Thunderstorms in the Forecast?

We did it! For the first time this year, we have hit the 80-degree mark in Rockford, nearly a month earlier than last year when it first happened on May 6th! The 80° we saw today was only 6° shy of our record high for the date, which was set back in 2002. The good news if you're a fan of the warmth is that it isn't going anywhere for another two days. Both Sunday and Monday should feature high temperatures in the upper 70s and lower 80s with ample sunshine each day. Things will begin to change once Tuesday arrives as our strong area of high pressure finally weakens and moves away from the region.

A weak disturbance will arrive Tuesday and bring some scattered afternoon and evening showers, possibly even a rumble of thunder or two. Not only that, but temperatures will be much cooler in the 60s. Wednesday also features a chance of showers and thunderstorms ahead of a low pressure system that will likely move overhead on Thursday, sparking an additional chance -- and likely the best chance -- of rain and storms. There is some CAPE (instability, or energy for thunderstorm development) available through the week, which will support some thunderstorms, but severe weather doesn't appear very likely at this time.

Another difference next week will be dew points and relatively humidity values. They will be higher than they have been of late, with dew points exceeding 50° each day. That isn't necessarily considered humid per se, but it will feel a little more humid to you on Tuesday, Wednesday and Thursday.

Very Sunny Weekend Could Spell Problems

Temperatures finally eclipsed our average high for this time of year on Thursday. They will likely eclipse that number for the foreseeable future as well. As we have been discussing all week long, a dominant area of high pressure just to our east is acting as a block, disallowing any precipitation to move into the Midwest and Great Lakes regions. It is also putting the Stateline in such a position that we see southerly winds. This, in turn, is sending very warm air into the area. The warmest of that air will arrive this weekend into Monday of next week in the form of middle and upper 70's. It will also continue to be sunny.

We will experience a brief and slight cool down next Tuesday and Wednesday with high temperatures likely remaining in the 60's, but we warm right back up after that to end next week. We could be talking upper 70's and lower 80's by the time next weekend rolls around if current model projections hold true. The other side of the high pressure system is the dry pattern that it will continue bringing to the region. No single day through next weekend features a chance of rain higher than 20-25% as it looks now.

With the increasing temperatures and abundant sunshine, it is likely that many of you will be venturing outdoors this weekend to a park, river, or even your own backyard. An important thing to remember this time of year is that sunburn can and does happen despite it only being mid-April. The sun angle is very strong in the spring, so contrary to popular belief, sunburn is a very real possibility this weekend. Our UV index values will range from 7-8, which falls into the "high" category, meaning sunburn risk is quite high. Therefore, it is important to utilize plenty of sunscreen this weekend if you're going to be out and about enjoying the rays.

Soil Temperatures on the Rise

Not only have our air temperatures been rising, soil temperatures have been on the rise as well.  This is good news for anyone wanting to get out and start spring planting in the garden and in the farm fields.

Soil temperatures need to be right around 50 degrees to begin planting.  Earlier in the month of April soil temperatures were in the middle to upper 30's thanks to a cold start to the month.  Those numbers have quickly gone up with the warm recently.

Two inches under bare soil temperatures are in the middle 60's, with even a few low 70's in west-central Illinois.  Temperatures four inches under bare soil are in the low to mid 60's.  So over the next couple of days, you'll probably see more farm equipment on the roads.  By next week I expect corn planting to be in full force.

Soy beans usually go in the ground during the first week or two of May.

How Long Can We Stay Dry?

It seems like a broken record at this point. The dry, warm weather is still here, and will continue to be here. But, how long can we keep it around? Well, the dominant area of high pressure that is centered to our east is going nowhere. It will remain along or near the East Coast through the beginning of next week. That means sunshine will remain in the forecast, as well as warm, southerly winds. And, as those southerly winds continue, temperatures will continue their incline into the weekend with high temperatures comfortably reaching the lower to middle 70s.

In fact, by the time we get to late next week, some of our long-range models are suggesting upper 70s and lower 80s across the Stateline. Now, is that a guarantee? No. Is it feasible? With the pattern expected to last through next week, yes.

The only blemish in an otherwise stellar forecast is the threat of a few very isolated showers Tuesday and Thursday of next week, in addition to a brief cool down early next week. However, there is not a single day in the next 7-10 days that features high temperatures below the current average high of 60°!

Extended Outlook Holds on to the Warmth

That's what we want to hear, right?  The warm weather expected for the upcoming weekend may return, and even warm further, by the end of next week.

The long range outlook from the Climate Prediction center places nearly all of the United States under a higher probability of experiencing above average temperatures.  But look at the center of the country.  Another dome of high pressure will build over the Heartland warming temperatures possibly into the middle and upper 70's, with the 80's not that far away!  So if you're a warm weather fan, this may just be the forecast for you.

As for precipitation, we remain dry for the next week with very little rainfall expected through next week.  There could be a few more showers/storms developing over the Upper Midwest and out west, with only a slight chance for above average precipitation in far Northern Illinois.

Omega Block Setting Up

So what is this "Omega Block" that is being discussed among meteorologists this week? Well, in its simplest terms, it is a pattern that features an upper-level pattern that looks like the Greek letter omega: Ω. If you look at the map to the left, you can see that overall shape setting up with two dips in the jet stream surrounding the ridge of high pressure that is developing over the Great Lakes, Midwest, and Plains. The reason why it is referred to as a block is because the high pressure system is going to anchor itself over the Great Lakes and not move much for the next week or so. That set up is "blocking" those low pressure systems -- or dips in the jet stream -- from moving.

In other words, with this pattern, the areas under the influence of the dome of high pressure see sunny skies and warmer temperatures for a longer duration of time. Meanwhile, the locations contained within those jet stream dips tend to see cooler-than-average temperatures and an increased risk for precipitation. You can see these patterns clearly on the GFS temperature forecast for this weekend -- the blue shades representing colder air and the yellow shades representing warmer temperatures.

So the next time a meteorologist mentions an "Omega Block" pattern, you will know that wherever the omega/high pressure is located is where warmer temperatures can be expected.

Record Warmth this Week?

Not really.  Record high temperatures this week are in the middle and upper 80's.  Our warmest temperature this week will be 73 degrees on Sunday.

Even though we won't be nearing any records, this week is going to be nice.  So make a point to get out and enjoy it!