Tuesday, February 28, 2017

Severe Weather Tuesday evening

(5:04:22 PM) nwsbot: Local Storm Report by NWS LOT: De Kalb [De Kalb Co, IL] trained spotter reports HAIL of half inch size (E0.50 INCH) at 04:50 PM CST -- 

(5:04:57 PM) nwsbot: LOT continues Tornado Warning [tornado: OBSERVED, tornado damage threat: CONSIDERABLE, hail: 1.75 IN] for Grundy, Kendall, La Salle [IL] till 5:30 PM CST

(5:18:34 PM) nwsbot: Local Storm Report by NWS DVN: 3 ENE Rock Falls [Whiteside Co, IL] trained spotter reports HAIL of golf ball size (E1.75 INCH) at 04:58 PM CST -- largest slightly larger than golf balls.

(5:19:19 PM) nwsbot: Local Storm Report by NWS LOT: Marseilles [La Salle Co, IL] amateur radio reports TORNADO at 05:06 PM CST -- at the intersection of ne 30th and e 25th. electrical tower down blocking road and multiple buldings damaged. house with roof blown off. power line down on road.

Non-severe thunderstorms will continue with the passage of a cold front.  Severe weather will remain likely south of I-80 closer tied to the higher instability.  Storms moving through northern Illinois will remain heavy rain producers and could occasionally produce pea sized hail.

7:00pm Update: Tornado Watch canceled for Stephenson and Jo Daviess counties.  Will likely see a few more of these canceled early with the severe threat winding down.

5:30pm Update:  Severe Thunderstorm Warning continues for southeast Ogle, northern Lee and central DeKalb counties until 6pm.  This storm has produced nickel to quarter sized hail and is capable of producing wind gusts near 60 mph.  Cities in the path of this storm include: Steward, Rochelle, DeKalb, Malta, Creston and Genoa.

4:25pm Update:  Tornado Warning canceled for Whiteside County, however, a NEW Severe Thunderstorm Warning has been issued for Carroll and Whiteside counties until 5:30pm.

A Tornado Watch has been issued for all of Northern Illinois until 10pm Tuesday evening.  Thunderstorms have quickly developed ahead of an area of low pressure near the Quad Cities and along and south of a warm front riding along I-88.

With the rapid development of thunderstorms many of them have turned severe, including one storm that did produce a tornado in eastern Iowa and is currently moving into western Whiteside County.  There is a Tornado Warning for Whiteside County until 5pm.

Along and south of the warm front will be the focus for rotating thunderstorms and this looks to occur mostly south of the immediate area.  However Whiteside, Lee and DeKalb counties do need to remain alert because the warm front could make a little progress northward over the next couple of hours.

Non-severe thunderstorms have developed north of the boundary producing heavy rainfall and frequent lightning.  Hail would be the primary threat with those storms as they have become slightly elevated over top of a more stable air mass.

Spring-Like Storms as we Close February

It's been a very abnormal February to say the least, with a record breaking string of days in the 50's, 60's, and briefly hitting 70°. We have the potential to make it into the upper 50's and low 60's this afternoon, but with the spring-like warmth comes spring-like thunderstorms.

While a few scattered showers and a rumble of thunder or two is possible through the early and mid afternoon, we're watching the late afternoon for strong to severe potential. Right now we have a lot of ingredients in place, but they all have to come together.

The timing will be a little after 3pm into the evening, around 11pm. With storms developing west in Missouri and Arkansas and then moving quickly northeast.

All severe harzards are possible in storms today, however northern Illniois and southern Wisconsin has the highest potential for large hail, strong winds, and heavy rain. We can't rule out the threat of a tornado this evening, however it is not that primary threat.

The threat for strong tornadoes lies in southern and central Illinois, where the Storm Prediction Center has upgraded that area to a Moderate Risk for severe storms. This is where the highest potential is for severe level hail, damaging winds, strong tornadoes, and heavy rain. Along with areas in the enhanced risk, though not as highly favored.

Storms will develop today near an area of low pressure and its warm front. Some storm development will be favored near the front, so we want to watch this area and how far north it travels. The farther north it goes, the farther north the severe threat goes as well.

With this type of set up you have winds changing directions quickly with respect to height, along with increasing moisture and instability. Which are currently forecast at late-spring like levels, even though we are currently at the last day of February.

Southerly winds today will usher in dew points into the mid 50's and even close to the low 60's through the afternoon. This will begin to generate instability, along with northward advecting warm air. One limiting factor though could be thick cloud cover over the region, this can typically limit the amount of instability that can be generated.

It's best to have a severe weather preparation plan, and while it is February severe weather can still happen. You also want to be mindful this evening, with storms also possible after dark tonight. Have a way to receive and warnings should they be issued! 

Again we'll want to watch for strong to potentially severe thunderstorms in the late afternoon and evening, capable
of producing large hail, heavy rain, strong winds, with an isolated tornado possible.

Monday, February 27, 2017

Another Round of Soggy Weather Arrives Tuesday

It's been the trend this February, but we're in store for more mild temperatures Monday and Tuesday, with highs in the 50's to near 60° both Monday and Tuesday. With the warmth comes a chance for more rain by this evening.
In the previous post we discussed the severe threat with a couple of rounds of thunderstorms set to arrive Monday night into Tuesday and then again late Tuesday afternoon into the evening. Despite the severe threat being low, storms still have the potential to drop a good amount of rain.

Right now the Weather Prediction Center shows about a half of an inch to 1.25" of rain possible through Wednesday morning before colder air arrives behind a departing low. With temperatures dropping into the 30's bring in scattered but light snow chances Wednesday and Thursday.

Sunday, February 26, 2017

Severe storms south Tuesday afternoon and evening

We've definitely had more rain this winter season than snowfall, and the upcoming week features another chance for more rain in northern Illinois and southern Wisconsin.

A strong low pressure system will develop late Monday out west, pushing a warm front towards the Stateline Monday night.  Showers and even a few thunderstorms will possible Tuesday morning followed by a brief break in the weather by the afternoon.  If the warm front makes it this far north, temperatures could reach near 60 degrees Tuesday.  But this could also help fuel additional thunderstorms during the late afternoon and evening.  While most of the stronger storms will remain south, it's possible that storms with strong wind gusts could occur late Tuesday night. 

Colder air gets wrapped in following the passage of the low Wednesday.  If enough cold air is present with still a decent amount of moisture, there could be some accumulating snowfall by Wednesday night. 

Big snowstorms can happen in March and April

This winter has been really hard for anyone who depends on snow for their business or is just a snow lover.  It's been since before Christmas where we had over an inch of snow on the ground - over two months!  Only 0.7" of snow fell during the month January and February only a trace since the light snow fell this past Friday night and Saturday.  And even that didn't amount to much with only 0.2" officially being recorded at the airport.  According to the Chicago National Weather Service, Rockford has never gone the entire month of January and February with no measurable snow on the ground since records began back in 1905.  In order to be considered measurable snow on the ground, the total has to be an inch or higher.  Both January and February fell below that number!

Even though Meteorological Winter ends February 28th and Meteorological Spring begins March 1st, big snows have still occurred during the months of March and April.  On average, six inches of snow does fall during a typical March and April period, although it varies considerably from year to year.  So I guess there is some hope for those who still want some snow.  And it's possible some might fall following a strong low pressure system this Wednesday.  Stay tuned!

Saturday, February 25, 2017

Warm Temperatures Make a Comeback

We had to deal with the snow last night along with temperatures that were in the 20s, but luckily that doesn't last for much longer.  The warm temperatures will make a return starting tomorrow where we will be in the upper 40s!  We had a ridge of high pressure to the southwest of us earlier today, which brought colder winds into our area and kept us in the 20s today.  However, that same ridge is now to the southeast of us, which means it will start to bring warm, humid air from the south into our area.  This will warm our temperatures into the mid 40s for tomorrow.  On Monday, a low will move into the southern plains to accompany the ridge of high pressure to the southeast.  This will channel even more warm air into our area and is the reason why we will see temperatures continue climb even higher as we move into Tuesday.

Friday, February 24, 2017

Snow is Out...And the 40°s are in

The snow continues to move in towards our area while light drizzle has persisted.  The snow is expected to start around 9pm and will continue into tomorrow morning until about 6am.  Areas south of the stateline are expecting up to an inch, while areas north of the stateline could see as much as 1.5".  Winter weather advisories have been put out for Green, Rock, and Walworth counties as they are above the stateline.  After the snow moves out early tomorrow morning a ridge of high pressure will move into our area.  The ridge will keep our skies clear for the rest of Saturday and then bring us some southerly winds on Sunday, where temperatures will warm up into the mid 40s.  We stay in the mid 40s for Monday with partly cloudy skies, but will cloud up in the overnight as light rain will move through early Tuesday morning.  After Tuesday, we will have temperatures in the 40s with mostly sunny skies for the rest of the week.

Thursday, February 23, 2017

Stormy weather moving into the Stateline Thursday night

Nickeled sized hail reported SW of Franklin Grove Thursday evening.
Photo: Joan Bereman

(11:17:05 PM) nwsbot: Local Storm Report by NWS LOT: 3 NW Amboy [Lee Co, IL] trained spotter reports HAIL of quarter size (M1.00 INCH) at 11:06 PM CST -- nickel to quarter sized hail. hail completely covering the ground.

Update: Severe Thunderstorm Warning for Lee County has been canceled.  The storm has fallen below severe limits, but pea to penny sized hail still possible.

A Severe Thunderstorm Warning has been issued for Lee County until 11:30pm.  A severe thunderstorm was located southwest of Amboy and moving northeast around 55mph.  Quarter sized hail is going to be the biggest threat with this storm.  Cities impacted will be Dixon, Amboy, Franklin Grove and Ashton.

Wintry weather returns to the Stateline

From six straight days of record warmth to the potential for accumulating snow, we are riding quite the weather roller coaster ride this week.

Snow has already started over the central Plains and Upper Midwest with rain falling just to the east.  Low pressure moving over southern Kansas has taken a slight shift to the south with recent forecast model runs.  This will cause the wintry weather that was initially thought to be a little further north of the immediate Sateline to shift south as well.  And we can see how that shift in the storm track has affected the southward issuance of winter weather headlines.  Winter Weather Advisories have been issued just north of Janesville and Monroe and over northeast Iowa, while Blizzard Warnings and Winter Storm Warnings have been issued for parts of Iowa, Minnesota and western Wisconsin.

The southward shift in the storm track does have an impact on our weather here in northern Illinois and southern Wisconsin.  The first will be a cooler high temperature for Friday afternoon.  Earlier in the week it looked like a warm front would be able to make it this far north, pushing temperatures close to 60 degrees as winds shifted around to the south.  As of Thursday morning, the warm front stops just shy of I-88 keeping temperatures north of the front in the upper 30's and mid 40's, but south of the front in the 50's and 60's.

Strong to severe thunderstorms are likely east of the low pressure system and south of the warm front.  This places far eastern Illinois, all of Indiana and western Ohio in line for stronger thunderstorms late Friday into very early Saturday morning.  For us, colder air gets wrapped in behind the passing low after 6pm/7pm Friday evening.  A transition from light rain to a rain/snow mix will occur first, and then a switch to all snow will occur late Friday night into Saturday morning.

The biggest impact to the forecast, aside from the cool down for Friday, will be the potential for light accumulating snow Friday night.  It looks more likely that northern Illinois and southern Wisconsin could receive close to an inch of snowfall, with isolated totals nearing two inches over southern Wisconsin and far NW Illinois.

Winds will also be on the increase through Saturday morning, gusting close to 35 mph.  The light snow will be coming to an end from west to east mid-morning Saturday with clearing skies expected by Saturday evening.

Our weather pattern remains pretty active going into next week with a chance for precipitation nearly every other day.  Unfortunately it doesn't look like any 60's or 70's will accompany that forecast.

Winter Returns with a Bang

Across the Plains and Midwest the past several days, record breaking temperatures have been recorded. Unfortunately, the spring-like weather we've had won't last, especially across Nebraska, South Dakota, Iowa, and Wisconsin.

Winter Weather headlines in place now across the center of the country with Blizzard Watches and Warnings, and Winter Storm Watches and Warnings ahead of a strong low pressure system. These warnings will be for heavy snow in Nebraska today through Friday, with some totals in Nebraska up to 18 inches!

For the Iowa area, the blizzard  warning is for extreme winter weather tonight into Friday. In northwest Iowa, up to a foot of snow is possible with heavy snow tonight through Friday evening. With winds in northwest Iowa gusting over 40 mph, visibility will be extremely low. Travel across the plains and portions of Iowa and Wisconsin will be hazardous to treacherous the next couple of days.

Here's a look at some of the forecast snow totals from the National Weather Service in Sioux Falls, SD.

Wednesday, February 22, 2017

All time record high for winter tied Wednesday afternoon

The impressive stretch of warmth is about to end, although temperatures will still remain above average through the end of the week.

Wednesday's high reached 70 degrees in Rockford!  This once again broke the all-time daily record high temperature for the sixth straight day AND tied the all-time record high for February and Meteorological Winter (December - Friday).  That previous record was also 70 degrees set back in February of 2000.  To say this warmth has been exceptional would be an understatement. 

Unfortunately, the trend will favor more of a cooler pattern by the weekend following a strong low pressure system.  Temperatures will fall nearly 50 degrees by Saturday night!

From Soggy to Snowy?

After almost 6 straight days of record breaking high temperatures, the weather will go from May to February once again. A deep area of low pressure will track across the plains and move into northeast Iowa by Friday.

Ahead of the low a warm front will be positioned in central Illinois, with showers and storms developing ahead of it Thursday evening. These will be general storms in the evening and overnight through Friday morning. The low will then move overhead Friday morning with the systems dry slot bringing a break from the rain midday. But, as the warm front lifts north more storms will be possible Friday afternoon. We'll have a southwest wind going into Friday which will draw in a lot of moisture from the south, which will lead to the potential for a lot of rain Thursday into Friday.

With a couple rounds of storms and rain, totals through Friday could add up to closer to 2" in northeastern Illinois and along the Wisconsin border. Thursday's rain could bring about one inch, and then we could add another inch by Friday afternoon.

By Friday evening the low pressure system will be situated northeast of the area, but will pull in colder air by Saturday. This will allow for a transition to a rain/snow mix to then lighter snow by Saturday morning.  Right now, accumulations don't look to be high, but we'll keep you posted as we get closer. Nonetheless, it will be a shock to the system by Saturday!

Tuesday, February 21, 2017

Elevated Fire Danger by Wednesday

If you stepped outside yesterday, you definitely felt a difference in the air mass. Not only was it very warm for February standards with a high temperature in Rockford of 69°, it was also more humid with dew points climbing into the 50's.

A weak cold front passing Tuesday morning will begin to usher in drier air as winds turn to the west. Another system passes north of the area on Wednesday and winds turn to the southwest. With a tight pressure gradient over the area with that passing system, winds will strengthen and will gust up to 25mph. With dry air advecting in, relative humidity will drop below 30%. So with a dry and warm air mass in place, and then gusty winds on top of that, there will be an elevated fire danger through the afternoon.

You'll want to limit any burning through Wednesday evening and into early Thursday.

Monday, February 20, 2017

Strong storms possible Friday afternoon

A strong low pressure system will bring us back to reality by the weekend.  A weak frontal boundary will pass through northern Illinois late Wednesday night and Thursday morning.  This front will stall south of Rockford Thursday and then be pulled back north as a warm front Thursday night into Friday.

Showers and even a few elevated thunderstorms will be possible Thursday night.  Low pressure is forecast to strengthen and move along the warm front Friday morning.  As it strengthens, instability will be drawn northward during the day Friday.  And depending upon where the warm front ends up will determine where strong, to possibly severe, storms will develop.

There will likely be a big temperature difference from north to south of the warm front.  North of the front temperatures will warm only into the 30's and 40's, while south of the front temperatures will warm into the 50's and 60's.

North of the low heavy snow will fall over the upper Midwest.  Colder air will get wrapped in behind the low late Friday night and Saturday morning.  This could cause a few snowflakes to fly during the morning Saturday.  Highs through the weekend will be in the 30's.

As for the severe potential Friday, there is definitely a possibility that strong to severe storms could occur.  Especially considering how warm it has been this past week.  With a strong jet stream moving in overhead Friday, we do have to be alert for the potential for gusty thunderstorms Friday evening.

Fourth straight day of record breaking warmth

I think by now we've become used to this warmth and many of us may be getting spring fever.  But as the old saying goes, 'All good things must come to an end' and that end appears to be at the end of the week.  More on that cool down can be found here, but this post will focus on just how significantly warm these past four days have been.

Another record high temperature was achieved in Rockford Monday.  The high officially made it up to 69 degrees, breaking the previous record high of 61 degrees set back in 1983.  Not only did we break the daily record high, it was also the fourth straight day where the high temperature exceeded 60 degrees.  This has never occurred before during meteorological winter, or winter alone!  So you could say you were a part of history Monday afternoon.  The past four days have also gone down in the record books as all-time February highs and all-time winter highs!

There are a few showers ahead of a cold front that will move through Monday night and very early Tuesday morning.  Following the front temperatures will warm into the 60's, with highs possibly reaching the low 70's on Wednesday.  Both days the forecast high is expected to exceed the record high for that day.  If that occurs, this winter warm spell with have provided us with six straight days of record breaking warmth!

Sunday, February 19, 2017

Record warmth continues, but a pattern change looms by the end of the week

Sunday's high of 67 degrees made it the third day in a row with record breaking warmth!  Incredible considering our highs should be in the middle 30's.  Several more unseasonably warm afternoons are in store before our pattern changes to more of a late winter pattern.

The reason behind the significant warm up has to do a lot with what's happening out west.  A very strong and active jet stream the past several days has brought significant amounts of rain to California.  So much that flash flooding, mud slides and sink holes have become a big problem.  As the jet stream remains very active out west, a blocking ridge of high pressure has settled over the middle of the country.  Numerous record highs were achieved over the southern Plains and Ozarks late last week.  As surface winds shifted around to the southwest in northern Illinois and southern Wisconsin Friday, it pulled the extreme warmth northeast.  With a very little changing pattern through the weekend, the warmth continued Saturday and Sunday.  The lack of snow cover has also played a role in the unseasonable warmth, along with the fact that since January 19th, 90% of the days have been warmer than normal, per the Chicago National Weather Service!

Another strong low out over the Rockies will move into the Upper Midwest Monday evening.  This low is currently bringing severe weather up through central and northern Texas and Oklahoma Sunday evening.  As the low moves closer Monday, rain will begin to fall late Monday evening and night.  The cold front associated with the low will have originated from the Pacific, and not the north.  This means there is very little cold air following the front, pushing temperatures Tuesday back into the low 60's.

Another, but weaker, low passes to the northwest Wednesday afternoon pushing highs back into the upper 60's!  By the end of the week, the wave train of low pressure systems out west finally break down the strong central U.S. ridge.  A fairly strong low pressure system will develop over the middle of the country Thursday and Friday.  And depending upon the track of the low, we could very well end up with thunderstorms Friday afternoon before temperatures drop back below normal for the upcoming weekend. Any snow associated with this low will remain to the north.  A further break down of the jet stream looks to occur by the beginning of March, possibly bringing the chance for snow to kick off the beginning of the month.

Saturday, February 18, 2017

A Record Breaking Weekend

We got to break another record today as our high temperature peaked at 68°, which is 5° than the previous record of 63° set back in 1930.  We have done this 2 days in a row now and we could possibly do it again for a third day in a row!  The ridge of high pressure over our area has continued to strengthen the past couple of days, which is why temperatures have gotten much higher.

 The reason that we've had this massive warmup is due to the placement of these high and low pressure systems.  On Friday, we had a high pressure system to the southeast and a low pressure system to the northwest.  High pressure systems have winds that rotate clockwise around them, while low pressure systems have winds that rotate counterclockwise around them.  So once these systems are lined up as they are in the photo, you get a massive channeling of warm air from the south, which has been the main reason for our temperature warmup.  However, the reason for our clear and sunny skies can be attributed to the high pressure system to the southeast in the photo.  The high has helped to push the low up north, which is why the clouds have continued to move north of us and miss our area.

This trend continues into next week, but the low pressure system moving in from the west will bring us some rain on Monday night.  A weak warm front will move through Monday morning increasing our cloud cover, but a weak cold front behind it is what will bring the light accumulation of rain Monday night.  Rain is also expected for Thursday afternoon, as another low moves in through our area.  There will be a little more rain than what we'll have on Monday, but overall the accumulation will still be light.  The rain will filter into the early hours of Friday morning, before clearing out for the afternoon where we will have cloudy skies.  The spring-like weather will disappear next Saturday as northwesterly winds move into our area and bring us back down into the 20s, but the majority of next week stays warm with temperatures in the upper 50s to low 60s!

Friday, February 17, 2017

Spring-Like Weather

It was an amazing day outside as we had lots of sunshine and temperatures in the low 60s.  We ended up breaking our old record of 58 set back in 1981 as we peaked at 66 today.  Although we technically won't break the record on Monday, we will break the record temperatures during the weekend and on Tuesday as well.  The sunny and warm weather we had today will continue on for the weekend, but will be stopped briefly as a low pressure system brings a warm front through our area on Monday.  The warm front will begin to increase the cloud cover in the early hours of the morning, and will bring some rain once we get into the afternoon.  The rainfall will be medium, but the accumulation will still be light.  Another low will move through Thursday, but it will only bring drizzle on Thursday late at night.  Other than Monday and late Thursday night, the skies will continue to stay mostly clear and the temperatures will remain in the upper 50s and low 60s for the week.

Consecutive 60° Stretches in February

Well...it hasn't been much of a secret...but in case you haven't heard we have multiple 60° days in the forecast!

Friday, Sunday, Monday, and Tuesday are all forecast to reach 60° or higher. Saturday is a day to watch, as temperatures will be close to the 60° mark. A weak cool front will sink south on Saturday morning and this will direct surface winds to the northwest. The northwest wind will be light, but could potentially drop temperatures a degree or too. If we were to reach 60° on Saturday then there would be a stretch of 5 days of 60° in February which we have never seen on record! The longest stretches we've seen have been 3 days, which has only happened twice, and two days which also happened twice in recorded history data.

No matter what though, the 7-day forecast looks fantastic!

Thursday, February 16, 2017

Brightness of Venus peaks next couple of nights

Earlier this week I had a viewer ask me what the bright star was in the west sky.  She said it was brighter and larger than normal.  That star was the planet Venus.

According to Accuweather.com, only a quarter of the planet was illuminated earlier this week.  However, Venus is moving closer to the Earth each evening allowing more and more of the surface of the planet to become illuminated.  Eventually it will pass between the Earth and the sun in March, becoming only a very thin crescent during that time.

We've got several clear and warm nights heading into the weekend.  Perfect for viewing the evening sky.  Enjoy!

Thursday evening sunset photos

Woody Mott
Wanda Hoffman Orlick
Tracy Tadlock
Terri Brenz
Susan Haas
North of Shirland
Phyllis Broenneke
Pauline M.

Sunset pictures continued

Nancy DeLucia Ferrin
Mary Anderson
Mark Meyers
Marian Strang
Lynne Nelson

Sunset pictures continued

Laura Harris Stites
Katy Ramsey
Kathy Lapp
Jenni Listerud
Loves Park
Janet Phelps
Delavan, WI