Category: Forecast Discussion

Jan 13

Cold, Snowy Pattern Reloading…

I sure hope you’ve taken time to get out and enjoy a couple of days of milder air (temperatures have run 10-12 degrees above seasonal levels the past couple days) and even some sunshine.  Given what I see coming down the road, the trend that looks to take a colder turn this week may really go into the tank week two.

Here’s an overview of the latest GFS and ECMWF ensemble data out at Days 8 through 10 (January 21st-23rd).  Both of these, more trusted, mid to long range computer models suggest a cold pattern locks itself into the East once again, and spells for colder than average temperatures and potentially a snowier than normal regime.

test8

 

 

 

 

 

 

 

We’ll now dive a little deeper into the forecast model vault, courtesy of the unbelievable Weatherbell Analytics model suite (can’t brag on that company enough).  We’re looking at the Northern Hemisphere Upper Air Pattern, courtesy of the European ensemble control run from this afternoon.

Note the mid week trough set to deliver a return of arctic air into the region.  That’s reinforced with a late week trough and renewed arctic air.  Both cold air masses will be capable of producing light accumulating snow across the area.

Per yesterday’s post, as we get into the early to middle portion of next week, we’ll have to keep a close eye on the potential of the southern and northern branches of the jet stream phasing, which would lead to a significant winter storm across some parts of the eastern half of the country (far too early for specifics or details).

We then note the Polar Vortex recharges itself and threatens to turn the last week to 10 days of January very cold.  How cold is yet to be determined, but I think it’s a safe bet sub-zero temperatures aren’t finished with our area just yet.

Intrusions of very cold arctic air will “pinwheel” around the Polar Vortex and likely lead to a bitterly cold end of January and open to February…

Permanent link to this article: https://indywx.com/cold-snowy-pattern-reloading/

Jan 09

Bet On The Colder Look…

Sometimes in life there are things much more important than the weather and so has been the case the past few days. Moving forward, posts will be a bit erratic,…

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Permanent link to this article: https://indywx.com/bet-on-the-colder-look/

Jan 05

“Memorable” Winter Storm Just Beginning…

Our severe winter storm is just in the beginning stages and we’ll note rapidly deteriorating conditions moving into the afternoon and on into the night.  Please don’t take this storm lightly. Conditions will become life threatening this afternoon into Monday and don’t be surprised if Blizzard Warnings are issued today.

 Here are some quick bullet points you need to know:

  • 2″ per hour snow rates develop this afternoon
  • The pressure “gradient” tightens tonight leading to Blizzard conditions from late afternoon into Monday morning
  • 9-12″ of snow from Indy and points north, 5-9″ south-central Indiana
  • Drifts grow to 3-5 feet overnight into Monday (local drifts to 6 feet likely for the open country)
  • Monday’s high: 12 BELOW zero (not a typo)
  • Wind Chills: 40-50 BELOW zero by Monday morning

Latest high-resolution model data in house puts down widespread snow total of one foot, including Indianapolis, Zionsville, Noblesville, Avon, Anderson just to name a few…

hires_snow_acc_indy_11

Please be sure to hunker down today and remain inside if at all possible.  Conditions will become life threatening upon venturing out of your home tonight and Monday.

Permanent link to this article: https://indywx.com/memorable-winter-storm-just-beginning/

Jan 04

Serious Winter Storm Takes Aim On Indiana

We awake this morning to most of the data very consistent with what we’ve been passing along to you over the past few days…a very serious winter storm is taking aim on Indiana and will result in a combination of significant weather events that ultimately may end up being something we’ll remember for quite some time…

Quick Bullet Points:

  • Snow develops early Saturday morning
  • Heaviest snow falls between 10a-5p
  • Wind increases through the day Sunday and gusts in excess of 30 MPH leading to white outs and severe blowing and drifting
  • Temperatures crash to 10-14 below zero Monday morning with wind chill values of 40 to 50 below zero.
  • Widespread snowfall of 5-9″ is likely across central Indiana, with a heavier band of 9-12″ including Indianapolis and running along and just north of the I-70 corridor on the south side north to include Vermillion to Adams counties on the north side.

This is a hazardous and severe winter weather event that will likely lead to road closures from the heavy snow and wind, as well as extremely dangerous conditions to spend anytime outdoors Sunday into early next week due to the cold.  The bitter wind chills will be capable of frostbite in less than 30 minutes to any exposed skin.

Latest model data shows consistency in precipitation amounts, or QPF. We’re showing you the GFS, Canadian, and European models below.  Please note that the numbers and maps below don’t show snowfall amounts, but show precipitation totals.  Bring in a 12-15:1 snowfall ratio with these numbers and you get the snowfall discussed above.  We’re leaning heavily on a Canadian/ European model blend as the GFS has been more erratic.

gfs_total_precip_east_9cmc_total_precip_east_10ecmwf_tprecip_indy_10

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Much more later this evening!

Permanent link to this article: https://indywx.com/serious-winter-storm-takes-aim-on-indiana/

Jan 02

Rare And Potentially Crippling Winter Storm Brewing…

Fresh on the heels of a significant winter storm that impacted central Indiana Wednesday night-Thursday, we’re eyeing our next winter storm and, quite frankly, it could be a memorable one.

We continue to keep a close eye on the pending winter storm Sunday and remain impressed with what we see.  A severe winter storm is brewing and may require blizzard watches and warnings before all is said and done as a combination of heavy snow, strong winds, and severe blowing and drifting promises to make travel difficult, if not impossible, for some areas Sunday.

Setting the stage:

A powerful arctic boundary will drift south towards Indiana Saturday night and Sunday morning.  As this takes place, low pressure will track off the lee of the Rockies and move east, northeast.  Model data continues to suggest this area of low pressure taps into some Gulf of Mexico moisture and really begins to deepen (strengthen) as it tracks into the central/ eastern Ohio Valley Sunday.  To the northwest of the low’s track, a deep blanket of fresh snow will fall.  As the winter storm departs, the coldest air since 1994 will pour into the region on a gusty northwest wind.  Temperatures will reach record territory, and downright dangerous levels, by Monday and Tuesday.

Last night we mentioned a couple of things going “for” and “against” a major winter storm here in central Indiana.  While there’s no doubt going to be a sharp “cut off” of heavy snow with this storm, this “cut off zone” is most likely well north and west of central Indiana.  Additionally, the impressive thermal gradient between the brutal arctic air mass to the north and the warmer air (relatively speaking) to the south and east will only add fuel to a deepening storm moving northeast into the Ohio Valley.  Finally, with arctic air pouring into the region, the “fluff effect” will be in full-go mode, meaning the northwest flank of the heavy precipitation is likely to have snow ratios of 15:1 as compared to the “normal” 10:1 ratio.  This will be very important to watch as the system develops and will most likely be the spot (far too early to pinpoint at this juncture) where snowfall amounts in excess of one foot will fall.

All of our medium range model data is in agreement on central Indiana receiving quite the blow from Old Man Winter Sunday.  Here’s a look at the latest GFS, European, and Canadian forecast models, valid Sunday afternoon:

GFS1EC1CMC1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As you can see, there’s excellent agreement and this leads to a rather high confidence idea on a high-impact and rather rare severe winter storm set to impact Indiana.  Can we tell you with certainty exactly where the 12″+ band of snow will lie across the state?  Not at this time.  That said, we suggest preparing now for a rare and potentially crippling winter storm Sunday.  The combination of heavy snow, strong winds, historic cold, and severe blowing and drifting will make for an extremely dangerous situation Sunday, continuing into early next week.  Temperatures by Tuesday morning will approach 20 degrees below zero, with wind chill values plummeting to 40-50 degrees below zero Monday into Tuesday…

Permanent link to this article: https://indywx.com/rare-and-potentially-crippling-winter-storm-brewing/