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  1. Following up on my previous post regarding correlating the November pattern and temps to DJF pattern and temps during Ninas, I added individual month data for each composite (summarizing the 5 warmest Novembers as all +4 or more). At least based off Chicago data, the dataset features no cold Niña winters when November was far above normal. The warmest November to precede a colder than normal winter was 2010 at +1.2. Still can never rule things out in long range forecasting, but based off this it seems safe to have higher confidence in leaning normal to colder than normal if November manages to end up cold and warm if November torches like last year. For what it's worth, the new Euro weeklies trended much colder for early to mid November with a strong signal for AK ridging/-EPO. The rest of the month seems to relax the pattern on the weeklies, but noteworthy that it's been at least a few runs of the weeklies in a row without a signal for an extended duration of a black hole over Alaska. Sent from my SM-G935V using Tapatalk
  2. I haven't seen any reference of the typically higher skilled Euro weeklies (vs. the CFS), which do not show a warm look for November. Sent from my SM-G935V using Tapatalk
  3. The SAI theory has simply not worked out the past few winters so perhaps it's not as useful as was thought. It makes sense conceptually that Canadian snow cover would correlate to winter temperatures because that's our source region in times without true cross polar flow, which is fairly often. So Canadian snow cover will be another variable to watch moving forward. Sent from my SM-G935V using Tapatalk
  4. Yeah I'm hoping for a more classic Niña pattern this winter, would be fine to have an 07-08 like pattern. It seems like there's some cause for optimism that November won't be an all out torch like last year. Just realized I forgot 08-09 in cold Niña composite but it doesn't really change the results I showed. Sent from my SM-G935V using Tapatalk
  5. In a prior post, Hoosier posted stats for warm La Nina Novembers and what the winters ended up doing. For the research for our local winter outlook at NWS Chicago, I did something similar. First I grouped all winters of the 1950-2017 ONI from the CPC page into warmest 22, middle 23 and coldest 22 at Chicago. Then I grouped the Niña episodes of those terciles into warm (9), near normal (6) and cold (6). Here are the November h5 composites, November climate division temperature anomalies, and subsequent DJF h5 composite anomalies. From these graphics, it appears there will be utility in how the mid/upper pattern sets up in November to potentially give clues to the winter pattern. If a big northeast Pacific/AK vortex sets up, that could increase odds for warmer to well above normal winter, and perhaps within range of normal to below if sustained Aleutian (-WPO) or -EPO ridging sets up. Sent from my SM-G935V using Tapatalk
  6. Good find on that stat. Will be using it in a graphic we're sharing on social media today and included in September 2017 review top news story. Sent from my SM-G935V using Tapatalk
  7. The SPC sounding climatology page helps give a sense of it with the max 500 mb heights by RAOB site. Clicked onto ILX and it had an October max of mid 590s registered in mid October. I don't think there's a way to check the date that occurred on though. Sent from my SM-G935V using Tapatalk
  8. I think upper 80s are becoming less likely now in the LOT CWA with respect to guidance trends over the past few days. Understand having to account for the very dry conditions but 925 mb temps have trended slightly cooler. ECMWF had been warmer on Tuesday but it came down to around 20 Celsius on 12z run today, with NAM and GFS around 18-19C. Also, models are suggesting broken cloud cover is possible on Tuesday. I'm wondering if that is overdone but nonetheless, with the slightly cooler thermal profiles, thinking mid 80s peak in LOT CWA now. Definitely not ruling out upper 80s considering how the heat wave went though. Will be interesting to see how tomorrow performs with a cooler start but lower dewpoints, similar 925 mb temps progged vs Tuesday though slightly cooler at 850 than progged for Tuesday.
  9. Models are still handling mid to late work week differently but whether via frontal passage and/or clouds/precip issues, better agreement now on Monday and Tuesday being the only very warm days in the central and western sub, with Wednesday likely quite warm farther east if a GFS like scenario verified. The quicker frontal passage of the Euro op and GEM does have support from 00z EPS ensemble mean. Lots of uncertainty next weekend on op models and ensembles, with possible attempt in bringing back warmth at least aloft but again potential clouds/precip issues. All in all, Tuesday would appear to be best day as things stand now to challenge October 2007 peak temps in western sub including Chicago. A tool we have locally for 925 mb climo using top 1/3 percentile and warmest values of the day suggests mid to upper 80s (85-88) in northern IL. Monday is warmer on Euro and GEM and they may support mid to upper 80s using warmest 1/3 percentile and warmest of day, while GFS is slightly cooler aloft and more supportive of low 80s. Unless models come in with mid 20s at 925 mb, currently leaning against 90 occurring on Tuesday at ORD.
  10. By departures from normal (going by Chicago data), the recent anomalous warmth stretches rank March 2012 first, February 2017 2nd and September 2017 third. Sent from my SM-G935V using Tapatalk
  11. Agree there that if you're gonna have a setup to produce a 90 in Chicago in October, this would be it. Since the record for latest 90 is 94 degrees on October 6, 1963, could make a run at that depending on setup next weekend. Sent from my SM-G935V using Tapatalk
  12. Probably some wiggle room on how extreme the outcome is at this lead time as Hoosier alluded to, but very impressive signal. The 12z operational Euro is probably on the upper end, with the the ensemble means impressive in their own right. Given the antecedent developing drought, would at least anticipate multiple 80s in a row for many climate sites in the sub. Sent from my SM-G935V using Tapatalk
  13. Fall 1953 would be the season closest to what could occur. Using Chicago data, a few 100s in early September, multiple 90s in later September including the 99 on the 29th, a 90 in early October, and then 8 consecutive 80s in mid to late October. 1953 also had 8 consecutive 60s in mid November, and during that stretch, 5 consecutive 70s occurred. Sent from my SM-G935V using Tapatalk
  14. One thing I was curious about with this streak is if the lakefront location prior to 1942 helped with breaking some of these records. It turns out that it may have with the records on 9/20 and 9/24. On 9/20/1931, Midway Airport hit 92 degrees, so this year would've been a tie using MDW data as the official Chicago record. On 9/24/1891, the previous record holder for 9/24 with 91°, the Aurora COOP hit 96 degrees. Midway was the Chicago climate site for previous 9/21-22 records and none of the non-lakefront sites on 9/23/1937 were warmer than this year, so those are very impressive record highs. Sent from my SM-G935V using Tapatalk
  15. If you're including ties, then March 2012 had 9 consecutive. Including only new records set, it was 5 straight 3/14-18 a tie on 3/19 and 3 straight on 3/20-22. Sent from my SM-G935V using Tapatalk