Wind-driven rain showers continue Sunday evening

 

A chilly rain continues to fall area wide Sunday evening as low pressure deepens over the Great Lakes. The rain has become widespread over the last several hours and has been heavy at times. We will continue to see scattered showers throughout the evening, but the coverage should become less during the overnight.

Temperatures have been rather chilly Sunday warming only in the low to mid 40s. There won't be much of a drop in temperatures overnight thanks to the cloud cover. Lows will dip into the upper 30s.

Northwest winds have been gusting to around 35 mph throughout the afternoon and are expected to remain blustery through the night. Wind speeds may actually increase during the day Monday as a strong low-level jet pivots around low pressure over the eastern Great Lakes. This could cause winds to gust as high as 40-45 mph throughout the afternoon.

Winds will remain strong both Monday and Tuesday but should ease up Tuesday evening as high pressure

moves back in. Highs on Monday will only warm to the mid/upper 40s and then low 50s on Tuesday.

Light rain Saturday, Light wintry mix Sunday

 

Light rain showers will continue to move in from west to east Saturday morning behind a cold front that is already nearing north-central Illinois. The rain will last only for a couple hours, ending by 9a/10a. Drier air moving in briefly behind the showers may allow some breaks in the cloud cover late morning and afternoon. Temperatures are expected to warm into the middle and upper 50s.

Scattered showers will move back in during the

evening and overnight as temperatures fall into the middle 30s. Colder air wrapping in around a deepening low pressure system Sunday will hold high temperatures in the mid/upper 40s. This will keep not only scattered rain showers in the forecast throughout the morning and afternoon, but also the chance for a few wet snowflakes and graupel mixing in. No accumulations are expected, but definitely not something we want to see at the end of April and beginning of May.

Winds are also going to increase with the strengthening low, gusting from the northwest at 30 mph Sunday, and then near 40 mph Monday. This will only help reinforce the colder air.

Sunshine will gradually return throughout the day Tuesday with highs in the middle 50s. We are back in the 60s Wednesday and Thursday, but the chance for rain returns with an unsettled jet stream.   

Spring chill returns for the weekend

 

It has been a beautiful Spring afternoon as temperatures Thursday warmed into the mid and upper 60s. Skies have been clear as high pressure continues to hold firm across the Great Lakes. A few clouds may move in late in the evening and overnight, but skies are expected to remain partly cloudy through Friday morning. Overnight lows will remain seasonable, in the low 40s.

Cloud cover will continue to increase as low pressure moves through southern and central Illinois Thursday night, then into the Ohio Valley Friday. A stray shower or two can't be ruled out during the day but a better chance for rain returns Friday night.

Scattered off and on showers are likely Saturday, but there does appear to be some dry time during the early afternoon. A stronger cold front moving in Saturday night will not only bring temperatures back down below average, but also increase the chance for widely scattered rain Saturday evening and night.

Sunday appears to be the best day for rain, possibly mixed in with some snow or graupel throughout the afternoon. Highs on Sunday will struggle to make it

much above 50 degrees. Temperatures remain near 50 degrees Monday with temperatures back into the 60s by the middle of the week. 

  

Frost Advisory issued Wednesday night

 

A FROST ADVISORY has been issued for all of northern Illinois beginning late Wednesday night, lasting through Thursday morning.

Areas of frost are likely once again as temperatures fall at, or below, freezing Wednesday night. While there may be some locations that dip into the 20s, temperatures shouldn't be quite as cold as Tuesday night. Be sure to cover up or bring in any plants or vegetation that may be sensitive to the cold. Temperatures will slowly warm through the week before falling back below average by the weekend. 

Freeze Watch issued for Tuesday night

 

A FREEZE WATCH has been issued for all of northern Illinois beginning Tuesday night, lasting through Wednesday morning.

Skies will slowly clear as high pressure builds in from the north Tuesday evening. This will allow temperatures to fall into the upper 20s and low 30s under mostly clear skies. Areas of frost are also likely Wednesday morning. Be sure to cover up or bring in any plants or vegetation that may be sensitive to the cold.

This cooler than normal pattern will carry us through the end of April and beginning of May. Temperatures will warm by the end of the week, climbing into the middle and upper 60s Thursday and Friday, but will drop right back down by the weekend. The reason, another cold core low-pressure system over the Great Lakes. 

The chilly pattern as of late - and going forward - is the result of a blocking pattern in the jet stream. This is known as a 'Greenland Block'. High pressure becomes stationary near Greenland causing the jet stream to 'back up' to the west. A ridge of high pressure builds over the west coast of the United States, forcing the jet stream to buckle over the Midwest and Great Lakes causing the colder air to spill south. 

Blocking patterns are hard to break and can last for several days. We will see the pattern weaken slightly by the middle of the week, but it looks to take hold once again by the weekend. Longer range outlooks continue to show a higher probability for below normal temperatures over the Great Lakes and East, as well as out West. 

There remains a higher probability for above average precipitation over the Plains and out west,

with below average precipitation over the Great Lakes.     

Light rain expected Monday night

Cloud cover has filled back in Monday afternoon as low-pressure inches closer to the Stateline. Skies will remain mostly cloudy through the night as scattered rain showers move in. The highest coverage in rain will remain south of I-80, but light showers are expected across northern Illinois and southern Wisconsin. Rainfall totals will remain under a tenth of an inch.

Temperatures will fall into the mid and upper 30s

Monday night, rising back into the low 50s Tuesday afternoon. There are likely to be a few widely scattered rain showers around early Tuesday morning, possibly lasting into the early afternoon. Skies should then begin to clear by late afternoon and evening.

Dry conditions are expected through the rest of the week with the next chance of rain returning late in the day Friday.

Cooler pattern settles in for the weekend

 

Temperatures Thursday afternoon warmed into the low to mid 70s, reaching 76 degrees in Rockford. A cooler than normal trend, however, appears to occur through the end of April and beginning of May.

There also remains a higher probability for below average precipitation during that time as well.

Temperatures have dropped following a strong cold front Thursday evening. Overnight lows will dip to the low 40s, climbing into the low 60s Friday

afternoon. Winds will turn back to the southwest during the day as sunshine returns. A couple upper-level disturbances moving across the Midwest during the afternoon and evening will bring back the cloud cover, along with a chance for a few isolated showers Friday evening. 

Saturday we'll see mostly cloudy skies and scattered rain/snow showers as a cold core low pressure system sits over the Great Lakes. This will hold temperatures in the 40s for both Saturday and Sunday. Overnight

lows will fall below freezing. Highs next week will gradually warm through the upper 50s but remain slightly below average through the end of the month.   

Second day of 80 degree heat, Fire weather concerns continue

Temperatures Wednesday afternoon warmed into the low 80s and it looks like we will do it all over again Thursday. Under mostly sunny skies Thursday highs will quickly warm from the low 50s in the morning, to the low 80s during the afternoon.

RED FLAG WARNINGS have once again been issued for Stephenson, Jo Daviess, and Carroll counties beginning at 11am. A FIRE WEATHER WATCH has been issued for Green, Rock, and

Walworth counties in southern Wisconsin. Both mean conditions will be favorable once again for any fire to quickly become out of control due to the dry vegetation and gusty southwest winds. Please avoid any outdoor burning Thursday afternoon and evening. And be mindful of any sparks or flames, as those could cause fires. 

Moisture and cloud cover will both be on the increase for Friday before rain moves in Saturday. 

Unseasonably warm pattern breaks by the weekend

 

Temperatures Wednesday afternoon warmed into the low 80s making it feel more like mid-July rather than mid-April. While the record high temperature still stands for April 12th for Rockford, we did come close with a high of 81 degrees.

Thursday is likely to be a repeat of Wednesday, gusty southwest winds and temperatures warming into the low 80s. Thursday's record high is 83 degrees set back in 2006. To put this into perspective, our average high temperature is 59 degrees.

The warmth continues into Friday, and even Saturday, but some big changes are coming with a strong cold front that'll move in late Saturday night/Sunday morning. Moisture will slowly begin to increase both Friday and Saturday leading to an increase in cloud cover. Temperatures should still be able to warm into the mid and upper 70s. A strong low-pressure system will develop across the Plains, moving into the Midwest Friday afternoon and evening. The cold front will still be west of the Mississippi River Saturday afternoon, allowing some instability to build across the Stateline late in the day. As the front moves closer, showers and thunderstorms will develop ahead of the front, moving in late afternoon and evening.

The strongest dynamics aloft stay southwest of the Stateline, but a strong to severe thunderstorm or two will remain possible locally. Wind would most likely be our biggest threat. This will be something we need to keep an eye on going into Saturday afternoon.

The cold front will pass early Sunday with temperatures falling through the afternoon. Northwest winds will be strong, making it feel quite the opposite of the weather we are currently experiencing. Temperatures on Sunday will remain in the 40s, but we should see the 50s return by next week.

  

UPDATE: Fire Weather Watch for Wednesday

 

Green, Rock, and Walworth counties have been added to the Fire Weather Watch that'll go into effect Wednesday late morning, lasting through evening.

Temperatures Wednesday afternoon are expected to warm into the upper 70s and low 70s. At the same time, southwest winds could gust as high as 35 mph. This could bring relative humidity values down as low as 20 percent during the afternoon.

The combination of dry vegetation, low relative humidity, and strong winds will create conditions that are favorable for fires to rapidly spread. The fire risk will be highest Wednesday as wind speeds will decrease some Thursday. Moisture will increase Friday ahead of a showers and thunderstorms Saturday.

Be sure to limit, or avoid, any outdoor burning Wednesday.

  

Updated tornado count from Friday, March 31st

 

Damage surveys continue following the severe weather that swept through northern Illinois and southern Wisconsin Friday, March 31st. A couple additional tornadoes have been confirmed, with a few areas still needing to be surveyed. The National Weather Service will continue to survey damage that occurred in northwest Winnebago County from Pecatonica, Durand, Shirland, Rockton, and South Beloit, as well as in DeKalb and Rochelle.

The latest: an EF-1 tornado touched down 3 miles east/southeast of Lanark in Carroll County, moving northeast into northwest Ogle County before eventually ending about 3 miles west/northwest of Baileyville. This tornado had peak wind gusts of 100 mph and was on the ground for 11.1 miles. It had a path width of 200 yards. It caused extensive damage to several farm buildings and also downed a few trees on its path.

The tornado that touched down in Machesney Park traveled to Roscoe and was on the ground for 8.7 miles. It was rated an EF-1 with peak wind gusts of 100 mph. It had a path width of 300 yards. This tornado began at the southwest intersection of Elmwood Rd and Rockton Avenue and tracked northeast. This tornado caused damage to several trees and outbuildings, as well as multiple homes, which primarily had suffered roof damage. A couple homes did have their roofs removed where the tornado was at its peak intensity with winds of 90-100 mph.

The Caledonia/Poplar Grove tornado traveled 25.6 miles from where it started in Boone County, moving into Walworth County in southeast Wisconsin. It had peak wind gusts of 95 mph and a path width of 150 yards. It started 4 miles west/southwest of Poplar Grove moving northeast before ending 2 miles northeast of Delavan Lake, WI. The most extensive damage was to a farm east of Caledonia on IL-173.

For more on the tornadoes that touched down that night in southern Wisconsin and northern Illinois, as well as additional damage that occurred, click on the links below:

Wisconsin

Northwest Illinois

Northern Illinois

Elevated fire risk this week

 

As temperatures continue to warm this week, the threat for quickly spreading fires also increases. Both relative humidity values and dew point temperatures will drop this week, specifically Wednesday and Thursday.

As a result, this could elevate the fire risk both days as southwest winds increase. The combination of warm temperatures, gusty winds and low relative humidity values could allow fires to spread quickly. Because of this, you'll want to limit any outdoor burning, especially Wednesday and Thursday.

'Rex' block brings summer-like warmth to the Stateline

 

A 'rex' block has nothing to do with dinosaurs (as exciting as that may sound). It's actually an upper-level blocking pattern that features high pressure north of low pressure.

A trough of low pressure will pass through the Midwest and Great Lakes Sunday night and Monday. This will cause clouds to thicken up through Sunday evening, lasting into Monday. As the trough passes through the Great Lakes a cut-off low will develop, closing off from the main flow of the jet stream.

This low will settles across the southern U.S., remaining fairly stationary throughout the week. In turn, it causes a northward shift in the jet stream allowing temperatures to warm well above average. Blocking patterns tend to remain fairly stationary for several days until something comes along and breaks the block. This break in our pattern looks to come by the end of the week and next weekend.

Highs throughout this week will warm into the 70s,

perhaps even close to 80 degrees Wednesday and Thursday. By the end of the week, we'll settle back to a little more seasonable pattern with temperatures in the 50s/60s, but it may be short-lived. Highs the following week look to warm back into the 70s. 

Sunshine continues into Easter weekend

 

Skies were filled with plenty of sunshine Thursday afternoon, warming temperatures into the upper 40s and low 50s. Winds were a bit on the breezy side, however, holding chills just a few degrees cooler. Winds will gradually ease following sunset, turning light after Midnight. Overnight lows will once again cool down into the upper 20s.

High pressure remains the dominant weather feature through Easter weekend, warming temperatures each day. Highs on Friday will rise to the upper 50s, low 60s on Saturday, and upper 60s on Sunday. We may see a little more cloud cover as a warm front lingers over the Midwest Friday and Saturday, but conditions are expected to remain dry. Cloud cover may continue to increase Sunday ahead of a cold front that'll sweep through southern Wisconsin and northern Illinois Monday afternoon.

Moisture is fairly limited with the front, so outside of a brief passing shower Monday, skies will remain dry. Temperatures on Monday will warm to the upper 60s. A strong ridge of high pressure moving through the Plains and Midwest next week will help warm temperatures into the mid and upper 70s beginning next Tuesday. It's likely that warmth will last through next weekend, possibly coming close to 80 degrees! The pattern looks to change, though, during the following week as temperatures look to settle closer to where they should be (low 60s) by the middle of the month.