• Category Archives CFSv2
  • Looking Ahead To Spring…

    Meteorological spring begins in a few days (runs March through May).  We’ve already touched on the expected busy severe weather season and want to dedicate this post towards looking deeper into the weather pattern and the resulting precipitation and temperature impacts.

    The latest longer-range data continues to be in very good agreement on the upper air pattern.  In short, the balance of the spring season looks to offer up a continued theme of warmer than average temperatures for our region.  (Not saying we won’t have to deal with a wintry “trick or two” over the first couple weeks of March).  When we look at spring, as a whole, we believe it’ll be one known more for the warmth and active, stormy times.

    CFSv2 March Temperature Anomalies
    CFSv2 April Temperature Anomalies
    CFSv2 May Temperature Anomalies
    JAMSTEC March through May Temperature Anomalies

    The latest JMA monthly idea is one that has to raise an eye brow as it would paint an early summer across the Ohio Valley and Great Lakes.  Anomalous warmth (true summer-like air) would develop with a strong ridge over the Great Lakes and northeast.  This is something we’ll have to keep an eye on.  A big caveat here is how strong and quickly the coming El Nino develops.  It should be noted, El Nino years can feature some of the hottest air early, not late, in the summer season (relative to averages), and the JMA would, indeed, yield an early summer with such a look.

    JMA May Forecast 500mb Pattern

    It should also be noted modeling is suggesting a wet look, locally, especially during the early portions of spring.  The JAMSTEC and JMA are particularly bullish on a wet pattern.

    JAMSTEC March through May Precipitation Anomalies
    JMA March through May Precipitation Anomalies

    The CFSv2 hits the wet March hard before a drier regime mid and late spring.

    March Precipitation Anomalies
    April Precipitation Anomalies
    May Precipitation Anomalies

    In closing, we seem to have a bit of a bumpy ride in front of us as meteorological spring begins.  While Old Man Winter hasn’t been seen much as of late, don’t be shocked if he makes his presence felt a few more times through the first half of March- both from a cold and snow perspective.  That said, data really points towards more of an overall warm regime developing the second half of the month, and continuing through the majority of spring, for that matter.  We’re keeping a close eye on May for an early summer-like feel to take hold, locally.  Subsequent JMA updates will be monitored closely.  We also remain confident of an active severe weather season.  Note the tendency of model data (above) to pull the mean trough position to the northwest March into April.  The clash of late-season wintry conditions west, combined with unseasonably warm temperatures across the east (not to mention the warmer than average Gulf of Mexico) likely will equal busy times as we progress through the spring severe weather season.


  • 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.

    nino34monadj

    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-10-52-54-am

    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-10-58-16-am

    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.

    ssta-glob-djf2017-1sep2016

    tprep-glob-djf2017-1sep2016

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

    screen-shot-2016-10-02-at-11-08-26-am

    screen-shot-2016-10-02-at-11-09-00-am

    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…


  • Looking Ahead To Christmas Week And The Rest Of December…

    Finally, it’s a cold start to the day, and feels like a mid December morning should!  Temperatures are running significantly behind where we were across the east this time yesterday.

    t0Highs today will only climb to around freezing across central Indiana.  Add in a stiff NW breeze and wind chills will be colder.  Grab the coat before heading out to finalize that Christmas shopping.

    SaturdayHighsThis cold is coming in the face of what’s been a very warm month.  Meteorological winter, as expected, has opened warmer than normal.

    DecToDateBy the way, we think changes towards colder loom mid and late January on.  That likely carries us into spring this year with winter continuing.

    Christmas week is coming into better focus now, and the “blend” of model solutions was, indeed, the best path to take.  The European’s blow torch 70 degree idea was laughable.  Still warmer than normal, Christmas morning should start in the middle 30s with highs in the upper 40s.

    The lead up to Christmas will be an unsettled one after a dry weekend.  Moisture returns Monday.

    MondayAnother surge of moisture comes in advance of a cold front and associated area of low pressure Christmas Eve before colder air oozes in.

    ChristmasEveChristmas morning opens chilly, but dry, as high pressure is overhead.

    ChristmasMorningLooking ahead, an active close to 2015 appears to be in the cards.  Model solutions at this distance have ranged from a major winter storm to a flooding rain threat.  We’re not confident on either idea at this point.  Without blocking, it’ll be mighty tough to get anything wintry from this storm, and we also note models have been overdoing rainfall totals in the 5-10 day range as of late.  That said, is this the storm that can begin to set us up for the expected overall pattern change to winter coming in January?

    Note the wild differences between the GFS, GEM, and European for the storm leading up to New Years.

    29th

    cmc_pr6_slp_t850_conus2_36

    ecm_mslpa_conus_11When we turn to the ensembles to attempt to gain a clearer picture of what we can expect, we see they are of no help either.

    f228Are we confident of a storm coming to wrap up 2015?  Absolutely, but, again, far less confident on the specifics from this distance.  An overall wetter than average pattern is likely, however.

    LateDecTo wrap things up this morning we still note a favorable SST profile for wintry conditions mid and late winter.  In other words, hang in there winter fans.  🙂

    sst.anomBy the way, a major crash is coming that will send us into a La Nina by the second half of 2016.  The implications this can have are vast, and include an active severe season and big time Atlantic tropical season.

    ps2png-atls20-95e2cf679cd58ee9b4db4dd119a05a8d-59vNMa

    figure42


  • Sweaters Or Shorts For Christmas?

    Before we get into the thinking behind our set-up for Christmas, we want to be very clear in saying the overall warm pattern will continue as we head through the holiday season and into early parts of 2016.  We do see signs of changes brewing that could (and should) lead to a dramatic flip of the coin for the second half of winter.  With a weakening Nino, it’s also likely that the cold and wintry changes last deep into spring this year, but that’s for another discussion down the road.

    In the grand scheme of things, mid and long range model data strongly suggests a very warm pattern remains across the eastern half of the nation, while cold dominates the west, through the end of 2015.

    CFSv2

    NAEFS

    GEFSJust to be clear, we’re very confident on the medium range warmth to wrap up the year (and most likely open 2016).  Contrary to how confident we are on the overall warm pattern through the mid range, we’re much less confident with the shorter term pattern that encompasses the all-important Christmas Eve – Christmas Day forecast.  Getting right to the point, the American GFS forecast model suggests we’re dealing with a FROPA (frontal passage) Christmas Eve night that sets up a blustery, colder Christmas with morning snow flurries possible.  The GFS says we make it into the lower to middle 40s for highs Christmas.  On the flip side, the European model (usually, but not always, more accurate than the GFS) says we blow into early summer-like levels with highs around 70 degrees Christmas, including a mostly dry forecast with strong southwest winds.  How does an afternoon BBQ sound Christmas with that sort of idea?!

    When we get down to the dirty details, the differences all have to do with the way the models handle the eastern (Bermuda) ridge.  A snap-shot of the 8-10 day ensemble composite (that shows the Euro, GFS, and Canadian) highlights small, but significant, differences with the ridge placement.

    Source: Penn State e-wall
    Source: Penn State e-wall

    The GFS model (and Canadian, as well) suggests we’re dealing with a more progressive pattern Christmas that results in the cold “sloshing” it’s way east much quicker than its’ European counterpart.  Meanwhile, the European model says the eastern ridge flexes it’s muscle going into the Christmas period and results in the warmer, breezy solution as opined above.

    When we dig in further, experience tells us we should “raise an eyebrow” to both solutions.  How many times have we seen the biases that both models have impact the mid to long range forecast?  The GFS has an eastern (more progressive) bias while the European has a western (slower)  bias.  Hint: It’ll be important to remember that as we rumble into more active cold and wintry times come mid and late in the season.

    To sum things up, while we’re supremely confident in the long term warm pattern to wrap up the year, we remain very cautious with either solution currently being portrayed by either *normally* more-trusted mid range models.  Lets give it a couple more days and see where things go.  I wish we could be more certain with that all-important Christmas forecast, but we simply can’t at this juncture.  Both solutions have been very consistent with their respected idea for the past couple days.  One thing’s for sure and that’s that we’ll be looking at a major model bust sooner rather than later…


  • Iron Bowl Saturday: December Rambles…

    This is a special day in the McMillan house.  Iron Bowl Saturday only comes around one day a year… Needless to say, the Auburn flags have been on the vehicles since Wednesday, we’re decked out in our orange and blue, and game faces are on for this evening’s matchup.  WAR EAGLE!

    As we get set to flip the calendar to December, we wanted to post some latest thinking.

    Let’s take a look at the latest teleconnections.  As we’ve been talking, there’s a lot of “noise” in model land, including conflicting signals.  The positive NAO and AO argue for warmer than average conditions, while the positive PNA suggests chillier than normal times should prevail.

    We wanted to post the latest model predictions of each teleconnections, courtesy of Weatherbell.com.  Additionally, courtesy of madusweather.com, here’s what each teleconnection “phase” would normally lead to in December.

    NAO

    Screen Shot 2015-11-28 at 10.55.21 AMNAOpos_12dec

    AO

    Screen Shot 2015-11-28 at 10.55.07 AMAOpos_12dec

    PNA

    Screen Shot 2015-11-28 at 10.55.34 AMPNApos_12decSimply based on the teleconnections, you would build a December forecast that would lean more warm than cold, as the short term positive AO and NAO should trump the positive PNA.  As we look at the month, as a whole, the AO and NAO are forecast to trend more neutral, while the PNA remains solidly positive.  Does this suggest colder air, relative to normal, would invade mid and late month?  – Certainly something to watch.

    Additionally, the latest Southern Oscillation Index (SOI), has begun to take a negative hit.  This is after weeks of positive SOI values- relative to the base state.

    Screen Shot 2015-11-28 at 10.47.52 AM

     

     

     

     

    While it takes a while to impact the pattern, locally, this negative hit does suggest mid and late month could be a bit more interesting from a wintry perspective.  We shall see.

    The CFSv2 remains very consistent on a warm month, relative to normal, particularly across the northern tier.

    cfs_anom_z500_noram_201512_w3cfs_anom_t2m_noram_201512_w3

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

    While we can’t post the European weeklies here, the latest run suggests colder, and stormy times around Christmas week.  Now, we should also note the overall performance of the Weeklies hasn’t been as accurate compared to normal over the past few months, but it’s another interesting trend to keep an eye on.

    The MJO will begin the month in Phase 3 before going into the “wheel house.”  All-in-all, we don’t get a “hat tip” from the expected monthly MJO forecast, with the exception of Phase 3 to begin (warm phase).

    EMON_phase_MANOM_51m_full

    Screen Shot 2015-11-28 at 11.53.45 AMTo sum up:  Long range forecasting is always a gamble.  Only the good Lord knows what the future holds.  That said, there are times when we feel more confident about our long range, monthly outlooks, more so than normal.

    We’ll lean warmer than normal for December (+ 1.5 at IND), and this really plays into our Winter Outlook (slow start expected with the emphasis on the cold and snow mid and late winter), but that doesn’t mean we’re expecting a “boring” month.  Keep in mind November has been both warmer AND snowier than normal, with a very busy 2nd half of the month.

    We’ll have plenty of challenges to handle as we rumble through the month no doubt, but we expect the positive AO and NAO to trump the positive PNA to start to the month.  As we progress into mid and late month, we’ll have to be on alert for potential impacts of that significant SOI hit to open the month.  We’ll also keep the Weeklies in check to see if the colder, stormy look Christmas week remains.  It’ll be fun, as always.

    To close, here’s one more emphatic WAR EAGLE from our home to yours! 🙂


  • CFSv2 Catching On?

    Just a quick post to highlight the recent trend from the CFSv2. Note as we’ve progressed through the past couple weeks the model has been shifting the mean ridge position further and further west for October.

    9.14.15-9.28.15 average:

     
    9.21.15-9.28.15 average:

     9.25.15-9.28.15 average:

      
      
    With each updated model chunk the mean ridge position is shifting further and further west. We would lean towards this trend continuing as the model continues to update. 

    The end result is a colder than average pattern for the Plains into the east in the face of what was once projected (by the CFSv2) to be a very warm October for the aforementioned area. Needless to say, this is interesting and something to consider as we continue to rumble deeper into the colder months ahead….


  • 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…