.92 cool 2014: +0.89 cool 1963: +0.69 cold 4 2 Link to comment Share on other sites More sharing options...
olafminesaw Posted October 29, 2023 Share Posted October 29, 2023 6 weeks later and we'd be looking at a nasty little ice event 1 Link to comment Share on other sites More sharing options...
GaWx Posted November 5, 2023 Share Posted November 5, 2023 The Oct 2023 PNA came in at +1.20, which is a little higher than the +0.85 to +1.15 range that I had expected. For El Niño winters since 1950, here are the Oct PNAs along with the nature of the subsequent winter’s temperatures in the SE US: 1953: +1.91 warm 2015: +1.78 warm 1979: +1.53 normal 2023: +1.20 ???? 1965: +1.14 cool 1977: +0.98 cold 1986: +0.92 cool 2014: +0.89 cool 1963: +0.69 cold 1976: +0.68 cold 1987: +0.53 cool 2009: +0.43 cold 1969: +0.35 cold 1957: +0.27 cold 1968: +0.26 cool 1951: +0.24 warm 2018: +0.21 warm 1958: +0.16 normal 1994: -0.23 mild 1997: -0.26 mild 2002: -0.65 cool 2006: -0.84 mild 1982: -0.93 normal 2004: -1.39 normal 1972: -1.50 normal 1991: -2.28 warm Like most here, I prefer BN winters. Note that 11 of 12 of the BN SE El Nino winters since 1950 occurred when the preceding Oct PNA was within +0.26 to +1.14. Based on the assumption that this clumping isn’t mainly due to randomness (I don’t think it is), I’m content with the idea that the +1.20 Oct 2023 PNA suggests an enhanced chance of a BN SE winter though I would have preferred that the Oct PNA had come in a little lower (say ~+1.00) to within the clump rather than just above the clump. The +1.20 is still good enough in my mind. Let’s say that the Oct PNA had instead come in, say, either negative, or +1.75+. I definitely wouldn’t have felt it was enhancing BN SE winter chances and probably would have felt it meant the opposite, if anything. PNA monthlies back to 1950: https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table 1 1 Link to comment Share on other sites More sharing options...
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