Domestic Weather:

• Strong high pressure sits over the Great Plains this morning, running from ND down to TX, and this is a dividing line between what’s happening in the eastern and western parts of the country.
• Lake effect snows are pounding areas in the Great Lakes region and isn’t associated with a system, it’s more wind-driven.
• As high pressure moves east through tomorrow, a strong low will take its place, working into the central plains overnight tomorrow night.
• Moisture will move in well in advance of the low, stretching from the northern plains through the Great Lakes and into the eastern Corn Belt through Sunday morning.
• The heaviest snows will start in southern MN and northern IA, then will move through southern WI and northern IL, and ending up in IN and OH.
• The low will lift northeast Sunday night-Monday of next week, dragging more moisture with it through the Corn Belt, and a lot of that moisture will be snowfall; from I-70 northward you’ll see snowfall and from I-70 southward, it’ll be rain fall.
• Totals from the weekend event will be 4-8” maximum, with the liquid equivalent will be .25-.75” of moisture.
• High pressure will move in behind it on Monday night-Tuesday, then with bitter cold arctic air coming in, we’ll see several clipper systems move through.
• When the cold air advances in on Tuesday, snows move through the Upper Midwest and Great Lakes and all the way down through IN.
• Snows likely will be a coating to 1” or so, and then dry weather moves in behind that little event.
• After the first clipper moves out, that’s when temps begin to ratchet down, with the zero-degree line coming all the way down to I-80 on Wednesday-Thursday.
• A strong system will come together later in the week as high pressure moves out.
• Low pressure moves out of the central Rockies into the central plains on Friday, putting down significant snows in NE, IA, IL, and IN.
• That low tracks eastward on Saturday, moving across the boot heel of MO before lifting northeast; it could set down significant snowfall totals in the eastern Corn Belt.
• Models are in wide disagreement on totals, but I think we could be looking at a classic winter storm in the Corn Belt, putting down anywhere between 4-10” of snow or better, depending on how things emerge.
• High pressure moves back in behind the event and that cold air just doesn’t go anywhere as we see another arctic blast as we kick off the week ahead of Christmas.
• Light snows move through the middle of the country on Dec 19-20, including KS, NE, MO, and IA, with totals of up to 3” with more cold air advancing.
• Overall, the pattern is very active and very cold across most of the country.
• There will be less of a stormy picture ahead for the Deep South, since the cold air pushes far enough south to make it through the Mason Dixon line.
• By the end of next week, the 32-degree high line will push down to settling in across MO, AL, and GA borders with TN, through central/southern AR.
• That cold air will cause a pullback in stormy weather that’s developed recently in the Deep South.
• There isn’t a lot of action in the western US, with the southwest likely trying to be above normal this week before going below normal the next week.
• There will be some nice snowfalls in the higher elevations, but there won’t be much going on in CA and the Pacific Northwest.
• The pattern would seem to suggest not a lot of moisture falling up in the Canadian Prairies, but there will be a whole lot of cold air, with temps falling below zero and staying there for the next couple of weeks.

South America weather:

• Watching a frontal boundary coming together down south as Paraguay picks up heavy rains today-tomorrow.
• This front looks to move northward slowly, moving through Matto Grosso do Sul through Sao Paulo with rain totals of 2-3” easily over the next 2-3 days combined.
• It takes its time moving north, so we’ll see scattered
  showers yet this weekend in Matto Grosso, Goias, and Minas Gerais, but the front does fall apart the further north it goes.
• Scattered showers in the central/north areas of Brazil will add up to 1-1.5” over the next 4-5 days, but still no significant frontal boundary will arrive with the moisture.
• By the second half ofnext week, an organized front will lift north from Wednesday night-Friday, putting down 1-3” across MG, Goias, southern Bahia, western Minas Gerais, with coverage at 80-90%.
• The second half of next week won’t see much moisture in the southern half of Brazil and that’ll continue into early next week; some areas in the south could actually be completely dry.
• Some of the drier areas could include Paraguay, southern MGDS, through Parana and Sao Paulo, and southward through Rio Grande do Sul.
• Still, the ten-day picture has nice moisture in Brazil and the 11-16-day forecast shows that pattern continuing.
• Temps will be normal/slightly above in the daylight hours, but the overnight periods continue to be cooler with temps below normal each night.
• This kind of setup will continue to favor crop development and we don’t see any major headaches or problem areas in Brazil at this point.
• The trade has been talking a lot about lack of moisture in Argentina; it will be mostly dry today-tomorrow, with a few scattered showers in northern Argentina.
• A few scattered showers come together late in the weekend/early next week, especially on Tuesday, with scattered showers falling over 30% of Argentina’s growing areas.
• High pressure moves in Wednesday-Thursday of next week, but more precipitation will follow at the end of next week.
• A batch of showers will develop over Buenos Aires province, northern La Pampa, and southern Cordoba on December 18-19, lifting across 60% of Argentina’s growing areas.
• It looks like Argentina isn’t in quite as good a shape as Brazil over the next ten days as they’ll only see scattered hit and miss showers covering roughly 40% of the region over the next 10 days.
• It won’t do anything to address the perceived dryness in southwestern parts of the country.
• At the same time, we continue to see temps below normal in Argentina and no significant heat is looking to move in.
• There is a warmer push of air in the south by the weekend, but this will go away quickly moving through next week as a good chunk of it will be back to below normal temps.
• The dryness isn’t the best-case scenario for Argentina crops, but it’s also not the worst-case scenario either.
• If the pattern changes between now-December 30, things will be in good shape; we’re not raising any red flags just yet.

Well, the time has come. We all know there is a snow producing system headed our way, and by this point you probably have heard all sorts of different takes on the system. Some have been talking up “snowmageddon”…others not so much. We told you a few days back the range numbers we were using for our “working theory”, and therefore, this morning, you should not be too surprised at our thoughts. But, before we get there, a quick look at today and tomorrow is warranted.

Lake effect snow developed late yesterday in extreme northern Indiana, and will continue this morning to affect those northern tier counties that we have mentioned over the past few days. Those counties are LaPorte, St. Joe, and Elkhart, Lagrange and Stueben. We are seeing a slightly farther south push to the snow into Kosciusko and Marshall Counties too, although the snow tapers off rather quickly. The snow will fade back as the day wears on, and farther south, we see just a mix of clouds and some sun. Tomorrow looks similar early, with clouds and minor bits of sun, but clouds will be building again through the day, ahead of our winter systems arrival.

Now to that snow event…snow develops overnight Saturday night, but will be pretty
minor. WE look for snow accumulations through the day Sunday and through Monday mid-afternoon. The heaviest snows will fall in the Sunday afternoon and Sunday night period. Our official snow totals forecast is as follows: from US24 northward we see 4-8 inches of snow Sunday and Monday with many areas in the higher half of the range. We won’t rule out a few 10 inch totals, but they will be isolated, created more by brief bursts of intense snow than a large scale advancing wave. Coverage will be 100%. From I-70 to US24 we see 2-5” with 100% coverage. From I-70 south to US50, a coating to an inch or two with coverage at 70%, and then south of US50, flurries or nothing in the way of snow. However, those southern areas could see some rain mix in at times, so coverage
of any type of precipitation will be between 80 and 100%. Winds will not be too bad in areas where there is snow, definitely much lower wind speeds than what we saw yesterday and today. Still, there can be some blowing in drifting to watch for. Sunday and Monday will be a mess over most of the state. The map above shows snow totals as of Monday afternoon. The 11” totals take into account some lake effect snows that still hang on this afternoon and evening, and are not a true representation of the snows from just our weekend system. However, this snow distribution mirrors our thought for this system very closely (NOTE…we made our forecast independent of any 1 model, as no model could be trusted in the lead up to this event and our forecast this morning…but this representation from the Canadian model just so happens to fit our forecast pretty close).

Following that system, we see cloudy weather, but more importantly, another arctic blast coming in from the NW. This air mass will be colder than what we have seen this week, taking temps to well below normal levels for the balance of the week. In this cold air push, we see several clipper like waves moving through, bringing additional light snows.  One of these will be in for Wednesday bringing only some light snow and flurry action with little to no accumulation. A bigger, more impressive wave hits for Thursday night through Friday, and it can bring good accumulating snows to 80% coverage in the state. For now, we will pencil in 1-4 inch potential, and keep in mind those will be our “working numbers” going forward – not an official snow forecast. We will tweak over the course of the next 5 days as things come into sharper focus. Still, look for a somewhat interesting close to the week next week. Drier for the end of next weekend, the 18^th, into the following week.

In the extended period, we see potential for another frontal complex ahead of Christmas around the 22^nd that brings accumulating snow potential. However there could be a warming surge ahead of the cold front, so we may not have a significant snowpack as that system comes in. time will tell. AT this point, we would put odds at about 65% that we have a white Christmas over most of Indiana, however.

 

Colder air comes into the state starting today, and the weather pattern begins to get very interesting. Lake effect snow will be an issue tomorrow over the extreme northern part of the state. This will be something to watch for in eastern LaPorte County, St. Joe, and Elkhart and to a lesser extent in Lagrange and Stueben counties. The better lake effect set up will be in western MI. There can be decent accumulations tomorrow from the Toll road northward, and then on again-off again lake snows down to US 6. South of 6, precipitation will be pretty limited from the lake effect event. Clouds can dominate over the northern part of the state, but the farther south you go, the better chance at sun over the next 3 days…today, tomorrow and Friday. Either way (clouds or sun), the much colder air just keeps coming, with a strong west/northwest flow ripping out of the Upper Midwest right on down into our area.

Clouds build back in on Saturday ahead of our next system, which is beginning to look a little more impressive. Snows develop Saturday night, potentially statewide, with some accumulations. Then Sunday we see good accumulating snow potential over northern parts of the state, while the central and southern parts of Indiana can see a rain snow mix. Then Sunday night into Monday, we see a heavier swath of moisture moving in that can add more snow to the equation. It is way too early to talk specifics yet, but as just a working theory, let’s say we are kicking around potential for some 3-8 inch snows over northern half of Indiana, and a mix of rain and snow south that can produce a slushy few inches. Again…these are by no means our official snow totals…we will publish those Friday, but it looks a little more interesting than it did 48 hours ago for the state. Most of the impact from this event will come down to where the freezing lines set up…and those are still fluid (no pun intended ) at this time…with track of the low and differing air masses the biggest variables. The map above is a snapshot of snow potential at 7 am Sunday morning.

 

Either way, consider the start of next week kind of a mess. Then, we see wave number 2 of colder air on the way. The clouds do not leave behind the early week system, and we can see some residual flurries as the cold air comes in. The biggest chance of this light snow and flurry activity will be overnight Tuesday into early Wednesday, but we don’t think it will be a big issue for anyone planning to travel to see us at the Indy farm show. By late week, we can be pushing 0 for some minimum temps across a good chunk of the state. In the extended window, look for another system to work in closer to the 21^st. Overall, our outlook for much colder and more active weather for the month is right on track. There will be no “bounce” to our temps.