• Times Are Changing, Or Are They?

    January-to-date is running milder than normal across the region- to the tune of 3.3 degrees (F).  This is after a frigid open to the month, as you recall.

    conus_mtd_t2max_anom_2017The second week of the month warmed significantly and continues, overall, for the next week.

    ncep_cfsr_noram_t2m_week_anomThe mid-January warmth is attributed to a roaring PAC jet which is currently helping flood the country with temperatures much more like spring than the dead of winter.  We continue to forecast 60+ this weekend across central IN.

    Winter lovers, have no fear as changes appear to be in the offing as we go through the last few days of January and head into February.  The winter so far has featured conflicting signals that continue to try and compete with one another to take hold of the pattern.  Can we get these drivers to align in a way that would pull a more persistent trough into the east for the second half of the winter and, ultimately, set-up a sustained cold pattern helping make up for lost time in the snowfall department?  Time will tell, but we do note the following late month:

    • (+) PNA pattern
    • Sudden stratospheric warming event
    • High latitude blocking

    All are encouraging for a shift back towards a wintry regime.  As always, the devil is in the details and we’re skeptical as to the longevity of these signals.  “Cautiously optimistic” would be the way to sum up our current feel longer-term into the month of February, but we’re not as bullish on lock and hold cold, wintry conditions at this time as what you may hear from some of our national compadres.  Understanding that various drivers can have a different impact mid and late winter as opposed to early is one thing.  It’s also important to note that long term modeling has been abysmal as of late and we want to tread through the next couple of weeks with caution to see whether or not the cold drivers can finally take hold.

    Needless to say, at least through late month, one can see the significant changes take place at 500mb.

    Thursday:

    ecm_eps_z500a_noram_2This Weekend:

    ecm_eps_z500a_noram_5Next Thursday:

    ecm_eps_z500a_noram_9Next Weekend:

    ecm_eps_z500a_noram_11The pattern begins in the short-term with a look that will power anomalous warmth through the weekend, along with renewed rain chances Thursday night into Friday (another 1″+ for most), but begins to shift next week towards the colder look.  The 2nd (weekend) storm system will be significant and poses a severe risk to the southeast region.  Modeling has backed away on the heavy rain threat Sunday, but showers will be around early next week along with very windy conditions (40+ MPH gusts).  Blocking is forcing the low south.  By the time we get to next weekend, the pattern has done a 180 and in a position to drill unseasonably cold air back into the central and eastern portions of the country.

    As far as storms go later in the period, it’s far too early to discuss specifics, but the pattern seems to be one that will promote the chance to get into the act on high-ratio producing clippers.  It’s the first time we can say that this year.  Time will tell…


  • Unsettled And Mild…

    Screen Shot 2017-01-17 at 10.06.05 PMHighlights:

    • Crossing our fingers for a few looks at the sun
    • Windy, rainy conditions return
    • Spring-like weekend ahead

    Hang On To The Rain Gear…We’re in the midst of a downright gloomy stretch of weather and, unfortunately, the overall trend remains locked in to a dreary regime.  That said, there will be an opportunity for at least a few looks at the sun Wednesday as we’ll be in between storm systems.  Our fingers are crossed!

    Any sun will quickly fade and give way to increasing clouds Thursday and blustery, rainy conditions by the afternoon.  Rain will likely grow heavy at times Thursday night into early Friday morning before another stretch of briefly drier conditions build in Friday PM through early Saturday.

    Our active pattern remains this weekend, as a wound-up storm system promises a wet, windy, and stormy close to the weekend.  Similar to our late week storm, additional heavy rain seems likely, as a gulf connection will be in place.  Though heavy rain will take the headlines, the “spring fling” is also noteworthy.  Highs this time of year normally are in the middle 30s.  For some through central IN, highs will approach a whopping 30 degrees above normal.

    Upper level energy remains early next week with pesky showers continuing, along with breezy conditions.

    Upcoming 7-Day Precipitation Forecast:

    • Snowfall: 0.00″
    • Rainfall: 1.50″-2.00″ (locally heavier totals)


  • Warm, But Unsettled Week…

    Screen Shot 2017-01-16 at 7.26.31 AMHighlights:

    • Unseasonably warm week
    • Multiple rounds of rain and embedded thunderstorms
    • Eyeing winter’s return next week

    Have The Rain Gear Handy…While we’ll enjoy unseasonably mild temperatures, the wet and unsettled theme we’ve been dealing with as of late we’ll continue this week.

    Most of the daytime today will feature more dry time than wet with just scattered showers expected before more widespread rain and embedded thunderstorms arrive by nightfall.  Wet and periodically stormy times continue tonight into the early morning hours Tuesday.  After a predawn high in the mid 50s, temperatures will slowly fall during the day Tuesday before remaining steady in the middle to upper 40s for the balance of the afternoon.

    We may get a brief (rare) look at the sun Wednesday as we’ll be in between weather systems, but have no fear, as our next storm will be developing to our south and arrive with showers Thursday.  🙂  Rain and perhaps a thunderstorm continue Friday, especially through the first half of the day.

    The majority of Saturday will feature dry and warm (early spring-like) conditions, but clouds will increase during the second half of the day and showers will push north into the state at night.  Windy, wet conditions continue Sunday.

    Longer-term, forecast models continue to paint a significantly colder, wintry pattern as we go through the last week of the month.

    Upcoming 7-Day Precipitation Forecast:

    • Snowfall: 0.00″
    • Rainfall: 1.50″ – 2.00″


  • Sunday Afternoon Rambles…

    1.) January, month-to-date, is running slightly above normal at IND (+1.2 F) and nearly 1″ above normal in the precipitation department.  Keeping true to the winter, overall, greatest cold departures are centered over the northern Plains and northern Rockies.

    conus_mtd_t2max_anom_20172.)  Showers will creep north overnight into Monday morning, but shouldn’t amount to much.  They will be scattered in nature across central Indiana.

    hrrr_ref_indy_183.)  More widespread rain and embedded thunder will develop Monday night into Tuesday morning.  This should amount of widespread half inch to one inch totals across the viewing area.

    hires_ref_indy_37

    hires_ref_indy_404.)  A moist southwest flow will help push a warmer regime northward for the second half of the week.  Though warm, we’ll also have to deal with periods of rain as disturbances track northeast.  We circle Friday and Sunday as the wettest days and remain optimistic Saturday will feature dry and unseasonably warm conditions (lower-middle 60s).  Between the rainy days Friday and Sunday, additional rainfall totals of 1″-2″ seem like a good bet.

    SW Flow

    D75.)  The evolution of the pattern just beyond the 7-day period we’ll begin to take on an increasingly wintry look and we remain confident on a flip back to wintry conditions as we roll through the last week of the month.  We’ll have to keep a close eye on a storm system in the 8-10 day period.  It’s obviously way too early to discuss specifics, but this will be the time the pattern is beginning to turn back towards a wintry regime…

    ecm_eps_z500a_noram_11

     


  • January Thaw For The New Week Ahead…

    Screen Shot 2017-01-14 at 4.13.32 PMHighlights:

    • Damp, chilly Sunday
    • Milder week ahead
    • Spring-preview late next week

    Improvements Coming…Most of tonight will feature dry conditions along with temperatures settling back below freezing (most of central IN will fall into the middle to upper 20s).  Another surge of light precipitation will arrive Sunday morning into the afternoon and this could begin as a period of freezing rain from the city and points north.  Similar to today, we don’t expect any major problems from the freezing rain and all of the region should warm above freezing during the afternoon.

    While Monday could feature a quick-hitting shower at any given time, more widespread steady rain will push into central Indiana during the day Tuesday, along with breezy conditions.  Those breezy southwest winds will help give temperatures a boost into the middle 50s for afternoon highs.

    We’ll shift that southwest wind around to the northwest Wednesday and this will help push cooler air into the state for mid week.  Despite the cooler feel, we’ll remain well above average with breezy conditions.  (Average highs in central Indiana are in the middle 30s this time of year).

    The big news for the latter portion of the forecast period will be a true spring-like feel developing as we rumble into the weekend.  In fact, temperatures will surge well into the 60s next Saturday.  Modeling isn’t in total agreement on rain chances with a moist southwest flow in place.  We’ll take the “optimistic” route at this time and forecast a dry Saturday, understanding that we’ll have to maintain a close eye on things.

    Quick heads up, longer term data continues to suggest we’ll flip into a much colder and stormy pattern as we wrap up January and head into February.  Winter is far from over…

    Upcoming 7-Day Precipitation Forecast:

    • Snowfall: 0.00″
    • Rainfall: 0.50″ – 1.00″


  • Saturday Morning Freezing Rain Update…

    More widespread precipitation is spreading across central Indiana this morning.  Most of this precipitation is falling as freezing rain.

    Radar at 7:19a.
    Radar at 7:19a.

    Modeled forecast radar continues to show moisture streaming across the region through around the lunchtime hour before diminishing.

    9a forecast radar
    9a forecast radar
    12p forecast radar
    12p forecast radar

    Temperatures will remain around 30-32 degrees along and north of the I-70 corridor as this rain falls so it’ll freeze on contact.  Allow extra time if you must travel and slow down.  Due to our phenomenal road crews and marginally cold temperatures, we don’t expect major travel issues this morning, but do use caution if traveling.  A light glaze of ice (around 0.10″) is possible on elevated surfaces, including tree limbs and power lines.

    Temperatures will go above freezing this afternoon across most of central Indiana and precipitation will end.  Highs both today and Sunday should top out in the middle 30s across the region.

    5p forecast radar
    5p forecast radar

    Lows tonight will settle back down into the middle to upper 20s, but dry conditions should remain for most of the night.

    10p forecast radar
    10p forecast radar

    Our next round of precipitation looks slated for a Sunday morning arrival and, similar to this morning, this precipitation will likely fall as a mixture of light rain and light freezing rain.

    Updated 7-day out later!  Have a great Saturday!


  • Surge Of More Widespread Precipitation Saturday Morning…

    Light freezing rain and drizzle has been falling across central Indiana this evening, mainly from the city, itself, and points south. A light glaze of ice has been reported into the forecast office in Monrovia and Plainfield. 

    For the next several hours, patchy light freezing rain and drizzle will continue, but nothing in a widespread, “uniform” fashion (great news for those night owls out and about).

    However, we do note some of the higher resolution forecast models suggesting a waive of more widespread precipitation arriving into central Indiana Saturday morning. This most likely pushes in sometime between the hours of 7a-9a and encompasses the heart of the state, including Indianapolis. 

    This “slug” of moisture will continue to fall across central Indiana through the morning hours before tapering off and diminishing around lunchtime. The afternoon and evening should be void of any widespread precipitation of significance. 

    While this won’t be a crippling event by any stretch of the imagination, be careful for slick spots Saturday morning and allow road crews room for salting. In general 0.05″-0.10″ of glaze still seems like a good bet for most central Indiana neighborhoods by lunchtime Saturday. 

    More in the morning! Have a great night!


  • Quick Friday Evening Notes…

    1.)  While we’re still expecting freezing rain across central Indiana tonight into the early morning hours Saturday, dry air will really limit totals.  Instead of the 0.10″-0.20″ of glaze per our first idea, we’ll cut that in half and say anywhere from 0.05″-0.10″ possible across central parts of the state tonight into Saturday morning.  This, obviously, won’t be enough to create power concerns or downed tree limbs, but could be sufficient enough to create slick spots in places.  Light freezing rain should increase in coverage across central IN from 10-11p.  Allow extra time to reach your destination tonight and early Saturday and slow it down.  All in all, this is not a significant event for central Indiana.

    Additional waves of light precipitation (rain mixed with freezing rain, primarily north of I-70) will be with us for the weekend, but similar to tonight, this won’t be a big deal and shouldn’t result in any need to cancel your weekend plans.

    2.)  A more significant surge of moisture will come out Monday night into Tuesday as low pressure (finally) pulls northeast out of the central Plains into the Great Lakes.  Localized amounts around 1″ will be a good bet, along with a warmer southwest flow.

    3.)  We’ll turn briefly cooler (still above average) mid week, before a stronger push of mild air late week.  Widespread highs in the lower-middle 60s seems like a good bet heading into next weekend and a rare January White Leg Alert may have to be issued.  😉

    4.)  Enjoy the January thaw while we have it.  Guidance continues to align and suggest winter roars back with authority to close January (last week of the month) before potentially locking in as we move into February and well into March.  More on this later this weekend.

    Complete updated 7-day will be published late tonight or early Saturday!


  • Weekend Ice And Heavy Rain Next Week…

    Screen Shot 2017-01-12 at 7.08.19 AM

    Highlights:

    • Turning colder
    • Freezing rain develops Friday night
    • Wet times continue

    Active Times; Excessive Rainfall Risk Next Week…The overall weather pattern remains very active AND very wet.  By the time all is said and done, an additional 3″ of rain is possible for a widespread portion of the region by the middle of next week, with locally heavier amounts.  Lets time it out.

    The focus in the shorter-term is for colder air to build in.  Temperatures today will fall (after a spring-like feel during the wee morning hours).  We’ll be in the 30s by mid to late afternoon and below freezing later this evening.  Arctic high pressure will continue to force cold, dry air south across central IN as we wrap up the work week.  At the same time, warm, moist air aloft will ride over the cold air trapped at the surface and trouble looms by Friday night.  We expect light freezing rain to develop after dark and continue into Saturday morning.  As disturbances move along the arctic boundary, additional precipitation (mostly light) will overspread central Indiana from time to time over the weekend.  We want to continue to reiterate that a 1-2 degree temperature difference will mean a tremendous difference between additional ice accumulation and plain ole cold rain.  Thinking is that the freeze line will shift north of the I-70 corridor Saturday afternoon before settling south towards I-70 again Saturday night and Sunday morning.  We still have time to fine tune things, but as of now it seems likely that anywhere from 0.10″ to 0.20″ of glaze (freezing rain) will be possible across most central IN communities Friday night into Saturday.

    We’ll get rid of the freezing rain early next week and bust back into a warm southwesterly air flow.  Models are struggling with the precise details of how things evolve in the early-mid week period, but confidence remains very high on continued wet times.  In fact, the GFS pulls a slug of 1.5″ precipitable water values (PWATs) north into the state the middle of next week and suggest the heavy rain threat remains Tuesday and Wednesday.  By the middle of next week, we have to start becoming concerned for flood potential across the region.

    Hang in there, we’ll see the sunshine return…some day.

    Upcoming 7-Day Precipitation Forecast:

    • Snowfall: 0.00″
    • Rainfall:  2.50″ – 3.00″ 


  • 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.