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Snow Talk And A Look Ahead Towards Christmas Week…

Latest data in house still suggests a plowable snow is ahead for most of central Indiana this weekend.  We think wintry precipitation expands northeast to encompass all of the region between 7pm-9pm Friday evening (southwest to northeast).  This wintry precipitation still appears to take the form of all snow for IND and points north, but we caution that south-central Indiana communities will have to deal with a mixed bag of precipitation, including sleet and perhaps some freezing rain along with the snow.  The primary snow zone will have no trouble seeing snow amounts of 4-5 inches, but for south-central Indiana neighborhoods, snowfall accumulations appear to be closer to 2 inches, with additional accumulations of sleet also possible.  Needless to say, we feel pretty good about our initial snowfall forecast posted last night in our 7-Day forecast video (always available to the right of these posts in the video player).  The limiting factor, in our opinion, of even higher snowfall totals will be due to the speed of the system.  We think this is primarily a quick 6-8 hour “thump and go” type snow storm followed by some lingering light snow/ snow showers and gusty winds Saturday PM.  The sunshine returns for Sunday along with another surge of bitterly cold air with highs in the 20s.

Friday night-Saturday Snow Storm Highlights:

  • Wintry precipitation arrives between 7p-9p Friday across central Indiana.
  • Primarily all snow from Indianapolis and points north
  • Mixed precipitation south of IND will include sleet and freezing rain
  • Snowfall accumulations of around 2″ south-central Indiana, increasing to 4-5″ amounts along and north of the I-70 corridor.
  • Accumulating snow tapers off late Saturday morning.

Our attention then turns to what may lie ahead Christmas week.  After the chance of some brief “relaxation” from the current bitterly cold pattern, we look to reload the cold with authority around Christmas week.  In fact, if latest data comes to fruition, the current cold would pale in comparison to what lies ahead.  Additionally, a rather significant storm system could precede the arctic blast.  It’s far too early to talk specifics on precipitation type or amounts, but don’t be surprised if a storm of “significance” is on the maps as we approach Christmas week…

The latest ensemble plot from the GFS and European (below) agree on first class cross-polar flow setting up shop, which will help refrigerate the Lower 48 with some seriously bitter air just in time for Christmas.  Stay tuned…

test8

Permanent link to this article: https://indywx.com/2013/12/11/snow-talk-and-a-look-ahead-towards-christmas-week/

What A Difference A Year Makes!

Our colder than normal pattern has really been in place since mid October.  Looking ahead, despite some potential brief “relaxation” from the cold a few days next week, the mid to long range pattern continues to look colder than normal.  Here’s a look at December so far, temperature-wise.  Note the presence of the southeast ridge keeping that particular portion of the lower 48 warmer than normal, so far.  Everywhere else, the freezer door has been left open!

4

What a difference a year makes, snow-wise, as well!  Here’s a look at the snow cover on this date last year compared to present.  Amazingly, this year, nearly 64% of the country is snow covered compared to 31% on this date last year.

The combination of more than normal snow and colder air for the majority of the country can be traced back to the expanding snow pack across Canada earlier this fall.  Now, the cold and snow are essentially in “feed back” mode with one another, as the overall pattern ahead is one that’s plenty cold…and snowy.

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Permanent link to this article: https://indywx.com/2013/12/11/what-a-difference-a-year-makes/

Snowy Pattern Continues…

Considering we’re only a third of the way through December, we’re certainly running “snowier” than normal at this very early stage in the game.  As we look ahead at the upcoming 10 days, or so, we see this snowier than normal pattern continuing with multiple systems to contend with over the course of the upcoming couple weeks.  Up next will be the threat of some light snow showers and flurries with reinforcing arctic air Wednesday PM.  Nothing significant is anticipated here on Wednesday, accumulation-wise, but snow showers will blow through the area Wednesday afternoon.  The latest high-resolution NAM shows this well.

hires_ref_indy_37

 

 

 

 

 

 

Then our attention turns to a developing winter storm for the weekend. We think clouds increase Friday and snow develops Friday night into early Saturday.  Here’s a look at the latest GFS forecast model, valid Friday night.

gfs_ptype_slp_east_17

 

 

 

 

 

 

Fast forward that to Saturday morning and snow grows heavier…

gfs_ptype_slp_east_18

 

 

 

 

 

 

The GFS suggests a weak surface low tracks into eastern Ohio with backlash snow showers and embedded squalls continuing here Saturday night into Sunday.

gfs_ptype_slp_east_20

 

 

 

 

 

 

It’s important to remember that we’re still a few days out from this event and I can guarantee you things will change as we go through the course of the upcoming few days that will require us to do some adjusting to our forecast Friday-Sunday.  That said, at this early stage in the game, unlike with our last storm, I’d favor areas from IND and points north as the place where heavier snow falls this go around.

Latest GFS ensembles suggest something similar to the operational run shown above with one low tracking into the eastern Ohio Valley as another coastal low develops.

f120

The European ensembles provide an “intriguing” look for an Ohio Valley winter weather event this weekend, as well.

Geopotential32at32500hPa_North32America_96

 

 

 

 

A couple of additional items to consider at this early juncture- this will be a fast moving winter storm so that will have an impact on snowfall accumulation.  Additionally, there’s also the chance enough warm air aloft advects (WAA or warm air advection) into the southern portions of the region to result in “mixing” issues (i.e. sleet and freezing rain).  In the primarily “snow zone” Friday night-Saturday (again, we’re currently targeting IND and points north for the snow zone) several inches of snow could accumulate.

Here’s an early look at what the latest mid-range forecast models are seeing in terms of potential accumulations with this event.  Top to bottom: ECMWF, GFS, and Canadian.  Stay tuned, we’ll have another update later!  Enjoy your day!

ECMWFGFScmc_snow_acc_east_24

Permanent link to this article: https://indywx.com/2013/12/10/snowy-pattern-continues/

Monday Morning Weather Rambles…

1.)  Light freezing rain and freezing drizzle led to numerous reports of a light glaze and associated very hazardous travel across central Indiana overnight.  With temperatures remaining below freezing today,…

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Permanent link to this article: https://indywx.com/2013/12/09/monday-morning-weather-rambles/

Heavy Snow Warnings Ahead?

Good evening, Indy.  As of late morning, we began spreading the word, via our social media accounts, of the need to “beef up” snow totals.  Sure enough, latest data continues to point towards a snowier solution as of this update.  We now think widespread 5″-8″ snow totals will be common across most of central Indiana, but there will be heavier amounts where localized banding sets up.  As expected last night, the transition from sleet to snow was a rather rapid one this evening and we now think this will be an all-snow event for the majority of central Indiana through the duration of the storm.

While it won’t snow the entire upcoming 24 hours, waves of moderate to heavy precipitation will move in from the southwest and result in a widespread heavy snow event Friday.  There’s the chance the National Weather Service will transition Winter Storm Warnings over to Heavy Snow Warnings to account for the all-snow event ahead.

Latest raw data breaks down like this for Indianapolis:

  • GFS:  0.68″ (equates to nearly 7″ of snow on a 10:1 ratio)
  • NAM:  1.00″ (equates to 10″ of snow on a 10:1 ratio)
  • ECMWF: 0.58″ (equates to nearly 6″ of snow on a 10:1 ratio)

We’ll have your updated, custom-built, 7-Day forecast video posted shortly.  For now, here’s a look at what the local radar may look like tomorrow morning when we think another wave of moderate to heavy snow moves back into the region from the southwest:

NAM

Permanent link to this article: https://indywx.com/2013/12/05/heavy-snow-warnings-ahead/

A Closer Look At Two Winter Weather Events.

Your updated, custom-built, Thursday video forecast can be found to the right of this post in the video player.  We typically update our video forecast during the evening.

Good Morning and happy Thursday!  We continue to monitor the latest data for our upcoming winter weather events.  It’s a busy time of things and by the looks of the overall pattern, I’ll have to stock up on the coffee for the weeks ahead.  Quite honestly, a very cold and snowy pattern appears to be setting up shop now through the end of the month.  Anyone dreaming of a white Christmas? 😉

Here are some quick bullet points for the upcoming few days:

  • Snow/ sleet overspreads the region this evening
  • (2) waves of snow/ sleet move through the region between this evening and Friday
  • Saturday will be a very cold and dry day
  • Renewed snow and potentially freezing drizzle move in Sunday
  • We continue to forecast a total of 3-6″ of snow between tonight and Monday morning

Latest forecast models continue to suggest temperatures fall through the day with a mixture of snow and sleet overspreading the region as early as 3-5pm from southwest to northeast.  We anticipate a rather rapid transition from sleet to snow, especially from IND and points north.  Here’s a look at the latest HRRR simulated radar data, valid tonight at 6 o’clock:

hrrr_ref_indy_15

Here’s a look at the GFS model.  (We think this particular model has a much better handle on things now that we’re closer to the event).  Note the “waves” of wintry precipitation forecast and we agree with this.  Wave #1 arrives for the evening rush with wave #2 arriving Friday morning into the afternoon.

GFS1GFS2GFS3

Additionally, after a very cold and dry Saturday, renewed accumulating snow will overspread the region Sunday, potentially ending as a mixture of light freezing rain or freezing drizzle atop the fresh snow Sunday afternoon.

GFS4GFS5

Permanent link to this article: https://indywx.com/2013/12/05/a-closer-look-at-two-winter-weather-events/

Wednesday Morning Weather Rambles…

1.) Fog will hang tough this morning, but strong southerly winds will blow this afternoon and help the fog burn off.  2.) With the cold and snow talk ahead, be…

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Permanent link to this article: https://indywx.com/2013/12/04/wednesday-morning-weather-rambles/

Video Model Discussion On Upcoming Wintry Threat

  Tonight we discuss the various model solutions for the upcoming wintry pattern ahead Friday through Monday.  This is the data that helped us come to an official IndyWx.com forecast…

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Permanent link to this article: https://indywx.com/2013/12/03/video-model-discussion-on-upcoming-wintry-threat/

Potential Long Duration Winter Event Looming…

Your complete 7-Day IndyWx.com forecast can be found in the video player to the right of this post.

Before we begin to discuss the potential wintry mischief ahead for late week, it’s important to stress that there are still several unanswered questions out there that will have to be ironed out with time as we go through the next couple of days.  That said, the latest data continues to suggest the potential is there for a rather prolonged, multi-day, winter weather event looming.  This won’t come from some sort of powerhouse storm system, but instead multiple waves of energy (low pressure) moving along a pressing arctic boundary.  The continued “curious” item here is the interaction with the arctic boundary’s progress south and east and the resistance that will be put forth from the southeast ridge.

The latest 500mb pattern off the 0z run of the GFS forecast model has “trouble” written all over it and we must keep a close eye on things as we move forward the next couple of days.  Additional model data from the European forecast model and Canadian are also suggesting fun times ahead.

gfs_namer_144_500_vort_ht_s

This image is valid Saturday evening and shows a couple of important items- the southeast ridge and the associated fight it’ll put up with the pressing arctic front, as well as “renewed” energy organizing across the Four Corners region, organizing before a track northeast.

The way we currently see things panning out would suggest the threat of light accumulating snow is on the table late Thursday night through Friday followed by a dry and cold day Saturday. That said, as shown above, renewed energy will move northeast the second half of the weekend into early next week and be responsible for spreading moisture back over what will be an unseasonably cold air mass in place, certainly one conducive for wintry precipitation.

It’s important to note that this isn’t just a snow event, but some places of the immediate coverage area (central Indiana, in particular) could experience an icy mixture of sleet and freezing rain, as well.  It’s far too early to talk about any sort of storm total accumulations as these type “overrunning” events can surprise…  That said, we are gaining confidence on “part 1″ of this event providing light accumulating snow for most of central Indiana Friday- light meaning less than 3”.  Additional accumulation of wintry precipitation would occur with “part 2” of this event during the back half of the weekend.

Again, it’ll be crucial to keep up to date with the latest forecasts and developments as things become clearer as we move forward.  As of now, keep a mental note in the back of your mind that the possibility is there for accumulating snow late Thursday into Friday, as well as later in the weekend…

Permanent link to this article: https://indywx.com/2013/12/01/potential-long-duration-winter-event-looming/

Questions Around Next Week’s Arctic Front…

Your complete 7-Day forecast can be found in the video to the right of this article.

We continue to keep a close eye on the developing weather situation here late next week.  Many questions remain in regards to the track, timing, and strength of the cold air associated with an arctic cold front that will result in record-breaking cold for portions of the country next week.  How much fight will the southeast ridge put up as the front progresses east?  Will we have to deal with a wave of low pressure along the arctic boundary, potentially leading to some wintry “mischief” around these parts?  We hope to give some clarity around those questions by looking at some of the latest data below.

First, let’s take a look at the various model solutions for late next week.  It should be noted that the latest run of the National Weather Service’s GFS forecast model has taken a turn to look more like the overnight run of the European forecast model and suggests we have to deal with a wave of low pressure moving through here Friday into Saturday of next week, leading to the threat of wintry precipitation.  Taken at face value, this would suggest the threat of an accumulating snow event for central Indiana Friday night into Saturday morning of next week.  This is in stark contrast to the 0z GFS run signaling dry, cold weather during the aforementioned time frame.

Here’s a look at the latest GFS solution, valid next Friday evening:

gfs_namer_180_1000_500_thick_s

There’s relatively good agreement in the GFS ensembles, but, again, we’ll have to fine tune the details.  It’s encouraging to see the agreement in the pattern evolution, though, this far out.

f192

Here’s a look at the latest European forecast, again valid for next Friday evening.

As we spoke about above, the 0z ECMWF run suggests we have to deal with a wave of low pressure in the cold air here next Friday into Saturday.  Similar to the latest run of the GFS model, there would be the potential of accumulating snow here.  The ensembles are on the left and the operational run is on the right.  The precise details will have to be ironed out, but we note relative agreement here.

Geopotential32at32500hPa_North32America_192

The latest Canadian forecast model also sees the wave of low pressure along the pressing arctic front, but suggests the wave is too far south to result in any sort of significant snowfall accumulation for central Indiana.  (As of this post time, the 12z Canadian ensemble package hadn’t arrived).

cmc_precip_mslp_east_31

So, with all of that said, we still have plenty of time to watch things unfold in the coming days.  What are we confident in as of today?

  • Brutally cold arctic air invading the northwest early in the week before slowly spreading east and south as we progress through the week.
  • We’ll be in a much warmer (though very brief) pattern here Thursday as highs zoom into the middle 50s to near 60 with rain.
  • We target the arctic front to blow through here during the day Friday.
  • While we’ll turn MUCH colder than normal next weekend, we aren’t looking at the brutality of the cold that our friends out west will have to deal with.

What are the answers that have to be ironed out this week?

  • Strength and depth of the cold air coming east.
  • Strength of the upper ridge over the Southeast US.
  • The resistance of the ridge will be crucial into determining where the “wintry precip. zone” sets up shop.

Permanent link to this article: https://indywx.com/2013/11/29/questions-around-next-weeks-arctic-front/

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