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…

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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/questions-around-next-weeks-arctic-front/

QUICK Wednesday Evening Video Update

  I’ll try and have a more in-depth post later tonight.  Have a great evening!

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Tuesday Night Video Update: Lake Enhanced Snow Showers

Tonight’s Video Highlights: Lake Effect Snow Showers And Squalls Set To Impact Central Indiana Coldest Thanksgiving In Years On Deck Eyeing The Potential Of An Arctic Invasion Next Week

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Clouds Today; Snow Showers For The Big Travel Day

Good morning and happy Tuesday, Hoosiers!  Yesterday’s forecast went as planned with most folks not receiving any snowfall accumulation and a couple reports of a dusting to half an inch type snow.  We saw a couple local weather sources forecasting 1″ of snow and never understood that call as a lot of dry air had to be overcome initially.

Today will feature lots of clouds and another cold day as we watch a big southern storm begin to “make the curve” and impact the interior east.  Places as close as eastern Ohio will deal with heavy snow tonight and early Wednesday.  Additionally, locations as far south as east Tennessee will have accumulating snow by late tonight and early Wednesday.

Back here on the “home front” we’re looking at our next chance of snow arriving Wednesday afternoon.  The wind trajectory off Lake Michigan should allow a couple of lake-enhanced snow bands to push south into north-central Indiana, primarily from IND and points north.  It’s impossible to pinpoint with any degree of certainty the precise locations of these snow bands, but should your neighborhood end up under one of these snow squalls, don’t be surprised if you pick up a quick coating to 1″ of snow Wednesday afternoon/ evening.

Most model data (below) shows the lake-enhanced snow showers and embedded heavier squalls arriving Wednesday afternoon.  We’ll have a complete forecast update (and probable video) here later tonight.  Make it a great day.

hires_ref_indy_30snow1snow2

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