Wednesday, February 29, 2012

Tornado near Mounds, Illinois

Here are the damage survey results from the tornado that touched-down near Mounds, IL early this morning. This survey was conducted by the NWS office in Paducah, KY:


748 PM CST WED FEB 29 2012







* PEAK WIND..........120 MPH
* PATH LENGTH........26.5 MILES


Wednesday afternoon update

Temperatures across the area are in the upper 40s/low 50s with a pretty brisk southwest wind.  Not too off to the west snow has been falling in Iowa and has caused some problems with visibility.  A Winter Weather Advisory has been issued for northeast Iowa and for Jo Daviess county in far northwest Illinois.  While the snow has been light the strong winds have caused poor visibility, especially along Highway 20.  These snow showers will begin to move east through the afternoon and could create a few visibility concerns for your evening commute.  Winds will remain gusty through the overnight.

It's just a tad windy out....

A Wind Advisory has been issued for all counties in northern Illinois except Winnebago, Boone and McHenry as well as Rock, Green and Walworth counties in southern Wisconsin.

Sustained winds have already reached 25 mph with gusts nearing 40 mph, especially to our west.  Temperatures in Rockford have reached the low 50s but in Galena the temperatures is already beginning to fall.  Look for these winds to continue through the remainder of the day and temperatures to fall back by this afternoon.

Wednesday Morning Weather Update

7:30 am Update:  The fog is beginning to lift this morning and temperatures are rising through the upper 40s and low 50s. 

Further south the quick moving line of thunderstorms has now entered into western Kentucky where several tornado warnings remain.  Unfortunately, there are reports beginning to come in of injuries, one of them involving a small child.  A moderate risk of severe weather has now been issued for Kentucky, Tennessee, far northern Mississippi, Alabama and Georgia.

Overnight rain and embedded thunderstorms have moved east this morning with rainfall totals ranging anywhere between 0.20" and 0.50". 
Dry air is beginning to wrap around the strong low pressure system in northwest Iowa and this has helped to cut-off the rain here but has allowed a line of strong thunderstorms to develop further south.  Initially, this line began in Missouri and has now moved east through Illinois, Indiana, Kentucky and Tennessee were several tornado warnings have been issued.

Closer to home, we'll see some sunshine early this morning as warm air is drawn into northern Illinois and southern Wisconsin.  Temperatures will rise into the low 50s this morning before clouds wrap back in around the low.  Winds will increase from the southwest with gusts as high as 40 mph.  As the clouds move back in there will be a chance for a few light sprinkles/snow showers going into the evening.  Temperatures will also fall into the upper 30s/low 40s by this afternoon.

Tuesday, February 28, 2012

Windy Wendesday

The National Weather Service office out of the Quad Cities has issued a wind advisory for Whiteside county from 9am until 6pm tomorrow. A stong area of low pressure passing from southern Minnesota into Wisconsin on Wednesday will bring strong west/southwest winds to the Stateline area. With the dry slot of this storm system punching through the area around mid-day, some sunshine is expected. This will destabilize the atmosphere enough for stronger, upper-level winds to mix-down to the surface in some areas. Wind gusts of 45 to 50 mph are possible in the advisory area, with 40 to 45 mph gusts across the majority of the Stateline.

Major winter storm across the Upper Midwest

Noon Update:  Reports of light rain and even a little sleet have come in across north-central Illinois as the leading edge of the precipitation begins to move northward.  Look for on/off showers to persist through the remainder of the afternoon.

Winter Storm Warnings and Blizzard Warnings have been issued for what is shaping up to be a fairly sizable winter storm that will impact the Upper Plains and Midwest later today and tonight.  Snowfall totals across northern Wisconsin and central Minnesota could top over a foot!  Already this morning there have been a few light snow showers falling across northern Wisconsin, while a mixture of sleet, rain and freezing rain has been falling in Iowa. 

Late morning and early this afternoon we may have that light mix of sleet and rain as temperatures warm above freezing aloft but remain right at freezing at the surface.  By this evening and overnight, temperatures should have warmed enough at the surface to support all rain through Wednesday morning; with the possibility of a few embedded thunderstorms.  Rainfall totals may approach half an inch in some locations as the heaviest of the rainfall appears to fall around midnight.

Cooler and drier air will wrap in across north-central Iowa by Wednesday morning.  This will cause the rain to change back over to a mixture of rain/sleet/snow west and northwest of Cedar Rapids.  Closer to home, the precipitation should cut-off as that dry air moves into the Great Lakes.  This is what's known as a 'dry-slot'.  Typically within these dry-slots skies may briefly clear and winds tend to increase.  In fact, we could have sustained winds around 25 mph with gusts topping 35-40 mph.  Temperatures will rise into the upper 40s early Wednesday before dropping into the upper 30s by Wednesday afternoon bringing back the chance of light snow by Wednesday night.

Tuesday morning weather update

8:45am: A mixture of sleet and rain has been falling and actually increasing across Iowa this morning.  Freezing rain will likely increase in coverage across northwest Iowa where rates could reach as high as 0.10"/3-hr.  Warm air is moving in just above the surface, however, temperatures at the surface remain close to freezing causing the mixed precipitation.

Things are quiet for the moment but clouds will continue to increase through the morning and afternoon.  Southeast winds will increase ahead of a warm front that will lift through the Plains today.  As this warm front moves closer a brief period of a light mix of rain/sleet/freezing rain may occur before temperatures warm enough to support all rain this evening and tonight.  

The leading edge of the precipitation is just southwest of the Quad Cities where a little sleet has been reported near Muscatine, IA.

Monday, February 27, 2012

Wrapping-Up February with... Thunder?

It's possible that we'll finish February with a few thunderstorms Tuesday night into early Wednesday morning! A strong upper-level jet will swing into the central and southern Plains on Tuesday night, causing a surface low to strengthen to our west. Although a warm front attached to this low will get very close to the area late Tuesday night, I don't think it will clear us. Therefore, any thunderstorms that develop won't have a whole lot of instability to work with. That's why the Storm Prediction Center out of Norman, OK is predicting (see graph above) the more active, severe storms will stay to our south -- in the "warm sector" of the storm.

Active weather the last few days of February

It's amazing to think that after the snowfall early Friday morning, highs Sunday afternoon ranged from the lower 40s all the way to the mid 50s!  High pressure will help keep skies partly cloudy this afternoon but it won't be quite as warm as it was Sunday.  Look for temperatures today to reach the middle 30s. 
Low pressure currently off the southwest shores of California will lift northeast out of the central Plains Tuesday afternoon.  While we'll remain on the 'mild' side of the storm, blizzard like conditions will be felt across the northern Plains as Blizzard Watches and Winter Storm Watches extend from central Wisconsin back west through North and South Dakota.

Winds will increase from the southeast Tuesday with temperatures reaching the upper 30s/low 40s.  As warm air initially begins to move in a light mix of rain/snow/sleet remain possible early Tuesday before changing to all rain Tuesday afternoon and especially in the evening.  As the warm front moves closer Tuesday night, a few rumbles of thunder will be possible.  In fact, temperatures will likely rise overnight Tuesday into Wednesday morning.  There is some indication that a little dry air will wrap around the low Wednesday which may cut-off some of the precipitation Wednesday morning.  By Wednesday afternoon the cold front will have passed so temperatures will fall back into upper 30s.  A light rain/snow mix remain possible Wednesday night. 

Sunday, February 26, 2012

An Active Weather Pattern This Coming Week...

A strong area of low pressure is located on the shore of Lake Superior near Bayfield Wisconsin this evening. The relatively tight pressure gradient around that low was responsible in part for the nice warm up in temperatures on Sunday afternoon. Strong southerly winds to the south of the low blew across northern Illinois eating up the recent snow cover, and warmed temperatures to 47 degrees after an early morning low of 13 degrees. In fact, areas to the south and west of Rockford, where there was very little snow or none at all, saw temperature rises into the 50's. Sterling reached 54 degrees, and Galena touched on 51 degrees.  A cold front has pushed through most of northern Illinois by 11 pm.   Moisture is very limited, there was not any precipitation with the passage of the front. There will be a few clouds overnight and Monday morning, but it is expected to be mostly sunny on Monday with high pressure over the northern plains switching the winds to northwesterly.   It will be colder on Monday with a high in the middle 30's.  It will start off mostly clear on Monday night, but it will become mostly cloudy overnight as the high pressure ridge shifts across the area, and a weather system works itself through the Rocky mountains.  It will be cloudy on Tuesday, and winds will be southeasterly.  It appears as if precipitation will hold off untill late morning, or perhaps even into the afternoon.  The sooner it starts, the more likelihood that there could be some snow mixed in with rain.  If it holds off until afternoon, it will be rain with temperatures rising into the upper 30's.  By 6 pm on Tuesday evening an intense low pressure storm center will be over Nebraska.  A warm front will stretch from Omaha to Paducah Kentucky.  With plenty of Gulf moisture surging northward over the front across the Stateline, and fairly strong instability, there may even be some thunderstorms in the evening.  In any case, it will be a rainy night across northern Illinois.  The low temperature will be in the middle 30's.  The strong low will be occluded out over Iowa by early Wednesday morning, and a dry slot will work its's way across northern Illinois early in the morning.    The low will continue to work it's way east across the area on Wednesday, and wrap around precipitation will develop.  With colder air aloft some rain and snow showers are expected.  There could be a minor accumulation of snow, but nothing significant is expected over northern Illinois.  On Thursday a weak ridge of high pressure will make for partly cloudy skies with afternoon temperatures in the upper 30's.  The next Pacific system to affect the area will cause mostly cloudy skies of Friday.  Temperatures will reach the low 40's, so any preciptiation that falls will be in the form of rain.  Colder air will follow in behind the departing system.  It will remain mostly cloudy on Friday with a chance of some flurries or snow showers possible.

Saturday, February 25, 2012

Nice Warm up on Sunday!

Canadian high pressure still dominates Stateline weather tonight, but it is beginning to shift off to the east .  A light southerly wind has developed, but with mostly clear skies early tonight, and fresh snow cover,  good radiational cooling is taking place, and some spots have already dropped into the single digits as of 9:55 pm.  The overnight low in the Rockford area shound be around 10 above with slowly rising temperatures late as a south to southeast wind picks up to 10 to 15 mph  before daybreak.  Winds will already be brisk by 8 am on Sunday gusteing 20 to 30 mph by 8 am.  The strong winds will last through the early to mid afternoon.  High temperatures will rise into the low 40's melting some of the snow the recently fell.  It appears as if all of the precipitation with this system will fall across northern Minnesota, extreme northern Minnesota, and the upper peninsula of Michigan.  A dry cold front will pass across northern Illinois during the Sunday evening supper hour.   High pressure will take control of area weather on Monday.  It will be sunny and colder with a high in the middle 30's.  High pressure will shift off to the east early Tuesday allowing a significant weather system over the plains to shift eastward toward the Stateline. Gulf of Mexico moisture will move in with the next system.  Skies will quickly cloud over on Tuesday morning and there could be some rain or snow.  With warmer temperatures during the afternoon precipitation will change over to rain.  It will be breezy, and there could even be some thuderstorms on Tuesday night.  The low will occlude out over Iowa on Wednesday and begin to weaken as it moves slowly across the midwest on Wednesday and Wednesday night allowing rain and snow showers to continue off and on ending as snow showers on Wednesday night as colder air follows in behind the departing low pressure system.  Weak high pressure will ridge into northern Illinois on Thursday, and skies will become mostly sunny with high temps in the upper 30's.  Yet another low pressure system has the area in it's sights late in the week, but it is far to early to estimate expected weather conditions for next Friday.

Friday, February 24, 2012

Friday afternoon weather update

The clouds, wind and even a few light snow showers is what you can expect heading into the remainder of the afternoon.  The main low has passed but a few upper level disturbances moving through the Great Lakes will keep those pesky clouds around and a few light snow showers.  In fact, there are a few popping up on our radars across Wisconsin.  Should anymore light snow fall - very little accumulations are expected.  The winds will remain gusty from the northwest and with temperatures only in the lower 30s, wind chills have dropped into the lower 20s and will remain that way through the rest of the afternoon.

Snow pictures from today

Everett Peterson
Everett Peterson
Elizabeth: Capron
Mary Bonavia: Rockford
Mary Bonavia: Rockford
Nancy Burnett: Dixon
Nancy Burnett: Dixon

Thursday's Big Snowflakes!

Brooke Mechling: Lake Summerset
Deb Sweeney: Monroe Center
Robert Grone: Elgin
Steve Williams

Tony Honchar: Freeport

Friday Morning Weather Update

9:00am:  All Winter Weather Advisories have either been expired or canceled.

The back edge of the snow is beginning to move through our western counties this morning with the heaviest of the snow well to our east.  Visibility has been gradually improving the past hour as the snow has become a little more light.  Flurries/light snow will continue through the morning with little additional accumulations.  So far, totals have averaged about 5" to 6" - although further east there have been a few reports of just a little over the 6" mark.  Travel with caution this morning as roads are slushy and slick.  Clouds and a few more flurries will remain through the afternoon.

(8:57:37 AM) nwsbot: LOT: Woodstock [Mchenry Co, IL] trained spotter reports SNOW of M8.3 INCH at 07:00 AM CST --

(7:26:30 AM) nwsbot: MKX: Milton [Rock Co, WI] public reports SNOW of M5.2 INCH at 07:24 AM CST --

(7:28:26 AM) nwsbot: LOT: Oregon [Ogle Co, IL] broadcast media reports SNOW of M5.5 INCH at 07:16 AM CST -- relayed by media 

(7:28:27 AM) nwsbot: LOT: 5 S Pecatonica [Winnebago Co, IL] broadcast media reports SNOW of M6.5 INCH at 07:22 AM CST -- snow measured in seward

(7:36:44 AM) nwsbot: MKX: Afton [Rock Co, WI] co-op observer reports SNOW of M6.0 INCH at 07:26 AM CST -- wwtp observation

(7:02:27 AM) nwsbot: LOT: Franklin Grove [Lee Co, IL] broadcast media reports SNOW of M4.0 INCH at 06:44 AM CST -- relayed by media

(7:02:27 AM) nwsbot: LOT: Rochelle [Ogle Co, IL] broadcast media reports SNOW of M5.0 INCH at 06:44 AM CST -- relayed by media

(7:02:27 AM) nwsbot: LOT: Winnebago [Winnebago Co, IL] broadcast media reports SNOW of M5.0 INCH at 06:44 AM CST -- relayed by media

(7:02:27 AM) nwsbot: LOT: Huntley [Mchenry Co, IL] trained spotter reports SNOW of E5.0 INCH at 06:52 AM CST --

(7:02:27 AM) nwsbot: LOT: Forreston [Ogle Co, IL] broadcast media reports SNOW of E6.5 INCH at 06:54 AM CS

(6:31:38 AM) nwsbot: DVN: 3 Nne Stockton [Jo Daviess Co, IL] co-op observer reports SNOW of M5.0 INCH at 06:21 AM CST -- storm total.

(6:31:38 AM) nwsbot: DVN: 2 Wnw Freeport [Stephenson Co, IL] trained spotter reports SNOW of M6.0 INCH at 06:23 AM CST -- storm total. since 9 pm yesterday 4.4 inches.
(6:27:40 AM) nwsbot: LOT: Rockford Airport [Winnebago Co, IL] asos reports SNOW of M4.8 INCH at 06:00 AM CST -- storm total so far
(6:22:32 AM) nwsbot: LOT: Capron [Boone Co, IL] trained spotter reports SNOW of M4.9 INCH at 06:00 AM CST --

(6:22:32 AM) nwsbot: LOT: Mchenry [Mchenry Co, IL] cocorahs reports SNOW of M7.3 INCH at 06:00 AM CST -- 7 on ground
(6:15:25 AM) nwsbot: LOT: Rockton [Winnebago Co, IL] broadcast media reports SNOW of M6.0 INCH at 06:04 AM CST

(6:15:25 AM) nwsbot: LOT: Capron [Boone Co, IL] broadcast media reports SNOW of E5.0 INCH at 06:08 AM CST -- relayed by media  
(6:15:24 AM) nwsbot: LOT: Roscoe [Winnebago Co, IL] broadcast media reports SNOW of M5.5 INCH at 05:53 AM CST

(6:15:25 AM) nwsbot: LOT: Stillman Valley [Ogle Co, IL] broadcast media reports SNOW of E5.0 INCH at 05:53 AM CST

Thursday, February 23, 2012

Updated Snow Totals

 Snow totals are generally around 2" or less so far. Most of the accumulating snow has been reported from areas near and to the north of Rockford. To the south, places like Dixon and Rochelle have seen a rain/snow mix which has limited accumulations to 0.5" or less.

However the rain is changing to snow, even as of this writing. And our models suggest that the heaviest snow will fall between midnight and 6am. So we are still thinking 4-7" of snow will fall in most areas by
tomorrow morning.

Few snow totals so far

The rain has now changed over to snow and will continue to fall through the remainder of the evening as the snow extends back through Iowa and Nebraska.  There have been some totals near 3" reported in Iowa.  Here are a  few snow totals so far:

4:45pm:  Snow Depth Measurement 0.9", Freeport - Tony H. Weather Watcher & Trained Spotter
5:40pm: 1.2" 2WNW Freeport - Total so far - light snow still falling
6:30pm: 1.5" McHenry - Storm total so far
7:09pm: 1.8" 1W Freeport - 7 hour snowfall snow depth is 1.2" - Slushy and snow covered roads - temp is 35°
4 W Mount Carroll [Carroll Co, IL] trained spotter reports SNOW of M2.0 INCH at 07:40 PM CST

Afternoon Weather Update

A heavier band of precipitation is lifting north near the Illinois/Wisconsin state line.  Within this band, heavier wet snow or a mix of rain and wet snow has been occuring.  Where the heavy snow has fallen the flakes have been very large!  This mixture of rain/snow will continue before completely changing over to all snow by this evening.  Minor accumulations are likely where the snow falls this afternoon.  This will keep roads wet and slushy.


Light rain mixed with snow is now beginning to lift north of I-88 late this morning and will continue northward through the afternoon.  There is a very warm layer a few thousand feet above the surface which should support the rain going through the afternoon, however, right above the warm layer colder temperatures are found.  These colder temperatures will eventually begin to trickle down allowing some snow to mix with the rain.  As the low begins to move closer this evening a complete change over to snow will occur; this appears to be somewhere during the 6pm to 8pm time frame.  Right after the complete change over to snow is the greatest potential for thundersnow to occur.  If thundersnow were to happen, totals would likely be increased due to higher snowfall rates. These rates could exceed an inch per hour.

Right along the I-88 corridor holds the greatest potential on totals possible exceeding six inches.  This puts Lee, Ogle, DeKalb and maybe even southern McHenry counties in the bullseye.  Further north snow totals will likely range from 3" to 6" and further south totals will be a little less.  

The dynamics of this storm are that of what we would typically see in spring in terms of instability, hence the potential for thundersnow.  Temperatures will range from 31° to about 36° as the change over to snow occurs and will slowly fall overnight.  With temperatures in the lower 30s the snow that does fall will be heavy and wet in nature.  Winds will begin to pick up tonight, but hopefully there shouldn't be too many concerns with blowing and drifting just because the snow will have some weight to it.  The reason an advisory has been issued for all is because the heaviest of the snow will fall later this evening and overnight when there won't be a lot of traffic on the roads.  The snow should be winding down by daybreak Friday.  

Many weather concerns today

Dense Fog Advisory issued for Winnebago, Boone, McHenry, Ogle, Lee and DeKalb counties through 8am

First order of business is the fog and freezing fog this morning.  Dense fog has formed across northern Illinois and southern Wisconsin as moisture continues to pool in the Midwest.  The fog will last through the morning and as temperatures have fallen well below freezing, there will likely be slick spots found on elevated surfaces, sidewalks and parking lots.  Visibility has gone down to less than a quarter mile in many locations so be sure to give yourself extra time.

Once we get rid of the fog this morning all eyes will turn to our evolving storm system currently across the Plains.  Light rain is now falling across southern Iowa and Missouri this morning out ahead of a warm front.  As this system moves closer, I would expect light rain or a mixture of rain and snow to begin either late this morning or early afternoon.  By this evening any rain/snow mixture should change over to all snow and potentially become a heavy, wet snow.  The heaviest of the snow will likely fall after about 6pm tonight and into the overnight as low pressure tracks out of the Plains and into Missouri and southern Illinois. 

Winter Storm Watches continue for Winnebago, Boone, McHenry, Ogle, Lee and DeKalb counties while a Winter Weather Advisory has been issued for Rock and Walworth counties beginning this evening.  Our western counties have been dropped from this watch because of the more southern track of the low.  The heaviest of the snow is likely to fall just to our south and across northeast Illinois where totals could near six inches as the best lift and forcing will be found there.  Overall, about 3" to 6" will fall, but some of this snow may melt initially when it reaches the ground due to the recent mild weather.  Our northwest counties may experience totals closer to the 3" mark or less due to the fact that they're further away from the forcing of the storm.  In the band of the heaviest snow, this is where totals may exceed the six inch mark.  I want to continue to stress that this system has changed dramatically over the past 24 hours so some adjustments will likely be needed going forward today.

Wednesday, February 22, 2012

Still Watching Big Snow Potential...

8:50pm Update: The NWS Chicago office is now including the rest of the Stateline area in the Winter Storm Watch. Time frame is Thursday evening into Thursday night.

Although the NWS in Chicago has yet to include its counties in the Winter Storm Watch, Stephenson, Jo Daviess, Carroll, and Whiteside counties are still in this watch on Thursday.

I can't criticize the good folks at the Chicago office for not including us in this watch. This is a very complicated forecast, perhaps the trickiest one we've had so far this "winter." There is still a lot of uncertainty as to where the surface low will track tomorrow, and this could throw a wrench into the above snowfall forecast.

Right now, this low is in southeastern Montana and is about to cross into northeastern South Dakota. Some of our models suggest this low will track along the I-80 corridor, just to our south. This solution would suggest light rain mixed with snow for the Stateline, with little or no accumulation. However, other model solutions suggest this low will move into central Iowa by morning, then re-develop further south over southern Illinois in the afternoon. If this happens, colder air would reach the area and most of our precipitation would fall as snow. Recent trends lead me to believe that the southern track will be closer to reality, which would mean wet, heavy snow for the Stateline area.

With a strong piece of energy moving through the jet stream late in the afternoon into early evening, snowfall rates could briefly approach 1" per hour, with some "thundersnow". Although this could lead to a quick 2-4" for some of us, snow accumulations earlier in the event will be limited by warm ground and air temperatures above freezing. That's why I think 3-6" will be the rule for most locations.

Thursday's Snow Potential Update

The latest morning model runs have started to come in regarding Thursday's storm and snow potential.  Unfortunately, they have come in stronger with the low as well as with more moisture. 

A Winter Storm Watch has been issued for Jo Daviess, Stephenson, Carroll and Whiteside counties beginning at 6am Thursday.  A Winter Storm Watch has been issued for Green, Rock and Walworth counties beginning at 8am Thursday. 

Low pressure will move out of the Plains later tonight and almost overhead by Thursday mid-morning.  The morning run of the GFS takes the low across northern Illinois while the NAM is a little further north.  With these likely tracks the heaviest snow band would set up across northern Iowa, southern Wisconsin and northern Illinois.  I want to stress that the exact track of this storm is still uncertain and ultimately this is going to affect where the heaviest axis of snow falls.  Right now it appears to be along the Highway 20 corridor.  The total QPF, or amount of moisture/precipitation, with this storm is between about 0.30" and 0.60"  Using a 10:1 ratio that would yield snowfall totals between 3" and 6".  Temperatures will likely be in the low to mid 30s during the time the snow falls so this could lead to more of a wet snow.  One important aspect to keep an eye on along with the track will be the temperatures aloft.  There will be a brief period of southerly winds ahead of the low which may warm the upper layers.  If that were to occur there's a possibility of rain mixing with the snow which may cut down on totals. 

Updates will continue here later this evening and tonight!  Further analysis and monitoring of this system will be done throughout the day today!  Stay tuned!

Active and unsettled weather this week

Strong jet stream winds are currently moving into the Pacific Northwest bringing rain and snow to Washington and Oregon, but also aiding in the development of quick moving storm systems that have been moving across the U.S the past several days.  The first impacted us early Tuesday morning with the snow and then again this morning as light snow fell south of Rockford.  The next storm to hit will come late tonight.  Low pressure has been developing across the eastern Rockies and will quickly move through the Midwest by Thursday morning.  As it does, a warm front will lift closer to the Stateline this evening which could induce a few light rain or even snow showers.  As the low moves closer tonight it will pull in a little warmer air aloft which may keep the mixture of rain/snow before changing over to snow showers by Thursday morning.  Just like Tuesday morning, the possibility remains for accumulating snow Thursday - some of which you may have to shovel!
The low pressure will then move into Ohio and actually strengthen as 130 kt jet streams winds move overhead.  On the backside of the low a trough of low pressure will extend northwest through Wisconsin and Minnesota which will keep the snow chance going Thursday night and Friday.  High pressure finally moves in Saturday afternoon giving a little more sunshine.  The sunshine will fade away to clouds by Sunday afternoon, however, as a stronger low moves into the Plains by Sunday night.

Tuesday, February 21, 2012

A Week's Worth of 40s

The unusually mild winter continues for the Stateline area. We hit 43 degrees this afternoon, marking the 7th day in a row in which the mercury has climbed to 40 degrees or higher. Our average high for this date is 36. Tomorrow and Thursday should also be in the 40s, but cooler weather is in-store for Friday. If our forecast high of 36 works-out for Friday, our consecutive 40-degree day stretch will stop at nine.

Tuesday Morning Weather Update

The main batch of snow has moved east, however, there is a little redevelopment on the backside of the low.  This light snow, possibly mixed with rain & sleet, is currently moving through Stephenson, Carroll and Whiteside counties and should be near the Rockford Metro within the next 30 minutes.  Once this passes that will be it for precipitation, but the clouds will remain and winds will begin to pick up.

5:30:00 AM) nwsbot: DVN: 4 Wsw Loran [Jo Daviess Co, IL] trained spotter reports SNOW of E1.0 INCH at 05:28 AM CST -- light to moderate snow continues.

Light snow will continue to fall for the next several hours this morning as low pressure moves through central Illinois.  Accumulations will remain light with many locations receiving an inch - possibly close to two.  The snow has begun to accumulate a little on roadways, sidewalks and parking lots this morning.  Roads will remain wet and there could be a few slick spots this morning.  The back edge of the snow is right along the Mississippi River and will be moving through north-central Illinois through mid to late morning.  There may be a period where light rain or even sleet mixes with the snow.  Winds will begin to pick up behind the low from the west/southwest gusting close to 35 mph.  Temperatures will

Monday, February 20, 2012

Another Active Severe Weather Season?

More than 1,700 tornadoes touched-down across the US last year. This was the second-most tornadoes reported in a single year behind 2004. A La Nina and warmer-than-normal Gulf of Mexico water contributed to the active 2011 season.

In 2012 La Nina is still in place -- although it is weaker than last year's. Still, a more active than normal jet stream across the nation's midsection is expected due to La Nina. The Gulf of Mexico is also warmer than normal. This could lead to higher evaporation rates, and more powerful thunderstorms in return.

In my opinion, below average snow cover across the northern tier of the US into Canada could be a limiting factor to severe weather. This could mean cold fronts coming in from the north will be less powerful. Still, there are more signals for an active severe season than a slow one.

For more on this topic, here's an article from

Quiet today - a little more like winter tonight

The clouds you see outside are in advance of an approaching low pressure system that will be joining us later tonight and early Tuesday morning.  
Quiet weather is expected this afternoon as a breezy southeast wind bumps temperatures into the lower 40s.  By this evening, mostly cloudy skies will be found with a few light rain showers; possibly mixing with a little snow around midnight.  After midnight, temperatures may cool enough at the surface (lows will fall into the lower 30s) and there may be enough dynamical cooling aloft that a change over to snow showers will be found through Tuesday morning.  If the precipitation does change over to all snow some locations could receive up to two inches by Tuesday morning's commute making roadways, sidewalks and parking a little slick.  The low will quickly move to the east by Tuesday evening leaving mostly cloudy skies and gusty west/southwest winds in its wake.  Temperatures will rise close to 40° during the afternoon and then remain in the lower 40s through Thursday. 

Mild Winter - Little Ice on the Great Lakes

Temperatures reached the 40s once again this weekend making it 36 days since meteorological winter began (December 1st) that we've recorded 40° or higher - putting us in the top ten of number of days that have reached 40°.  The latest March outlook from the Climate Prediction Center highlights the month with above average temperatures for a good portion of the U.S. (the Stateline included) and above average precipitation.

What's even more interesting is that the mild weather has allowed very little ice to form on the Great Lakes this season.  This image is a visible satellite image of the Great Lakes taken late morning Sunday.  Notice Lake Superior where you would typically see at least some ice along the shores - very little ice is found.  The white coloring you see over the eastern portion of the lake is actually cloud cover.  Same thing across the eastern Lakes.  Almost all of Lake Michigan is open for business and water temperatures remain in the low to mid 30s.  If this view were expanded back to include more of the Midwest and Plains you would also find very little snow cover!  To me, I think this is amazing and goes to show just how mild this winter has been.

The 40° weather will continue for the next couple of days, but by the end of the week we'll tap a little into the Canadian air which will drop our temperatures back near average, if not slightly below. 

Sunday, February 19, 2012

Good Weather For President's Day

A large area of high pressure is centered just off to our east.  Skies will be mostly clear tonight, with just high thin cirrus moving in from the west later on tonight, and winds will be light with temperatures dropping off to near 20 degrees by daybreak. It will be mostly sunny in the morning on Monday as the high shifts further off to the east. The winds will pick up, and become breezy from the south to southeast at 10 to 20 mph by the mid day hours. It will become partly cloudy in the afternoon as a low pressure system over the plains begins to pull moisture into the mid west, and the high temperature will reach the middle 40's. The system will move into the area on Monday night. Some scattered light rain showers or sprinkles may develop before midnight. Colder air will move in after midnight, and light snow will develop, but little accumulation is expected. The low temperature will be in the low 30's. There could be some lingering light snow in the morning. With temperatures rising into the low 40's in the afternoon, any persistent precipitation will change over to scattered light rain showers.  It will be partly cloudy on Tuesday night with a low around 30 degrees. A series of disturbances will move quickly across the area from mid and late week. The next one could cause some widely scattered light rain showers on Wednesday. There could be some rain and snow mixed on Wednesday night and Thursday. It will get a little colder, and there will be a chance of light snow on Thursday night and Friday. Little if any accumulation is expected. Saturday will be partly cloudy with a high around 34 degrees, and Sunday will be mostly cloudy with temperatures recovering to near 40 by afternoon.

Saturday, February 18, 2012

Another Fabulous Day on the Way!

High pressure will move slowly across Wisconsin overnight.  Skies will be clear, and winds light. The overnight low will be near 20 degrees, although a little colder than it has been, that is a bit above average for this time of year. The average low for tonight is 19 degrees. Ordinarily it would be colder, but the lack of snow cover does not allow temperatures to fall as low as they usually would. On Sunday, with the high pressure just to the northeast of the Stateline, and with the ridge of high pressure right across the area, skies will be sunny again. The winds will be light, and the afternoon high will be close to 40 degrees.  It will remain clear on Sunday night with temperatures dropping to near 24 degrees.   On Monday the high pressure will be east of the area over Ohio in the early morning.  Skies will start off sunny, but will become partly cloudy in the afternoon as the high pressure moves to Virginia.  A good southerly breeze will develop by afternoon with an area of low pressure emerging from the Rockies, and moving out on to the plains.  Temperatures will reach the middle 40's, and could easily get higher by mid to late afternoon.  The system will move into the mid west on Monday night.  Temperatures will hold up around 32 degrees overnight.  There could be some light rain before midnight, and there will be a good chance of some sleet and snow after midnight that will linger into Tuesday morning.  Tuesday will be mostly cloudy with an afternoon high in the low 40's.  Another system could cause a light wintry mix on Wednesday as it swings across the area.  The unsettled weather pattern will continue Thursday, and with colder weather on Friday there could be a little light snow.  Even colder weather will move in from the north on Saturday giving the Stateline it's first below average temperatures for the whole week.

Friday, February 17, 2012

Severe weather season is right around the corner

As this 'winter that never really was' begins to wind down, it's time to start thinking about this upcoming severe weather season.  It's that time of year again where the surrounding National Weather Service offices will hold their annual Severe Weather Spotter classes.

Weather spotters play such an important role when severe weather, and winter weather, threaten.  Your eyes and ears are the ground truth as to what's going on!  Not only do the meteorologists at the NWS rely on your reports, but we do too!  During the class you'll talk about how to remain safe when storms threaten, the difference between a wall cloud and shelf cloud, what types of reports are useful, funnel cloud versus tornado, basic thunderstorm structure, etc.  It's a wonderful time - free of charge- and you gain a lot of valuable information!

Here's a listing of the classes divided by which county is covered by which National Weather Service office:
Southern Wisconsin (Rock, Green and Walworth counties)
North-central/north-east Illinois (Winnebago, Boone, McHenry, Ogle, Lee and DeKalb counties)
Northwest Illinois (Stephenson, Jo Daviess, Carroll and Whiteside counties)

Storms in the south block moisture further north

A weak upper level disturbance will keep the cloud cover in and out today with only a slight chance of a passing shower later this afternoon.  Once that passes Canadian high pressure moves into the Midwest and while it will bring a slight cool down temperatures will still remain above average; highs will be in the upper 30s
Further south a developing low pressure system will move through the Gulf states and into the southeast by Saturday night.  This brings the threat for heavy rainfall along with the potential for severe weather - especially Saturday.  The low is in the 'developing stages' today so a few storms may fire across Texas and Louisiana this afternoon.  As the low moves east it will gain a little more support from the upper levels as a cold pocket of air aloft interacts with the warm, moist surface.  The greatest threat for severe weather exists from far southern Louisiana, Mississippi, Alabama and the Florida panhandle.  This could also bring heavy snow to parts of the Mid-Atlantic by Sunday.  Despite our southerly winds this afternoon moisture will remain confined to the south due to the developing low.