Category: Winter Storm

Dec 23

An “Appetizer” To Christmas Eve’s “Main Course…”

In general, northern ‘burbs picked up between 1″ to 3″ of wet snow earlier this morning before drier conditions arrived for the afternoon hours.  A couple of reports include Whitestown with 1.6″, Carmel with 2″, and Lebanon with 2.5″.  A sharp cut-off with slushy coatings to less than 1″ made it as far south as the city, itself.  Today’s event will be viewed as the “appetizer” to Christmas Eve’s “main course.”

Vigorous upper level energy will track through the Ohio Valley Christmas Eve afternoon into the evening, itself.

Snow will begin to overspread the state, especially north of the I-70 corridor during the mid-to-late morning hours and we expect a steady snow to fall across the northern half of the state throughout the majority of the day.  A period of moderate to heavy snow should develop during the mid-to-late afternoon, continuing into the evening hours across central Indiana.  Road conditions will begin to really deteriorate during this time frame as surface temperatures fall into the 20s.

Eventually, snow will end from west (around 8p) to east (around midnight) tomorrow night, but not before depositing a widespread swath of 3″-5″ for areas generally north of I-70.  For the city, itself, we think 2″ to 3″ is a good call, with generally an inch, or less across far southern portions of the state.

Don’t be surprised if enough Christmas “magic” results in localized heavier totals with potential banding that develops tomorrow afternoon into the evening hours.  All in all, this will be a classic, picturesque snow event for Christmas Eve.  Hoosiers will wake up Christmas morning with a fresh blanket of white.

We have additional wintry fun and games to track later next week!

Permanent link to this article: https://indywx.com/an-appetizer-to-christmas-eves-main-course/

Dec 21

VIDEO: Sure Hope You Like Winter…

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Permanent link to this article: https://indywx.com/video-sure-hope-you-like-winter/

Mar 06

Thoughts Shift From Storms To Snow…

Before we discuss the weekend winter storm threat, we still have to get through the overnight period-morning hours Tuesday with embedded heavy rain and storms.  Some of these storms could offer up gusty winds and a few could be strong as they rumble across central Indiana Tuesday morning.

Most of the storms should push through west-central Indiana well before the morning rush hour.

Forecast radar 4am Tuesday.

Forecast radar 6am Tuesday.

Attention will then shift to the winter storm threat this weekend- particularly Friday night through early Sunday morning.  We still have to fine tune the all-important specifics, but confidence is rising on the possibility of a significant wintry event impacting at least portions of the region this weekend.  March snow events provide added headaches of dealing with the impacts of marginal temperatures, higher sun angle/ time of day, etc.  Conversely, the tight thermal gradients noted with most late season, spring snow events can be impressive, as they can quickly feedback, ultimately leading to swaths of thumping wet, heavy snow.  Hoosiers don’t have to think back too terribly far to some impressive and impactful March snow events.  Modeling today is in relatively good and surprising agreement, especially considering the lack of agreement models have dealt us weather ‘folk for the past few months.  🙂

GFS ensemble members are focusing in on a snow event this weekend.

It’s still early in the game and a lot can (and likely will) change with model runs over the next few days.  It’s wise not to make knee-jerk reactions to the operational model solutions, but instead understand the overall pattern driving the potential of this memorable March wintry event.  Anomalously cold air in southern Canada will spill south this weekend and help aid in the “fun and games” ahead.  At the same time, given the time of year, “suppression depression” isn’t likely as their will be resistance from the south-central Plains and southeast ridging in place.  As of now, we think the I-70 corridor could be the “sweet spot” for snow totals, understanding fine-tuning will be required moving forward.  Where a snowpack accumulates this weekend, expect temperatures Sunday night/ Monday morning to fall into the 10s.

Much more later!

Permanent link to this article: https://indywx.com/thoughts-shift-from-storms-to-snow/

Feb 08

Heavy, Wet Snow “Thump” This Afternoon…

The set-up:

A cold front is stalled across TN and lower Ohio Valleys this morning.  Meanwhile, upper level energy is moving out of the north-central Plains.  This upper level energy will continue to slide southeast and “feed” a developing surface low along the stalled front by evening.  Strong frontogenesis is forecast and this will aid in development of localized heavy snow bands and associated intense snowfall rates by afternoon, continuing into the evening.  (If you’re interested in learning more about frontogenesis and it’s impact on winter weather, please read this fantastic paper).  Here’s our updated snowfall forecast.  Please note snow amounts won’t necessarily follow the clean lines below, but this is our best idea as of now.

SnowEvent2.8.17FinalTiming:

We expect initial light to moderate snow to impact northern areas this morning, but it’s not until this afternoon when the “real deal” begins.  The onset of heavy snow will set-up just north of the city and the “bulls eye” with this event from a heavy snow perspective may very well paint itself across Indy’s northern suburbs, including several hours of heavy, wet snow from 12p-5p.  Moderate to heavy snow will then shift south to encompass the city, itself, mid to late afternoon, including the rush hour.  We highly recommend getting home early today if at all possible as the heaviest snowfall rates for the city, itself, will likely center on the evening rush.  Things will likely be very, very messy for travel as heavy wet snow falls.  In periods of heaviest snow, visibility near zero can be expected, especially just north of the city.

Forecast radar 1p, courtesy of Weatherbell.com.

Forecast radar 1p, courtesy of Weatherbell.com.

Forecast radar 4p, courtesy of Weatherbell.com.

Forecast radar 4p, courtesy of Weatherbell.com.

Forecast radar 6p, courtesy of Weatherbell.com.

Forecast radar 6p, courtesy of Weatherbell.com.

Snowfall should begin to diminish and pull east between 7p-8p for most of central Indiana.  Cold air will follow as lows tonight dip into the middle teens for most with a significant snowpack down.  Highs Thursday will only top out around 20.

As always, be sure to follow us on social media (Twitter: @indywx, Facebook: IndyWx.com, Instagram: IndyWxCom) for more updates on the go!  Be safe and happy snow to all!

Permanent link to this article: https://indywx.com/heavy-wet-snow-thump-this-afternoon/

Jan 11

Icy Set-Up This Weekend…

Unfortunately, a strong arctic high still looks like it’ll descend into the upper Mid West Friday before moving east over the Great Lakes (Saturday) and into the northeast (Sunday).  This will help shove a cold front south to the upper TN Valley Friday and dense, cold air will bleed south to encompass central Indiana as we wrap up the work week.  As we progress into the weekend, warm moist air will override the shallow cold air locked in place at the surface.  Ripples of energy will move along the boundary and periods of more concentrated, steadier precipitation will fall.  Significant ice accumulations (greater than one quarter inch) will be possible for portions of central Indiana.

gefs_ptype_ens_ky_14GFS ensemble members above show the overall good agreement on a central IN ice set-up for portions of the weekend.

Timing:  As of now, I think most of Friday is dry and cold before moisture overspreads the region late Friday night into Saturday.  Additional waves of moisture will push through the region during the second half of the weekend, as well.

Confidence:  We have very high confidence on at least light to moderate icing in the Friday night – Saturday time frame, but confidence on additional icing thereafter begins to drop, thanks to disagreement in modeling.  The GFS is warmer for the second half of the weekend and would reduce the threat of significant ice build-up as some brief thawing would be in place in between waves of moisture thanks to temperatures rising into the middle 30s.  However, the European model is much colder and keeps IND below freezing Saturday and Sunday, with nearly half an inch of liquid during that time frame.  That’s downright concerning and would result in significant issues with potentially downed tree limbs and power lines.

We do have concern the European could have a better handle on things right now.  Modeling is notorious for underestimating the strength and depth of the cold air with these arctic highs and similar overrunning events of the past.  Stay tuned.

Impacts:  Greatest concern right now is for icing on exposed and elevated surfaces (bridges, tree limbs, power lines, etc.).  With the milder air of midweek, along with marginally cold air, it’s possible crews will be able to keep roads passable during this event.  Additionally, something else to consider is the rate of precipitation.  While bad for elevated ice build-up, if precipitation rates are heavy enough, this can help reduce ice build-up on roadways.

Summary:  We still have concern for the potential of an impactful ice event this weekend through central Indiana.  Winter Storm Watches (and potentially Ice Storm Warnings) may be hoisted by the National Weather Service later this week for this event.  Despite an overall high confidence in at least some icing impacting the region, questions do remain in regards to the temperature profile later in the forecast period this weekend, and caution the slighted deviation in surface temperature can make all the difference to impacts.  At the very least, low pressure should pull out of the southern Plains early next week and this will serve to push enough warm air northeast to change everything over to plain ole rain early next week as we rise into the 50s.

Permanent link to this article: https://indywx.com/icy-set-up-this-weekend/