Category: Forecast Discussion

Jan 15

Reviewing The Snowy Details…

After a brief thaw, winter’s set to return with authority in the days and weeks ahead.  In fact, the overall long range weather pattern looks colder and snowier than average into early February, at least.

A current look at the National Radar shows the next clipper system taking shape to our northwest this evening.

usa_None_anim

A dive into the latest model data continues to highlight two distinct opportunities for accumulating snowfall in the days ahead.  The first comes Thursday into Friday while the second (potentially more robust) snow maker arrives Saturday afternoon and evening.  By the way, my hat’s off to the GFS for jumping on Saturday’s system well in advance of the other modeling.  Sometimes it’s easy to hammer the GFS, but it should be pointed out during the model’s shining moments, as well.

Back to the near-term… We think widespread snow overspreads central Indiana Thursday morning and continues through the majority of the day and on into Friday in varied intensity.  By the time all is said and done, 2-4″ of new snowfall will be likely across central Indiana, with some locally higher amounts possible.

Here’s a look at the latest HRRR simulated radar valid 10am Thursday. Some moderate to briefly heavy snow is possible late morning into the afternoon.

hrrr_ref_indy_16

Of interest, we note forecast models carrying a vigorous upper level disturbance across the state Thursday night/early Friday and this will help carry accumulating snow into Friday for some.

500mb

We’ll note an intrusion of briefly drier air Friday afternoon into Saturday morning, but by this time all eyes will be focused on the next clipper system that promises to keep snow shovels and plows busy for parts of Indiana into the weekend.  We think snow overspreads the region from northwest to southeast Saturday afternoon and evening.  Steadiest snow falls Saturday night and could accumulate to the tune of a few inches by daybreak Sunday within the axis of best moisture.  Just to the north of the clipper’s track will be where you find the highest snow totals with Saturday’s system and the precise track of this clipper will be tough to iron out with any sort of certainty until Friday evening.  Stay tuned.  By the way, the snowy and cold events keep on keepin’ on in the longer range…

gfs_ptype_slp_east_12

 

Permanent link to this article: https://indywx.com/reviewing-the-snowy-details/

Jan 15

Series Of Fast Moving Snow Makers…

A series of fast moving snow makers will make for busy times in the good ole forecast office in the days (and weeks) ahead.

Of course we’re dealing with scattered snow showers this morning, but this really isn’t a big deal as accumulations will be nothing more than a dusting for most communities.

Our next clipper system will deposit light snow and snow showers across the region Thursday and Friday.  Short-term, high resolution data, highlights the chance of some light accumulation Thursday into Friday- generally an inch or less for most.  Here’s a look at the latest simulated radar valid Thursday morning at 8am and Friday at 4am:

hires_ref_indy_32

 

hires_ref_indy_52

We then look ahead towards Saturday when potentially the best shot of accumulating snow arrives.  The GFS has been leading the way on this system and now other forecast models are following it’s lead.  It’s important to note that these northwest flow systems can be over-achievers (as mentioned in previous posts) and the “fluff effect” can really kick into gear thanks to high snow ratios with the cold air.  We’ll continue to monitor this.  As of now, we think a few inches of snow is possible Saturday as this clipper moves through.  Stay tuned…

gfs_ptype_slp_east_15gfs_ptype_slp_east_16

Permanent link to this article: https://indywx.com/series-of-fast-moving-snow-makers/

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,…

You must be logged in to view this content. Click Here to become a member of IndyWX.com for full access.  Already a member of IndyWx.com All-Access?  Log-in here.

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/