• Category Archives SST Discussion
  • Digging Deeper As Winter Nears…

    Thanksgiving is only a week away (where on earth does time go?!) and more and more folks are asking what we think winter will hold for central Indiana.  In case you missed it earlier this fall, here’s our official Winter Outlook.

    We’re continuing to dig in and monitor new data that’s streaming into the office, as well as ocean profiles.  With that said, we wanted to share some of our findings with you this morning with respect to how various ocean regions can impact our weather this winter.

    We’re noticing significant changes, particularly in the north Pacific, with the famous “warm blob” emerging (image 1). This is a big factor that aided in persistent cold; wintry weather during the ’13-’14 winter (images 2-3). Notice the difference from last year, too (image 4). This isn’t a full blown cold PDO (Pacific Decadal Oscillation) yet, but trending in that direction and “ups the ante” for cold, wintry conditions, locally this year.

    What makes seasonal forecasting so challenging (and fun :-)) are the multiple features that can impact a forecast.  We’ve talked about the importance of ENSO (various types of Nino and Nina events) in past updates, as well as low solar and QBO.  All of these moving parts and pieces are coming together in a manner that seems to be favoring more of a cold, wintry regime, locally, this year.  Is that us saying another blockbuster 2013-2014 winter awaits?  Absolutely not (there are other differences noted above with the SST configuration).  However, it is suggesting that this winter will be absolutely nothing like the past couple…

    Might want to think about getting the snow blower tuned up!

    More later today on the short-term.  Make it a great Thursday!

  • Winter Ideas…

    We continue to finalize our winter forecast, which will be posted, as always, here later this month.

    As little as only a few months ago, data suggested a major La Nina for the upcoming winter season.  That data has since backed off significantly.  In fact, some runs suggest we’re back into a weak-ish El Nino state by spring.  At the very least, we are confident on avoiding a strong La Nina this winter and lean more in the direction of a weak Nina, at best, to neutral signal.  The CFSv2 is interesting, as always, with the spread in region 3.4.


    sstanimIn addition to the central PAC anomalies, we also are keying in on some other items of interest in the overall SST configuration:

    I. Warmth in the GOA (Gulf of Alaska)

    Argues for central cold this winter, spreading east with time.

    II. Warmth off the eastern seaboard

    Will likely serve to limit the ability for the cold to spread east early on in the season

    92916sstThe SST CA model is quickly becoming one of our more trusted seasonal forecast models.  We note how it becomes increasingly bullish on a central and eastern trough as winter wears on (by the way, this is likely to go deep into spring this year, too).


    screen-shot-2016-10-02-at-10-53-04-amCold overwhelms the pattern and when you combine it with the active storm track (noted by the green hues, suggesting above normal precipitation through our neck of the woods), confidence is continuing to grow for an above normal snow season.


    screen-shot-2016-10-02-at-10-58-05-amThe SST configuration on the JAMSTEC would suggest a cold, stormy set-up, locally.  That said, while it sees the above average precipitation, it’s awfully warm at the surface.



    temp2-glob-djf2017-1sep2016The NMME (to no surprise…) would suggest a very warm, wet winter.



    screen-shot-2016-10-02-at-11-08-47-amAs a reminder, our complete and final annual winter outlook will be posted here during the second half of October.  That will include additional model data, along with several other points behind our reasoning for our winter forecast.  As we always do, we’ll put “pen to paper” when it comes to our winter forecast, including our expected temperature and snowfall anomalies.  Given the data above, including the warm JAMSTEC and NMME, it’s going to be very, very hard to see a warm winter here.  In fact, our idea is for the exact opposite, given the SST configuration, and lines up more closely with the SST CA idea at this point.  We’re also in the camp of a very, very active storm track through the Ohio Valley.  “Big-hitter” potential is present from a winter storm perspective, especially given that we are likely to see resistance from the SE ridge.

    Much more later this month…

  • New SST CA Model Weighs In On Winter…

    The updated Sea Surface Temperature Constructed Analog model is in for the winter. In short, it suggests a slow start to winter gains momentum and turns much colder as mid and late winter arrive. It’s also a stormy look, locally, and would imply big-hitter potential in the Ohio Valley.

    500mb pattern

    *Note how the trough becomes more established over the central and east during the January through March period. 

    Temperature anomalies

    The consistency is remarkable on the bullish cold signal for the central and east for the January-March time frame. We note high agreement, month-over-month, on the J-M time frame being significantly cold. 

    Precipitation anomalies

    *No doubt a stormy signal through the Ohio Valley.

    Time is ticking…winter will be here before we know it! Our official annual winter outlook will be out in October. 

  • SST CA Model Weighs In On The Upcoming Winter…

    It may only be August, but thoughts here are solely focused now on the upcoming fall and winter seasons.  We received an update today from the sea surface temperature constructed analogue model and the look is a “mighty fine one” if you enjoy wintry conditions, locally.

    As we’ve mentioned in previous video and text posts, the once-thought moderate to strong La Nina doesn’t appear to be taking shape and instead we’re likely left with a weak La Nina to neutral look.  Factor in the positive PDO and the overall pattern is one that could yield cold, snowy times, locally, especially the middle and latter parts of the winter season.  (No reason to get too specific this far out).

    In any event, today’s update is an “intriguing” one for winter enthusiasts across the region.

    Upper air pattern for DJF and JFM, indicating the colder, more wintry regime for mid and late winter:

    Screen Shot 2016-08-03 at 6.36.29 PM

    Screen Shot 2016-08-03 at 6.18.03 PMPrecipitation DJF

    Screen Shot 2016-08-03 at 6.17.55 PMTemperature anomalies DJF and JFM

    Screen Shot 2016-08-03 at 6.38.08 PM

    Screen Shot 2016-08-03 at 6.17.47 PMHmmmmm… 🙂

  • UPDATED SST CA Model Is In The House…

    As promised, we wanted to provide some thoughts around the updated sea surface temperature constructed analog model that was released this morning. 

    In short, there aren’t many huge differences from the previous couple months, and strongly argue against those warm, dry winter outlooks that are floating around out there. Perhaps the most interesting item is the expansion of cold and wet anomalies the deeper we go into the winter season. We agree with this in that the greatest deviations away from normal are more likely to occur mid and late winter than the beginning. That isn’t saying December is going to be a warm, dry month by any stretch of the imagination, but just that we think the greatest departures from normal are likely to occur during the 2nd half of winter as opposed to the 1st half.

    Dec, Jan, Feb 500mb pattern

    Dec, Jan, Feb SST Forecast

    Dec, Jan, Feb Temperature Anomalies

    Jan, Feb, March Temperature Anomalies

    Dec, Jan, Feb Precipitation Anomalies

    Jan, Feb, March Precipitation Anomalies

    At the end of the day, we still very much think this winter will be a challenging and fun one.

    A look over the current Nino state would imply a modoki event evolves as winter progresses. Additionally, the SST configuration both in the PAC and ATL argues for central and eastern cold.

    If you haven’t had an opportunity to view our full 2015-2016 Winter Outlook, you can do so here.

  • Monday Morning Weather Rambles…

    September is still running much warmer than normal, despite the recent well below average regime.

    See the temperature anomalies over the past (7) days:

    and the month-to-date:

    It’s also been a dry month. Officially, IND is down nearly 1″ month-to-date. For the year we’re still running wetter than normal, powered behind a wet start to the year and wet July.

    After a dry August and first half of September, some “abnormally dry” areas have kicked in on the drought monitor around the region.

    The fall feel of late last week and the weekend will begin to moderate this week as ridging develops. 

    The PNA, or Pacifc North American pattern, can be a huge help in forecasting patterns in the mid to long term. The state is one that screams warmer than normal (predominantly negative PNA), but not to the extent of the early September persistence. Note the return to neutral over the weekend. This will be associated with cooling after a front moves through Saturday.

    Speaking of that front, the GFS sees it moving “limping” through Saturday with little moisture followed by cooler high pressure building in Sunday.

    But, as shown above, the cool won’t last as the PNA takes another significant nose dive. Ridging will follow.

    The tropics are beginning to show some life as we’re in peak season now.

    The latest SST anomalies remain bullish on the strong El Niño signal, but we note recent cooling in Nino 1+2. Is this just a temporary thing or more of a trend towards a central-based Nino (modoki)? An El Niño with warmest anomalies in 3.4 argues for colder and snowy times compared to normal for our region, versus a warmer, drier regime when located in 1+2.

    Also note the central and northern PAC warm anomalies. This is also crucial to our winter pattern.

    The latest CFSv2 says lovers of winter shouldn’t get too excited for the upcoming cold season.

    BUT…the CA model and JAMSTEC paint a much different picture.

    Note the JAMSTEC really likes the idea of a modoki El Niño coming on as the warm anomalies shift west as we progress into winter.

    Stay tuned as we have a long way to go…

  • More Winter Chatter…

    Now that we’re in September (where does time go?!) we wanted to touch base on some of our latest thinking as we rumble closer to winter…

    * Our official 2015-2016 IndyWx.com Winter Forecast will be posted in mid October.

    The latest sea surface temperature anomaly chart continues to point out items of interest:

    • Strong El Niño in play, but….this is also highlighted by recent cooling in Niño 1+2 and a “spreading out” of warm anomalies into Niño 3 and 3.4, or more centrally based.


    • Positive PDO (warmer than average eastern PAC waters). This supports western Canada ridging and associated warmer conditions than average across the west, with cold favored east.

    It’s a “battle” of two juggernauts and it’ll be fascinating to watch the fight unfold. The strong niño argues for warmer, drier than normal times this winter, but the positive PDO, or Pacific Decadal Oscillation, argues for the opposite (see the past two winters for most recent examples).

    No niño is like another, and one can’t simply broad brush a seasonal forecast based solely on the ENSO state. Many other factors play crucial roles in seasonal forecasting.

    At this stage in the game, we would lean more in the direction of an “average” winter than one that’s dry and milder than average. If we had to pick snowier than average or less than average snow we would lean towards the snowier regime. This is based off the warm north and east anomalies in the Pacific. It’s important to factor in that positive PDO just as much as the strong niño. 

    Speaking of the positive PDO, here’s what meteorological winter looks like during positive phases from a temperature perspective.

    The constructed analog SST model is going towards that look:


     Also, see the JAMSTEC’s idea. Very similar, huh?

    We could go on and on about why this winter is going to be a challenging one, but the main “meat of the message” that we’re trying to get across is the idea that we have a long way to go and a lot of “players” on the field. To build a winter forecast that rests solely in the hands of the niño isn’t providing the public a fair idea for what lies ahead to close 2015 and into 2016. 

    Much more later! 

  • Saturday Morning: A Look Where We’ve Been And Where We’re Going…

    August has been cooler and drier than normal month-to-date.  As we’ll get into below, this cooler, dry trend should continue to wrap up the month.

    * Click on any image to enlarge.

    August temperature departure- month-to-date.
    August temperature departure- month-to-date.
    August precipitation departure- month-to-date
    August precipitation departure- month-to-date2015 to date has been cool central and east:2015 to date has been cool central and east:

    2015 to date has been cool central and east:

    4The upcoming winter looks fun and challenging.  It’s a volatile look with the strong Nino and warm northern, eastern Pacific (positive PDO).  Certainly can’t “broad brush” the upcoming winter forecast solely based off similar strong Ninos of the past…

    10Positive PDO temperature anomalies favor western Canada ridging and troughiness east.  It’s a pattern that favors a cooler than normal regime across the east and southeast.

    11As we go into the weekend, sunshine and comfortable conditions today will give way to increasingly cloudy skies Sunday with a threat of a shower or thunderstorm, especially during the afternoon and evening.  A few of these storms could reach strong levels.  The culprit?  Another strong late August cold front.  Most rainfall totals will be around a quarter inch Sunday, but there will be some locally heavier totals with stronger storms.

    5Warmer conditions will build in briefly in between the early week cool spell and stronger push of cool inbound Sunday night that will remain with us through the majority of the upcoming work week.


    7Longer term, we think conditions warm going into next weekend after a very cool, fall-like week, but don’t necessarily agree with the GFS ensemble plot below into early September.

    3We expect ridging to build in to close the last couple days of August.

    9However, recurving Typhoon Atsani argues for a return of cooler air (briefly) and an associated trough arriving between September 2nd and 4th…

    8Images credited to the following:

    • weatherbell.com
    • http://www.usno.navy.mil/JTWC/
    • http://mrcc.isws.illinois.edu/cliwatch/watch.htm#seasonMaps