Thursday, October 27, 2016

Nice & Mild Stretch Ahead

Well, if you aren't a fan of cooler and cloudy weather, the upcoming week will feature plenty of weather right up your alley. For the next week or so, there doesn't appear to be a single day where temperatures will be below average. That is a complete turnaround from the upper 40's we have seen over the last few days. The warmest days will likely be Saturday and Monday. Each of those afternoons will feature temperatures eclipsing the 70-degree mark. A few locations could easily see middle 70's if more sunshine develops than what is currently expected.

Even when temperatures don't hit 70°, middle and even upper 60's are forecast across northern Illinois and southern Wisconsin. Sunday will be the coolest day of the next week behind Saturday's cold front. However, upper 50's are still above average for this time of year. Over the course of the next week, the average high temperature will range from roughly 55° to 56°. Additionally, our overnight lows will likely stay at or above 40° through this entire period of warmer weather.

There are a few caveats to this warmth, though. First, there will be strong -- at times, very strong -- winds on both Friday and Monday. But it's those strong southerly winds that will be ushering in the warmer air. Secondly, it appears there will be more clouds than sun on most days. That does not mean skies will be overcast, but there will likely not be a day where there will be more sun than clouds.

Howling Winds for World Series Game 3

After a few gloomy and cool days in the Stateline the sunshine and warmth returns on Friday. Temperatures have the potential to warm into the upper 60's and low 70's across the area. Even mid 70's just a little south of us. The reason for this will be strong warm air advection ahead of our next low pressure system. The low will track from the northern plains into the upper Great Lakes, while the low will stay north of the area it will still impact our weather in a couple ways.

First it's warm front will lift through the region turning our winds to the south west which will help bringing in the warmer air. However, it will be a very windy day with southwest winds that will gust around 30-35mph. With high pressure over Ohio and a fast moving low pressure system over the northern Great Lakes, the pressure gradient (or difference in pressure over a certain distance) will tighten. This in turn strengthens the wind speeds.

Winds will increase through the afternoon and stay gusty into the evening. If you're planning to hang out around Wrigley through the afternoon winds will first gust closer to 20 mph around noon and then steadily increase into the early evening.

There will be a lot of sunshine though with mostly sunny to partly cloudy skies, and temperatures rising into the upper 60's across the park. And maybe even the Cubbies will use that SW wind to their advantage and knock a few out of the park!

Wednesday, October 26, 2016

World Series Forecast: Chicago

If you are fortunate enough to either have tickets to any of the World Series games this weekend, or if you plan on being in Chicago for the great atmosphere, the weather should cooperate for the most part. For Friday, temperatures will be very mild in the lower 70's under a partly cloudy sky. Skies closer to the first pitch time around 7 PM will be mostly cloudy, but temperatures will still be warm in the upper 60's. In fact, the temperatures shouldn't fall much at all through the game thanks to strong southwesterly winds. Those winds will occasionally gust upwards of 25-35 MPH. And, due to Wrigley Field's orientation, those winds will help fly balls carry on Friday, which could support more home runs and create issues for outfielders.

For Saturday's game, temperatures will be noticeably cooler in the middle 50's around first pitch. They will dip into the low 50's by the time the game ends. Skies will be mostly cloudy throughout the game with a 30% chance of showers. Any rain that may fall will be light and scattered in nature, but there certainly is a chance of some shower activity. Sunday's game will be entirely dry under a partly cloudy sky. Temperatures will be jacket-worthy in the low 50's at first pitch. By the game's end, temperatures will be in the upper 40's. GO CUBS GO!

Tuesday, October 25, 2016

Indian Summer Ahead?

Technically speaking, Indian Summer is simply referred to as warm and dry (typically sunny) conditions occurring in late autumn. Many times, it is used only after the first killing freeze of the fall. However, that is not a rule that is written in stone. The other aspect of the definition is that it cannot be one warm and sunny day. It has to be a period of days strung together in a row of warm and sunny conditions. That may occur late this week in the Rockford region. After seeing highs struggling to reach 50° Wednesday, upper 60's and lower 70's -- possibly warmer -- return by Friday and Saturday. The asterisk in the equation will be cloud cover. Skies could very well be partly to mostly cloudy on both afternoons, which technically is not "sunny" as the definition of Indian Summer suggests.

Nonetheless, warmer air is set to return for Friday and Saturday behind strong southerly winds. After a brief cool down on Sunday, temperatures are poised to ramp right back up into the upper 60's and lower 70's! That will provide excellent conditions for those heading out and Trick-or-Treating!
As it looks now, lower to upper 60's will be present under a mostly cloudy sky during the early evening hours on Monday. Winds will be breezy out of the south, which may cause some of your Halloween decorations to blow around a bit. Otherwise, it looks like a perfect day for Halloween festivities. Of course, last year Halloween featured rain and a high temperature of only 52° in Rockford.

Winter Outlook: La Niña Effects

NOAA (National Oceanic and Atmospheric Association) has released it's 2016-17 winter outlook.

This year's outlook is almost an exact reversal of last year's outlook. In terms of temperatures this winter, areas of the south will experience a 30-60% chance of above average temperatures, including most of the western U.S and the southern Plains. While portions of Montana, the Northern Plains, Minnesota, and Wisconsin have a 30-40% probability of experiencing below average temperatures. The Stateline area right now is on track for an average winter in terms of chilly conditions.

On the snowy/precipitation side of things, again areas in the west and south have a 30-50% probability of experiencing a drier winter. While those around the Great Lakes and Northwest have about a 30-40% probability of a wetter winter ahead.

When we say winter, we mean meteorological winter which includes December, January, and February.

But as mentioned above the outlook is almost the reverse of last year's winter outlook, but why? The reason: A transition from El Niño to La Niña. Last year featured a very strong El Niño, which is the warm phase of something called the El Niño Southern Oscillation (also known as ENSO). El Nino is generated by or associated with an area of warm ocean water that develops in the central equatorial Pacific Ocean. La Niña is the opposite of this, and is formed when there are cooler temperatures in the Pacific.

This year there is a La Niña Watch for the fall, with a 70% chance that a La Niña will develop.  But, confidence is low in this feature lasting through the winter. There is only a 55% chance that it will last through the winter months.

Not only does this climate phenomenon correlate to ocean temperatures, but it also requires action in the atmosphere as well. During a La Niña event, the ocean surface in the equatorial regions of the Pacific are cooler than normal. This leads to sinking air and less rain in that region, in turn the waters near Indonesia get warmer and in turn cause rising air and more rain.

walker circulation, ENSO, La Niña, convection, circulation, walker cell, tropical circulation, Pacific Walker Circulation, Pacific Walker Cell
Generalized Walker Circulation (December-February) anomaly during La Niña events, overlaid on map of average sea surface temperature anomalies. Anomalous ocean cooling (blue-green) in the central and eastern Pacific Ocean and warming over the western Pacific Ocean enhance the rising branch of the Walker circulation over the Maritime Continent and the sinking branch over the eastern Pacific Ocean. Enhanced rising motion is also observed over northern South America, while anomalous sinking motion is found over eastern Africa. NOAA drawing by Fiona Martin. 

Here's a great depiction of this circulation from the National Climate Prediction Center:
"This atmospheric circulation works to enhance the cooler ocean surface, both by blowing across the surface just like you’d cool the surface of your coffee, and also by causing cold water from the deep ocean to rise up. Have you ever blown on the surface of a cup of coffee that has cream in it, but hasn’t been stirred up? You’ll see the cream rise up to the surface, brought there by the circulation you’ve created."

If you'd like to read more about ENSO click here.

As stated in previous articles, just because there a 50/50 chance, of 'average' temperatures expected for our area doesn't mean that we still won't experience mild temperatures and arctic cold snaps at times this winter, these outlooks indicate patterns we look to see and the winter as a whole over the three months. Same goes for any rain or snowy conditions. Just because we could see more snow this year does not mean that there will be extremely large snow events, it just indicates that some climate factors point to there being a more active pattern this winter, thus leading to more snow.

We just want to make sure you are prepared for all sorts of winter weather this year! We live in the Midwest so we can expect cold temperatures and snowfall this winter!

Monday, October 24, 2016

Cool Start To The World Series!

Big game tomorrow night!  It looks like the weather will cooperate as well, although it will be much cooler than it was for the Cubs NLCS clinching game on Saturday night! 

At game time, expect temperatures to be 45 degrees with a light north wind.  Calm conditions and cooler temperatures might limit the number of long balls, but our Cubs have been defying those odds all year!  

The weather for Game 2 on Wednesday could prove to be a little more challenging as there is a 50% chance of rain showers that evening.  Temperatures will be a little warmer, but with the moisture it will feel much cooler.  

Games 3-5 will then move to Chicago where it will be a bit warmer, but there is a chance for rain on Friday.   Go Cubs!

Soggy Work Week Ahead?

After a beautiful and warm Sunday, things will start to change come Tuesday. For Monday, though, sunshine will warm temperatures into the upper 50's. By Tuesday, clouds will be on the increase out ahead of an area of low pressure as high pressure pushes to our east. By Tuesday evening, showers become increasingly likely. The showers will be around through the night Tuesday and through the day Wednesday. At times, moderate to briefly heavy rain is possible as low pressure looks to push right overhead. That could also support some thunder and lightning in spots with the rainfall.
Not only will it be rainy on Wednesday, but temperatures will struggle to reach the lower 50's and winds will be blustery. By the time all is said and done, rainfall totals could eclipse 1" in many backyards. In fact, some locations could easily see 1.5-2" if some heavy rain does make its way through the region. The good news is we do need some rainfall here in northern Illinois. The bad news is the rain will create for quite the raw day on Wednesday.