Home News Weather Traffic Sports Hot Topics
 Blog Homepage

Author Archive

Nov
13

Coldest Day Since Early March And Weekend Snow Likely

Posted By · November 13, 2014 at 4:51 pm

The early taste of winter air continues to be impressive.  We’ve certainly been much colder before and it’s not record breaking, but temperatures 25-30 degrees below the average high gets your attention.

TEMPS

Wind chills are flirting with single digit territory early this evening with areas of flurries and light snow to continue.  A few locations have had a quick dusting today and heavier showers can drop a quick .25″ in spots.

WIND CHILL TEMP TREND

Not only are temperatures colder than the average high, but Indianapolis and the rest of Central Indiana are a good 10 degrees colder than the average low for this time of year.

COLD

This is the city’s first sub-30 degree high since March 3rd when there was a 2″ snow pack… which again quantifies the impressiveness of the air mass in place.  It appears many we’ll get their first 1″ snowfall ahead of schedule, which climatologically speaking is December 9th.  Better chances of accumulating snow arrive Saturday evening into Sunday morning with a trickier system in play Sunday night.

HEADLINES PLANNER FRIDAY

Friday may offer some peeks of sunshine, but overall there will be more clouds and continued cold.  Morning lows may drop into the teens if clouds break enough this evening.  Highs Friday again struggle to hit 30 degrees.

RPM RPM 2

Saturday begins dry and partially sunny before clouds quickly race in during the afternoon.  Snow should overspread the region by sunset Saturday but should quickly depart by midday Sunday.

RPM 3 RPM 4 RPM 5 RPM 6

There is excellent agreement in mid-range computer models regarding snow amounts with the first of two systems to impact the region.  Most locations will be near 1″ but locally lower and/or higher totals are possible.

WEEKEND SNOW RPM 7

There is greater uncertainty in relation to the second, and potentially heavier, system this weekend.  As mentioned in prior posts, it’s too early to tell if surface low pressure intensification will occur closer to the Ohio River (which leads to higher snowfall) or farther east/south from the viewing area (less snow).  At this point there is a large region, including the Indianapolis metro area, that’s in play for greater than 2″ snowfall Sunday night into Monday morning with potential to impact schools Monday.  We recommend you check back for updates on a highly changeable forecast.

RPM SNOW SUNDAY NIGHT RPM JET

In the wake of this system even colder air blows in early next week.  Notice the continue sharp trough in the image above in the mid-levels which serves as the conveyor belt of Arctic air supply.  Admittedly our forecast “high” of 24 degrees Tuesday may be too warm and there should be a few mornings easily in the teens.  GFS ensemble mean temperature graph below (via WeatherBell.com) shows the cold grip easing around/after the 21st of the month.

GFS ENSEMBLE

As I mentioned in a blog post back on November 3rd, we’ll need to keep an eye out Thanksgiving week as that warmth may feed a robust storm system.  Indeed medium to long range guidance is already picking up on a formidable feature.  Obviously this far out it’s impossible to pinpoint an exact location, strength, impacts.  But the idea of an eventful mid-latitude storm shouldn’t be ignored.  More on this feature in the weeks ahead.

GFS EURO ENSEMBLE

7day

Have a great evening and thanks for reading my discussion – Sean Ash

 

Comments (0)
Nov
11

Cold Arrives Marking Active Pattern Change

Posted By · November 11, 2014 at 2:37 pm

The time for talk is over as the much advertised Polar Plunge continues its path across Central Indiana.  Though not as dramatic as the rapid temperature falls in the Rockies yesterday, the wind will make it feel 30-40 degrees colder this evening than the early day highs in the 60s.

WEATHERBUG

At time of this blog posting eastern Indiana remains in relatively balmy air, but that changes big time this evening.  The Indianapolis metro area is in the 40s now behind the front and the temperature tumble continues into the 30s by 5pm.

TEMPS WIND CHILL

A band of showers along the cold front may mix with snow as the cold air catches up to the moisture.  Though no accumulation is expected it serves notice of the shift to a January-like air mass that will hold a tight grip on a good chunk of the eastern U.S. 10 days or more.

RPM RPM 2 PLANNER EVENING

A persistent northwest fetch off of Lake Michigan may deliver lake effect flurries or snow showers later tonight into Wednesday morning…. primarily for areas northeast of Indianapolis.  Lows tonight fall into the 20s and wind chills early tomorrow will be in the teens.

RPM 3 RPM WIND CHILL

Any early morning sunshine Wednesday should give way quickly to a scattered to broken low-level cumulus cloud deck.  Highs will likely be below 40 degrees for the first time since mid-April.

PLANNER WEDNESDAY RPM 4

An upper level disturbance diving across the Ohio Valley Thursday could trigger snow showers and squalls late afternoon into the evening.  At the very least it will reinforce the already chilly air and knock daytime highs into the lower 30s Thursday and Friday.

RPM 5 RPM 6 JET STREAM

Weekend Snow Potential:  This upper level pattern is primed for cold and a few potential snow-makers.  The first of which locally shows up Saturday evening into Sunday.  Current modeling continues to support the notion of a quick-moving feature that doesn’t intensify until reaching the Appalachians.  Providing this holds we’re only expecting light snow, but possibly enough to accumulate Sunday.

JET STREAM 2 JET STREAM 3 JET STREAM 4

Bigger System Next Week?:  We continue to watch the possibility of potentially stronger system in play next week.  In fact both medium range GFS and EURO models show a deeper surface low (stronger system) impacting the Ohio/Tennessee Valleys Wednesday/Thursday of NEXT week.  The images below show surface pressure (black lines) and precipitation INTENSITY and not type.  Current modeled temperature profiles during that time would support winter precipitation and snow accumulation in Central Indiana.  However it’s 8-9 days away and will likely change between now and then.  But we’re watching it and will post updates as needed.

EURO GFS

With or without accumulating snow we’re not missing out on an impressive cold snap for mid-November.  As I’ve mentioned many times in the past few days… we’ve certainly had colder temperatures but the departure from normal and duration make this noteworthy.  Have a great evening and a big THANK YOU to those who have served our country.  Happy Veteran’s Day – Sean Ash

7day

Comments (0)
Nov
09

From 60s To January-Like Cold This Week

Posted By · November 9, 2014 at 5:14 pm

Hope you’re enjoying the weekend despite the limited sunshine we’ve seen in Central Indiana.  Highs Sunday made it into the lower 50s but temperatures should soar well into the 60s Monday as a south-southwest wind teams up with sunshine.

TEMPS

You can see that warmth downstream in Missouri and central Illinois.  You can also see the well advertised chill we’ll have later in the week lurking north side of boundary along the U.S.-Canadian border.

HIGHS REGIONAL RPM RPM 2

Tonight and Monday:  Expect clouds to linger around this evening and overnight with seasonably cool lows in the upper 30s.  The passage of a warm front Monday ushers in a taste of warmer than normal air.  Highs will range from 60 in eastern Indiana to the mid/upper 60s in western Indiana.  Wind gusts late Monday may approach the 30-40mph range.

PLANNER MONDAY HIGHS TOMORROW RPM 3

This is in response to a developing fall storm that will drop accumulating snow from the Dakotas into the upper Great Lakes.  Windy conditions continue into Tuesday as the center of the storm passes to our north.  Showers become likely along a cold front on Veteran’s Day and some thunder is possible.  After highs briefly hit the upper 50s Tuesday, colder air filters in behind the front Tuesday night.

RPM 4 RPM 5 PLANNER TUESDAY HIGHS WEDNESDAY

Wednesday morning marks the beginning of a prolonged cold spell that will last a good 7 to 10 days… and possibly longer.  During this time expect temperatures to be 20 degrees colder than normal which equates to lows near 20 and highs in the 30s.

RPM 6 7DAY

Light snow is possible Thursday and we’ll need to get close tabs on snow potential next weekend… though it’s uncertain if the cold air will suppress any systems south of the Ohio River.  Get the cold weather gear ready and have a great evening – Sean Ash

Comments (0)
Nov
04

Soggy Evening Marks Beginning Of Active, Cold Pattern

Posted By · November 4, 2014 at 4:52 pm

This afternoon is quite the contrast to 24 hours ago as we’ve gone from 60s to rain showers and chilly 40s.  Temperatures this evening are some 15 degrees cooler than this time Monday.

3PM TEMPS 24HR CHANGE PLANNER EVENING RPM

Rain continues through early evening but the steadiest axis gradually ends from northwest to southeast by midnight.

Left behind tonight will be cloudy, damp conditions as temperatures slowly settle into the lower 40s by sunrise Wednesday.  We’ll likely be under a blanket of gray early tomorrow, but some peeks of sun are possible heading into early afternoon… with highs struggling into the lower and middle 50s.

RPM 2 RPM 3 RPM 4 PLANNER WEDNESDAY RPM 5

Another quick-hitting upper level system dives into the Ohio Valley with showers and breezy conditions.  On the backside of this feature Thursday evening rain may mix with snow showers.  Flurries remain possible into Friday morning with a gusty northwest wind providing chilly conditions to finish the week.

RPM 6 RPM 7 RPM 8 HIGHS FRIDAY

The active pattern continues this weekend with another wind-maker racing across the Great Lakes.  We’ll be on the warmer side of the storm track Saturday in the upper 50s.  Cold air quickly returns Sunday with areas of flurries and light snow possible and highs in the lower 40s.

JET STERAM JET STREAM 2

Long range data continues to support a cold air outbreak in the eastern U.S. next week.  Both the GFS (top graph below) and European (bottom graph below) ensemble means (which modifyextremes) show temperature departures of nearly 15 degrees cooler than normal Tuesday evening to the end of next week.  If this verifies we could be staring down several days with highs in the 30s/low 40s and lows in the 20s.

ENESMBLE MEAN HIGHS(image courtesy of WeatherBell.com)

It’s nearly a week away so it’s highly subject to change, but at this point there is global indicators to support the model output theories.  This type of cold is something that would be more fitting for December than mid-November.

NOVEMBER TEMPERATURES 7DAY

 Stay tuned for updates and have a great evening – Sean Ash

Comments (0)
Nov
03

60s Today With Next Bout Of Winter Cold Arriving Later This Week

Posted By · November 3, 2014 at 4:06 pm

Sun and a southwesterly wind teamed up to deliver a warmer than advertised Monday afternoon.  Highs are well into the middle 60s and a good 15 to 20 degrees warmer than Sunday afternoon.  This will easily be our warmest day in quite sometime, as all signs point toward a return of much below normal conditions later this week.

3PM TEMPS 24HR CHANGE

The mild afternoon sets us up for a pleasant evening overall, though the wind remains gusty in the 10-20mph range.  We’re still on target for a damp Tuesday as showers expand across central Indiana late morning into early midday.  High temperatures will be significantly cooler tomorrow with clouds, showers and temperatures in the low to mid 50s.

PLANNER EVENING RPM RPM 2 RPM 3 PLANNER TUESDAY RPM 4

The axis of rain will slowly sink southward to the Ohio River Tuesday night, but residual cloud cover and drizzle remain very much in play Wednesday.  Another potent upper level system dives into the Ohio Valley and delivers a new surge of colder than normal air from Canada.

RPM 5 RPM 6 RPM 7 RPM 8

High temperatures quickly drop into the 40s and rain showers mix or change to snow showers Thursday night into early Friday morning.  This is part of an active storm pattern and persistent flow from the northwest and leads to a prolonged spell of chilly temperatures.

HIGHS THURSDAY JET STERAM

Does the jet stream map above look familiar?  It’s very similar to the upper level set up from Halloween and we’ll experience a chill like last Friday with temperature departures of 15-20 degrees below normal.

JET STREAM 2 GFS TEMP DEPARTURE(image courtesy of WeatherBell.com)

Model ensemble guidance from the GFS (American model) for Days 5-10 agree with this theory and is supported by other medium range model data (not shown).

GFS ENSEMBLE MEAN(image courtesy of WeatherBell.com)

Notice the raw high/low temperature graph above for Indianapolis for the next 16 days is more indicative of late November/early December conditions.  Quite frankly some of those temperatures are likely too warm!  Bottom line… the idea is for a below to much below November and we’ll need to monitor the evolution of Super Typhoon Nuri.  Sometimes the residual energy of typhoons in the west Pacific, especially strong typhoons, can impact the eastern United States.  Let’s keep an eye out for late November.

NOVEMBER TEMPERATURES

Enjoy the rest of your evening and keep the winter coats and gloves nearby – Sean Ash

7DAY

Comments (0)
Nov
02

Monday Is Warmest This Week, Rain Returns Tuesday

Posted By · November 2, 2014 at 5:32 pm

Central Indiana enjoyed a decent temperature rebound after the coldest morning since late March.  Lows Sunday morning were frosty in the lower 20s area wide… a good 15-20 below normal.

LOWS THIS MORNING FACTS 24HR CHANGE

Sunshine and a southwest wind helped push highs to near 50.  That’s nearly 10 degrees below normal but warmer than Saturday’s chill.

NOW

Temperatures drop rapidly after sunset this evening but will level off as clouds and a steady wind mix up the air.

PLANNER EVENING RPM RPM 2

Overnight low temperatures will be well above the hard freeze levels of last night.  Heading out the door Monday morning expect lows in the 35 to near 40 degree range.  The warmer start leads to a warmer finish tomorrow.  Though highs Monday near 60 degrees, a strengthening southwest wind will make it feel cooler.

PLANNER MONDAY RPM 3 RPM 4 RPM 5 RPM 6

We’re still targeting Tuesday as our next best rain chance.  Showers are likely that day with damp highs in the lower 50s.  Another surge of much colder than normal air hits the Ohio Valley Thursday.  This air mass will be accompanied by showers that may mix with snow after sunset Thursday into Friday morning.  This system drop highs down to the 40s and lows to the lower 30s heading into next weekend.  The overall trend is for a below to well below pattern to continue past the middle of the month.  Have a great evening – Sean Ash

JET  7DAY

 

Comments (0)
Oct
30

Rare Halloween Snowflakes Possible Friday

Posted By · October 30, 2014 at 4:06 pm

Enjoy what’s left of any sun you’re seeing today.  Clouds increase this evening and we wait for the arrival of a potent storm system that may deliver Central Indiana’s first Halloween snow in nearly two decades.

RPM

Some showers are possible by 7pm this evening with the highest chance being across the southwestern corner of the state.  Due to the insulating cloud cover, lows tonight won’t be nearly as cold as this morning.  But with overcast, and a strengthening northwest wind, morning temperatures in the low/mid 40s Friday morning won’t budge much all day long.

RPM 2 RPM 3

Rain becomes widespread by midday tomorrow and wind gusts near 30-40mph by 5pm as the storm intensifies over the state.

PLANNER FRIDAY RPM 4 RPM 5

Anyway you slice it, trick-or-treating conditions will be far from pleasant.  Temperatures drop into the 30s by 7pm with wind chills in the 20s.  Rain showers will mix or changeover to snow showers as the coldest air of the season arrives.  While widespread accumulation is unlikely, stronger snow showers may overcome the warmer ground to produce some areas of grassy accumulation.

PLANNER FRIDAY EVENING WIND CHILL WIND CHILL 2

Friday will be only the 6th Halloween since 1954 to have a high temperature below 50 degrees and possibly just the 8th occurrence of snow (trace or more) at the Indianapolis Airport on October 31st… the last coming in 1993.  The record daily snowfall is just .10″ set in 1890.

HALLOWEEN FACTS WIND CHILL 3

Saturday morning temperatures drop to their lowest levels since mid-April with lows in the 20s.  If you’re running the Indy Monumental Marathon expect a steady 15-20mph northerly wind that may gust to 25mph.  This produces wind chills in the teens for several hours early Saturday.  Though some sun is possible early in the day, we believe much of Saturday will be mainly cloudy.

MONUMENTAL HIGHS SATURDAY LOWS SUNDAY

The coldest temperatures this weekend occur Saturday night into Sunday morning under a clear sky and calm wind… when lows fall into the 20-26 range.  After a bright start Sunday morning clouds increase with chilly highs in the 40s.  Have a great evening and check back over the next 24 hours for updates – Sean Ash

7DAY

Comments (0)

You can certainly feel a chill in the air over Central Indiana… and this is just an appetizer to the coldest air since mid-April that hits Halloween evening.  The viewing area is split in half this afternoon by a layer of overcast.  Up north it’s gray and in the 40s.  South of I-70 it’s significantly brighter and near 60.

NOW PLANNER EVENING

Tonight and Thursday:  Cloud cover will vary this evening and even the overcast may break by 8pm.  Temperatures will drop into the mid 30s for lows tonight and we’ll similar conditions Thursday… though I believe the overcast eventually becomes more widespread.  By late day tomorrow sprinkles and spotty showers are possible.

PLANNER THURSDAY RPM RPM 2

Halloween:  Rain chances ramp up by midday Friday as an upper level storm system dives southward into the region.  The passage of this feature creates a dramatic wind shift to the north that will keep temperatures in the 40s for Halloween day.  Wind increases from the north later in the day and the atmosphere will be cold enough to support snow showers and flurries by 5-6pm.

RPM 3 RPM 4 RPM WINDCHILL

Temperatures drop into the 30s toward sunset and wind chills plummet into the 20s as wind gusts range between 30-40mph.  Confidence is high on the temperature and wind portion of the Halloween forecast, with medium confidence on wintry precipitation developing for some.

HALLOWEEN HALLOWEEN WINDCHILL

We’ve certainly had colder and wetter Halloweens in Indianapolis.  But this will become only the 6th Halloween since 1960, and 28th since 1871, to exhibit a high below 50 degrees in the city.

HALLOWEEN FACTS

Weekend:  Due to the slower departure of this system, and its intensity, we’ve upped the wind speeds for Saturday morning.  A steady brisk northerly wind of 15 to 20mph will have a big impact on the Monumental Marathon.  Start time temperatures will be in the upper 20s and expect Saturday morning wind chills in the 15 to 20 degree range.  Not ideal running conditions.

LOWS SATURDAY MARATHON JET STREAM

The pressure gradient between a Canadian high to our northwest and a developing coastal low put Indiana in the crosshairs of a “wind sandwich.”  This keeps the funnel to unseasonably cold air open all weekend long and puts highs in the lower 40s Saturday afternoon.

SATURDAY SET UP SATURDAY SET UP 2 HIGHS SATURDAY

A calming wind and clear sky set the stage for a hard freeze and frosty start Sunday morning when lows drop into the lower/mid 20s.  Morning sun gives way to increasing clouds Sunday afternoon as highs struggle to hit 50 degrees.  Don’t forget to set your clocks back one hour before you go to bed Saturday night.

7DAY

Temperatures rebound Monday but rain quickly returns to the Ohio Valley Tuesday.  We need to monitor Thursday/Friday of next week for another potential shot of colder than normal air.  Have a great evening – Sean Ash

 

Comments (0)