• Category Archives Snow/Ice Cover
  • Icy Concerns Grow Again Tonight…

    After a night of freezing rain, many roadways throughout central IN remain glazed over and hazardous as of this update.  If you absolutely don’t have to travel today, please don’t.  Allow road crews to do their job.  Additionally, we have growing concerns of a new round of freezing rain to sleet and eventually snow tonight.  Lingering moisture on roadways will result in “flash freeze” conditions and treacherous travel tonight into Sunday.

    First, a tip of the hat to short-term modeling, including the NAM, for suggesting we’d have a very difficult time eroding the shallow arctic air at the surface across most of central IN today.  While we never bought into the mid/ upper 50s idea the GFS and Euro were once suggesting, we did initially think 40s were in store today.  Forget about it.  Mid to potentially upper 30s are the best we can do today and temperatures will crash this evening as not one, but two, arctic fronts push through central IN.  Even if we didn’t have additional precipitation inbound tonight, “flash freeze” conditions would develop from lingering moisture and lead to renewed problems on area roadways.  Throw in another wave of low pressure riding along the pressing arctic front and a whole slew of problems will develop yet again from a freezing and frozen precipitation perspective.

    Note the incredible temperature gradient from downstate to central and northern Indiana early this afternoon.

    hrrr_t2m_indy_6The heavy, dense, arctic air will win out as evening turns into nighttime.  Indianapolis is back to the freezing mark around 6p and into the 20s by 9p.

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    hrrr_t2m_indy_13Temperatures will continue to fall through the day Sunday and by Monday morning central Indiana will be in the single digits, with below zero readings across northern parts of the state.

    hires_t2m_indy_49Wind chill values of 10 to 20 degrees below zero will be common by Sunday night into Monday morning across central Indiana.

    gfs_windchill_indy_8Areas of drizzle and freezing drizzle will continue across the region into the early afternoon, but begin to expand in coverage and intensity once again by evening.  Note the area of freezing rain expand across central IN, including Indianapolis, between 4p and 7p.

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    7pFreezing rain will eventually begin to mix with sleet and eventually transition to light snow during the overnight from northwest to southeast.  A coating of snow to less than 1″ is a good bet on the new icy glaze that develops tonight.

    When you factor in the current hazardous conditions in place along with the fresh push of arctic air and precipitation tonight, it’s a good idea to hunker down inside and remain off area roadways.  We have big concerns of new travel problems developing by evening across central Indiana.  By this time tomorrow, our attention will turn to the bitterly cold air and dangerous wind chill values developing.

    More later, including prospects of snow around Christmas.  As always, you can follow our updates on social media by following us on Twitter (@indywx) and Facebook.  Stay safe!

     


  • Frigid Start; Looking Ahead To Thanksgiving…

    Screen Shot 2015-11-22 at 9.27.08 AMHighlights:

    • Arctic air begins to moderate
    • Next storm system arrives late Thanksgiving
    • Another punch of cold air next weekend

    Before we discuss what lies ahead, let’s look back at yesterday’s snow event that “overachieved” for many.  Particularly just northwest of the city where 2″-4″ fell.  Snowfall rates were heavy enough to overcome the initially warm surface temperatures, and it was very impressive to see the way the snow accumulated considering this was a November event that took place from late morning into the early afternoon (when the sun angle does the majority of it’s work).  This was an impressive first snow of the season and this morning’s snowpack is widespread throughout the Mid West.

    nsm_depth_2015112205_MidwestThe visible satellite this morning shows the snow cover across the central and northern portions of the state, where single digits and teens were common.

    SnowpackThe next few days will feature dry and cold conditions.  While we’ll remain below average, temperatures will slowly begin to moderate from the arctic intrusion of today.

    We’ll get into a SW (milder air flow) regime for a brief period of time Thanksgiving Day out ahead of our next storm system that will move in Thanksgiving Night and Black Friday.  Clouds will increase and moisture will spread into the region during the aforementioned time period.  Most of the rain will fall Friday, so plan on taking the rain gear with you as you venture out to begin that Christmas shopping.

    Thanksgiving

    BlackFridayMuch colder air will pour into the region Thanksgiving weekend and we’ll have to maintain a close eye on the evolution of things late next weekend into early December.  Models will continue to waiver on specific solutions over the next few days, but there will be an attempt of a southern stream storm system coming out and “attacking” the cold air in place…


  • Looking Ahead…

    January is off to a colder than average start across a large portion of the country, including the Hoosier state:

    ncep_cfsr_noram_t2m_anomThe snow and ice pack has expanded over the past couple of weeks in rather significant fashion:

    nsm_depth_2015011205_National

    Two storm systems have offered up busy times over the Ohio Valley the past week. Note liquid equivalent numbers the past (7) days- most significant over central Indiana.  Most of this has been in the form of wintry precipitation (snow and ice).

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    A weak weather system may offer up light snow chances mid week.  The high resolution NAM and European print off light snow while other models “see” us mainly dry mid week.

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    The other big story in the short term will be more bitterly cold arctic air (single digits tonight and close to zero Wednesday morning).

    While we’ll certainly “warm” compared to the freezer we’ve been in the first two weeks of January, sneaky arctic highs remain on the field and will put a dent in the air masses from reaching unseasonably mild levels for any length of time this weekend and Week 2.  See Friday’s GFS output and the sneaky arctic high north:

    gfs_ptype_slp_east_18

    The next significant storm system brews around the 20th (give or take a day, or two) and could offer up rain or a more wintry option.  Keep a close eye on the period 01.20 – 01.23.

    Thereafter, the arctic hounds likely come calling again as the period quickly returns to “lock and load” cold late January into February.  The European and GFS ensembles both show a rebuilding blocking AK ridge and suggest arctic air floods the country yet again as cross-polar flow gets involved:

    GFSensembleslateJan

    It’s all part of a package that should be the beginning of a colder than average and stormy mid and late winter stretch.  Sea surface temperature anomalies are a textbook setup for a very wintry time of things for our neck of the woods.  Note the Modoki El Nino and warm waters sitting off the PAC NW- both cold/ stormy indicators here:

    SSTLateWinterSetUp


  • Wintry Sandwich Sunday Evening-Monday; More Bitter Cold Follows.

    Busy times continue in the good ole weather office as we get set to deal with yet another winter storm during the upcoming weekend.

    First, we’ll deal with more below zero temperatures tonight and Saturday morning as overnight lows bottom out between 5 and 10 degrees below zero tonight area-wide.  Wind chill values, of course, will be even colder (-15 to -25).  Dangerous cold continues with considerable blowing and drifting in the open country.  Saturday will be the “calm before the storm” with unseasonably cold conditions continuing, but with lighter winds and sunshine.

    Clouds will increase Saturday night into Sunday and we’ll begin to introduce precipitation into your forecast as early as Sunday afternoon (not a bad day for two classic back-to-back playoff games if you ask me).  Here’s our best idea of what you can expect statewide after reviewing all guidance today:

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    Some initial thinking would place the following numbers (a bit early to be too specific), and we caution this will have to be fine tuned as we move forward.

    Snow accumulation of 2″-4″ across north-central Indiana, particularly just north of Indianapolis.  In the “mainly snow” zone, expect amounts of 3″-6″.  Ice storm criteria accumulation of freezing rain is possible (0.25″, or greater) across central Indiana, as well.  South of the city, early ideas suggest roughly 1″-2″ of snow and glaze potential closer to that potentially damaging 0.25″ amount.  Again, we state that these numbers are very early ideas and will have to be fine tuned.

    Precipitation should initially overspread central Indiana Sunday afternoon in the form of sleet and snow (more sleet south-central, more snow north-central) before transitioning to more of a sleet and freezing rain event.  Finally, we anticipate the wintry mixture of precipitation to end as snow before moving out Monday morning.  Timing and duration of precipitation types will obviously determine how much ice and snow a given location sees.

    Another big item we want to be sure to mention is that yet ANOTHER push of bitter arctic air will invade behind this storm and set the stage for another dangerously cold period Tuesday into Wednesday (back below zero we go)!

    Stay tuned as we continue to fine tune the forecast over the weekend!


  • Catching Up On Where We’ve Been And What Lies Ahead…

    January is off to a frigid start. After a mild December, January is certainly reminding folks that there’s a lot of winter in this pattern.

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    Precipitation is running above normal through the Ohio Valley and south month-to-date.

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    Snowpack is being laid down further and further south with time.

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    The past 365 days have been wettest extreme PAC NW and east of the MS River.

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    This morning fresh arctic air is pouring into the region on gusty northwest winds. Considerable blowing and drifting snow will continue in the open country today. Drifting in Boone County is more than 3 feet in spots already. After a “balmy” high around 20° after midnight, temperatures crashed with the passage of another arctic front. We’ll “enjoy” single digits for daytime temperatures today before falling to 5° to 7° below zero tonight. Wind chill values will range from 15° to 25° below zero.

    Noon temperatures

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    Modeled forecast lows Saturday morning

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    Another winter storm takes aim on the region Sunday night into Monday. As of now we forecast this to be mostly a snow event from Indianapolis and points north. South of Indianapolis and down state expect more of an icy mixture of sleet and freezing rain. This will likely be an impactful event to Monday’s commute so stay tuned.

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  • Tracking A Late Weekend Winter Storm

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    5/ 18

    8/ 14

    2/ 23

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    20/ 30

    10/ 20

    5/ 18 

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    Light

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    Forecast Updated 02.26.14 @ 7:43a

    Frigid Midweek…A brutally cold air mass is blowing into the region this morning, especially considering we’re nearly into March!  This is laying the groundwork for a snowy weekend, but we’ll get to that in a bit.  Forecast highs average at 44 degrees this time of the year and today’s high will be lucky to reach 18.  EVEN COLDER air blows in late tonight into early Thursday and will result in continued dangerous below zero wind chill values.  Needless to say, plan to bundle up upon heading outdoors.  While the calendar may suggest spring is near, Mother Nature and Old Man Winter have other ideas.

    Late Week Light Snow…A warm front will lift north through the region Saturday morning and will be responsible for producing a round of light snow Friday night into Saturday AM.  As of now, early numbers suggest around an inch of snow is possible, but we’ll continue to monitor things and update as needed.

    Late Weekend Winter Storm…While details are still far from etched in stone, there’s no doubt behind a significant winter storm brewing for the second half of the weekend.  This storm will have significant snow for portions of central Indiana and significant icing potential for others.  As of now, we anticipate air cold enough to support frozen, or freezing, precipitation across our immediate viewing area of central Indiana.  All of that said, we caution that the track and intensity of the storm will likely change between now and Sunday and we’ll continue to keep close tabs on this event.  Early numbers are impressive as far as precipitation goes with liquid equivalent amounts around 1″ churned out, on average, from a variety of computers models.

    Arctic Air Reloads…We may be into meteorological spring next week, but Old Man Winter continues his relentless ways that we’ve grown so accustomed to over the past several months. Fresh arctic air will plunge into central Indiana’s potentially snow packed ground early next week and could ultimately help yield below zero air by the middle of next week.  What an impressive winter.

    Upcoming 7-Day Precipitation Forecast

    • 7-Day Snowfall Forecast: 4-8″
    • 7-Day Rainfall Forecast: 0.00″

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    For weather updates and more “behind the scenes” data on the go, be sure to Follow Us on Twitter @indywx or become a Friend of IndyWx.com on Facebook!

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  • Sunday Afternoon Thoughts…

    1.) A scan over the latest data continues to point towards an absolute mess of a Monday afternoon.  Our accumulation ideas remain relatively unchanged from this morning’s update, aside from “beefing” expected snow totals for Indy’s northern ‘burbs by 1″.  Most of this falls from noon to 6pm and will be followed by a dry, cold, and blustery Monday night.  After likely a white-nuckle evening commute Monday, the combination of sub-freezing temperatures and gusty northwest winds Monday night will likely lead to another rough commute for Tuesday morning.

    ** We caution that this will be another “now cast” situation when it comes to precipitation types and their respected precise zones tomorrow afternoon.  Stay tuned here or to your favorite local weather media for updates and potential changes.**

    • Indianapolis northern ‘burbs, including Zionsville: 2-4″ snow and sleet with less than 0.10 of freezing rain.
    • Indianapolis proper: 2″ snow and sleet with around 0.10 of freezing rain
    • Indianapolis southern ‘burbs, including Greenwood: 1″ snow and sleet with up to 0.25 freezing rain.

    Snow:IceForecast021714

    2.) We continue to monitor what will be a brief thaw and associated flood risk mid week.  Even without rain, water rise would occur and urban flooding from the combination of melting snow and blocked (from all of the snow) drainage zones.  When you add 0.50-1″ of rain atop the melting then problems could arise Wednesday into Thursday.  Additionally, we’ll need to prepare for the likelihood of dense fog Wednesday as milder air surges north over a deep snow pack.

    3.) For anyone thinking spring is setting in during our mid week thaw will need to think again. Latest model data continues to suggest we reverse things quickly later this week and for the upcoming weekend.  In fact, some model data, including the European, suggests central Indiana is under the gun for a weekend winter storm.  We’ll continue to monitor closely…

    021614ECSatWinterStorm022214

    4.)  Additionally, prospects continue to grow for another extended period of well below normal cold and renewed wintry precipitation chances in the long term (into March).  Both the GFS and European models are in agreement on the mid to long range pattern with a trough settling back into the eastern half of the country.

    02161412zGFSEC


  • Cold Today; Messy Monday Ahead.

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    16/ 25

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    20/ 39

    24/ 42

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    0.00”

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    0.50″-1.00″

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    Forecast Updated 02.16.14 @ 11:15a

    Cold Sunday…Fresh off celebrating our snowiest winter on record (surpassed last night at IND at 51.6″ and the Record Event Report can be found here), we’ll enjoy a dry day, but blowing and drifting snow will remain an issue in the open country. A few breaks in the cloud cover can be expected this afternoon on what will otherwise be a rather cloudy day.  Highs will only climb into the lower to middle 20s (well below the average high of 40 and closer to the normal low of 24).  Yes, our cold, snowy winter just keeps on keepin’ on!

    Snow And Ice Issues Monday…A storm system will move through the region Monday and deliver a mixture of precipitation types across central Indiana.  The way we see things unfolding as of this forecast update brings a wintry mix of sleet and snow into the city around noon with periods of moderate to even heavy wintry precipitation falling into the mid to late afternoon hours before we begin to see the shield of moisture push northeast.  This will be a “thump and go” type event.

    As for precipitation type, this remains a challenge and will require much fine tuning later tonight and through the day tomorrow (another now cast scenario).  We’re thinking mostly snow is the dominant form of precipitation from the northern suburbs of Indianapolis and points north.  Here, 2-3″ of wet snow is possible, polished off with a light glaze of a freezing rain/sleet mixture before precipitation ends.  For the city, itself, we think around 1-2″ of snow is possible with a glaze of freezing rain of around a tenth of an inch. Farther south, to include the southern Indianapolis suburbs, an icy mixture of sleet and freezing rain will be the concern with glaze potential approaching one quarter inch.  Again, we caution this is our best idea at this point and we’ll post some fresh thoughts later this evening.

    Needless to say, tomorrow stands to include treacherous driving conditions in and around central Indiana and the National Weather Service will likely issue Winter Weather/ Freezing Rain Advisories later this afternoon to account for the wintry conditions anticipated tomorrow afternoon.

    Flooding Concerns On The Rise…With such a deep snowpack across central Indiana, combined with a frozen ground, flooding concerns will be on the rise as early as the middle to latter part of the week.  We think dry and chilly (albeit milder) conditions will be with us Tuesday, but low clouds, fog, and drizzle likely develop by Wednesday as milder air streams north over the snowpack locked in across the region.

    By Thursday, our attention turns to the potential of heavy rain and a couple of thunderstorms as a cold front blows through the region.  Early ideas of Thursday rainfall numbers would suggest anywhere from .50-1″ of rain is laid down and when combined with the heavy snow pack and milder air, flooding concerns will certainly be present.  Needless to say, if you live in a flood prone area, please monitor the situation closely later this week.

    Winter Blows Back In…As promised, the briefly milder shot of air would be just that- brief.  We continue to monitor data that suggests a colder, more wintry, pattern blows right back into the region to wrap up February.

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    For weather updates and more “behind the scenes” data on the go, be sure to Follow Us on Twitter @indywx or become a Friend of IndyWx.com on Facebook!

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  • Saturday Morning Notes…

    * Your full, updated, 7-Day Forecast will be published later tonight.

    1.) In the long range, credit the Canadian model for being spot on with yesterday’s snow storm.  It was forecasting a moderate to heavy snow event late last weekend while American models were struggling to catch up until 24-48 hours prior to the event. Even the Euro struggled.  The HRRR did a phenomenal job with heavy snow placement from a short-term perspective.  In the end, many communities across central Indiana added 3-6″ of snow on Valentine’s Day- simply piling on what’s already been a record snow season.  The record of all records will fall later tonight when we pass the 51″ mark for seasonal snowfall… 2.) With that said, yes we are tracking another snow maker tonight.  It’s a clipper system that will push snow into central Indiana around, or just before, sunset.  We think steady snow falls tonight with an additional 1-3″ of accumulation laid down.  (Is anyone else running out of places to put all of this snow? 🙂  My drive way looks more like a ski cabin in the Rockies with the growing snow banks).  3.) Another wintry event is scheduled Monday.  Model data has trended colder and as a result, a wintry mix of sleet, snow, freezing rain, and rain can be expected Monday…yes, all-in-all, a nasty day!  We’ll have more on expected accumulations later tonight with your full forecast update.  4.) While we’re certainly going to enjoy a brief thaw next week, it may be accompanied by thunderstorms and flooding concerns late week.  5.) Brief is the key word there as mid and long range data suggests any milder spell is simply transient and replaced, in a big way, by another cold, wintry pattern.  Latest indications suggests this cold pattern rolls into mid March, at least…


  • Complicated And Complex…

    If you have travel plans across central Indiana Friday and Friday night, please make sure you leave plenty of time to get to your destination and prepare for a variety of precipitation types.  In fact, it’s entirely possible (depending on what time of day you’re traveling) that you have to deal with rain across south-central Indiana and snow by the time you arrive into the northern Indianapolis suburbs, complete with an icy mixture “in between.”

    Digging through the weather playbook for Friday into Saturday:

    A cold front is expected to move through the region Friday morning, allowing a wind shift out of the north to arrive into the city in the early to mid morning Friday. We’ll have to be in “nowcast” mode Friday to determine just exactly how far south the front makes it as this will go a long way into determining precipitation types across central Indiana.

    Ultimately, a wave of low pressure will move along the front Saturday, which will help milder air push north and result in a changeover from a wintry mix to all rain during the majority of the day Saturday. In fact, there’s the chance portions of central Indiana may not have to deal with much, if any, precipitation through the majority of the day Saturday- especially south.  Before that, however, we’ll have to deal with a wide variety of wintry precipitation issues Friday and Friday night…  Warmer low level air will be drawn northward and overrun the colder air at the surface Friday and Friday night.  What will initially be a period of snow Friday will transition to an icy mixture of sleet and freezing rain Friday night and all rain Saturday.  That said, we note the milder push will be brief, and colder air will pour back into the region on gusty northwest winds Saturday night. This may result in a brief period of light snow Saturday night (not a big deal).

    We think the latest high-resolution, short-term, NAM model (courtesy from the fine folks over at Weatherbell Analytics model suite) has a very good handle on accumulation ideas Friday and Saturday and is in best agreement with our analysis laid out above.  This is a look at forecast snow accumulation between now and Saturday night, but we also note there will be some light sleet and freezing rain accumulation on top of any snow that falls Friday. As far as that snow goes, we think a 1-2″ band is laid down from the city and points north, increasing further as you travel into north-central and northern Indiana.

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