Early Evening Update

Thanks to everyone who participated in today's live chat ! It was a lot of fun. It will be open throughout the evening, so be sure a chime in with your thoughts, reports (once the snow starts in your neighborhood), or with any Q's you might have.

Snow expected in Louisville late evening... really - really slow northward progress due to the arctic air in place. The snow is expected to make it to areas just north of Louisville overnight and that should be about it as the dry air will be too much to overcome for as you go north through southern Indiana. All 18z models, and 12z Euro models came in today with qpf amounts in Louisville of .20 to .40". Over .50" areas south and a QUICK drop off in the qpf as you go north. Ratios will come into play... Bufkit data suggesting as high as 15:1 near the Louisville area with somewhat lower ratios as you go south. wouldn't be a bit surprised to see an inch or so in southern Clark county to nearly 4 inches or so near the Jefferson/Bullitt county line -- FUN TIMES !!

I have to admit... I'm still a bit nervous about all this dry air in place but we will watch it close and keep you updated...

Jay

10:30 am

Checking the latesst 10am obs / metars, the snow seems to be reaching the ground when ceilings over ant one location reach 3500 to 4000 ft AGL. You can see how this matches up pretty well with the 15z (10am) ruc H9 moisture field (immediately below) of 80 to 90% and higher...

By 7pm tonight (below) still very dry air over north central KY / southern IN... But saturated across the southern third/half of KY.

as we've been talking about already, snow will develop later this afternoon southern areas... but hold off closer to the metro area until later tonight.

GFS should be coming in shortly

9:30 am

You know what guys... due to the sharp- sharp cutoff nature to the northern edge of the expected snow, and the fact it'll likely be very close to the Ohio river, this loooks like it'll be more of a short term or even nowcasting event - again for the metro area - south of Louisville... it's gonna happen !!

Quick updates....

This was a comment just received....



"Wow! what a let down"



and I replied...

"Don't give up just yet !! Let's see what the new stuff is saying. I havn't seen any new data yet, but maybe the upper system will be a bit stronger or come out a bit farther north to bring us better snowfall - at least alond and north of the Ohio river. No doubt, areas south are gonna get hit pretty hard.."

I'm having trouble getting data..?? any new data in yet ? i.e. 12 z stuff

pray to the snow gods everybody

Friday morning Update

GM all... well that was a short night !! Quick and dirty update... Still some snow expected but holding off until later tonight into tomorrow morning. The 00z and 06 z data still suggesting the heaviest of the snow will fall south of the Ohio river and the metro. Arctic air in place and it is very dry in the lowest layers with continued dry advection this morning and really this evening as well as this is the major problem with this system for Louisville and areas north. With the H7 / H5 confluent zones just north of the Ohio river... this will ensure cold high pressure (and the dry air) will continue to nudge into the region. Bottom line, the snow that we get will have to wait until the column saturates from top to bottom because there's no low level moist advection in this set up.



Yesterday, we were thinking this dry air may be overcome early enough to give the metro (near I-64) around 3 inches... with higher amounts to the south (up to 6" in the far southern areas) and a sharp drop off in the amounts to the north.
Well last night for the 11pm newscast due to the fact the dry air intrusion was even drier than what the models were earlier suggesting, I downed the expected amounts to more in the 1 to 3" range for the metro, with the lower end of the 3 to 6" line pushed south to near a Hardinburg, KY to Springfield, KY line. We still like 6" + along and south of a Bowling Green to Columbia line but also the very sharp drop off in the expected snow amounts just north of the Ohio river.

Looking at radar trends this morning and still how dry things are way to the west of us in MO, It appears the "downed" forecast amounts - or pushing the bands farther south was justified.

As I mentioned, this is still going to be a substantial snow especially for areas south of Louisville but it looks like it going to be a fairly low impact event for the metro and points to the north simply due lighter expected lighter accumulations and also the time of day and week when the system will be impacting the area.

Let's not totally wave the white flag just yet (when it comes to significant accumulations for the metro) as we still have more data getting ready to come in as we speak, but.................

talk to you in a bit c,mon snow !!!!!!!!!!!!!!!!!!!!!!!!!!!!

tell me your thoughts... as you know this has beena tough one to call

Oh, oh... not looking good for the home team !! NAM has really - really - really changed its tune for areas near the Ohio river - including Louisville. Here's the deal, the air in the low layers is progged to be mainly too dry for the precip to overcome. And to add insult to injury for you snow lovers, the dewpoints were initialized to high for what is actually happening.

I'm not throwing in the towel based on one run from one model.... but .....
We'll wait and see what the GFS has to say.

Everybody pray to the snow gods now ... that is if you are a snow lover.


Jay

12:30 pm update

Canadian is in and looking very bullish !! Quick and dirty QPF totals from this model give you .40 to .45" total !! Liking 3 to 6 for Louisville more and more. Again, would really-really like to see more support from thhe Euro models but guys, it's looking better and better !!

Late Morning Update

Hey, check this out !!!!!





Look how close the qpf fields are from the last 2 (real) runs of the GFS (00z & 12Z). That is amazing stuff. Looks like start time will be late tomorrow or even wait until tomorrow evening. Looks like we get most of our snow with the associated def zone. Matt and I have been talking all morning and we really like .20 to .30 total QPF for the metro. More south, .40 to .70". Then a sharp drop off going north with less than .10" in our northern areas.

Ratios will come into play. Looking at extracted / bufkit data, max temp in the sounding during this event is around -4C to -5C then cool some towards the end. We think ratios will be on the order of about 12 or 13:1 at the first half of this event and gradually going closer to 15:1 towards the second half of the event. As a result, we have shifted the northern edge the 3 to 6" line farther north to include much of the metro (to make it easy... close to and south of the I-64 corridor. Even with higher QPFs south still kept much of the southern regions in the 3 to 6" band as ratios will be lower. Still like 6"+ for Bowling Green east to southern Adair county and points south.

More updates later

Jay

Mid morning update...

Havn't had a chance to really disect the 12 NAM yet but WOW !!!! what a change from last night's 00z run. The big change may be due to the fact that the upper system last nifght was over Mexico where the actual sampling that's put into the models is relatively poor. Maybe now that the system is getting over an area where there's more and better sampling, the NAM is getting a better picture ?? Hard to say but that was a huge change in overall QPF amounts. When there's that big of a change in such a sshort time, no doubt, you always want to be cautious. I don't think we'll bite on the 12z NAM solution just yet but instead wait for some support from the other models. If the 12z GFS is still steady (and it seems to be the most consistant so far - except for timing), and we get further support from the Euro models then perhaps it'll be time to pounce. One thing is for sure... For us snow lovers that was a nice change to see in the NAM - - - getting more excited now...

another update later

Jay

Thursday Morning Update...

Arctic boundary passing through right now. Temperatures will likely drop towards the upper 20s the rest of the morning then hold fairly steady.

Still watching the southwestern system for some snow here later tomorrow - with a bulk of it coming Friday night. Yesterday we talked about potential amounts of 1 to 3" along and south of a Vincennes, IN - New Castle, KY line (including Louisville). Bascially South of a Hardinsburg, KY to Bardstown, KY line : 3 to 6"... Closer to the KY - TN border: 6 inches +.

After looking at the 00z stuff ... overall that still looks okay - for now. There are some things bothering me about this system though..... 1) We are dealing with an arctic airmass which usually implies a very sharp cutoff to the snow accumulations as you go north. 2) There's not a real well developed low-level system for good moisture transport into the colder air. 3) the upper level energy is getting minored out and weakening as it shoots northeast into the confluent zone on the south side of the PV in southeast Canada.

My concern is that some of these models may be overdoing the QPF with this system. The NAM and Euro models are suggesting less QPF overall and they just may be right. Basically that would mean shifting the afore mentioned snowfall bands a bit farther south and cutting back totals some - especially across the southwern sections of the viewing area.

Start time looks about the same as yesterday... later Friday afternoon for Louisville (and it may hold off until dark Friday evening), and earlier for areas south and southwest. The Friday morning commute will be just fine and we may get away without much snow for the Friday evening commute as well.

12z data is coming in right now.... we'll have another update later today after that suite of data gets in.

Jay

Wednesday morning update

GM all, been "putting out fires" around the house this morning and have to pick up kids from school early so this will be quick....

I have had a chance to look at the 12z data and the GFS loooks to have initialyzed quite well this morning.

Light snow will gradually overspread mainly the southern 2/3rds of the viewing area (from south to north) during the day on Friday. Start time in Louisville looks to be later Friday afternoon at this point.

Based on the current data and past runs we still like the heaviest snowfall southern areas.

Basically (and we will fine tune this of course) 1 to 3" along and south of a Vincennes, IN - New Castle, KY line (including Louisville). Bascially South of a Hardinsburg, KY to Bardstown, KY line : 3 to 6"... Closer to the KY - TN border: 6 inches +.

again some movement of these zone is likely the next day or so based on exact storm track.

Full update later today... sorry for being so short... lots going on

Jay

Late morning Tuesday update

GM all, hope you didn't get stuck in the Tuesday morning mess.

There has been an overall southward adjustment to the models over the past 1 to 2 runs. Question is will this continue or was this just a model run hiccup ? I received an email from a friend of mine asking me about my thoughts for this storm and the latest model trends and this was my response to him...
"Well the GFS does have a cold bias and usually there's a correction (of some extent) to the north the closer we get to the event. Also, it does look as if the air will be cold enough in the column to beef up the ratios some. Quick and dirty Low/mid 20s at sfc would yield 12 or even 15 to 1.

One thing that does bother me is that the northward correction to the GFS has not shown signs of happening yet and we are within the 84 hour time window now. If anything there's been a slight southward adjustment to the overall QPF field !! Also the Canadian, which has been steady as a rock and giving us some substantial snow also showed a southward adjustment on its 00z run.

But not giving up the faith at all yet... Keep in mind, the upper short (our snow producer) is still out in the Pacific ocean - not a lot of raw weather data out there to feed into the models ! I think the overall track will become better defined once this upper energy is over the U.S. where raw weather data will be much more readily available. That should be tonight's 00z run or tomorrow's 12z run. "

Bottomline folks there's still the potential for some substantial snowfall around our region on Friday. Having said that, with the arctic origins for our cold air source and the dryness aspect associated with it, there will likely be a very rapid cutoff to the significant accumulating snowfall as you go north. In other words when it comes to talking about the track of this thing - a few miles either north or south will mean a the major difference between a whole bunch of snow or hardly anything at all ! This will be a tough one to forecast (which Ohio Valley storm isn't right ??) and it'll likely take another 24 to 36 hours or so before it really shows its hand.

keep you posted

Jay

Tuesday Morning Update...

Talk about a wrong time for a dusting of snow - an hour before and during the AM commute . It's slick out there folks... BE CAREFUL. The light snow showers and flurries will taper off this morning and accums will stay on the very light side with dusting type amounts - The problem - those roads.

Allow the extra time this morning...

A full update on the potential late week winter storm a bit later on this morning

Late Evening Update...

Latest 00z GFS model run still has a significant storm winter storm for the lower Ohio and Tennessee Valleys but what is a little different is the timing of the system - a little delayed and a bit farther south with its QPF field (when compared to the ensembles).... .25"+ line running from around Madison to Vincennes. 0.50"+ line running close to I-64. 0.75"+ line running fairly close to the Western KY and Bluegrass Pkwys. 1.00"+ far southern KY into TN.

Still looks like the thermal profile could support higher ratios as well so no doubt... even though system looks a bit delayed on the latest GFS run, still very substantial. Keep those fingures crossed you snow lovers.

Jay

Monday Evening Update...

Flurries and snow showers on occasion tonight through tomorrow... Minor accumulations but watch out for the potential for a few slick spots later tonight into tomorrow morning.

Looked over the latest 12z and 18z runs. Models still quite bullish on a pretty major winter storm for later Thursday night into Friday. Ensemble data also quite impressive with the QPF amounts - .75" to 1.00" near Louisville ... a solid 1.00" or better for areas south !!!!! Also looking at the the latest thermal profile on the GFS, higher ratios would also come into play. Folks if these models pan out... there's gonna be a lot of snow across the area. I'm not biting on these amounts as of now as it's still way too early to put numbers on this thing and no doubt, the exact track and strength will likely change some as we get closer to the event. But what all of this is telling me is that the chances for a significant winter storm across our area continue to increase.

keep ya posted,
Jay

More Wintry Weather This Week...

GM all... The the stage is set !! Colts - Saints !! Should be a great shootout between Brees and Manning. In the end though , even though Brees is a great QB, can you really go against Manning ?? Don't think so... Colts 34 - Saints 28. Should be fun to watch.

Colder air spilling into the region as we speak. Column progges to become saturated again throughout the day and into tonight as we drop below critical. Upper disturbances moving through large scale trough overhead will squeeze out some light QPF mainly in the form of flurries/light snow - although a few rain drops may mix in this afternoon (if it starts early enough) as lowest 50 mb is still just above critical. Some areas will likely see a dusting to locally 1/2 inch tonight into Tuesday morning - and that should be about it.

Then we look ahead to Thursday night and Friday of this week. Interesting pattern looks to be evolving. Strong upper H5 system in northern stream dropping south through Canada (essentially the PV (polar vortex)). This will brings in plenty of cold air to the Ohio Valley as polar / arctic boundary passes through Thursday morning. This boundary progged to work south into the TN valley and then become stationary as low pressure begins forming near the ArLaTex region in response to southern stream shortwave in the southwest U.S.




Southwest upper energy does not look like it will phase with the northern energy (PV) but instead start weakening / minoring out as it moves east,northeast so major "bombing out" or deepening of this system looks unlikely.

Even so, this energy is pretty strong and the progged track looks quite favorable for some decent wintry weather across (or very close) to our region. Latest ptype progs indicate mainly a snow event with many of the models indicating southern KY in the heaviest snow band (potential for several inches) with lighter amounts closer to Louisville and points north.

However, just about every system thats has tracked across the southern U.S. this season has actually tracked a little farther north than what the models said it would. We'll watch for this trend again with this system.

Still early in the game - plenty of time to watch it but just know that it looks like some wintry weather looks to be on the way.

Have a great day...
Jay

Thursday Midday Update... Winter's Return Next Week ?

Light rain and drizzle to continue for much of the day as intense H5 wave continues to push across the lower OH and TN valleys. Modified sfc warm front is positioned across southern KY. Along and especially south of this boundary, 0 to 6 K shears values overlays the region of weak to moderate instability. SPC has slight risk for SVR across southern KY into TN for this afternoon. Looks like a great call ! Some elevated thunder will be possible in the Louisville area but the better chances for more widespread thunder and even a few strong / svr cells should remain south Cumberland Pkwy.

GFS has been hinting at a possible winter event for late next week for the past couple of runs now. Two distinct streams/shortwaves. Northern short plunging south with plenty of cold air with it. A southern stream short working east across TX heading for the region with plenty of moisture. Still a LOT of things need to come together to bring us a significant winter storm but the overall upper synoptic field is looking better ... finally after 3 weeks !!

We'll keep you updated

Jay

More Unsettled Weather...

Low pressure systems have been tracking along the temperature gradient that has been positioned across the local area all week ! 50s and 60s JUST south of Louisville with 30s and 40s through town and points north.

Two more storm systems to impact our region... The first today. The second comes over the weekend.
Today's system will put down about 1/2 inch of rain on average. Some thunder will be possible especially south of the metro.

Scattered showers are expected to hold on (although gradually diminish) through tonight with another gray day expected tomorrow with low clouds and occasional drizzle.

The next system moves in Saturday night. A band of rain and some embedded thunder is expected at that time. This batch of rain should be mainly east of the local region by Sunday morning. However, the main cold frontal boundary will still be west through midday Sunday. Substantial mixing and even a few breaks in the clouds will likely allow temperatures to climb easily into the mid/upper 50s on Sunday. Then as the front moves in and interacts with the upper trough overhead, scattered showers and low topped thunderstorms will be possible Sunday afternoon. Lots of wind energy will be over the region, but mainly unidirectional. If (IF) the low topped convection can fire, gusty winds and some hail would be possible with the stronger cells. Colder air spills in behind this weekend system with even a few flurries possible early next week.

Have a great day all and stay dry...

Jay

Unsettled... No Signs of the Cold Air Returning.

After a wet Sunday, today (MLK day) will feature a slow decrease in clouds and mild temperatures for the afternoon. Looking at the H5 flow, a series of shortwaves will move the the flow the next several days. One such short will affect the area later Wednesday and Thursday with another bout of rain. Then yet another stronger system will affect the central U.S. and the Ohio Valley this weekend. This one will bring us rain (possible thunderstorms !) but likely very heavy snow and possible blizzard conditions to the northern plains states.

Temperatures will cool off behind this stronger weekend system but only temporarily. The overall upper flow the next 7 to 14 days looks to be dominated by the strong Pacific jet. A flow which will be an active one but also a mild one.

We'll keep you posted.

Jay

Warming Later this Week...

Not much happening with that little clipper for our area... A reinforcing shot of cold air will move in for the about the next day to day and a half then a warming trend and pattern change... see prvious post.

Jay

Some Light Snow This Afternoon, Cold Pattern Breaking Down

A fast moving clipper type system will bring some patchy light snow and flurries to the region later today and into the evening. Not much moisture to work with, possitive tilt to upper system, and its fast movement all mean NOT much snow with this one. Model QPF fcsts spit out just a few hundreths across the region. Accumulations look very light all locations with everybody coming in at less than 1/2 inch of snow - at best !!

Little bubble of Canadian high pressure builds into the area for later tonight through Tuesday night behind the afore mentioned clipper system. Temps will stay cold through this period but then a major change will take place.

The upper pattern / block that brought us the extended period of cold weather (Dec. & early Jan.) is breaking down. The Pacific jet will become the dominant player for the next 2 weeks - at least, as the polar jet retreats well north. The southern stream will remain quite active but with an absence of a cold air source, there will be little chances for wintry weather across out "neck of the woods". As a matter of fact, the progged upcoming 2 week pattern is almost resembling what it did in late November / early December, i.e. large trough near Alaska, with a stronger jet on the south side of this trough. The flow then splits in the eastern Pacific - with the polar branch running well north, and the southern branch across the lower 48 and quite active. The main stormtrack looks as if its going to shift back to our west across the middle sections of the U.S. This would put us on the warm side of storm systems moving across the U.S. thereby keeping the better chances for the bigtime wintry weather well to our west and northwest.

In this type of of a pattern, precip would be at or above average but so would temperatures. So I guess it's safe to say that the January thaw is about ready to commence.

Big Q is... how long does the pattern last ?????? 2 weeks, 3 weeks, longer ??? Well most of the longer range models do have this pattern lasting well into late January.

We'll keep you posted.

Jay

Flurries continue, so does the cold !

Well from about 36 hours of flurries, I've picked up an additional 1/2 inch of snow. This stuff has got to be 25 or 30:1. Man is it fluffy ! Flurries will continue on occasion through tonight as we remain saturated in the lowest layers with temperatures still capable of ice crystal generation. The flurries the next 12 to 18 hours should be much lighter and intermittant though as those cloud temperatures are getting on the lower threshold for generating icy crystals.

Next event is yet another "clipper" type system for Monday. Although this one is much weaker than the one that came through here last Thursday. Model guidance is spittting out just a few hundreths at best. Looks like some light snow with the upper level vort/trough later Monday and Monday night (less than 1 inch).

We then warm up for Wednesday and Thursday and the melt down will commence.

I won't spend a lot of time on this but I have to say the 06z run of the GFS was very interesting for next weekend. Check out the large southern trough and associated sfc system to our south !! More importantly, the 06z run of the GFS has a much stronger H5 wave moving across southeast Canada and this will be key as to what type of precip we receive from this southern system. If this verifies, this would mean a stronger push to the arctic air back south into the U.S. - hence the 1044mb high the GFS has pushing into the Great Lakes region. Could this mean a potential winter storm / ice event ??? Maybe but remember this was a off hour run of the GFS (I don't like off-hour runs as they tend to flip-flop quite a bit), and-well, it is the GFS afterall and we all know how the GFS changes from run to run especially out past 84 hours. Buuuutttttt it is something to watch.

have a good Saturday all

Jay

And Now The Flurries

Good morning all.... a solid 2 to 4 inches of snow on the ground from yesterday's snow. Now... the flurries. With this cold of air across the region and the fact we're saturated in the -14 to -16C layer, not to mention the polar jet axis is now south of us, we are going to really squeeze out the flurries. It should flurry pretty much all day into tonight. Sure, it will take a long time for the flurries to accumulate but it's going to flurry for a long time. Most models are squeezing out several hundredths of an inch QPF. With these ratios, up to an inch is likely across the region today into tonight.

Another little "clipper" type system is on the way for early next week. I haven't looked with great detail at this event just yet, but at a quick glance it looks like some light accumulations will again be possible next Monday. I'll dive into the data later today and have a full update later on.

stay warm all and enjoy the snow.

Jay

Early Afternoon Snow...

What a great band of fluffy snow. A quick 1/2" to 1 inch with that one that just moved through.
Right now, 12:35pm, my total is 2.5"! Matt has 2 to 4" going along and north of Western KY & Bluegrass Pkwys with 1 to 2" south of the Pkwys. Looks like a great call ! We're thinking a solid 2 to 3 inches across all off the metro for totals. Some areas north/northwest could see 4 inch amounts with 1 to 2" in the far southeast.

There is another band to our northwest. That will give a bit more snow this afternoon and then that should be the last of it as drier air works in from the west and sshuts off the snow.

What a great Snow !! It's about time !

Jay

Thursday midday Snow Update.

Still a couple of fast moving bands of light to at times moderate snow to get through. Could pick up an additional 1/2 to 1 inch with these bands of snow. NWS (official spot) has recorded just over an inch... so far (c'mon snow !!). I just measured off my drive and I'm almost to 2 inches. Clarkson, KY (Grayson Co.) : just over 1 inch, Bedford, IN: 2 inches. Most blog / phone call / email reports coming in with between 1 and 2 inches of snow. Looks like totals will range from 2 to 3 inches across the metro, 1 to 2 inches in the south, 2 to 4 inches over southern Indiana - north of Louisville. JCPS dismissing 1 hour early. Winds will increase late today and tonight and blow this light snow around. Also with a continuation of the flurries, it is going to be very wintry out there. So again, not a mega-storm, but certainly some decent accumulations for our real first snow of the season,

Jay

Thursday Morning Snow Update...

Wow, not a lot of snow but a bad time for it to come - AM commute. Took me almost 2 hours to get my daughter to school. In other words from Northeast Jefferson county to Pitt Academy (near the airport).
Forecast really looks to be on track. I realize that wee at WLKY have been on the lighter side with snow amounts all along with this system - but it still looks like the lighter amount forecast - compared to most of the other forecast outlets, seems to be working out the best. I have a solid inch on my drive as of 8:50am. With the light snow that will continue to work through yet this morning, and then the additional flurries of tonight and tomorrow we should end up with close to 2 inches in Louisville - a little less south (around 1 inch or so) and a bit more up north (upwards of 3 inches or so). At this time I really think 4 inch amounts will be a stretch for any location in our viewing area.

Cold air surges in later today and tonight on gusty winds - so this snow will be blowing around.
Roads are slick but certainly "driveable". Just take that extra time to get to your destination.

We'll keep you posted .
Be safe and enjoy the snow !

Jay

Wednesday evening update.

Storm still seems to be on track... NWS has issued a winter storm warning for the area. This system looks like more of a "snow advisory" system to me than a "winter storm warning" system. Bottom line though is we are going to get some snow and with the very cold ground temperatures in place, it won't take long for the roads to slicken up so please be careful when traveling and allow some extra time to get to your destinations.

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Snow Still On The Way !!

Sioux Falls, SD 10am Wednesday.

The snow is falling across the northern plains this morning and it is heading for the upper midwest and the Ohio Valley. Previous forecast is still on track... check out the previous posts for a synoptic disscussion because it stills seems to be right on.

Expecting the snow to begin between 5am and 8am Thursday morning. Remember, the ground temperatures are cold so this snow will accumulate right from the get go and it's certainly possible Thursday morning's commute could get pretty nassty and slippery. Plan on allowing extra time to get to your destinations on Thursday.

I still like the amounts we have forecast.... Total snowfall in Louisville 2 to 4 inches. And this will come over two different "events". The first batch of snow will arrive Thursday morning as I mentioned previously. With the progged thermal profile expected at this time, this would yield a 12:1 ratio. We're expecting this band to put down around 2 inches Thursday morning into the early afternoon in Louisville, 1 to 2 inches for areas south, and 2 to 3 inches for areas north. This first batch of snow will diminish to flurries early / mid afternoon - with perhaps a break in the snow all together, as we get dry slotted at the H7 level.

Strong cold advection, low level moisture in the ice crystal growth layer, and the fact that the upper jet axis sinks south (cyclonic side of the upper jet) with bring back an extended period of flurries and snow showers from Thursday night into Saturday morning. With the much colder air, snow ratios will be much higher with these flurries and could approach 20:1. As a result, another inch or so of fluffy snow is likely during this time.

Add it all up and .......... and we still like our going forecast from the last 2 days:
2 to 4 inches across the viewing area for the entire event (i.e. Thursday through Saturday morning) - To really break it down: near 2 inches areas south, around 3 inches in Louisville, with the best chances for the 4 inch amounts north of the metro.

There has been some hype on other media outlets about blizzard conditions ??? I really don't think we have to worry about a blizzard here. Winds will increase behind the arctic boundary 15 to 20 mph with occasional gusts to 25 and 30 mph. Because of the fluffy nature to the expected snow, it will blow around quite a bit with areas of blowing snow Thursday night into Friday - but an all out blizzard ?? I don't think so.

Bottom line: More cold and snow on the way. It will get quite wintry around here the next several days including 2 to 4 inches of snow, slick roads, some blowing of the snow, and likely some school closings and delays.

Jay

No Changes To The Forecast...

Just glanced at the latest 00z runs and the going forecast looks to be on track. Snow develops daybreak Thursday (give or take an hour)... diminishes in the afternoon to flurries, but the flurries and snow showers will continue for an extended period of time - Thursday night through Saturday. Still think 1 to 2 inches with the band Thursday morning, then an additional inch or two in the flurries and snow showers that will follow. Total expected snow in Louisville Thursday through Saturday: 2 to 4 inches. 2 inches for southern areas and closer to 4 for the far northern areas...
A complete update Wednesday morning

goodnight all

Jay

New Day... Same Ole' Pattern - COLD! And Soon To Be Snowy

Arctic air continues to be entrenched across the region and by the looks of things, it's going to get alot colder by the end of the work week and into the weekend as yet another arctic surge blasts south into the region. The difference with this late week surge from those of the past couple of weeks.... it looks like we will have several inches of snow on the ground and a decent snowcover likely all the way from Tennessee - north into Canada. In other words, the late week arctic blast ain't gonna moderate all that much. Folks, It is going to get very cold around here !

This latest cold blast will be on the heels of a very strong H5 shortwave driving in from the northwest and slowing down and intensifying as it does. This is the upper energy that will provide us with accumulating snowfall beginning late Wednesday night into Thursday. The track of thiss H5 system is still just north of Louisville - so the heaviest of the accumulations are still expected to reside north of our region but we are also going to get a decent snow out of this.

Check out the latest 12z output from the NAM...

Notice how the the H5 upper system / sfc system pass to our north. Always - always - always - the heaviest snows with a system dropping south of east occur along and north of the H5 vort max and if an upper H5 center / low is developing, the heaviest snowfall transitions closer to the H5 low and north of its track. This area to our north/northwest will also be

where the overall atmospheric column will be much colder for good dentritic crystal growth and easily a 15 to 20:1 ratio. 4 to 8 inches likely running across much of IA, northeast MO, central / northern IL, central / northern IN .

For us... we also will pick up some decent snowfall ! As the system deepens, widespread snow will develop in the WAA / upper lift zone associated with the LFQ of the jet max. Our snow will essentially be the "feeder" band for the bigger accumulations to the north where the deformation zone snowfall will set up. Snow will likely develop later Wednesday night and continue into Thursday. The best accumulating snow for us will likely occur during the 12z to 18z window Thursday AM (i.e. 7am to 1pm). The accumulating snow should rapidly end from west to east Thursday afternoon as the H7 dry slot overspreads the region. After the main snow and during Thursday night into Friday night , the combination of strong cold advection, low level moisture, and being on the cyclonic side of the upper jet will keep our area in the zone of flurries and snow showers with additional light accumulations occurring during this time with very high snow to liquid ratios. As far as the amounts are concerned, I still like a quick 1 to 3 inches during Thursday morning with an additional inch or so during the extended period of flurries and snow showers Thursday night into Friday night.
So by the time everything is said and done, 2 to 4 inches of snow seems likely across our area - with the greatest threat for the 4 inch amounts occurring over the northern sections of our viewing area.

Still some time to look at things so we will for sure keep you up to date. On thing is for sure - it's going to be cold and wintry the next several days across our region.

Stay warm all,

Jay

Holidays Are Behind Us... But Not The Cold... or Snow Chances

Good morning all... Sorry for the long break but I promised the wife a nd kids no working while they were on break and I was on vacation.

Went to Chicago for several days last week and over the New Year's weekend. Wow, that was some cold stuff !!

Okay back to business this week as the holidays are now behind us. One arctic cold wave / high pressure zone building in today and tonight... another arctic blast will invade on Thursday. No doubt temperatures will stay WELL below average and likely below freezing the rest of the week and much of the upcoming weekend - although Sunday we may make it above the 32 degree mark. Okay that's the cold air side of things... what about the snowside of things ?? Looks like our first significant chance at some decent accumulating snow coming on Thursday.

An intense upper H5 wave will be sliding SE across the Northern Rockies and Plains tates on Wednesday, and into the Ohio Valley on Thursday. As the jet max dives to the southeast and rounds the base of the trough, the wave will close off as the H5 low forms to our north, northwest.

The best accumulating snow (4 inches +) looks to be north of us with this system and will be along and north of the H5 center/ sfc low track and under the deformation zone and also due to the fact that the atmosphere to our north will be much colder so snow/liquid ratios will be much higher and on the order of 15 to 20:1.

For us, it looks like a fast moving band of light to moderate snow will occur very late Wednesday night into Thursday morning as strong lift associated with the LFQ of the upper jet and decent WAA overspreads our area. This band of moisture/snow will actually act as the "feeder" band for the deformation snow -which will be north of us. Several inches (1 to 3" ) of snow will be possible at this time over our area with locally high amounts the farther north you go. The snow will quickly diminish to flurries Thursday afternoon as the H7 dry slot rotates over us. AT THIS TIME, I like around 2 inches or so for the metro with the 3 inch amounts the farther north you go and the lighter amounts to the south. The p-type would suggest all snow across all of the viewing area - and this looks correct considering the system is moving southeast - locking down the thermal patterns through Wednesday. But as the system bottoms out, late Wednesday and Wednesday night, stronger low level WAA will commence as low level cyclogenesis occurs to our north. The models often under-estimate the WAA with systems like this so I wouldn't be a bit suprised to see more of a mix of precip - especially for areas to our south. Still 66 to 72 hours away so no doubt, things could still change and of course we'll keep you updated over the next couple of days.

Good to be back. Stay warm all and c'mon snow !!

Jay