Thursday, May 30, 2019

U.S. Sets Record for Tornado Days

The U.S. set a record last night for the most consecutive days with a tornado with 14 days! Between May 16 and May 29 there were 226 total tornadoes reported across the country, at least 46 of those were strong tornadoes meaning EF-2 or greater. The strongest of these tornadoes was the Linwood, KS tornado that took place on Tuesday the 28th. This tornado was rated an EF-4 with wind speeds up to 170 mph. Luckily, no fatalities resulted from this particular tornado.

Wednesday, May 29, 2019

Storm Coverage Increases Wednesday Night

Heavy rain producing thunderstorms are expected once again Wednesday night with rainfall totals possibly nearing one inch by Thursday morning.

Skies are quiet now but severe storms, with several tornado warnings, have been ongoing across eastern Iowa Wednesday evening.  I do not anticipate those storms to impact northern Illinois, however, storm coverage will increase over west-central Illinois between 9pm and 10pm and will move into northern Illinois between 11pm and 4am Thursday morning.

More of the focus for severe weather will remain to the west and southwest through the night, but a few stronger storms can't be ruled out with wind and hail being the primary concerns.  Heavy rain will be our biggest threat overnight with another inch of rain possibly falling by Thursday morning.

Scattered showers will move out by morning following the passage of low pressure mid-morning Thursday.  Following the low a cold front will move through during the afternoon and evening.  This will bring another chance for showers and thunderstorms before dry air moves in Thursday night.  This will lead to a mostly dry, and warm, day on Friday.

2019 Setting Records for Rainfall

The month of May has been one of the wettest ever in Rockford and 2019 is on track to be one of the wettest years on record.

So far, Rockford has experienced 7.48 inches of rain in the month of May alone. This currently stands as the fourth rainiest May ever. Showers and thunderstorms Wednesday night are expected to bump May of 2019 into the number 3 spot.

The year as a whole has seen 20.13 inches of rain in Rockford which is the third wettest year to date through May 29th since recordings began in 1905. With nearly an inch expected Wednesday night into Thursday, 2019 should become the second wettest year ever through May 30th.

Tuesday, May 28, 2019

Flash Flood Watch Issued

A Flash Flood Watch has been issued for Jo Daviess, Stephenson, Carroll, Whiteside, Ogle, Lee and DeKalb counties until Wednesday morning.

Heavy recent rainfall combined with the heavy rain expected Tuesday night could lead to localized flash flooding over parts of northern Illinois.  Incoming rain and thunderstorms Tuesday evening have produced anywhere from a tenth of an inch of rain in southern Wisconsin, to over half an inch in Freeport. 

While the rain has lightened up briefly Tuesday evening, moderate rain showers in eastern Iowa will continue to move east reaching northern Illinois between 10pm and 10:30pm.  Most of the rain should be out by 1am/2am Wednesday morning.

Severe thunderstorms have been ongoing further downstate will remain well south of the area tonight.  Flash Flood Warnings extend all the way from west-central Illinois back down through Kansas!

Monday, May 27, 2019

More Severe Weather Expected Tuesday

Similar to Monday's setup, a strong warm front moving into the Stateline region will bring more showers and thunderstorms late Tuesday.
As a trough in the jet stream continues to deepen in the Southwest U.S., a new low pressure system is starting to strengthen and will make its way across the Central Plains tomorrow. Its warm front will extend eastward from its center and influence weather here in the Rockford area. Humidity is expected to be extremely high tomorrow evening and as this warm front makes its way across the area, it's going to rapidly lift this warm, moist air into the atmosphere triggering strong to severe thunderstorms.
The primary concerns with these thunderstorms are going to be strong winds and heavy downpours, although hail is a possibility with these storms as well, especially along the leading edge of this system. The rain should begin to come through a little after 8PM and stick around through about 2AM.

May Continues to Bring Rain and Flood Risks

As the month of May continues to dump rainfall on Northern Illinois, many of the rivers in the area are at a high risk of flooding...once again.

So far in May, we've had only 6 days of 26 without experiencing rain in Rockford. This puts us at a total of 6.29 inches for the month through May 26th. This is exactly 3 inches above the normal monthly rainfall to date of 3.29 inches. Note that these totals don't even include the heavy downpours we experienced earlier this morning and afternoon (the 27th).

The storms that we experienced today have triggered a handful of flood warnings and flood advisories for many of the major rivers throughout Northern Illinois. Some of these rivers include the Rock, Pecatonica, Fox, Illinois, and Mississippi Rivers. More rain and thunderstorms are expected tomorrow (the 28th) and will bring these rivers closer to their flood stages.

Severe Threat Ending Monday Night

8:15pm Update: Had a report of a brief tornado touchdown 2 miles southwest of Paw Paw shortly after 4:30pm with a tornado warned storm that moved through southern Lee County earlier this afternoon.

The Tornado Watch that had been issued earlier Monday evening was canceled early for Carroll, Whiteside, Ogle, Lee and DeKalb counties.

Several tornado warnings had been issued for Carroll, Lee, Whiteside and Ogle counties Monday afternoon with reports of a rotating wall cloud and funnel cloud with the supercell storm that moved through Whiteside and Lee counties.  There have also been reports of tree and limb damage in Amboy and Sublette as the storm moved through, but so far no reports of any tornadoes touching down.

Isolated showers and thunderstorms possible through the rest of the evening, but the severe threat has ended. 

Tornado Watch Issued for Parts of Northern Illinois until 9pm Monday

A Tornado Watch has been issued for Carroll, Whiteside, Ogle, Lee and DeKalb counties until 9pm.
Thunderstorms have quickly developed over northwest Illinois Monday afternoon following rainfall earlier in the day.  There was a severe thunderstorm warning for southeast DeKalb County earlier but that storm has moved further towards Chicago.

Tornado Warnings have been ongoing over southeast Iowa near a warm front that is draped from northeast Iowa, through the Quad Cities and into central Illinois.  Thunderstorms have developed north of the warm front in northwest Illinois and are currently moving to the northeast.  These storms do not have any warnings attached to them, but will likely bring heavy rainfall as they move through. 
Timeline for storms to move through northern Illinois looks to be between now and 6pm/7pm.  Isolated showers/storms expected Monday night into Tuesday morning.

Stormy Memorial Day Ahead

First of all, Happy Memorial Day to everybody. Today is normally a day where many of you spend a lot of time outdoors. It was a beautiful start to the holiday with comfortable temperatures and plenty of sunshine this morning. However, strong to severe storms will make for a stormy end to this Memorial Day. We currently have the first round of thunderstorms making it's way through. You can expect heavy downpours and frequent lightning with this round. The second round that arrives during the mid-afternoon is what we are concerned about.

That is all because of a lifting warm front. The cold front that came through yesterday stalled out over central Illinois and then became a warm front. As we progress into the afternoon, this warm front is going to lift northward close to or over our region. Behind the warm front is the area of the low pressure system known as the "warm sector".

This is defined as the area between the cold front and the warm front of the low. This is where the wind flow will be out of the south/southwest and where the transport of moisture from the Gulf of Mexico happens. It is in the warm sector where the storm potential is at its greatest because of how fast the atmosphere is known to recover or recharge.

At this time, the Storm Prediction Center has all of our northern Illinois counties under an Enhanced Risk (a 3 out of 5) for severe potential. This means that numerous severe thunderstorms are possible, with any one of them capable of producing all severe weather hazards For today's set up, thunderstorms (some strong to severe) are expected to develop in eastern Iowa and northwest Illinois around 2 PM and track into an environment favorable for tornadoes, damaging winds, and large hail.

Here is the 8 AM tornado probabilities from the Storm Prediction Center. The 10% hatched tornado contour (yellow shaded area with black lines) includes a majority of our northern Illinois counties including all of Carroll, Ogle, Lee, Dekalb, and Whiteside county. If you know someone inside the black outlined area, make sure that they also have a plan ready to go and know the forecast.

While celebrating Memorial Day today, it is also important that you are weather ready. Have somewhere safe to take cover in case a tornado warning is issued. Please do not rely on outdoor tornado sirens to alert you of tornado warnings. They are only designed to be heard if you’re outdoors.  It is also important to have multiple ways to receive watches and warning in case severe weather moves into your area.

Sunday, May 26, 2019

Climate Change Linked to More Frequent Heavy Rainfall Events

The recent wet pattern across much of the Midwest, and country, has many wondering when, if at all, we'll get a break from the very active pattern.

Unfortunately it doesn't look like the pattern will change anytime soon with more rain, and possibly severe weather, for the last week of May.  High pressure anchored over the southeast has placed the most active part of the jet stream across the southern and central Plains, right into the Midwest and Great Lakes.  Numerous days of severe weather over the Plains and heavy downpours in the Midwest are a result of this type of pattern as it pulls in quite a bit of Gulf moisture.  But it's not just this short-term pattern that's been causing the more heavy rain events.

According to Climate Central the average annual precipitation from 1950 to 2018 has gone up in 90% of the states analyzed, with the eight largest increases having all come from the Northeast and Midwest.  Heavy rainfall is a sign of climate change.  For every one degree Fahrenheit increase in temperature, the atmosphere is able to hold four percent more water vapor leading to more frequent and heavy downpours.

Since 1950 the annual average precipitation has increased in Illinois between four to six inches, not only having an impact on the amount of rain that occurs, but also increasing the overall streamflow within some of the local rivers.  According to the USGS the average annual streamflow into the Rock River at Rockton - which is measured often by the USGS - has increased 80% since the 1950s!  This means the river is running higher than it has in a very long time.  And a higher than normal river level will lead to more frequent river flooding with higher than normal rainfall events.

Unfortunately this could become more of the norm as our climate continues to warm.  So far precipitation to date in Rockford has added up to 18.94 inches, making it the 5th wettest year to date on record.  Within the top 10 wettest years to date on record, three of those years fall within this decade! 

Memorial Day Forecast - Could Get a little Stormy

The chance for rain and thunderstorms will increase as early as mid-morning Memorial Day, with the potential for a few stronger thunderstorms Monday afternoon and evening.

A cold front passed through northern Illinois and southern Wisconsin late Saturday night bringing a few stronger thunderstorms south of the immediate Rockford area.  That front will lift back north as a warm front during the day Monday but may be tempered a little with showers and thunderstorms during the morning.  Severe thunderstorms over the Plains Sunday will form into a complex of storms, shifting east Sunday night into Monday morning, and moving across the Stateline mid to late morning.

The first round of rain will move east early afternoon with possibly a second round of storms developing as the warm front lifts north into northern Illinois.  It's this second round of storms that could turn strong to severe with the potential for damaging winds, hail and even isolated tornadoes - especially along the warm front.

The storm threat will decrease Monday night into Tuesday but then pick back up Tuesday evening and night with thunderstorms and heavy rainfall going into Wednesday morning.  If you're planning on attending some of the Memorial Day parades that will be taking place Monday, be sure to keep an eye on the radar.

Friday, May 24, 2019

Tornado Warning near Iowa/Ilinois Stateline

A tornado warning has just been issued just south of Dubuque, IA until 9PM. This storm is moving northeast at 20mph and should make its way over the northwest portion of Jo Daviess county shortly. Inside the scope is velocity radar which has the ability to detect rotation within thunderstorms. The little splotch of green surrounded by red within the velocity radar along Route 151 is the area of concern for the moment, these differing velocity signatures is an indication of rotation within the thunderstorm. Check back a little later as we will continue to update you on this severe weather threat.

Tornado Watch for Northwest IL

A tornado watch has been issued for much of northwest and west-central Illinois until 12:00 midnight. The watch, highlighted in yellow, includes the following counties in the area: Carroll, Jo Daviess, Lee, Ogle, Stephenson, Whiteside, and Winnebago.
There is currently a tornado warning just east of Iowa City, IA in effect until 7:45PM. This system is making its way into the Rockford area. Thunderstorms should begin hitting Rockford after 9PM. Jo Daviess, Carroll, and Whiteside counties should see thunderstorm activity within the next hour (8:20PM).
Strong to severe thunderstorms are going to be developing along a strong warm front currently situated through eastern Iowa and central Illinois. As the night goes on, the warm front will advance northward shifting the threat for severe weather to the northern half of Illinois.
We will continue to post updates on this developing storm threat but in the mean time please stay safe and avoid travel until this system passes if you can.

More Severe Weather Tonight?

As if we hadn't had enough rain this spring - 7.1 inches above normal for the year, 2.9" above normal just for the month of May - we really need to dry things out. 

Unfortunately for this Memorial Day weekend, it doesn't look like that will happen.  On top of getting more rain (not a complete rain out!), we could see more severe weather in our area.  We are under a Slight Risk area for severe weather this evening with the greatest risks being hail, high winds and heavy rain (we could see 1-2" locally under some of the storms).  There is also a slight chance for tornadoes.

The storms should end by about 1 am and then we will see clearing.  Saturday looks much better right now with only isolated shower and thunderstorm chances - most of the day should be nice.  Sunday morning we could see another cluster of storms and then some clearing.  So keep your umbrella nearby - but enjoy the holiday weekend!  

Thursday, May 23, 2019

Rockford in Top 10 for Wettest Years to Date

So far, Rockford has experienced its 8th wettest year to date through May 22 and the rain is certainly not over yet!

With this strong jet stream overhead that's expected to deepen over the next few days, we are expecting the chance for showers and thunderstorms every day through the middle of next week including some potentially severe thunderstorms late Friday evening.

The 17.16 inches of rain we've experienced so far in 2019 is 5.99 inches above normal. The average rainfall through May 22 is 11.17 inches. So far, 4.51 inches of rain have fallen this month alone! Another 2 - 2.5 inches is expected to fall in Rockford over the next 5 days.

Sunny & Dry Today, Slightly Cooler

A beautiful May-like day was followed by another round of heavy rain and thunderstorms last night. Most spots ended up between one-half to three-quarters of an inch in a relatively short amount of time. This now puts us at 17.16" on the year which leaves us well above the average mark of 11.31". Only one year in the past 6 years has accumulated more rain that 2019, and that was in 2017 falling just short of 18".
The cold front that brought all that heavy rain last night pushed through the viewing area this morning. Clouds were quick to clear this morning as dry conditions moved in behind the cold front. Temperatures today will be slightly cooler, with most spots across the Stateline topping out in the mid to upper 70s. We will be seeing sunshine and blue skies throughout the rest of our Thursday. It will be a bit breezy as we head into the afternoon. But otherwise, today is definitely a beautiful day to go and do some outdoor activities. Just make sure you bring the sunscreen.

Now that cold front that passed through this morning will play a key role in the potential for severe weather tomorrow. This frontal boundary will stall out over southern Illinois and then begin to lift back north as a warm front tomorrow afternoon. This will help spark up a few strong to severe thunderstorms as we head into Friday evening.

The Storm Prediction Center in Norman Oklahoma does have our viewing area under a slight risk (category 2 of 5) for severe weather. Thunderstorms tomorrow will have the capability to produce damaging wind gusts, large hail, and also a tornado or two cannot be ruled out. Temperatures tomorrow will be around the same as today, in the mid to upper 70s. With a similar system coming in for our Saturday, the active pattern looks to continue in the beginning of next week. Enjoy the Sunshine today everyone!

Wednesday, May 22, 2019

Strengthening Jet Stream to Bring Rain and Unseasonable Temperatures

A huge dip in the jet stream has brought cold temperatures and sizeable snowfalls to much of the West-Central U.S. and will continue to do so for the next few days.

By Friday, a large ridge will form in the jet stream over the Midwest and will propagate over the Northeast by Saturday. This ridge will pull temperatures up for much of the Southeast and will even contribute to mild temperatures for the Rockford area through Memorial Day weekend.

However, this pattern will also bring strong thunderstorms to much of the Great Plains just about every day through the holiday weekend and it will also provide the threat for showers and thunderstorms through the weekend for Northern Illinois including some potential severe weather late Friday.

Strong to Severe Storms Possible Wednesday Evening

9:10pm Update: Scattered showers/isolated storms continue to move across northern Illinois while severe weather moves through west-central Illinois.  These storms will continue to move east into central Illinois, with the greatest severe weather risk remaining south of I-88 and I-80.

8:10pm Update: Heavy rain, isolated thunder, moving through Ogle County crossing over Highway 72.  This will lift into southern Winnebago County, impacting Rockford within the next 15 minutes.

7:50pm Update: Thunderstorms have become a little more scattered Wednesday evening.  Storms have not reached severe limits just yet but have produced very heavy rain, small hail and even strong wind gusts.

Strong southwest winds Wednesday afternoon brought temperatures area wide into the mid and upper 70s, with a few spots reaching 80 degrees!

Skies have been dry through much of the afternoon but an increasing threat for thunderstorms will occur after 7pm/8pm across much of northern Illinois.  Showers and thunderstorms have quickly developed to the southwest with a Tornado Watch issued for much of west-central Illinois and Missouri.  While I don't anticipate that watch to be extended further northeast into northern Illinois, storm coverage will increase between 7pm and 9pm.

These storms will develop in an environment with increasing instability and moisture later tonight.  Strong to severe storms will be possible between 9pm and Midnight with strong, damaging winds and large hail possible.  The line of storms will move out of the area after 3am Thursday with dry skies Thursday afternoon.

Make sure you have multiple ways to receive watches and warnings should severe weather occur.

May Returns from Vacation

As you were sleeping last night, round 2 moved through the region. This round brought not only heavy rain to the Stateline, but also a lot of lightning. Overall, Rockford received .67" of rain and that just adds on to the wet and chilly May we are having. In total, the Rockford International Airport has recorded 3.77" of rain during the month of May which is just over an inch above average.

The good news is, we are going to have a short break from the rain as we now enter the what is known as the dry slot of the low pressure system. This is the part of the storm system where dry air feeds into the center of circulation. Although we are starting out the day with some lingering cloud cover, clouds will be on the decrease leading a much drier afternoon.

Now only that, a warm front which is draped over Central Illinois this morning will lift northward bringing in much warmer air to the region. In fact, we are jumping from our chilly high of 56° from yesterday to near 80° this afternoon. A huge temperature jump in just 24 hours. But i think it is safe to say that May has returned from it's little vacation.
 Yesterday’s wind will continue to be a part of today’s forecast. This time, instead of those chilly easterly winds, the gusty breezes will be out of the southwest. Which will also help us warm up to much more May-like temperatures today. Winds this afternoon could gust as high as 35 MPH, making travel along east-to-west roads, especially for high profile vehicles and semis.

As we head into the late evening and overnight hours, a cold front will approach the region giving us a chance for scattered thunderstorms. And as of this morning, the Storm Prediction Center in Norman, OK had placed the entire viewing area under a marginal risk (1 out of 5) for severe thunderstorms.  The primary threats with line of storms that moves in around midnight will be gusty winds, and some small sized hail with the stronger thunderstorms.