Tropical Storm Isaias forms; Gulf Coast faces hurricane threat

Isaias Forms in the Gulf:

The Atlantic hurricane season has been a dud so far in terms of hurricanes. However, new, this morning, we now have our 9th named storm of the season, tropical storm Isaias. While hurricane hunters are en route to investigate the system, satellite imagery this morning alone shows a healthy and well-organized tropical storm in the southwest Gulf. 

Over the next few days, attention will be focused on its path towards the Gulf Coast, where landfall is expected later this week. As of this morning, the National Hurricane Center indicates the system could reach the coast as a category 2 hurricane. However, with very warm gulf waters in its path, we may see further strengthening occur, giving Isaias a chance to become a major hurricane. 

 

Severe Potential:

The Storm Prediction Center is also monitoring this newly named tropical storm, highlighting portions of the Gulf Coast under a 15% severe weather risk. This is equivalent to a level 2 of 5 Slight Risk. The area at risk includes the western Florida Panhandle and parts of Alabama, where the threat for tornadoes and strong damaging winds is expected to increase as the tropical system makes landfall and pushes inland. 
 

Cold front passes, but cooler air holds off until Thursday

Turbulent Tuesday:

Yesterday ended up being on of the breezier days of the fall season, with most Stateline locales recording a peak wind between 25 to 30 mph. 

Those gusty conditions developed ahead of our next cold front, which will sweep through today. As the front passes, winds will shift to the to the northwest, helping usher in a round of slightly cooler air for the second half of the work week.  

Warmer Wednesday:

Despite today's frontal passage, temperatures will remain on the mild side. A mix of clouds and sun will help temperatures climb into the upper 70s, making for a pleasant October afternoon.  

 

  

Cooler Thursday:

We finally see the cooler air behind today's cold front arrive overnight into Thursday, bringing one of the coolest days of the forecast so far. Afternoon highs on Thursday will be limited to the upper 60s, with a few locations briefly touching the 70-degree mark. While temperatures take a step down, dry conditions remain in place as high pressure builds in behind the exiting cold front, providing more sunshine.    

Tropical moisture could work toward the Great Lakes over the weekend

 While the tropics have been rather quiet so far this hurricane season, we are beginning to see development in the gulf. The Atlantic's first hurricane of the season is likely to develop, eventually becoming named storm "Isaias". As of Tuesday evening, this is just a tropical depression with sustained winds of only 35 mph.

But eventual organization of this system will develop it into a tropical storm by Wednesday afternoon, then a hurricane Thursday afternoon. Latest forecasts from the National Hurricane Center believe this storm will make landfall between New Orleans or the Florida Panhandle Friday afternoon before moving further inland over the weekend.

While we will not see tropical storm force impacts locally in Northern Illinois, the remnant tropical moisture may work closer to the Ohio River Valley and Great Lakes regions by Sunday morning. This will bring with it much more abundant moisture not far from the region. How far North this moisture gets is still to be determined, but there is an increasing likelihood of at least some sporadic shower activity across Central Illinois into Ohio Sunday and Monday from the leftovers of this tropical system.

Winds turn breezy across northern Illinois ahead of next cold front

Breezy Tuesday:

While this dry spell holds through Tuesday, expect a bit more of a breeze. The pressure gradient at the surface between the departing high pressure system to our east and the approaching cold front will tighten, driving up today's southwesterly wind. 

 

Expect wind gusts near 25 mph, possibly up to 30 mph throughout the day. Combined with plenty of sun, temperatures will climb back above average into the low 70s. Even as tomorrow's cold front moves through during peak afternoon heating, conditions remain mild with highs in the mid 70s. 

 

Fall leaves starting to change color, set to peak later this month

 The cool mornings and pleasant afternoons have kickstarted the process of leaves beginning to change colors for the fall. While not overly vibrant, colors are beginning to show across the region.

According to data from Explore Fall, the colors are really starting to explode across the Northern Plains and Rocky Mountains. Much of the country is not yet near peak colors, but those will continue to expand in the coming weeks.

As we get closer and closer to peak season for fall foliage, weather has a big impact on the fall colors we see. Brighter colors are a result of warm days with cool nights, while retaining adequate rainfall. Warm, humid nights and/or dry patterns result in dull colors by the time peak season rolls around.

Typically, peak colors arrive toward the middle of end of October. According to Explore Fall, we seem to be right on track or a couple days behind. Peak colors set to arrive between October 25th-31st. Be sure to make your plans now so you can catch the vibrant colors when they peak in just a few weeks!

Frost alerts issued for some across the Great Lakes

Frost Alerts:

A touch of autumn has arrived across the Upper Midwest this morning, with frost alerts posted in areas north of the Stateline where temperatures have fallen into the 30s. Closer to home, we're also off to a chilly start as temperatures across the region are hovering in the low 40s. While it may feel chilly, temperatures remain well above freezing locally, limiting the potential for frost.  

High Pressure in Control:

High pressure nearby will once again result in plenty of sun for the Stateline today. Temperatures will be a touch cooler than yesterday as winds turn to the north and northeast, keeping afternoon highs in the upper 60s. Despite the cooler air, it will remain a pleasant fall day with comfortable conditions. 

 

Breezy Tuesday:

Winds will pick up on Tuesday as our next cold front approaches from the northwest. A southerly to southwesterly breeze, with gusts up to 25 mph, will help usher in warmer air. Combined with plenty of sun, temperatures will climb into the low 70s during the afternoon, making for a mild day. 

Seasonably warm but dry throughout the week ahead

 Sunshine again dominated the sky Sunday, resulting in a pleasantly warm afternoon despite the slight breeze. The next round of high pressure is taking over, which will keep the sunny afternoons, but also bring a chilly night ahead. Temperatures will drop into the low 40s to start out Monday morning, but rebound quickly to the middle or upper 60s by the afternoon.

Southwest winds will begin to increase a bit starting Monday night, which will not allow for it to be quite as chilly, similar to Saturday night. A passing weather system well to the North will draw in some of the slightly warmer air from the South, which will push wind gusts up to 20-25 mph through Tuesday afternoon. This will help bring temperatures back to the 70s for the afternoon.

Similarly mild temperatures will continue for the next several days, with most afternoons topping out in the low 70s. Next weekend may bring another jump with a forecast high of 75 as of now. But rain chances remain absent from the forecast, with only about a 10-20% chance of some light showers between Friday and Saturday.