Hit or miss showers expected Tuesday afternoon

 The majority of the rain this past weekend missed us to the south, leaving many across northern Illinois and southern Wisconsin without a drop. While there are some opportunities for rainfall this week, it looks like the heaviest may once again bypass us to the south.

Skies will remain partly cloudy and dry Monday night. Temperatures will dip into the low 60s. Tuesday will start off with sunshine, but cloud cover will gradually increase for the afternoon. Highs Tuesday will warm into the low 80s. A weak upper-

level impulse moving across the Midwest may be just enough to generate an isolated shower/storm during the afternoon. This would be during peak heating of the afternoon. Widespread rain is not expected and it's likely that most will end up dry once again.

Any shower chance Tuesday afternoon will come to an end by sunset, leaving skies partly cloudy Tuesday night. A stronger storm system will move into the Midwest Wednesday, but once again it appears that the heavier rain will fall south as the storm track moves through southern Illinois.

We need the rain, even after some heavy downpours during the month of July. The Rockford Airport has only received a 'trace' of rain, which is nearly an inch below where we should be for the first week of August. Looking back to the beginning of June we are just over a three-and-a-half-inch deficit, and just under a three-and-a-half-inch deficit since the beginning of January. Dry to moderate drought conditions persist across northern Illinois, while extreme drought conditions have developed for some in southern Wisconsin.

Isolated shower early Monday, storm chances higher late in the week

Cooler Stretch Continues:

For those that had any weekend plans, whether that was attending Festa Italiana, the final days of the Ogle County Fair, or just simply with family, the weather cooperated for the most part. 

Highs for both Saturday and Sunday topped out in the upper 70s. A two-day stretch in which Rockford hasn't seen since the first half of June. 

Monday kicks off with an isolated shower chance as low pressure spirals to our south. As this storm system departs for the Ohio Valley, conditions will dry out into the afternoon. Winds will shift to the north and northwest, which should allow temperatures to warm back around 80°. Skies remain partly cloudy overnight, with temperatures falling briefly into the upper 50s by sunrise Tuesday.

Isolated Chance Tuesday:

Not much changes for Tuesday. Models do bring in enough lift and atmospheric juice for a isolated shower or thunderstorm during the afternoon. This will be something to watch if you are going to day 1 of the Boone County Fair. Otherwise, expect partly cloudy skies, with high temperatures will peak closer to average in the low 80s.

Boone County Fair:

Towards the middle of the week, our next weather will be taking shape. A warm front draped across the central plains will be the focus for thunderstorm potential, some of which could head our way by the time Wednesday evening rolls around. Again, there is time for the forecast to change. 

Temperatures warm into the mid 80s Thursday afternoon as a cold front sinks down from the northern Great Plains. This cold front is shown stalling somewhere near the IL/WI border, then turns into a warm front. This is what we'll have to monitor for thunderstorm chances Friday afternoon into Friday night. Conditions from there will quiet down for the weekend, with highs peaking in the low 80s.

Severe threat diminishing a bit for the Stateline Sunday

We have seen quite the stretch of consistent high temperatures. Since last Friday, Rockford’s high temperatures only fluctuated between 81° and 85°. Highs do become a bit more variable after this weekend, with a few highs dipping into the upper 70s next week.

After the passage of the first of two systems this weekend, temperatures will fall to the mid-60s again overnight tonight. We may see an isolated shower through around 10PM, but skies will clear out a bit after that. Clouds hang around through the night as well, with winds a bit breezy out of the Northeast.

Sunday brings a very similar day to Saturday cloud and temperature-wise, with highs reaching back near the 80-degree mark. We may see a few isolated showers early in the day with the system approaching from the Southwest, but the bulk of the rain will stay South, similar to what we saw Saturday. Higher chances for rain and even a few storms will move into the area later in the evening.

While most of the rain will pivot South of the area during the day, we may see a line of storms move through the region late in the evening Sunday going into the night. Some of these storms may be a bit on the stronger side, holding the potential for gusty winds and small hail. An isolated tornado is possible as well, but the higher chances for that will remain South of I-80, near the center of the low-pressure system.

The highest threat for severe weather has shifted again to the South, with areas mainly South of I-80 under the Level 2/5 Slight Risk. Locally, only a few counties to the Southwestern portions of the viewing area are under the Level 1/5 Marginal Risk. While the threat is lower than it appeared a few days ago, a strong storm is not out of the question tomorrow evening. Remain weather aware just to be safe!

After the storm chances tomorrow evening, we may see a few lingering showers on the back side of the low-pressure system into Monday. This system will continue to deepen across the Great Lakes Region, leading to a strong pressure gradient and breezy conditions Monday as well. Our next rain and storm chances come Wednesday and again Friday, with temperatures remaining just a touch below normal through the rest of the week.

 

Warm Friday ahead, storm chances increase over the weekend

Dense Fog Part II:

For the second morning in a row, portions of the area are waking up to dense fog. Thankfully, the fog this morning isn't as widespread as it was for the morning commute Thursday. However, the National Weather Service has placed Carroll and Whiteside Counties under a Dense Fog Advisory until 9AM. If you plan to be out on the roads, make sure to use EXTRA caution. Especially in open areas! 

More of the Same:

Friday looks to be a spitting image of Thursday, just bump highs up by a few degrees. Most this afternoon should peak in the mid to upper 80s. A cold front sweeping through may have enough "oomf" to spark up an isolated shower or thunderstorm, mainly in areas along and south of I-88. 

The absence of wind shear (change in wind speed and/or direction with height) will result in more pulse-like thunderstorms, meaning heavy downpours and gusty winds will be the biggest concern. The overall threat should come to a close quickly as the cold front pulls away, leaving us dry into the overnight hours. Clouds will increase somewhat overnight, with temperatures falling into the low 60s by sunrise Saturday. 

Good news for the first night of Festa Italiana! 

Rain Chances Increase:

As we hinted at in Thursday's discussion, guidance continues to show a strengthening storm system approaching late Saturday into Sunday. With it does come the chance for thunderstorms, some of which could be strong to severe. 

Sunday afternoon into Sunday night would the time frame to watch for severe potential as the associated cold front sweeps through. Earlier this morning, the Storm Prediction Center placed the eastern half under a level 2 Slight Risk, leaving the western half under a level 1 Marginal Risk. All hazards would be on the table, but that IF everything in the atmosphere lines up smoothly. 

For instance, we have to see if there is any activity passing through Sunday morning. That could play a huge role on the potential for strong to severe storms during the afternoon and evening. Also, the timing of the upper-level wave is still in question. Both of these uncertainties will be monitored as Sunday nears. For now, stay up to date on the forecast, especially if you have any outdoor plans.

Dense fog advisory issued for some, little warmer this afternoon

Dense Fog Advisory: 

Thursday is starting off with a round of dense fog thanks to a process known as radiational cooling. When you have clear skies, light winds, and a little moisture near the surface, this creates the perfect environment for dense fog to form. 

As of this moment, a DENSE FOG ADVISORY is in effect for Green and Rock Counties up in S. WI, as well as Jo-Daviess, Stephenson, Whiteside, Carroll, Boone, Winnebago, McHenry, and Dekalb Counties in N. IL until 9AM. Visibility values up until then could sit at or below one quarter of a mile. If you plan to be out on the roads, make sure to use EXTRA caution and allow enough following distance!

Little Warmer:

With the main upper-level flow still positioned to our southwest, Thursday remains fairly dry. Ahead of the first of two cold fronts, winds will be out of the south and southeast. That, along with today's sunshine, will help temperatures climb into the upper 80s. 

Not only will it be a touch warmer this afternoon, humidity levels rise a smidge, making it feel a bit more humid than the past few days. A secondary and slightly stronger cold front is then shown sliding through the region early Friday morning. Behind it, winds turn to the northwest, which will help slowly bring humidity levels down as we approach Friday evening. Other than an isolated afternoon thunderstorm, Friday remains dry with highs climbing back into the upper 80s. 

Storm Chances Return:

The drop in humidity doesn't last long. Ahead of our next storm system, dew points will climb back towards the 70-degree mark by Sunday. Tagging along with this weekend's rise in humidity will be our next best chance for rain, primarily late Saturday night into the day on Sunday. 

Forecast models show a strengthening storm system sliding to our north by Sunday afternoon. With it comes a strong cold front, which will be the focus for severe weather Sunday afternoon into Sunday night. As of this morning, the Storm Prediction Center has placed the entire area under a 15% severe contour, which is the long-range equivalent of a level 2 slight risk. Something to monitor for now as more details will come about Friday and Saturday!

Warm, tranquil stretch continues

More of the Same:

August began where July left off, with a good amount of sunshine, seasonable temperatures, and rather comfortable humidity. Officially, highs for all of our locales Tuesday peaked in the low 80s. As we move forward into the second half of the week, the weather aims to stay quiet as the main storm track in the upper-levels remains to our southwest.   

High pressure to our east will bring more sunshine to the region both today and Thursday, but in a mixed fashion. Thursday will be a touch warmer as we will be sitting ahead of our next cold front. 

Highs today will peak in the mid 80s, with upper 80s in the works for Thursday. Along with the climb in temperatures comes a climb in humidity levels, with dew point temperatures landing in the close to the 70-degree mark by Thursday afternoon. Forecast models bring said cold front in by Friday morning, which will help change our winds to the northeast. This will help bring a slightly cooler, less humid air mass in for Friday, with the effects lasting into the first half of the weekend.

Weekend Rain:

The focus for this weekend will be a disturbance that glides into the Great Lakes from the Midwest. This will bring us our best opportunity for rainfall over the next 7 days, primarily late Saturday night into Sunday. At this point in time, a few details regarding this weekend's chances remain unclear. One being the overall track of the storm as it approaches the region. And two, the storm system's strength.

Comfortably warm stretch ahead, rain chances remain isolated

Above-Average July:

The rainfall from Friday's thunderstorms brought July's total up to 4.32". Not only does this land 2.4" more than the entire month of June, but this also brought Rockford's it's first above-average month in the rainfall department since March.

 

 

Isolated Rain Chances:

August kicks off with a northwest to southeast oriented jet stream. This will still allow numerous weak disturbances to approach the region during the first few days of the month, with the main storm track being to our southwest. Locally, chances remain isolated. Otherwise, we can expect intervals of clouds and hazy sunshine, with highs peaking in the mid to upper 80s both Tuesday and Wednesday. Overnight lows will end up seasonable in the low 60s.

Best Chance This Weekend:

Forecast models hold off our best chance for rain until the late portion of the weekend. With high pressure sliding into the Great Lakes, Saturday will be mainly dry with highs in the low 80s. Behind the departing high, low pressure will swing into Minnesota and Wisconsin, increasing moisture levels. This will bring the chance for showers and a few thunderstorms late Saturday night into Sunday afternoon.