Latest on the Weekend Winter Storm

Yesterday I said that there will likely be some shifts in the model guidance today as our weekend storm gets fully sampled.  That has indeed been the case.  The data coming in continues to trend farther north and warmer for our weekend storm.  

Precipitation will push in Saturday evening around or just after sunset.  This will likely fall as mostly snow, with some rain possibly mixed in across southern Indiana.  Here is the 12-km NAM for 10pm Saturday, showing that push of snow moving in ahead of the main system.

Nam 12-km courtesy of tropicaltidbits.com

That shield of precipitation will work northward through the night, with a lull likely across the I-70 area southward later in the night.  As we head into Sunday morning, the main system is approaching with widespread precipitation moving in.  The area of low pressure will work through southern Indiana throughout the day Sunday, bringing heavy precipitation across the state.  Likely falling as snow along/north of I-70, rain across southern Indiana.  

NAM 12-km courtesy of tropicaltidbits.com

As we head into Sunday evening, the system pushes off to our east with precipitation diminishing.  However, check out that deformation band across northern Indiana.  Northern portions of the state are in the prime spot for heavy snowfall.  It is not out of the question that locations up there could see as much as 10-12" of snow.  This is where snow will be falling for the longest duration.  

NAM 12-km courtesy of tropicaltidbits.com

  
I think this model may have the track of the low pressure just a little too far north.  However, the other models have trended closer to this more northern solution.  The BIG question is how far north will the rain/snow line get????  Some of the models now try to take it as far north as Indy on Sunday.  I want to have a good look at the 0z data that comes in tonight before making any changes to my forecast.  Just know that the TREND for this storm is farther north which brings warmer air farther north into the state.  Could it still shift a little farther south with new data tonight?  It is still possible.  Here is MY current thinking on snow totals.... 

I have a feeling there will be a sharper range in totals south of Indy than I have, but I want to see some new data tonight before making any changes.  Here are the NOAA Weather Prediction Center probability maps for at least 4" (image on the left) and the probability for at least 8" (image on the right).  

I will post updates on my Twitter and Facebook pages once some new data comes in tonight to see if there are any big changes.  

Watching the Weekend Closely

Good Wednesday morning.  After a cold and frosty start, today is going to be a great day with sunshine around and seasonable temperatures.  Highs will generally be in the 30s with 40s possible across southwest Indiana.  

A weak clipper will bring some light showers tonight through Thursday, mixing with snow showers tomorrow afternoon and evening.  This should not be any big deal.  At most, a very minor accumulation possible over northeast portions of the state.  Highs tomorrow will be warmer with much of central and southern Indiana reaching the 40s.

Dry and cooler weather will be the rule Friday and Saturday.  For the second half of the weekend, the main focus continues to be on a potential storm that will impact the state.  Actually, confidence is very high that there will be a storm system moving through the region on Sunday.  This has the potential to be a decent winter storm for portions of our region.  How strong will the storm become?  Where will it track?  Those are the big questions right now.  The models should gradually come into a better consensus over the next few days.  If you have plans for Sunday, you need to keep a close watch to the forecast.  

Have a great Wednesday!  

Warmer Mid-Week - Wintry Weather this Weekend?

Roads are slick this morning after light snow and freezing drizzle overnight.  This has caused several accidents.  Another reminder that it only takes a tiny bit to cause major problems on the roadways.  Be careful as you venture out this morning.  Conditions will improve through the day, with any lingering precipitation ending by mid-morning.  We may even see some sun later today.  

The middle of the week will feature a warming trend.  Tomorrow looks mostly sunny, with highs ranging from the upper 20s over snow-packed northeast Indiana, to around 40 in southwest Indiana.

Our next system arrives Thursday.  Precipitation may start out as some light freezing rain early Thursday mainly across the northern half of the state.  Temperatures will quickly warm into the lower 40s during the day, so any travel issues would be short-lived.   Colder air will push in on the backside of the system, meaning a transition to light snow showers Thursday evening.  

After this, all eyes will be on a potential storm system this weekend.  All three major global models now show a storm impacting the state, but solutions vary with each model.  That is to be expected when we are still five days out.  Timing of this potential system would be Saturday night through Sunday night.  

The GFS (American model) is the warmest of the models for this storm.  It tracks the low pressure up near the Ohio River.  Taken at verbatim, this would be mainly snow north of I-70, with a mainly rain event for southern Indiana.

Image courtesy of tropicaltidbits.com

The ECMWF (European model) is a colder solution.  It tracks the low from central Tennessee up through central Kentucky.  This would be a very favorable track for accumulating snow for much of Indiana. 

Image courtesy of Penn State's weather models site.

The GEM (Canadian model) is the coldest/most suppressed solution tracking the system farther south.  Taken literally, this would put the heaviest snow swath across southern Indiana and Kentucky.  

Image courtesy of tropicaltidbits.com

Remember this is just guidance.  The models will continue to waffle around over the next few days.  Right now it is feasible to say the potential is increasing for wintry weather this weekend, but many, many details to be ironed out in the days ahead.  

Have a great Tuesday!!

Winter Storm Moving In

The NOAA Storm Prediction Center has issued a mesoscale discussion highlighting all of north central Indiana for the potential of 1"+ per hour snowfall rates tonight.

Here is the look at the winter weather advisories/winter storm warnings issued from the NWS.... 

As of 8pm snow is quickly moving into central Indiana.  Snow will fall heaviest from 10pm through 3am then begin to taper off.  We certainly can't complain about the timing - considering most of the snow falls while we are asleep and by the morning commute there will only be lingering flurries or light snow at best.  That said, still plan for a very tricky morning commute.  Here is my snowfall forecast.  A good 4-6" seems like a solid call for Indianapolis northward throughout north central Indiana.  I do think there may be a localized band or two with higher totals of 6"+ within that 4-6" area...the best chance for that will be for locations northwest of Indianapolis.  Lower confidence forecast across south central Indiana will there will be a sharp cut-off on the snow totals.  Areas south of Bedford/Mitchell completely miss out on this one.  

Once this storm moves out...it is all about the extremely cold temperatures that will stick around for the rest of the week.  More on that tomorrow.  Enjoy the snow!

Winter Storm Watch Issued For Tomorrow Night

Good Sunday evening.  I promised an evening update, and I apologize for getting it out so late.  I will make this post quick and to the point.  As I mentioned in the title, the National Weather Service has issued winter storm watches (counties in blue) for north central and northern Indiana where there is high confidence heavy snowfall tomorrow night.  The pink area you see up towards Iowa are winter storm warnings. 

I have been looking over the data and created a snowfall potential map.  Here are some quick headlines.....

-Snow pushes in from the west after 7 tomorrow evening.

-Snow will fall heavy at times with decent banding taking place tomorrow night along and especially north of I-70.  

-This will be a light, fluffy snow that can accumulate very quickly with high snow ratios and temperatures in the teens. 

-Snow quickly exits the state around 7am Tuesday. 

-The TRACK of this clipper is crucial as there is going to be a SHARP difference in totals on the southern edge of this system.

  

-The models have been shifting this system a little further south with the last few runs.  

-At this time I think north central Indiana will stand the BEST chance for up to 6" if not localized higher amounts.  I'm talking to you Lafayette and Kokomo.  

Here is my snowfall potential map. 2-4" along the I-70 corridor, 4-6" to the north, 1-2" south to Bloomington and Columbus.  Again, a slight jog southward will make a big difference in totals for south central Indiana...

I will have an update in the morning.  Take care.  

Latest on Monday night - Tuesday Snow

Good Sunday afternoon, everyone.  All eyes are on a clipper system that is set to arrive tomorrow night into Tuesday.  This system looks to put down a decent amount of snow for central and northern Indiana.

The data continues to be in pretty good agreement on the track of this system.  Here is the snowfall potential map from the GFS.  It puts down a good 4-6" snow for a good part of central and northern Indiana with a sharp cut-off across south central Indiana.  

Here is a look at the 4-km NAM.  It shows a 4"+ snow band north of I-70.  Note the very sharp cut-off on the southern edge!!

This is one of those snow events where we will be dealing with a drastic difference in snow totals from county to another.  One county can get 5" of snow and a county just south of there could have hardly anything at all.  Here is a look at my current thinking for snowfall totals.... 

Again this could EASILY shift a bit.  Overall, the latest trends have been taking this system a touch farther south, so something to watch.  I will have another update this evening.  Have a great Sunday afternoon!

Eyeing Monday night & Tuesday Snow Potential - Dangerous Cold Coming Mid/Late Week

It has been a soggy Saturday.  Radar estimates indicate anywhere from 1" to 2.5" of rain has fallen today across south central and southern Indiana.  

Thankfully the axis of the heaviest rain is shifting east tonight.  Temperatures will begin to drop off later tonight, and we will see temperatures falling throughout the day Sunday.  Expect to start the day with a few scattered showers, transition to snow showers during the afternoon and early evening.  These could drop a quick coating especially on grassy and elevated surfaces.  Any snow accumulations will stay under 1".  

A very cold air mass settles in Sunday night and Monday.  Expect a cold day Monday with highs not getting out of the teens north of I-70, with lower 20s in southern Indiana.  

All eyes are on a clipper system expected to move in from the northwest Monday night into Tuesday.  Let's dive into some of the data.  The GFS model brings in a swath of snow across central and northern Indiana. 

Graphic courtesy of tropicaltidbits.com

Here is the snowfall accumulation off the latest GFS.  It is putting down several inches of snowfall for areas along and north of the I-70 corridor with a sharp cut-off south of Indianapolis.  

GFS snow accumulation map courtesy of Earl Barker's Model Page wxcaster.com

Here is a look at the Canadian model.  Overall very similar to the GFS except it is a bit farther south.  

Image courtesy of tropical tidbits.com

Here is the snowfall accumulation map from this model.  It paints several inches of snowfall from roughly a Bloomington to Columbus line and points north.

Image courtesy of tropical tidbits.com

I will go ahead and post the NAM model too.  Note that it keeps the snow in northern Indiana, farther north than the rest of the models.  

Here is the snow accumulation from this model.  It says nothing at all for Indy metro with accumulations staying along and north of a Lafayette and Kokomo line. 

Image courtesy of wxcaster.com

My thinking?  I will say I do not buy the NAM solution keeping the snow that far north.  I think the Canadian may be a little bit too far south on the southern extent of the snow.  Overall I think the GFS idea is a decent solution right now.  If you live anywhere north of I-70, especially in north central and northern Indiana - your chances of snow are very very good.  Notice that every model I posted have several inches of snow for you.  There is going to be a sharp cut-off on the southern extent of this system, but where will that end up??  Right now I like the I-70 corridor area as a pretty good barrier between several inches of snow and very little snow to the south....but again - small deviations in the track will make a big difference.  If you live in southern Indiana, south of Bloomington/Columbus, your chances of snow are very low for this system in my opinion other than a few flurries.  Right now, early numbers would suggest a 3-6" snowfall across north central and northern Indiana.  The track of this system is not etched in stone and will be fine-tuned over the next couple of days.  

FRIGID dangerous cold moves in for the middle of the week.  Highs on Wednesday will only reach the single digits in most spots with lows below zero across the state Thursday morning.  Areas across north central and northern Indiana could see actual air temperatures drop into double digit below zero territory with the help of a decent snow pack!!  Check out the GFS numbers for Thursday morning....

These are actual air temperatures....NOT even factoring in the wind chill!  This is now just as cold as the crazy barbaric cold we had this same time last year that we thought was so crazy!  There is no way around it....dangerously cold air coming for the mid/late week.  The good news is that there will be a decent improvement in temperatures later next weekend into the following week....so this a relatively brief but very intense shot of cold air.  Make needed preparations.  

I will try to post another blog tomorrow...if not I will have updates on my Facebook weather page.  Thanks for reading and take care.