Sunday marked the 6th time in 2013 Central Indiana experienced highs in the 70s.  The filtered sun and spring warmth were certainly a welcomed change of pace, and 20-25° warmer than Saturday!

Clouds and a steady southerly wind will keep temperatures from dropping much below the mid 50s overnight.  So expect a milder start in the morning as you prepare to dress the kids for school and the bus stop.

Though I won’t rule out a stray sprinkle or shower in the morning, our best chances of rain/thunder will be during late afternoon/evening.

Monday marks the beginning of a daily chance of rain/storms in our forecast for much of the work week.  The culprit will be a stalled frontal boundary that will drape across the I-70 corridor.  South of the front will be much warmer than cooler air to the north.  The exact location of this boundary will prove challenging in forecasting temperatures this week.  Bottom-line there is BIG bust potential in daytime highs Monday-Thursday.

Below is a series of FutureTrak 13 images that exemplifies the temperature challenges ahead.

Notice Monday afternoon the 10° spread from Lafayette to Columbus…and the aforementioned higher rain chances that develop along the boundary in daytime heating.

The difference in temperature from north to south may be exponentially higher Tuesday.  Our latest FutureTrak 13 model run suggests as much as 15-20° differential due to the placement of the stalled front.

Monday-Wednesday rain/storms will be scattered in nature due to limited upper level forcing.  A stronger upper level storm arrives Thursday, and triggers widespread heavy rain along a cold front…and potentially severe storms.  It’s easy to understand why when you see temperatures going from the 70s Thursday to 40s Friday in the 7 day forecast.  Check back frequently for updates on severe storm potential.

Increasing cloud cover lowers the odds of already slim chances of seeing the lights in Indy.  Most reporting stations west of I-69 are reporting an overcast to mostly cloudy layer at 10-11,000 feet.

There is still a narrow window of oppurtunity in eastern/southeastern Indiana before the overcast increases overnight.  Based on latest infrared satellite… it appears Ohio may have the most optimal sky conditions tonight for viewing.

The odds were not high based on Central Indiana’s proximity to the southern edge of the auroa oval.  Nonethelss… good luck tonight and please post any pics on the WTHR Facebook page if you’re lucky enough to catch a glimpse

After a couple of colder than normal days, the temperature pendulum is set to swing in a much warmer direction Sunday.  Clouds and the stiff breeze we endured Saturday will both diminish this evening, leading to decent viewing conditions to potentially see a rare treat in Central Indiana.  It’s not 100%, but there is a chance of seeing the Aurora Borealis tonight…due to a recent solar storm from the sun.

Good luck and if you’re lucky enough to see the northern lights please share your pictures on the WTHR Facebook page.

Overnight temperatures will drop into the 30s and 40s.  Though late evening will be clear, I do expect clouds to return by the time you wake up Sunday morning.

In fact you’ll notice the sliver of precip on FutureTrak 13 by 5am.  This is along the leading of warm air advection, and it’s enough to warrant a chance of sprinkles/light showers early Sunday morning…especially along/north of I-70

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Notice by midday clouds begin to clear, and as a result temperatures will rise rapidly.  The hour-by-hour planner below shows 60s by midday and afternoon highs in the mid 70s courtesy of a bright sky/breezy (15-30mph) southerly wind.

Tomorrow marks the beginning of a prolonged stretch of warmer than normal days…as temperatures top-out a good 10°+ above average highs.

Notice Central Indiana is south-southeast of a stalled front on FutureTrak 13 Monday at 5pm.  This is a key player in the forecast for next week, with some model disagreement regarding placement of this boundary.  If we stay south of this front, and away from better atmospheric forcing for storms… the region will stay mainly dry and very warm.  However, if the boundary sags southward (looking like that Tuesday) storm chances/cloud cover increases and temperatures will be a bit cooler.

So please keep that in mind when examining the 7 day forecast below.  Models do agree that our best chance at widespread rain/storms is Thursday… with 2-4″ rainfall potential area wide.  This deluge is followed by another cold snap heading into next weekend.

Thanks for reading the blog and hope you enjoy the rest of your weekend!

Sean Ash

Several Central Indiana rivers are under flood warning for several days… including the White and Wabash.

This is due to the heavy rain that fell over past 24 hours (notice the 3″+ report in Kokomo) and what we expect to fall this afternoon/evening.

A highly saturated atmosphere will support an additional .25″ to locally 1″ of new rain between now and midnight.  This will aggravate lowland flooding and keep river levels high.

Thankfully cloud cover and cooler surface temperatures will spare Central Indiana from another round of severe storms…though a strong storm can’t be ruled out in extreme southeastern Indiana.  But the greatest severe threat is in eastern Kentucky southward into the Tennessee Valley where the air mass is much more unstable.

The humid air in place today will give way to much cooler air over the next 24 hours.  This sets the stage for temperatures to be 10-15° BELOW normal.

This transition will wring out another impressive bout of rain this afternoon/evening.

Expect soggy conditions for the ride home from work, and continuing well into the evening.  This will likely be enough to cancel soccer and baseball practices.

By Friday morning clouds should clear and you’ll definitely feel the change!  Bus stop temperatures will be in the upper 30s, with a stiff westerly wind making it feel much colder than that.

Afternoon temperatures will struggle to hit 50 for areas north and northwest of Indy.  The 50° high in Indianapolis as well below the average of 62°

After a chilly Saturday and Sunday morning, the air mass modifies significantly.  Expect a pleasant finish to the second-half of the weekend.  Long range models indicate we may be dealing strong to severe storms again next Wednesday night into Thursday.  Stay tuned for changes to the forecast.

Areas of moderate to heavy rain will lead to flooded roads in Central Indiana.  Use caution and expect potential delays/detours getting to work this morning, and don’t forget you can track Live Doppler 13 radar.  Severe storms are not expected this morning, but are possible in eastern Indiana later this afternoon.  Rainfall reports as of 3am exceeded 3.50″ in Kokomo!  An additional 1″ to locally 2″ is possible between this morning and afternoon.

Clouds and rain will lead to a cooler, but equally humid, day in Central Indiana.  Temperatures should hover in the upper 50s to mid 60s areawide.

FutureTrak 13 at 10am shows the axis of rain from Indianapolis and points to the east.

There’s some uncertainty on specific location of storm redevelopment along a cold front later this afternoon.  But it appears the greatest for severe weather will be east of Indianapolis, where better heating/instability is expected.

The forecast Friday quickly shifts from precipitation to temperatures.  After being 20° ABOVE normal Wednesday (high of 82°), highs Friday will be 10-15° BELOW normal and lows in the 30s Friday-Sunday morning.

After a chilly start Sunday morning temperatures quickly shoot into the mid 60s.  The long range outlook suggests a return to a stormy pattern next week.

A Severe Thunderstorm Watch is in place for Central Indiana until 9pm, and marks the beginning of a stormy period between now and Thursday.

Heavy rain and lightning will impact everyone the next 24 hours.  Areas of damaging wind and large hail will also occur…with wind gusts >60mph and nickel to golf ball sized hail in stronger storms.  This set-up is not particularly suitable for tornadoes, but brief spin-ups certainly can’t be ruled out.

It appears there will be two waves of storms to impact the region.  The first impact the I-70 corridor now through early evening.  

The second wave occurs late tonight into Thursday… with a big impact on the morning commute tomorrow.  Most of the region will see at least 1″ of rainfall, with local amounts of 3″+ possible.  One component in the severe weather set-up is a contrast in air masses.  Temps have hit 80+ today, and begin in the 60s Thursday.

But colder returns by Friday morning and sets the stage for a couple of chilly days.

But in true spring fashion, a quick resurgence to the 70s shows up early next week… our next best storm chance too.

Be weather aware this afternoon and tonight and don’t forget to download the WTHR Weather ‘App to get the latest radar and warnings.

A biting northeast wind kept central Indiana just cloudy and cold on St. Patrick’s Day.  However about a 100 miles south it’s a winter wonderland!  A band of heavy, wet snow dumped a narrow swath of 2-4″+ in southern Indiana… just outside of the WTHR viewing area.

Snowfall rates were heavy enough to overcome a relatively warm ground…and produced numerous slide-offs around Kentuckiana.  The picture below about 12 miles north of Louisville along I-65N near Sellersburg, IN.

The frontal system and associated atmospheric lift causing the heavy precipitation along the Ohio River Valley will push northward this evening.  Latest computer model data suggests the air mass over central Indiana will become saturated enough to produce precipitation between 8-9pm (give or take).

Though temperatures aloft (5,000ft+) will be warming rapidly due to an upper-level wind from the southwest… an easterly wind at the surface keeps ground level temps cold enough to support mixed precip at onset this evening.  I expect a burst of snow/sleet to move into the the I-70 corridor between around/after 8pm.  Between 8pm-2am snow, sleet and/or rain is fair game in any one given area.  Keeping in mind that 1° or 2° can change what type of precip falls in your backyard.  At this time I don’t envision any problems on area roadways, but that’s subject to change if banded precip becomes heavy enough to overcome warm soil/pavement temps.

After 2am it’s mostly a cold rain as temperature profiles warm from top to bottom.  Due to rather robust lift, don’t be surprised if you hear some thunder overnight either.  That lift may also produce some locally heavy rain.

No worries about roadways in the morning, with only wet pavement expected.

The focus quickly shifts to the much advertised colder than normal pattern for next week.  Temperatures will be a good 20° below normal.  This taste of winter air carries into next weekend and beyond.

Updates later this evening as needed to adjust forecast.  Thanks for reading the blog and I hope you can join us at 6pm and 11pm for the latest.

Sean Ash – Twitter / Facebook