Goose Lake Weather Blog

Average First Frost

The recent record rainfall produced a record mosquito population as of late. Their numbers have increased dramatically over the last few days and this has me thinking of our first frost. When is the average first frost? Statistics compiled by the Illinois State Climatologist indicate that on average we can expect our first frost during the first or second week of October. Our first 32° or lower temperature last year was later, it occurred on October 28th. It’s interesting to note that the standard height for air temperature sensors is around 4 to 5 feet above the ground and on calm and clear nights, the temperature at ground level can be a few degrees colder than reported by most thermometers.  So, it is possible to get frost when the air temperature may still indicate that it is above freezing.

We’ll have to wait and see what date our first fall frost will occur. I’m not looking forward to cold temperatures but a brief frost followed by warmer temperatures would make outdoor activities a little more pleasant.

Our 3 day storm total rainfall stands at an incredible 7.45 inches.  Our rainfall total for the month of September is now 11.78 inches. It’s amazing when you consider the dry June-August that we experienced. All the rainfall has resulted in extensive runoff and flooding. The Illinois River is cresting at record levels from Morris IL down to La Salle IL.

Radar Estimated Rainfall through 4PM CDT 9/13/08

Portions of northeast Illinois have received between 4 and 8 inches of rain during the last 24 hours. O’Hare airport in Chicago was shut down for a period this morning as roads leading to the airport were flooded. As of this writing, the storm total at Goose Lake Weather was 3.9 inches with additional heavy rainfall expected overnight. Backyard flooding was in progress around the area and many fields and small streams were flooded as well.

Join CoCoRaHS

Do you like observing weather from your own backyard? If so, we need you for the Community Collaborative Rain, Hail and Snow Network…known as CoCoRaHS.  We currently have only 2 active CoCoRaHS observers in Grundy county (including myself) and would very much like to increase the coverage throughout the county as well as surrounding counties.

You are required to purchase an official 4 inch diameter CoCoRaHS rain gauge ( $22 plus S&H) for accuracy and consistency. Data is entered via a web site and you can see your report and all the other CoCoRaHS daily reports in the county, state, and country. To learn more about this great volunteer program, go to the CoCoRaHS web page. Download the flyer on this training session here.

A CoCoRaHS training session will be held in Grundy County on:
Wednesday, October 1, 2008 at 6:30 p.m. in Morris, IL

Location: Grundy County Soil & Water Conservation District Office
3605 N. Illinois Route 47, Suite B
Morris, IL

To register, call the SWCD office at 815-942-0359, ext 3. Registration deadline is Friday, Sept 26.

Directions to the SWCD office can be found here.

I hope to see you there!

CoCoRaHS rain gauge

We had an additional 0.99 inch of rain on Monday. That brings our monthly total now over 4 inches. It is helping to replenish the soil moisture. More rain…possibly heavy…expected beginning late Friday. A cool low of 48° this morning and even cooler temperatures expected overnight tonight.

This morning’s low temperature dipped down to 49.6°. We haven’t had a 40 degree temp for some time now. The cool nights are great energy savers, no need to have the heat or AC on, just open the windows.

Remnants of what was Hurricane Gustav brought badly needed rainfall to the area during the last 24 hours. Our 24 hour total ending this morning was 2.88 inches! All of the rain soaked in with very little ponding observed. It was an ideal rainfall thanks to the steady and prolonged period from early Thursday morning until late Thursday evening.

How unusual is it for a tropical system to make it to northern Illinois? It certainly doesn’t happen that often but does on rare occasions. Here’s an interesting graphic from the National Hurricane Center

Hurricane Track History

on past hurricane tracks. It does show some, or more precisely the remnants of tropical systems, making it as far north as northern Illinois.

forecast rainfall

Moisture from what was Hurricane Gustav is streaming north into Illinois and heavy rainfall is possible over the next 48 hours. This image shows forecast rainfall for the period Wednesday evening through Friday evening.

Today’s high temperature topped out at 94°.  At this writing thunderstorms were occurring near here but  it appears that the heaviest rains of 1/2 to 1 inch have missed this station…again…by only about 5 miles. Let’s hope we get some more rain in the next 24 to 48 hrs to help with the extremely dry conditions.