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  Additionally, courtesy of, here’s what each teleconnection “phase” would normally lead to in December.


Screen Shot 2015-11-28 at 10.55.21 AMNAOpos_12dec


Screen Shot 2015-11-28 at 10.55.07 AMAOpos_12dec


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.

















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).


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! :-)

Extended Stretch Of Raw Conditions…

Screen Shot 2015-11-27 at 7.13.46 AMHighlights:

  • Periods of rain
  • Turning colder
  • Finally begin to dry things out

We sure hope you enjoyed those pleasant conditions on Thanksgiving Day, as rain (and eventually colder air) is settling in for the long haul.

The overall set-up shows a cold front slicing it’s way through the mid section this morning.  This front will continue to slowly settle southeast and much colder air will “ooze” into the area directly behind the boundary later tonight and Saturday.  Unfortunately, once the front passes to our south, additional disturbances will move along the front and enhance rain across our area from time to time over the weekend.

Here’s a snap shot, courtesy of, of what we the surface map/ simulated radar may look like as we rumble through the Thanksgiving weekend.



SundayMapAs mentioned above, the temperature story will also be a focal point later tonight.  Notice the incredible difference within just a matter of miles as we go deeper into the weekend.  While central IN will be in the “transition” period tonight, all of the area will be on the cold side of the boundary Saturday.  That forecast high in the upper 40s that you see above in our 7-day will be at midnight as most of tomorrow will be in the upper 30s/lower 40s.


Sat4pTempWe’ll continue to deal with unsettled and rather “raw” conditions into the early portions of next week, but we should finally be able to shake the damp conditions by Wednesday.  We’ll continue to keep a close eye on yet another system late next week, but models keep this storm to our south as of now.  Stay tuned.

Nice Today, But A Wet And Raw Weekend Coming…

Screen Shot 2015-11-26 at 9.31.37 AMHighlights:

  • Extended wet and raw stretch of weather
  • Turning colder next week

First and foremost, happy Thanksgiving from all of us at!  We hope you have a blessed day with friends and family and we’re incredibly thankful for your support of what we’re doing here at IndyWx!

Thanksgiving Day, itself, will be filled with very pleasant weather as a SW flow transports mild air northbound and results in highs around 60 this afternoon with a gusty breeze in place.  A scattered shower is possible, but it’s not until we get to late tonight and Black Friday that we expect more widespread rains across the region.

Rain will settle in Friday and temperatures will also go the wrong direction come evening as a cold front passes through the area.  This is the first in a series of rain that we’ll deal with over the Thanksgiving weekend.  A second surge of rain will arrive Saturday into Sunday, followed by a third push of rain Monday.  All total, between 1-2″ of rain is a good bet across a widespread portion of the region between Friday and Monday.

Colder air will settle in by the middle of next week.  We’ll have to closely monitor as a fourth system will be in play.  It’s far too early for details, but we’ll keep an eye on things to see if some sort of wintry precipitation may be in play late next week…

Rain Moving In Late Thanksgiving…

First, I apologize for the lack of posts today. I had my first (and hopefully only) encounter with food poison yesterday evening and it’s taken most of the day to recover. 

At any rate, we’re still looking forward to our next storm system that’s slated for an arrival Thanksgiving evening and during the overnight. Most of Thanksgiving Day, itself, will remain dry, breezy, and mild (upper 50s). Rain will stick around for a large majority of your Black Friday. Early rainfall numbers suggest somewhere between 0.50″-1″ falls. 

We’ll turn colder over the weekend and then eyes will shift to our next storm system that will impact the area late in the weekend into early next week. More details will have to be sorted out in the days ahead…

Hope to be back to 100% in the AM and have a complete update for you bright and early!

Frigid Start; Looking Ahead To Thanksgiving…

Screen Shot 2015-11-22 at 9.27.08 AMHighlights:

  • Arctic air begins to moderate
  • Next storm system arrives late Thanksgiving
  • Another punch of cold air next weekend

Before we discuss what lies ahead, let’s look back at yesterday’s snow event that “overachieved” for many.  Particularly just northwest of the city where 2″-4″ fell.  Snowfall rates were heavy enough to overcome the initially warm surface temperatures, and it was very impressive to see the way the snow accumulated considering this was a November event that took place from late morning into the early afternoon (when the sun angle does the majority of it’s work).  This was an impressive first snow of the season and this morning’s snowpack is widespread throughout the Mid West.

nsm_depth_2015112205_MidwestThe visible satellite this morning shows the snow cover across the central and northern portions of the state, where single digits and teens were common.

SnowpackThe next few days will feature dry and cold conditions.  While we’ll remain below average, temperatures will slowly begin to moderate from the arctic intrusion of today.

We’ll get into a SW (milder air flow) regime for a brief period of time Thanksgiving Day out ahead of our next storm system that will move in Thanksgiving Night and Black Friday.  Clouds will increase and moisture will spread into the region during the aforementioned time period.  Most of the rain will fall Friday, so plan on taking the rain gear with you as you venture out to begin that Christmas shopping.


BlackFridayMuch colder air will pour into the region Thanksgiving weekend and we’ll have to maintain a close eye on the evolution of things late next weekend into early December.  Models will continue to waiver on specific solutions over the next few days, but there will be an attempt of a southern stream storm system coming out and “attacking” the cold air in place…

Rain Changes To Snow Today; Busy Pattern Into Early December…

Screen Shot 2015-11-21 at 7.47.29 AMHighlights:

  • Rain changes to snow
  • Early season arctic air settles in
  • Next storm arrives for Thanksgiving
  • Eyeing a cold open to December

Our storm system is arriving on schedule this morning as rain is overspreading central IN.  Just north of the city, snow flurries are falling as we type this (Boone County).  Further north it’s mainly a snow event.  Elsewhere, rain will continue to overspread the region before transitioning to snow from late morning into the early afternoon from northwest to southeast.

Here’s what the radar may look like as we progress from morning into the afternoon


Forecast radar 8a, courtesy of

10a forecast radar, courtesy of

10a forecast radar, courtesy of

Forecast radar at 1p, courtesy of

Forecast radar at 1p, courtesy of


Forecast radar 2p, courtesy of

Forecast radar 2p, courtesy of

We think rain will transition to snow for Indianapolis, itself, just after lunch and may come down heavily for a time from early afternoon into the mid afternoon hours before tapering off as evening arrives.  While it may be falling “fast and furious” for a time, warm surface temperatures will limit accumulations from what they would be otherwise.  Here’s our updated snowfall map.

112115SnowMap3The big concern this evening will be flash freezing as a gusty NW flows travels over a fresh snowpack just to our north and helps temperatures plummet into the teens tonight.  Wind chills in the single digits can be expected followed by highs tomorrow only in the 20s.

Moderation will occur as we move through Thanksgiving week before our next storm system arrives late Thanksgiving Day.  Rain and breezy conditions will move in late Thursday into Friday before a much colder air mass oozes into the state late in the period.  This may set the stage for a rather “interesting” open for December as a storm system tries to “attack” the cold…

Potent System; Friday Evening Thinking…

This evening’s radar shows our potent weather maker providing a plethora of weather elements to our west.  Anything from heavy snow (numerous 12″ + reports coming in across IA) to thunderstorms across MO have made for an active Friday evening.

9pRadarThinking hasn’t changed much from the get go with this storm system, but we wanted to “freshen” things up a bit before bed.

Rain will overspread central IN through the morning hours before transitioning to snow from late morning into the early afternoon.  This transition will occur in a northwest to southeast fashion as colder air wraps into the region.

Here’s a timeline (thanks to of what the radar may look like as Saturday morning progresses into Saturday afternoon.


12pSatAs rain transitions to snow, it’ll likely come down rather “fast and furious” for a time before ending.  Despite what may be moderate to heavy snow for a time (especially along and north of the I-70 corridor- there’s the “magic” dividing line again :-)), warm surface temperatures will really limit what snow will actually accumulate.  As things stand now, we still forecast a widespread 2″-4″ snowfall across the northern portions of the state, with 4″-6″ amounts in favored lake effect areas.  Farther south to include central IN, a dusting to less than 1″ is a good bet before precipitation ends.

The growing concern Saturday night will be a stiff northwest wind driving MUCH colder air into the region.  This will help power a brief lake effect event across NE areas of the state before shutting down quickly by the wee morning hours Sunday.

LakeEffectAny lingering moisture on area roadways will freeze up quickly tomorrow night.  With a deep snowpack just to our north, the NW flow will keep things very cold around these parts into early next week.  Note widespread teens Sunday morning across north-central IN and even this might not be cold enough.  If we lay the expected snowfall down, don’t be surprised by some single digit temperatures (not counting wind chill values) across north-central IN Sunday morning.  Highs Sunday will remain below freezing for most.

‘Tis the season!  More in the AM, and happy snow dreams to all!


Saturday Snow…

There’s just something special about seeing the first flakes of the season.  While this initial wintry event won’t be a big deal accumulation-wise for central IN, a few inches of snow will be likely across northern portions of the state Saturday.  Here’s our initial snowfall forecast, brought to you by the next two days will be easy and rather “boring” as far as the weather goes.  Look for more in the way of sunshine today before clouds begin increasing as Friday progresses into evening.  The initial push of moisture should reach central IN Friday night (as rain).  Rain will then transition to snow showers before ending across central IN Saturday morning into the early afternoon.  Farther north, look for a quicker transition to snow where we forecast a 2″-4″ type accumulation event for places along and north of a Newton County to De Kalb County line.  This is an early call and may require some fine tuning as we go through the next 24 hours.  We’re about as confident as we can be with the forecast at this juncture, but do note a couple differences with the track of the low between the various models we use.

Here’s the track set-up:

A wave of low pressure will “scoot” east, northeast Friday into Saturday as highlighted here by the fine folks at



SaturdayMorningEnough of a south wind will keep us just warm enough to provide mainly a rain event for central and southern portions of the state.  Colder air will be deeper and more entrenched across northern IN where this should be a mainly snow event.  As the winds quickly whip around to the NW Saturday morning, temperatures will plummet and lingering moisture will quickly transition to snow for all of the state.

Behind the rain-to-snow event Saturday morning, the coldest air of the season will plunge into the state.  Lows Sunday morning will fall into the teens for many of central IN, especially if we can lay down a snow cover up north.  Throw in a gusty NW wind and wind chill values in the single digits are a good bet.

Can things still change with the track of this storm?  Absolutely.  While we feel as confident as we can be at this stage in the game, we do note a couple differences with the track of this area of low pressure (as mentioned above) between the various computer models we use.  We’ll continue to keep a close eye on things.  One other item of note is the relatively warm surface temperatures and that will cut back on accumulations across not only central, but northern parts of the state, as well.  Much more later!

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