December 2016 archive

Dec 11

Another Arctic Shot Inbound…

screen-shot-2016-12-11-at-2-49-00-pmHighlights:

  • Even colder this week than last
  • Light snow chances
  • Bigger storm next weekend

Bitterly Cold Week Ahead…We’ll kick off the work week with mostly dry, but mostly cloudy and continued cold conditions.  Be careful if traveling early in the morning as some refreezing may take place across central IN during the overnight.

Reinforcing arctic air will begin to blow into town mid week and an area of light snow may precede this next arctic punch to the gut Tuesday.  Scattered snow showers and flurries will fly in the bitterly cold, arctic, air mass Wednesday and Thursday.  Along with highs only in the teens Thursday, expect below zero wind chills.

Eyes will then shift to the end of the week as our next storm of significance approaches.  This storm appears to be stronger than this past weekend’s system, but similar to this weekend’s overall pattern, we expect a “mild up” and mostly a liquid event across central parts of the state.  The primary reason?  Lack of high latitude blocking to keep the storm track south (more on that in another post later tonight or Monday).  Add in a “feisty” southeast ridge that keeps flexing it’s muscle and you have the makings for what’s likely another cutter to the Lakes.  Unlike this current event, we will have to keep an eye on a potential second wave of moisture moving along the front Sunday as the arctic air returns.

Upcoming 7-Day Precipitation Forecast:

  • Snowfall: 1″ – 2″
  • Rainfall: 0.75″ – 1.00″

Permanent link to this article: https://indywx.com/2016/12/11/another-arctic-shot-inbound/

Dec 10

Busy Winter Pattern Continues…

screen-shot-2016-12-10-at-8-24-08-amHighlights:

  • Snow arrives tonight for central; northern parts of the state
  • Even colder air coming
  • Pattern of storms and rumors of storms

Snow Develops Tonight…Today is mostly dry and cold, including a mostly cloudy sky.  Clouds will lower and thicken this afternoon and give way to light snow late tonight across north-central Indiana and points north.  As milder air is pulled north Sunday, snow will transition to a wintry mix and eventually a cold light rain across central Indiana.  Further north, this will remain mostly snow before transitioning to a wintry mix.  Precipitation will end for everyone Sunday night.

Here’s the current thinking on storm total snowfall with this event. (Click to enlarge).

snowfallmap121116We’ll open the work week with dry and cold conditions, but all eyes will be on the next arctic front by this time.  It’ll blast through here the middle of the week with even colder air than what we’re currently “enjoying.” 🙂  Expect sub-zero wind chills mid week.  Snow showers and gusty winds remain in the mid week forecast and will require fine tuning as we draw closer.  A quick note, medium range modeling and beyond will really struggle in run-to-run consistency with such a pattern.  The slightest difference in handling respected upper air energy will lead to dramatic changes in the sensible weather the modeling paints.  There’s no sense in changing the forecast daily (or, in some cases, multiple times per day, only to change it back to where we began as time draws closer).

Finally, yet another winter weather maker awaits for the end of the week.  Clouds will be on the increase Friday with snow (or a wintry mix) developing at night.  It’s a busy, cold pattern…

Upcoming 7-Day Precipitation Forecast:

  • Snowfall: 1″ – 3″
  • Rainfall: 0.10″ – 0.25″

Permanent link to this article: https://indywx.com/2016/12/10/busy-winter-pattern-continues/

Dec 09

Buckle Up; Active Winter Pattern Is Only Beginning…

screen-shot-2016-12-09-at-7-32-12-amHighlights:

  • Very cold with snow showers diminishing
  • Messy second half of the weekend
  • Awaiting our next storm mid week
  • Frigid air awaits

Wintry Hits Are Lining Up…Fresh arctic air combined with even the slightest bit of upper energy can produce an overachieving snow shower event. As was the case overnight with many neighborhoods through central IN accumulating a coating to around 1″ of snow.  Take it slow this morning and leave extra time to reach your destination.  Bitterly cold air continues to wrap up the work week and head into the weekend (keep in mind our average high and low are in the lower 40s and middle 20s, respectfully).  As we look through the upcoming 7-day period, temperatures will run significantly below average throughout.

Our next storm system is dialed up this weekend.  Clouds will increase as we progress through the second half of the day Saturday and light snow will develop late Saturday night into Sunday morning.  As the area of low pressure tracks from northern MO into the Great Lakes, we’ll get into a milder southerly flow Sunday.  This will help bring in enough warm air to transition snow to rain during the day Sunday.  Beforehand, a light accumulation of snow is possible in and around Indianapolis (more on potential amounts this time tomorrow).  Heavier snow will pile up across northern Indiana.  Precipitation should shut off rather quickly Sunday night and we’ll be in between systems Monday.

By Tuesday, our attention will turn northwest as we await the arrival of another arctic cold front.  As the front moves in, modeling suggests multiple waves of energy move along the boundary, throwing moisture into the cold air and creating a rather snowy scenario as we progress through mid week.  We need to get through the weekend first, but this could also be an impactful event.  Very windy and frigid conditions move in Wednesday into Thursday, including sub-zero wind chills.  Additional snow chances await next weekend…

Upcoming 7-Day Precipitation Forecast:

  • Snowfall: 2″- 5″
  • Rainfall: 0.25″ – 0.50″

Permanent link to this article: https://indywx.com/2016/12/09/buckle-up-active-winter-pattern-is-only-beginning/

Dec 08

Quick Word On The Weekend Storm…

It’s been a ridiculously busy day and a longer post will arrive late tonight, including the updated 7-day. Models continue to struggle on the evolution of things this weekend. The…

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Permanent link to this article: https://indywx.com/2016/12/08/quick-word-on-the-weekend-storm/

Dec 07

Busy Winter Pattern…

screen-shot-2016-12-07-at-7-59-56-amHighlights:

  • Arctic air blows in tonight
  • Winter storm potential this weekend
  • Another blast of arctic air next week

Busy Times Ahead…The fun and active winter pattern has arrived and will keep us forecasters on our toes as we go through the next couple weeks.  Early sunshine will give way to an increasingly cloudy sky this afternoon and a couple snow flurries or scattered light snow showers may precede the arctic plunge this evening.  Snow lovers, unfortunately the arctic wave didn’t materialize as we once thought.  (Hang in there, you have many more snow opportunities ahead).  We’ll turn windy tonight and wind chills will fall into the single digits by Thursday morning.  We’ll stay dry, but cold to wrap up the work week.

Eyes will then shift to the weekend as a developing storm system pushes snow into the region Saturday night.  Snow and/ or a wintry mix will continue Sunday.  Where this remains all snow, it’s likely to be a “plowable” event.  We still need to fine tune the details over the next couple of days to hone in on just where the mixing line will set up.  Thinking now is that from Indianapolis and points north, this is mostly a snow event, but stay tuned.

Another round of snow and wind will blow into town early next week.  This will likely be ahead of an even colder push of air by the middle part of next week.

Upcoming 7-Day Precipitation Forecast:

  • Snowfall: 3″ – 5″
  • Rainfall:  0.10″ – 0.25″

Permanent link to this article: https://indywx.com/2016/12/07/busy-winter-pattern/

Dec 06

Would You Rather Be In The Game Fighting To Win, Or Sitting On The Bench?

The pattern over the upcoming 10-15 days presents a whole slew of challenges, but has the potential to be one winter enthusiasts remember for a long time.  Arctic air is beginning to press and will eventually overwhelm the pattern by the end of the week.  Additionally, a second and third surge of arctic air will be inbound next week.  Each arctic plunge may become more severe as we go, especially if we can get a snowpack down.  The potential is on the table for sub-zero temperatures (not even counting wind chills) by mid-month.  That, my friends, is not normal for December, and is in stark contrast from Decembers of recent memory.  Whether or not we get one “big ticket” event, or deal with a parade of storms that lay snow down is up for debate and will require burning the midnight oil in the good ole weather office as we progress through the next couple weeks.

mid-dec2016The overall set-up is certainly an intriguing one.  Cross-polar flow seeds pressing arctic air into the pattern (again, it comes in “waves” over the next couple weeks, each subsequently stronger).  What’s of particular interest is the battle that develops between a tag-team of ridges- SW and SE (at times these will put up more resistance than the other).  Long-time Hoosiers know that when cross-polar flow gets involved it can “suppress” storms, but rest easy in knowing that the SE ridge will provide resistance.  In fact, some across the lower Ohio and TN Valleys may eventually complain that the southeast ridge is providing too much resistance.

As confident as we are in the overall dramatic flip in the pattern to one capable of producing severe winter weather over the next couple weeks, per usual, the devil is in the details.  Expect a tight gradient between areas where heavy snow begins to stack up and little to nothing- at least initially.  Additionally, depending how things evolve, icing events may eventually require attention for portions of the lower Ohio Valley and TN Valley as that shallow arctic air “oozes” south over what may become quite the impressive snowpack north.  This will require further attention in week 2.

At the end of the day, there will be “haves” and “have nots” when it comes to storms (always are) and each will require our attention and fine tuning.  However, if you’re a lover of winter weather, it’s hard not to sit back and smile at what’s in front of us over the upcoming couple weeks, especially compared to the past couple Decembers.

Needless to say, we’re on the field and in the game…

Permanent link to this article: https://indywx.com/2016/12/06/would-you-rather-be-in-the-game-fighting-to-win-or-sitting-on-the-bench/

Dec 05

Arctic Air Inbound…

screen-shot-2016-12-05-at-11-19-01-pmHighlights:

  • Morning showers
  • Snow showers late tomorrow night
  • Arctic air arrives
  • Weekend storm system

Find That Heavier Winter Gear…Our next area of low pressure will push northeast between now (north-central Gulf Coast) and Tuesday night (central Appalachians).  Most of the widespread rain will fall across southeast IN this go around, but enough moisture will spread west to result in scattered to numerous showers Tuesday morning.  With temperatures in the lower to middle 30s, don’t be surprised if a sleet pellet or snow flake mix in at times.  All in all, expect another “raw” day.  Drier times will await for the evening rush home.

Wednesday will feature mostly dry conditions, but the arctic hounds will be howling to our northwest.  Snow showers will precede this arctic blast Wednesday night and Thursday morning and may be enough to accumulate for some.  While models remain drier than we’d expect (given the overall set-up), we may “eek” out just enough moisture to coat the ground up for some. Thursday will be a frigid day, including wind chills in the single digits.  Heavier winter gear will be required to wrap up the work week.

The weekend features more “fun and games” as an area of low pressure attacks stale cold air left over from the late week arctic push.  Is the cold air deep enough to create wintry problems or does the southerly flow help scour out the chill and lead to more of a liquid event.  Stay tuned.

Upcoming 7-Day Precipitation Forecast:

  • Snowfall: 1″ – 3″
  • Rainfall: 0.50″

Permanent link to this article: https://indywx.com/2016/12/05/arctic-air-inbound/

Dec 05

Monday Morning Rambles…

1.) Rain builds back in late tonight and Tuesday morning and will favor the southern and eastern half of the state.  Drier trends develop Tuesday afternoon as the moisture pulls northeast.

Forecast radar 11a Tuesday

Forecast radar 11a Tuesday

2.)  A surge of arctic air will pour into the region as we wrap up the work week, including single digit wind chills.  Lows in the 10s and highs in the 20s can be expected Thursday and Friday.

Forecast temperature anomalies to close the work week.

Forecast temperature anomalies to close the work week.

3.)  Despite the cold, snow chances look unimpressive, per the latest data.  While we, personally, still believe there will be more of an arctic wave to deal with along the arctic boundary pressing Wednesday night into Thursday (enough to accumulate), modeling says “we’re crazy” and brings the arctic plunge in without much fanfare (flurries).

4.)  Speaking of snow, modeling also says the 3rd wintry threat we spoke of Sunday (for about a week from now) arrives with a warm-up and is more of a liquid event.  While we tend to think this is still a threat that could deal our region wintry conditions, it would be irresponsible of us not to convey the lower confidence (heck, modeling suggests we’re close to 60 degrees next Monday).

5.)  Our thoughts on a snowy December began last summer as research began on the upcoming winter.  It’s based off a variety of solutions, but leans heavily on the idea blocking would develop and help “lock in” an active pattern with just enough cold air to create the wintry “goods.”  (Pressing cold and an active jet undercutting the cold to create winter storm potential).  While bullish on snow (still are), we’ve never had out a very cold December forecast (instead only “slightly,” or 1 degree, below average).  If the recent weekend trend is correct, it says the upcoming (10) day period we thought would essentially deliver a month’s worth of snow is incorrect.  Sure that gives us the second half of the month to still make up for it, but it becomes increasingly difficult to see the wild model swings and inconsistency without relaying those inconsistencies to you, the viewer.

Our overall thinking remains (as stubborn as it may seem) on December, but please know we also see how this could bust.  There’s a fine line between communicating both ideas to you.  Confidence is lower than we would like it to be…

Permanent link to this article: https://indywx.com/2016/12/05/monday-morning-rambles-2/

Dec 04

Active Wintry Pattern Is Here…

If you’re a fan of cold weather, including being on the field to “cash-in” on multiple winter storm threats, this is a pattern for you.  In all honesty, it’s tough to ask for a better pattern to yield such things.  With that said, each respected storm threat will have its’ own set of challenges that will have to be dealt with.  While we’re confident on IND being above normal in the snow department for the month of December by the 20th, it’s impossible to put numbers (from an accumulation perspective) on specific storm systems from this distance.  With that said, please know that the pattern is one that will have multiple impactful winter events lining up behind one another and it’ll be important to keep updated with forecasts as we progress through the next few weeks.  Needless to say, there will be plenty of opportunities to get those favorite photos with Christmas lights/ decor in the snow this season!

We’re tracking (3) winter systems over the upcoming week:

1.)  Today:  Dry air initially made it difficult for precipitation to make it to the surface this morning.  Heavier precipitation rates will arrive after lunch and fall for a few hours (between 1p-6p for most of central IN).  This will fall as mostly a cold rain from Indy and points south.  Further north, including north-central IN, this will fall as a rain-snow mix (snow should become the predominant form of precipitation shortly after starting.  Across northern portions of the state, this will be mostly snow and we note modeling trending colder with recent runs.  With heavier snowfall rates this afternoon/ evening, travel may become dicey across northern IN and wet snow accumulations of 2″-4″.  A coating to less than 1″ of snow is possible as far south as the northern suburbs of Indy.  The following time stamps can give you an idea what the radar may look like this afternoon into the evening hours.

1p forecast radar

1p forecast radar

4p forecast radar

4p forecast radar

6p forecast radar

6p forecast radar

Temperatures tonight will fall below freezing for most (upper 20s to around 30) and with the lingering moisture on area roadways and sidewalks, a couple slick spots could develop here and there so be mindful.  We don’t anticipate major issues, however.

2.)  Wednesday night-Thursday:  An arctic front will blow into town mid week and we remain bullish on the idea a wave of low pressure delivers a shot of accumulating snow as the arctic plunge moves in.  As we’ve relayed over the past few days, model data is far from being in agreement on this idea, but when one looks at the overall pattern, it’s easy to see how there should be more reflection of low pressure moving along the pressing arctic boundary.  These can be tricky and many times modeling is “forced” to play catch-up at last minute.  For now, we continue with the idea of accumulating snow across central IN in the Wednesday night-Thursday time frame ahead of the coldest air so far this season.  Temperatures will fall to between 10-15 degrees for lows by late week, including single digit ‘chills.

Arctic waves can be tricky in the medium range and must be watched closely.

Arctic waves can be tricky in the medium range and must be watched closely.

3.)  Saturday-Sunday:  Our next wintry threat appears to roll into town next weekend.  Similar to mid week, this, too, could be an accumulating event.  It’s far too soon to get specific on timing, snowfall amounts, etc., but just know we’re keeping a close eye on next weekend for potentially more of a widespread wintry event and will sure-up details as we progress deeper into the week.

GFS ensemble members show the snowy pattern ahead over the upcoming week.

GFS ensemble members show the snowy pattern ahead over the upcoming week.

Permanent link to this article: https://indywx.com/2016/12/04/active-wintry-pattern-is-here/

Dec 03

Sunday Mix; Heavier Winter Gear Needed Next Week…

screen-shot-2016-12-03-at-9-48-58-amHighlights:

  • Sunday mix
  • Wet Tuesday
  • Midweek snow and turning bitter

Winter Awaits…Today is chilly and dry. Thankfully, we’ll finally get to see the sun.  Enjoy it into the afternoon as clouds will quickly increase yet again later in the day as our next storm system approaches.

Speaking of that next system, moisture will spread into the chilly air mass Sunday morning.  Across central IN, this will fall as a wintry mix of light snow and chilly light rain.  Further north, this will be a mostly snow event, including a light accumulation possible (slushy amounts under 1″) across far northern portions of the state.  All-in-all, this won’t be a big deal.

We’ll have a brief break in between systems Monday before rain returns at night.  This is courtesy of another wave of low pressure lifting out of the northwest Gulf of Mexico, tracking northeast through the TN Valley and into southeastern Ohio.  Central Indiana snow lovers know that’s a classic track for snow around these parts this time of year.  We’ll keep an eye on it, but as of now, the air mass doesn’t look cold enough (yet).

A much colder pattern looms by the middle of next week.  Along with the arrival of the arctic air mass, we also favor a wave of low pressure delivering accumulating snow prospects Wednesday night into Thursday.  (That high Thursday will come at midnight with temperatures crashing through the day).  We’ll turn bitterly cold to close the week, including wind chills falling to around zero.

This is only the beginning of a very cold and wintry period.  There are plenty of “fun and games” awaiting as we rumble through the next couple weeks…

Upcoming 7-Day Precipitation Forecast:

  • Snowfall: 1″ – 3″
  • Rainfall: 0.75″ – 1.25″

Permanent link to this article: https://indywx.com/2016/12/03/sunday-mix-heavier-winter-gear-needed-next-week/

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