Mild signal to end of January/start February

All signs continue to point to a likely significant warmup across the central US heading towards the end of January and beginning of February. Temperatures look to push 10-20°+ above normal for the Midwest, Mississippi River Valley and Great Lakes.

The above forecast looks at temperatures in the 12-14 day window, or Feb. 2-Feb, 4.

Using the same model, here’s a look at the probability of being above normal, which is well over 80-90% cross a significant portion of the US. This will likely lead to a big melt of the thick snowpack that has been built up through early 2024.

Continuing a look through the analogs, the chance of reaching 60° is pushing at least 30% towards the Iowa border which is rather impressive. This is a heavily smoothed forecast at this range, and I would not be surprised if we do see 60s push up to I-80. Keep in mind this is a two-week heads up and much can change.

I think upper 40s to low 50s is pretty much a lock for many in the central US.

Part of what will lead to the warming trend ties directly to the teleconnections. The NAO/AO indices are pushing well above 0, which is a strong warm signal for North America in winter. This continues through at least early February.

By early February the trend may drop closer to zero, or dip back towards negative values. This could potentially signal in the long range a cool down will return by mid-February, but let’s wait until we get a clearer picture on the warming trend prior to talking about another drop.

The latest long-range European Ensemble hints at a prolonged drop below zero which could send North America back into a cold winter. It is still winter after all. A little premature to go too in depth here, other than this is a watch item.

Again, likely getting a little ahead of ourselves here, but this mid-February chill is also reflected well in the overall pattern on the European Ensemble. Cold, northwest flow over the central and eastern US.

Now, back on topic to the late Jan/early Feb warmth: If this was summer, this would be a classic heat wave with highs in the 90s for the Midwest, for some context. A significant ridge in the jet stream develops in late January and pumps the unseasonable warmth well up into the Canadian Prairie.

I’ll end with a look at one model’s take on the forecast for the next two weeks. Do not focus too much on the exact temperatures, but more so watch the trend. For this forecast in Cedar Rapids, Iowa, highs are looking increasingly likely to reach the 50s.

Until next time…

-Meteorologist Nick Stewart

Strong Midwest Winter Storm Forecast Next Week

Confidence continues to increase a potent storm system will traverse the central US in the January 9-11 time frame bringing the combination of snow, heavy snow and strong wind gusts. While confidence in amounts remains low as we remain several days out, the confidence continues to be rather high a storm will bring travel impacts to the region.

Water vapor satellite image late Thursday evening.

Let’s start with some context. The storm we are dealing with right now is more than 2,500 miles from the Tri-State region of Illinois, Iowa and Missouri. When it comes to high-impact snow, a difference of 60 miles means all the difference between rain, snow, a combination of the two or nothing at all. So when it comes to forecasting these things just know this is still a long ways away.

The European and American (GEFS) Ensembles remain in good agreement in terms of timing, placement and strength of the upper air pattern that will fuel the rapid development of the storm across the Southern Plains before it turns into the Midwest.

This alone indicates there will be a strong storm system, it just comes down to the details now.

The models are slowly honing in on the area at most risk of heavy snowfall with this system. The latest probability forecast off the European Ensemble shows a strong 70-80% chance of 6” of snow from Kansas, into northern Missouri, southeast Iowa, northern Illinois and southern Wisconsin.

While this can still shift, the theme is starting to really come into the light. An axis of heavy snow is likely that could push 6-8”, or more, along and just northwest of the low track.

The spread in surface lows has tightened considerably over the last 36 hour. There is a tight grouping of potential low locations valid noon Tuesday right around the St. Louis, Missouri area. This is a classic setup for heavy snow in northern Missouri and Illinois.

The threat of heavy snow will coexist with strong wind gusts in the 30-40mph range. This could lead to significant blowing and drifting of falling and snow already on the ground. This could lead to significant travel impacts across a wide area Tuesday and Wednesday.

In addition, slower to the low where the snow may be heavier and wetter, the snow buildup on trees and powerlines with the strong winds could also lead to issues with power. As of now wind gusts aren’t absurd, but this is worth watching anytime you have a rapidly strengthening low and will be better visualized on high-resolution models closer to the storm’s onset.

THE BOTTOM LINE

While we' remain a few days away, now would be a great time to start thinking about potential changes to travel or plans Tuesday and Wednesday in the Midwest as confidence in a storm is high, but the exact location of most significant impacts remains TBD.

-Meteorologist Nick Stewart

Winter system may be brewing next week

The trend is your friend - that is the mantra for meteorologists when watching for potential storms and pattern shifts. After a very mild December for much of the country, the trend is a big pattern shift heading into the second week of January.

The area of focus for this blog post will be January 8-11.

The European (left) and American (GEFS, right) ensembles both show a strong trough in the jet stream that features a winter storm in the central US with the potential of heavy snow. Even about eight days out, there aren’t major differences in the upper-level patterns which show higher-than-normal confidence in this winter storm threat.

Before getting too much deeper into the models, I did want to show the current thinking of the Climate Prediction Center regarding the snow threat. This goes to show the strong signal in the models that they are putting out a Moderate Risk for Heavy Snow.

While the upper-level pattern is coming into agreement, what happens at the surface is still rather uncertain. Above you can see the range of solutions with a center of the storm as far north as Clinton, Iowa to as far south as Birmingham, Alabama.

The main takeaway here is that there is rather high confidence in a storm, however location and impacts are still being worked out which is common a week out.

Based on the European Ensemble, the probability of at least 3” of snow is rather high stretching from western Kansas through the Great Lakes - therefore this is the area we are closely watching for impactful snow.

The actual width of heavy snow will be more narrow than indicated above, but eight days out the range in possibilities remains high. Eastern Iowa, northern Illinois and southern Wisconsin are most interesting at this stage.

Another thing worth watching into the extended period is the likelihood of winter temperatures finally making an appearance. Analogs show with pretty high confidence below-normal temperatures for much of the US following the storm early next week in the middle of the month.

That’s a cold signal!

That’s it for now, more to come as the forecast becomes more clear.

-Meteorologist Nick Stewart

Active pattern setting up with mild temperatures persisting

As drought continues to lead to lasting impacts on the Upper Midwest there continues to be some hope for some beneficial rainfall as we head towards the end of September across the Central US as a more amplified pattern brings stormy conditions and moisture northward.

Based on guidance, a well-above-normal supply of moisture will be present late this week into the upcoming weekend with precipitable water values approaching 1.5” to 1.75”. For this time of year that is quite high end. Assuming we can get storms to tap into this supply of moisture that would lead to good things.

Analogs show a healthy swatch of rainfall topping 1.0” across much of central and eastern Iowa, as well as northern Missouri. This is far from “drought-busting rainfall,” but it would certainly help add some moisture to the soils before we head into winter which is critical for next spring.

I do think this might be displaced too far east - I wouldn’t be surprised to see the heaviest rain along/west of I-35 with lighter amounts in eastern Iowa.

Above-normal precipitation continues to be the signal on the American GEFS model which is good news and has been the trend for the last week or so. The signal hasn’t wavered yet. The Climate Prediction Center is also highlighting the central US for the potential of heavy rainfall.

As far as temperatures go, near-to-above normal remains the theme through September and into early October. I have received a few questions about an “Arctic Blast” coming in early October and let me be clear - that will not happen. We will not see temperatures in the single digits. There is nothing aside from a frequently inaccurate model that showed a “cool down,” and even that was far from an “Arctic Blast.”

So no worries, we aren’t going to winter yet. In fact most guidance supports a very warm start to October.

A 15-day temperature outlook on the European ensemble shows temperatures hitting into the low 80s once again by midweek and 70s rolling towards Oct. 1.

-Meteorologist Nick Stewart

As drought expands, some relief may be in sight

The latest drought monitor released Thursday Sept. 14 continues to show an ugly expanse of Extreme and even Exceptional Drought across Iowa, Minnesota and Wisconsin. Looking longer range, however, some relief may be in sight.

The 200mb pattern centered on Sept. 23 based on the European Ensemble.

The overall pattern looks to get more energized by late September, especially in the Sept. 22-29 time frame. A rather rigorous subtropical jet is forecast to develop bringing stormy weather to the central/Midwest US. The agreement in the European Ensemble is quite promising to bring moisture and Upper-Level support for precipitation.

Analogs for precipitation centered Sept. 22-25.

Latest analogs show a classic early-autumn rain event with above-normal precipitation looking increasingly likely. Probabilities of above-normal precipitation are approaching 70% which is a strong signal this far out.

Probabilities of 1” based on analogs.

Even nearly two weeks out we are seeing heightened potential of 1"+ rainfall across much of the central US. This is a rather promising signal and bodes well for beneficial rains.

European ensemble precipitation matrix.

Above you can see the 50 members of the European Ensemble laid out through nearly the end of September. There is a noticeable trend towards the latter half of the period of more active weather. Mean precipitation is approaching 2” by the end of the month.

CPC forecast days 8-14.

The latest Climate Prediction Center forecast is also honing in on the increased potential of above-normal precipitation.

Bring it on.

-Meteorologist Nick Stewart