Monday late night update

Hi everyone... I know, I know... it's been forever since I last posted. Really sorry about that - as you know from my lasts posts during the big snowstorm, my kids (all of them) got pretty sick. Guess what ???? It hit me like a ton of bricks... I don't know - I wash my hands religiously - it's my wife who teaches and is around thousands of germs every day - who gets it ??? not her - no, it was me !! Oh well, I'm glad she didn't get sick because this was a nasty one !
Feelin' better now so let's talk weather.

Another big - very wet system on the way for the Ohio Valley. Looking at the latest guidance, the flood watch that NWS has out for the NW half of the viewing area looks good. I do think areas north and northwest of Louisville will get the heaviest totals from this storm. Great agreement in amounts and placement with the greater than 4 inch band - (the yellow shades) between the NAM and GFS


















Great overrunning event setting up for areas north of the Ohio River through Tuesday evening.

Then during the overnight hours Tuesday into Wednesday, frontal boundary will get kicked southeast a bit into Kentucky as shortwave travels through Great Lakes. The front will stall or move very slow, however, due to another sfc low forming on the boundary to our south/southwest in response to strong H5 shortwave moving east, northeast into the Ohio and Tennessee valleys.

It looks to me that the heaviest rain for Louisville and points south and east will come late Tuesday night into Wednesday as main system comes. Heavy rainfall potential will ease by Wednesday afternoon but the deformation zone will ensure a steady rain and cold temperatures are on tap - although a well defined dry slot at H7 will cut off steady rainfall for the southern half of the viewing area. BTW, i'm NOT expecting any severe weather with this system over our region.









System is out of here for Thursday and Good Friday - a couple of fast moving systems will pass generally north of us those two days - giving us intervals of clouds but also some pretty mild temperatures.... Thursday looks to be well into the 50s and on Good Friday we'll see temperatures back into the 60s !!

Have a great night and Tuesday all.
Later:
Jay

Thursday late night update...

Well, it took until March but it appears a big'm is on the way !! Both the new 00z runs of the GFS and NAM are in good agreement with the overall placement of the large scale dynamics that will come together for a major snowstorm... as a matter of fact, the GFS looks very very impressive with its upper features if you want a big snow !!. Looks like we got it all on this one. The WAA snow Friday first half of the day... a bit of a break - then the def zone for Friday night into early Saturday.
Check out the H5 chart valid 12z Saturday morning !! Nice !! The H5 low is closing off with strong divergence aloft right over us !! Oh and don't forget, by later Friday night and early Saturday, ratios will be on the order of 15 to 1 !!

I still like our forecast of 6 to 12 inches for a large part of the NewsChannel 32 viewing area-including Louisville. The system has indeed trended colder(east) a bit from 24 hours ago so amounts in the far west/northwest regions of the viewing area (i.e. Bedford, IN down to Jasper, IN) will be a bit less than we thought from last night - 3 to 6", but more for areas east and south of Louisville ( Frankfort, Bardstown, E'town etc) 6 to 12". In the far southeast, 3 to 6 is expected for places such as Lebanon, Columbia, Greenburg, Campbellsville.

The worst of the weather ( or best depending on how you look at it - you snow lovers) is expected to hit overnight Friday into Saturday morning as the def zone ramps up and temperatures fall into the lower 20s. Blowing and drifting likely as well.

Have a great Friday all..

Later:
Jay

Thursday midday update...

No doubt, the pulling out of the air continues.... although the new data, (12z runs) are starting to finally come into better agreement. A big snowstorm is on the way for parts of the NewsChannel 32 viewing area !! It appears enough cold air will be in place for a wintry mix going to snow - with significant accumulations likely.

I'm going to head to work now to really dive into the data so I can have the latest stuff for you during our evening newscasts, but at a quick glance the new data is suggesting 6 to 12 inches of snow from near the Ohio River and points northwest (i.e. Louisville on north) with a narrow ribbon of 3 to 6" just south of Louisville, and 1 to 3 farther south.
Check out the latest model snow charts from this morning's 12z data.....

Alright, gonna get going to work... and yes... the data could still change somewhat. I said the following in a response to a comment on the previous post and it really brings things into perspective as to how difficult these storms can be especially when that snow/ice/snow rain is expected to be right over the viewing area.......

"If a storm is still 1000 miles southwest of us and the exact track is off by just 5%, that would be a 50 miles deviation by the time it gets here !! And that's 50 miles in either direction - that's as big as our entire viewing area !! Still that would mean the data/forecast was 95% accurate - that's an A by any standards - but with winter weather - sometimes the viewers don't see it that way"

Wednesday Night Update

Wow... this is a difficult one...

Sorry, for the lack of posts the last 24 hours... I have three little kids and they all have the flu (sick as dogs) and at home with me until my wife can get off work - then she watches them while I go to work and vice versa - and over and over and over -- well you get the jist.

Can't talk long tonight because , well the kids of course.

Well, this storm has indeed trended west like we thought it would, and it's still going in that direction even on tonight's 00z runs (namely the GFS). The NAM had great run to run consistancy from it's 18z yest. output to tonight's 00z output. I know a lot of people are wanting to know how much snow is going to fall and the bottom line is that it's still really "up in the air" so to speak. I did mention amounts on the Wed. 11pm show - reluctantly, but I knew people wanted some numbers on this thing. Basically I went 1 to 3 inches for Louisville and points south and east. And this will be primarily for Friday overnight into Saturday as we get into the wrap around and colder air. Prior to that, I think enough warm air will be present to see mainly a cold rain or a mix of rain and some sleet from near Louisville and points south and east during the day Friday. Areas north and west will have colder air in place and likely see a mix of snow and sleet. Snow and sleet accumulations will be heaviest north and west of Louisville... question is how much and where will the bands set up ??!!, Keep in mind that the storm track is still uncertain and can (and most likely will) change - but I put a 6 to 12 inch band across the far north and western counties of the viewing area - mainly north of a line that extends from Jasper, IN to Crothersville, IN. 12 inches may be a bit over zealous but NAM qpf (and even GFS qpf when you consider higher snow/water ratios Friday night) can support it.
South of that line, 3 to 6 inches possible in southern Indiana with the 1 to 3 inches for Louisville and points south and east.
Probably the one thing you want to take away from this post tonight, and any other post/forecast/etc... out there in the weather world, is that this thing is still not set in stone and the forecast (including snow areas and amounts) is likely going to still be changing over the next 24 to 30 hours. Just know that Friday looks sloppy with much colder air and some snow flakes likely flying Friday night into Saturday.

really sorry about the lack of maps tonight - but I really have to get out of here and go check on the kiddos.

Drop me line if you have a few seconds and tell me your thoughts...
More on the coming storm tomorrow. Have a great Thursday all.

Later:
Jay

Tuesday Late night update

One storm system pulling away from the region... another one in the formative stages that will impact our region Thursday overnight and Friday of this week.

This next storm system is going to be complicated one to say the least and may not really show "its hand" (i.e. track) until Thursday !
Here's the set up.... a trough over southern Canada and the central US is expected to slowly push east and amplify at the same time. What makes things especially difficult is we are dealing with a southern stream shortwave and a strong piece of energy in the northern stream.

The latest model runs continue their idea of phasing occurring between the streams. The big question is.... where will the phasing occur ??? This will mean everything as far as the storm track is concerned and that will dictate what type of precip we will get out of this thing. Both the latest (00z) runs of the NAM and the GFS are in pretty good agreement with where the phasing occurs - over the Ohio Valley - although originally the NAM is stronger with its northern (trailing) stream short and farther west but its phasing occurs in the same basic region.

At this time... no doubt, there is a decent potential for accumulating snow across the area late Thursday night into Friday - and it could (could) be a pretty big snow for some.

What is bothering me (and these "bother points" are very similar to those of this most recent storm) is 1) persistence & 2) a fairly large western shift in the latest model runs from those of 12 and 18z.

Persistence: I've argued this all season... So far this winter season, the storm track has been from the lower Mississippi Valley northeast across our area. We have consistantly been on the warm air side of these storms. Again this is the reason why some areas of the Great Lakes have had there snowiest season of all time. Once this pattern is established... it's usually very persistent !

Shift West: There's no denying this, the system in question has indeed shifted farther west from earlier runs - (closer to the "persistent" track). I would not be a bit surprised to see this westward shift in the track continuing.

So here's the bottom line. Another storm system is expected for Thursday Night and Friday.
At this time, we are calling for snow (some rain possible at onset until the entire column cools) developing later Thursday night and continuing Friday. There's definitely a potential for accumulating snow (and it could quite substantial) across our area.
Of course, as any credible met would say, at this time it's way too early to talk accumulation numbers because of all the uncertainties still involved with this system.

We will of course keep you updated and have a much better handle on this system over the next 24 to 36 hours.

In the meantime. we will get a chance to dry out the next couple of days.

Have a great night all

Later:
Jay

Monday Late Morning Update

Going forecast looks to be on track...
Very windy conditions across the region today as the LLJ continues to crank from the south, southwest at 50 to 55 kts. Good mixing allowing gusty winds to reach the surface.

Severe threat to stay to our south today and tonight - and really tomorrow as well. I still think there could be a few low-topped thunderstorms tomorrow late morning through earl afternoon - and mainly for the southeastern counties of the viewing area. This is where there will be a narrow band of instability developing just ahead and south of the triple point.

Still a pretty high threat for some heavy rainfall tonight into early tomorrow morning across all of the viewing area. Talking about 1 to 3 inches of rainfall widespread - with even a few spots in southern Indiana approaching 4 inches.

Flood watch in effect through tomorrow morning for the northwest half of the viewing area.

It's windy out there but enjoy the 70 degree warmth again as this is will be it for a while...

Later:
Jay

Sunday evening Update

Wow, what a terrific weekend it turned out to be !! A little bit of rain this morning on the leading edge of the warmer air but overall..... 70 degrees felt awesome !!!

No doubt, I am real happy as to how this weather forecast has worked out - especially for the storm coming in early this week. Ever since last Wednesday, when others in this market were hyping it up and saying there was the possibility of 20 inches of snow here, we were just about the only one (at least that early) to say this storm would probably trend northwest from its original forecast position and give us more rain than anything else. Kudos to NWS folks as well as they came on board and didn't buy into the snow hype either as of last Friday.

Okay, let's get to the latest stuff then...
Frontal boundary currently out west and producing SVR in the central and southern plains states will continue to slide east the next 24 hours. Fropa looks to be Monday evening. I think much of Monday will be dry, windy and warm again with temperatures in the upper 60 to near 70 by midday and early afternoon. Much of the rain with this frontal boundary will be post frontal... Notice on the three following charts how the rain is immediately behind the front...



































This front will continue to work slowly southeast Monday evening but will eventually stall as upper flow backs in response to main jet energy (strong H5 short pushing in our direction).










As the upper wave approaches, sfc low pressure will rapidly intensify on the boundary to our south, southwest. Intense WAA/overrunning will setup over the region Monday night.












Rain (heavy at times) will develop over the region - some thunder will be possible but it look to me the greatest threat for any strong / severe weather will stay well south. Note SPC's moderate threat - looks good to me.










Some hydro (flooding) issues will be possible as rainfall will likely be in the 1 to 3 inch range.
Notice both NAM & GFS's accum precip charts.



















Heavy rain threat will end, however, Tuesday morning as H7 dry slot works over the region.











I even think we could see peeks of sunshine Tuesday midday - from near Louisville but especially points south and east. MLCAPEs are expected to reach 200 to 400 - as upper system drifts northeast across the area. Scattered showers will continue with even some thunder and lightning possible. If (IF) we can manage to pop some low topped convection, a few of the stronger cells may have some hail - we'll watch it close.






























Entire system continues to work rapidly northeast later Tuesday and Tuesday night. Fairly strong CAA will set up over the area at this time - but by the time temps drop to a level that's cold enough for decent ice crystal generation most of the moisture will be gone. Bottom line only a few flurries possible at best - overnight Tuesday, but most locations won't see much snow flurry activity at all !!

Wednesday looks to be quiet and pleasant with a good dose of sunshine and temperatures back into the 50s !! Not Bad.

Have a great night,

Later:
Jay