Category: Winter thoughts…

Dec 07

Patience Required…

Ironically, the only area of normal to below normal air (with the exception of the Rockies and southern Plains) is located over our region, month-to-date.

ncep_cfsr_noram_t2m_anomFrom a winter lover’s perspective, this December has been one to forget this far, and it’ll only grow more frustrating in the days ahead (we still forecast mid to upper 60s over the weekend).

The basic drivers of our pattern remain generally unchanged from ideas in October when we posted our Winter Outlook.  Our complete Winter Outlook can be found here.  We feel the need to remind some that we thought we would get off to warmer than normal and relatively quiet start:

  • “We feel this model best represents the likely milder than average start to winter before colder conditions mid and late winter.”
  • “We think the winter opens warmer than normal and relatively dry before shifting towards a colder than average pattern for mid and late winter.”
  • “The word “volatile” comes to mind at times.”

In short, there’s nothing out there that would suggest any reasons we should deviate from our current winter outlook that’s out there.  Despite the warm start, we still feel the winter, when all totaled up, will end up slightly colder than normal.  Additionally, though still falling short of normal snowfall, we also feel there will be plenty of winter weather potential come mid and late winter.

That leads us to the shorter term and what happens after the near record warmth of the upcoming weekend.

To sum it up:

  • A very active pattern develops this weekend with storms to track every 3-4 days.
  • Despite a storm or two that may have a favorable storm track for winter potential, it’s important to note sufficient cold air is tough to come by in the more immediate term.
  • Last week’s crashing SOI (Southern Oscillation Index) will lead to poor run-to-run consistency.
  • We do see a way the pattern could get cold enough for more interesting times the closer we get to Christmas.  Does this mean we’re guaranteeing a snow storm?  No, but, as mentioned this morning, the teleconnections will at least make an attempt to transition closer towards a state that could offer up wintry mischief at some point during the last (10) days of the month.

Bottom line is that the overall pattern is one that favors more in the way of warmer than average conditions through the next couple weeks before we begin transitioning towards more sustained wintry conditions mid and late winter.  The idea here is that with each successive storm that comes through, it’ll cut into the mean ridge position and the heights will continue to lift further and further north with time over the upcoming 10-14 days.  The GFS ensembles show this.

RidgepositionIs it an ideal set up for “lock and load” winter?  Not at all.  Is it an improvement that can at least offer up a couple attempts of wintry potential around Christmas?  Yes.

As stated above, in the longer term, based off current data and seasonal modeling, there’s no reason to walk away from the idea the slow start to winter continues for the duration.  Patience friends. 🙂

Permanent link to this article: https://indywx.com/patience-required/

Dec 03

Constructed Analog Model Holds Steady…

The updated constructed analog model is in the house and holds steady with the on-going idea from previous months.

Upper air pattern for Jan., Feb., and March

Screen Shot 2015-12-03 at 9.11.29 PMTemperature anomalies for Jan., Feb., and March

Screen Shot 2015-12-03 at 9.11.50 PMPrecipitation anomalies for Jan., Feb., and March

Screen Shot 2015-12-03 at 9.11.15 PMBased on this update, we really don’t see anything that would suggest we need to change our ongoing thinking this winter.

While the mainstream national media seems to continue to push the warmth this winter, we just don’t see it that way.  It doesn’t mean that we’re guaranteed to be correct, but at least we’ve outlined our reasoning behind why we disagree with that idea in countless previous posts (that can be found in the archives).

As it stands now, we are really becoming bullish on the possibility we turn much more active for mid and late month.  This will come after a relatively quiet and mild first two weeks of December.  The SOI has been tanking for several days, but has gone into an all-out tail spin today.

Screen Shot 2015-12-03 at 7.01.56 AMA couple things that come to mind right off the bat with that kind of daily negative value?  Poor model performance in the mid range, and an active pattern 10-14 days out.  Let’s see how things unfold.

Additionally, latest model data suggests our teleconnections may begin to align in a better fashion for central and eastern cold.  Latest runs take the AO slightly negative, the NAO neutral, and trend the PNA back positive towards late month.  Not perfect, but we’ll take it.

I heard one prominent national weather source today say December looks warm, quiet, and feature reduced chances of a White Christmas for most compared to normal.  Perhaps that will, indeed, be the case.  We’re, however, in the camp (small as it may be :-)) that believes a colder and more active period looms leading up to Christmas.  We shall see what we shall see…

Permanent link to this article: https://indywx.com/constructed-analog-model-holds-steady/

Dec 02

Hang In There You Lovers Of Winter…

As I sit here in the good ole weather office, snow is falling and the Christmas lights are shining at the McMillan household.  Just doesn’t get any better!  Unfortunately, for winter lovers out there, the overall weather pattern over the upcoming couple weeks won’t offer up much in the way of wintry precipitation, as strong ridging results in a rather prolonged period of uneventful and mild weather across these parts (at least compared to normals).

The GFS ensembles show ridging expanding over our region this weekend into early next week. Source: Weatherbell.com

The GFS ensembles show ridging expanding over our region this weekend into early next week. Source: Weatherbell.com

That said, there are indications that our weather pattern may be changing enough to at least put us on the playing field for wintry potential as we rumble into the back half of the month, including the all-important Christmas period.

The SOI continues to tank and while the impacts (storminess) of a tanking SOI are delayed, we’re in the time frame now where this may result in busy times, or an active storm track, come mid and late December.

Screen Shot 2015-12-02 at 6.28.52 PMRight on schedule, we see the GFS ensembles going towards a much different look around mid month.  Note the heights (ridging) pulling further and further north while the southern stream energizes.  This is likely a byproduct of that tanking SOI that we see now.

GFS ensembles. It's a "night and day" difference out at mid month. Source: Weatherbell.com

GFS ensembles. It’s a “night and day” difference out at mid month. Source: Weatherbell.com

We also note the AO, or Arctic Oscillation, trending more in a negative to neutral direction.  While still not significantly negative, this is an improvement from a winter lover’s perspective from the positive values we’ve seen of late.

AOWe’re only two days into meteorological winter and still feel very confident about our winter outlook, focusing on the back half of winter for the worst conditions, relative to averages.  That said, even though the first couple of weeks of December, as a whole, may not be as cold or snowy as you’d like, it doesn’t mean we can’t reverse things enough to put us in a position to make for more “interesting” times around these parts leading up to Christmas….

Could this be the scene this Christmas across central IN?  Much more later!Christmas

Permanent link to this article: https://indywx.com/hang-in-there-you-lovers-of-winter/

Dec 01

Welcome To Meteorological Winter…

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Nov 28

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! 🙂

Permanent link to this article: https://indywx.com/iron-bowl-saturday-december-rambles/