• Category Archives Canadian Model
  • Confidence Increasing On Leader-Follower Event; But Details Murky…

    A look over model data from overnight suggests we need to focus on a “leader-follower” event for the upcoming weekend.

    We’re confident the “leader” player is a rain maker for IN in the Thursday afternoon-Friday time frame (.40-.70 rainfall potential).

    Source: Tropicaltidbits.com
    Source: Tropicaltidbits.com

    As we progress into the second half of the weekend, details get quite murky on the specifics with the secondary (follower) area of low pressure that develops along a pressing arctic front.

    As we’ve been discussing, model solutions will vary within each respected model (GFS, Euro, GEM, etc.) in a run-to-run fashion.  Stack them up against one another, and we’ll likely continue to have as many different solutions as we do models that we’re looking at.  It’s a byproduct of a pattern transition and that crashing SOI (which is still crashing this morning, btw).  Case in point, note the various options below for Sunday.

    The GFS takes a low from southern AL into the coastal plain of NC. Source: Tropicaltidbits.com
    The GFS takes a low from southern AL into the coastal plain of NC. Source: Tropicaltidbits.com
    The Canadian is a blend of the GFS and European as it tracks low pressure from eastern LA into the central Appalachians. Source: Tropicaltidbits.com
    The Canadian is a blend of the GFS and European as it tracks low pressure from eastern LA into the central Appalachians. Source: Tropicaltidbits.com
    The European is most aggressive in the west track as it takes low pressure from the MO bootheel into northern IN. Source: Tropicaltidbits.com
    The European is most aggressive in the west track as it takes low pressure from the MO bootheel into northern IN. Source: Tropicaltidbits.com

    Past experience with similar patterns certainly leads us to lean more towards the European/ Canadian solution over the GFS from this distance.  We know that models have their own biases though.  Time and time again the GFS bias is to rush things along a bit too much from this distance and become too progressive.  On the flip side, the European is notorious for dragging it’s heels a bit and, at times, can be too slow with bringing energy out of the west.  This in return impacts things downstream…

    From this distance, we still can’t be too specific with snow/ precipitation prospects Sunday.  While confidence is increasing on at least some sort of snow to contend with, the significance of such isn’t possible to iron out at the moment.  Much fine tuning will be required.  Stay tuned.


  • Winter Delayed, Not Denied: Updated Canadian; MJO

    We’ll talk later today about the upcoming winter storm threat next weekend. While nothing is set in stone at this juncture, the pattern is aligning in a fashion for the region to at least be on the table for wintry potential early week 2. Again, more later.

    The updated Canadian monthlies are in and remain firm on the idea of a lot of winter as we progress into mid and late winter.

    February upper air pattern, courtesy of tropicaltidbits.com.
     

    February temperature anamolies, courtesy of tropicaltidbits.com

      

    March upper air pattern, courtesy of tropicaltidbits.com.

      
    March temperature anomalies, courtesy of tropicaltidbits.com.

      
    The model has things finally breaking come April.

      
    It should also be pointed out the model led the charge on forecasting a cold January. Other data is jumping onboard the cold train for January now. 

    Additionally, the MJO forecast supports this cold look in the upcoming several weeks, rolling right through the cold phases of 8, 1, 2, and 3.

      
      
    At the end of the day, we still don’t have changes in the short term (step-down process to cold the first half of January before turning colder in a more sustained fashion for the second half of the month) or long term (warm open to winter flipping to cold for mid winter into early spring). 

    When we look back at the 2015-2016 winter, it’s likely going to be known for being a case of delayed, but certainly not denied…  


  • Periods Of Heavy Rain…

    Saturday will dawn dry across the region, but that will quickly begin to change as morning progresses into afternoon. Moisture is streaming north and a “wavy” frontal system will remain draped across our region through the weekend into early next week before a surface low finally sweeps a cold front through here Monday evening.

    Forecast radar, courtesy of Weatherbell.com, shows rain expanding in coverage this afternoon.

      
    Periods of heavy rain will fall across the region between this afternoon and Monday. 

       
       
    We note precipitable water reaches in excess of 1.5″ and adds to our confidence of heavy rain coming. Note also the true GOM connection with this storm system.

      
    Models agree on heavy to excessive rains falling with widespread storm totals between 3″-5″.

       
       
    The storm system will finally begin to pull away Monday night, leaving drier, breezy, and cooler air in it’s wake. 

      
    The true push of cold air awaits until the end of the week.

    Your full 7-day outlook can be found here.


  • 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…


  • Warmth & Humidity Build; Storms Return…

    We’ve enjoyed a stretch of dry and pleasant air, but that will come to an end this weekend as warmth and humidity build and help fuel storms at times later today into Sunday.

    Debris clouds associated with a complex of storms to our west are drifting into the state this morning.

      
    Most of today will remain dry, but storm chances will increase this evening and tonight. We’ll note a very pleasant air mass this morning turn muggy by evening. Surface dew points will increase from the middle 60s into the lower 70s (oppressive range).

       
     
    Precipitable water will also be on the increase as a southwesterly air flow transports moisture-rich air northward over the weekend into early next week.

    Showers and thunderstorms that develop will be plenty capable of producing torrential rainfall and flash flooding in spots through early to mid week.

       
     
    Thunderstorms could develop as early as mid to late evening into the overnight and a few could be strong.

      
    The Canadian forecast model has a stripe of locally heavy rainfall through the region into early next week.

      
    The European leans towards the Canadian displayed above with heavy rains possible through Tuesday. The GFS is drier. We’ll hedge more towards the direction of the Euro and Canadian.

    In the short term, heat and humidity will be associated with a hot dome centered off to our southwest. We’ll have to be mindful of storms riding the periphery of the hot dome in northwest to southeast fashion. (Sound familiar)? That said, note significant changes for early August as we transition the hot ridge over the west and replace it with a rather significant late summer trough and associated cool air mass over our region.

    This week

      
    Early August

      


  • Cloudy, Cool Day; Rain Builds In Later…

    We’re off to a cloudy and cool start, but at least things are dry this morning. The frontal boundary that delivered the rain and flooding to central IN Tuesday has pushed south, but this boundary will shift north later this afternoon in response to surface low pressure lifting northeast out of the MS Valley. Light to moderate showers will build into central IN late morning into the early afternoon. 

      
    It’ll also be a cool day with temperatures in the 60s most of the day. 

      Heavier rain will build into central IN during the overnight thanks to the surface low. Flash flooding will again be a concern, and particularly dangerous since this will take place during the nighttime hours. 
       
     Longer term, unfortunately the very wet pattern will roll along in the mid to long range. (10) day rainfall numbers are quite impressive off the GFS, European, and Canadian (pictured below), and average out between 3″-4″ with locally heavier totals. 

      


  • Watching Bill…

    Tropical Storm Bill will make landfall later this morning along the central TX coast. 

       
     Models handle the track of Bill differently in the days ahead, but we must continue to remain on our toes. The overall weather pattern favors Bill’s remnant moisture moving in the general direction of the Ohio Valley late week and this weekend. That southeast ridge and associated hot dome will “sling shot” Bill’s moisture north and eventually northeast in the days ahead. 

      That said, there are issues with timing and the precise track of Bill’s moisture as you can see below, per the GFS and Canadian. 

       

      

    In the shorter term, north-central IN can expect a brief break in the rain and storm action today as the main action shifts along and south of I-70 this afternoon and evening. Unfortunately, the unsettled times and heavy rain and storm threat returns for all Wednesday. 

    Much more later! 


  • Chilly Now; Continuing To Keep A Close Eye On Sunday…

    Temperatures are more remenesant of early fall than late May and a stark contrast to the humid 70s to near 80 Monday. As we type this note both the 24 temperature change (image 1) and the departure from normal (image 2). 

       
     

    A storm system to our west is delivering more high mountain snow to CO and also responsible for tornadoes in TX. This system will weaken dramatically over the next 12-24 hours. Dry air will really “eat away” at the more significant precipitation and we’ll maintain mention of light rain in your Wednesday forecast (forecast radar at 12-noon is below) before it’s back to sunshine Thursday!

      
    Friday and Saturday will be fantastic days- slowly moderating temperatures and lots of sunshine! 

    Attention turns to Sunday and as of now we still don’t have any changes to our forecast. There will be a chance of a widely scattered shower or thunderstorm, but it continues to look like best rain and storm chances will remain off to our west most, if not all, of Sunday. Highs will be around 80°. 

    Better chances of scattered storms appear to arrive Monday. At this juncture it really doesn’t look like a bad Memorial Day weekend is shaping up in the least. 

       
       


  • A Much Cooler, Drier Trend…

    Screen Shot 2015-05-11 at 8.51.04 PMHighlights:

    • Much cooler and drier through Thursday
    • Moisture increases this weekend
    • Stormy early next week

    A cold front swept through the state this evening and a much drier and cooler brand of air is filtering into IN as we type this.  That cooler and drier regime will carry us into late week before moisture slowly begins to return.  High pressure will shift east and allow a moist return flow Friday into the weekend.  Add in a couple of disturbances and the associated forcing, combined with the increasing warmth and humidity, and the stage is set for periods of showers and thunderstorms over the weekend.  It certainly won’t rain the entire time, but plan on localized heavy downpours.

    hrrr_t2m_indy_14A MUCH cooler air mass will greet Hoosiers out the door Tuesday morning.  Even cooler air will be with us Wednesday and Thursday mornings.

    gfs_ptype_slp_conus2_9High pressure will supply plentiful sunshine and cooler than normal air through mid week.

    gfs_ptype_slp_conus2_16A southwesterly return flow will lead to increasing chances for showers and thunderstorms across not only our local area, but across a widespread portion of the Plains and Ohio Valley.  Furthermore, a significant severe weather outbreak appears to be a good bet across the Plains.

    cmc_total_precip_indy_33After a dry mid week stretch, active times return over the weekend into early next week.  Localized torrential downpours are likely.  Most of the 1″ to 2″ of rain forecast shown above (courtesy of the GEM model off the Weatherbell.com suite) is expected to fall early next week.