Archive for May, 2010

Come on Sunshine…
May 31, 2010

So far, my forecast for Memorial Day has been pretty good. Showers and a few storms were mainly out of the area by 9AM. Now, we have to clear it out. The clouds have been quite stubborn, especially from Milwaukee southward where they are closer to a big cluster of thunderstorms around Chicago. The clouds from those storms have crept into Wisconsin. I still think as the day progresses more and more sun will filter into the area from northwest to southeast. Kenosha and Racine may not be so lucky. I was expressing to my wife earlier today why the forecast was even more important than usual. I was sitting at the computer staring at the visible satellite and making sure that my forecast was going to be ok. I said that because thousands of people will be outside at parades and barbecues if I have a busted forecast it would not be good. Speaking of visible satellite…

A visible satellite is simply a picture taken from a camera in space. Note how the majority of the state is sunny with just the SE corner stuck in the clouds. Also take note of the thinner clouds across Waukesha, Washington, and Sheboygan counties. This is a good indication that the sun is filtering through the clouds. It may not be perfectly sunny, but you can still see your shadow.

Overall, it has been a dry couple of weeks in our area. There were a few spots this morning and last week that got a quick hit of heavy rain, but that missed most areas. Our plants and lawns could use some rain. There is a very good chance of rain arriving late Tuesday night into Wednesday morning and depending on the eventual placement of the stationary front, we may get another round on Thursday. There could be some heavy rain and even the possibility of some severe storms…most likely being strong winds. The best chance of severe weather would be early Wednesday morning. Take a look at the forecast amounts of precipitation below.

The image above is from our RPM model. It shows the heaviest rain staying to our south and builds high pressure into the area for Thursday keeping any rain to our south. Now, take a look at the QPF forecast from the Hydrometeorological Prediction Center.

The QPF or quantitative precipitation forecast…a fancy term for expected rainfall…keeps the heaviest rain just to our south, but still brings our southern counties an inch of rain.

With either forecast, it would be prudent to have an umbrella on Wednesday. Now we just need some rain up north. Here is the latest drought monitor for the United States. The worst drought anywhere in the lower 48 states is located in Northeastern Wisconsin.

Hopefully, some of the next few rounds of storms will bring some much-needed rain to the northern half of the state. However, it looks like the majority of the rain will stay to the south. Stay tuned and have a great Memorial Day.

Mark

First 90 of 2010… & Memorial Day Weather
May 30, 2010

Happy Memorial Day Weekend. Let’s all please remember what Memorial Day is about and honor the sacrifices that have been made so we can live in the greatest country in the world.

We had our first 90 degree temperature of the year on Sunday. We average ten 90 degree + days per year and we are off to an early start. We just missed the record high of 91 set back in 1994.

Memorial Day will be much different from Sunday. A cold front is about to bring a change. For those of you who did not like the hot weather, you will like Monday a lot more than Sunday.

The cold front will push into SE Wisconsin late tonight and bring a chance of scattered showers and thunderstorms. Severe weather is not expected and many areas will remain dry.

The image above is from our RPM model depicting some scattered storms at 1AM especially in our southern counties. The southern counties will have the best chance of rain as the front moves through.

By 8AM, most of the rain is moving to our east, although, some showers may hang on into Kenosha, Racine and Walworth until midday. I think the majority of the area will be dry by 9AM.

The amount of rain looks to be pretty small with most areas getting under a .25″ unless you end up under one of the thunderstorms and you could get as much as .50″ of rain. We have been dry for the last week, so some rain would be good. The northern part of Wisconsin really needs the rain. More on that tomorrow. Have a great holiday.

Mark

Warm Sunday, Wet At Times Monday
May 29, 2010

***Watch WISN 12 News at 5, 6, & 10pm for Milwaukee’s most accurate forecast!***

Thank you for stopping by the Weather Watch 12 blog!  I hope you enjoyed the sunshine and warm temperatures to start the holiday weekend.  Still more good than bad weatherwise for the next two days, but rain does creep into the forecast on Monday.

100% sunshine was the rule again on Saturday across southeast Wisconsin.  The blue skies and warm temperatures made for a great day for outdoor activities.  Sometimes a trip to the beach is out of the question on Memorial Day weekend, but not this year!

Lakeshore areas were cheated just a bit on Saturday.  A lake breeze kept Milwaukee in the mid 70s, while inland locations topped out in the low to mid 80s.  Below is a surfae map from 4 p.m. Saturday.  Notice the northeast wind in Milwaukee and a temperature of 70 degrees.  While farther west, it was 85 in Madison, and 90s were sprinkled in parts of the upper Midwest.  Just click on the map below to enlarge.

The warm temperatures in parts of Minnesota, Iowa, and western Wisconsin will pay our area a visit on Sunday.  A cold front will begin pushing through the upper Midwest, but we will stay in a southerly flow.  This means the lake breeze will be held at bay.  Highs in Milwaukee on Sunday should top out in the mid 80s, with upper 80s inland!  A day more typical of mid July!

By Sunday Night, the front will be close enough to push a few showers in our direction.  Anytime after midnight scattered showers will be possible, and continue through about Noon on Monday(Memorial Day).  Below is the surface forecast map for Monday morning at 7 a.m.  The area highlighted in green is an area that could see rain showers, and yes, southeast Wisconsin is in that area.

This will be a pretty quick moving front, so any showers should depart the region and leave a mostly dry afternoon.  If you have outdoor plans, especially in the morning, don’t cancel them, but have an alternate activity ready!  It will be breezy and cooler on Monday, with highs likely in the low 70s.  Rainfall amounts will not be very impressive.  Below is a rainfall forecast from our in-house high resolution computer model. 

For more weather updates this weekend, watch WISN 12 News!  Also, follow our forecasts on Facebook: WeatherWatch 12 and also on Twitter: WISN12News.

Have a happy and safe holiday weekend!

Jeremy Nelson

Good Start, Bad Finish To Holiday Weekend?
May 28, 2010

***Watch WISN 12 News for the latest weather information all weekend long!***

Happy holiday weekend!  Thank you for stopping by the Weather Watch 12 blog.  Lots of good news weatherwise in the weekend forecast.  However, a cold front will push into the region, and this front will likely produce a few rain showers.  In this entry we will talk about the weekend from start to finish, and also look at the time window when showers may fall.

Before we chat about the weekend, I want to remind everyone how you can stay updated with the Weather Watch 12 forecast all weekend, even if you are on the go!

  • Interactive Radar  www.wisn.com/irad
  • Facebook: WeatherWatch 12
  • Twitter: WISN12News
  • iPhone App: WISN
  • WISN 12 News

Let’s start with the good, and let me tell you, the good far out weighs the bad this weekend.  On Saturday, we should enjoy nearly 100% sunshine!  Temperatures will climb into the 80s inland, but an east to southeast wind of 6-13 mph near Lake Michigan will keep areas close to the lake in the mid-70s.

Below is the forecast temperature map for 1 p.m. Saturday.  Notice the 80s poking into parts of southern Wisconsin.  Just click on the map to enlarge.

The weather should remain very quiet heading into Sunday.  With high pressure shifting to the East, and a cold front approaching, winds will turn to the south on Sunday.  This means the lake breeze will be kept offshore for part of the day.  As a result, highs should soar into the 80s!  Low to mid 80s in Milwaukee, with possibly 87 degrees well inland.

Below is the surface forecast map from the HPC for Sunday.  The cold front looming to the west may spell trouble for Monday!

The cold front will pay southern Wisconsin a visit early Monday.  This means the best chance of rain showers over the next 3 days will be on Monday.  The highest chance of rain on Monday will occur during the morning hours.  If you have outdoor plans, please don’t cancel them, but do have an alternate plan ready.

The showers should be scattered, nothing severe looking at this point, but rain is rain and can spoil the best made plans.  To give you a ROUGH ESTIMATE of the rainfall expected, here is just one model forecast for Monday.

Below is the 24 hour rainfall forecast from the 18Z NAM(North American Model).  The darker green shade represents rain totals of 0.25″ to 0.50″.  At this point I think most areas should stay under 0.25″.   

We will continue to track the cold front and possible rain chance all weekend long on WISN 12 News, and right here in the blog. In the meantime, grab your sunglasses and sunscreen and enjoy the sunshine on Saturday and Sunday!  If you have questions, please post them to the comments section of the blog!

Have a happy and safe holiday weekend!

Jeremy Nelson

Summer Forecast (June-August)
May 27, 2010

***Watch WISN 12 News at 5, 6, & 10pm for Milwaukee’s most accurate forecast!***

Thank you for stopping by the Weather Watch 12 blog!  With the ‘unofficial’ start of summer arriving this weekend, I thought it would be a great time to discuss the Weather Watch 12 long range summer forecast!

In today’s blog I will go over, what our forecast is based on, how our forecast compares to that of the Climate Prediction Center, and also give the temperature and precipitation forecast for the next 3 months!

Since starting at WISN back on December 1, I have been providing long range forecasts based on a weather pattern theory that I learned about while working in Kansas City.  The theory is called the ‘LRC’, or Lezak’s Recurring Cycle.

Here is what the theory states:

  • A unique weather pattern sets up every year between October 1st and November 10th
  • The weather pattern cycles, repeats, and continues through winter, spring and into summer. Identifying the cycle length helps tremendously when making long range weather predictions.
  • Long term long-wave troughs and ridges become established and also repeat at regular times within the cycle. These dominant repeating features are a clue to where storm systems will reach peak strength, and where they will be their weakest.
  • The LRC is a winter/spring/early summer-long pattern! There is a pattern! It isn’t just one long-wave trough, storm system, or ridge. It is a sequence of troughs and ridges that are cycling across the Northern Hemisphere.

As I have mentioned many times, this year’s cycling weather pattern is on roughly a 60-62 day cycle.  Looking back from when the pattern formed in October, thru the winter months, and now into Spring, will help in making an accurate long range summer forecast. 

Let’s start by looking back at the pattern and what I term the ‘signature’ storm of this year’s weather pattern.  The pattern is best viewed at the 500mb level, or the middle of the atmosphere since we are looking at large scale features.

The signature storm of the pattern has occurred like clockwork around October 22-25, December 21-25, February 21-24, and April 22-25.  Each time through the pattern this has been a wet period with rain or snow.  Let’s look back to October, and then compare it to April.

Below is the 500mb map for October 23, 2009.  Notice the large low over the Midwest, this is our ‘signature’ storm.

What’s amazing is this storm repeated in December, February, and again in April.  Let’s look at the 500mb map from April 25.  The ‘signature’ storm once again cruised through the Midwest.

Will this storm repeat in June for a fifth time?  The quick and easy answer, yes.  What amazes me is not only does this feature repeat, but the overall long term long wave ridges and troughs continue to cycle!  What does this year’s pattern have in storm for the summer?  Here is the Weather Watch 12 Summer Forecast!

Temperatures

Forecast: Above Average

Discussion: The current pattern has only produced 1 month(October) with below average temperatures from October-May.  I expect the trend of above average temperatures to continue into summer.  The warmest temperatures of the summer may occur around July 18-25.  This pairs with other warm-ups in previous parts of the cycle, including the 86 & 88 degree temperatures from May 23-24. 

As a side note, Milwaukee averages 10 days each summer with a high of 90 or warmer.  I think the warmest high temperature this summer in Milwaukee will be 95 degrees.

Rainfall

Forecast: Around Average (11.17″)

Discussion: Predicting summer rainfall is always tricky.  Thunderstorms are spotty by nature, and can produce a wide range of rainfall totals.  But based on the pattern over the last 8 months, I think we will hang close to average this summer in regards to rainfall.

June looks like the wettest month of the summer.  Active periods for weather to watch for come around June 7-9 and then a wetter period the last week to 10 days of the month.  This is when the ‘signature’ storm should occur.  Severe weather season should heat up in June, and likely will be the most active of the summer.  Several disturbances will pass by in the more active parts of the pattern.

***As a side note…the pattern begins to break down in late July and into August.  Out of the next 3 months, the forecast confidence for August is the lowest.*** 

That is our summer forecast, now let’s look at the Climate Prediction Center’s temperature forecast for June-August.  The forecast from the CPC calls for an increased chance of a cooler than average summer for our area. 

The Climate Prediction Center’s precipitation forecast calls for about average rainfall for our region.  For our area I think it will be difficult to abruptly shift from having 7 consecutive months with above average temperatures, to a pattern that keeps us cooler than average for the summer.

I would love to hear what you think!  Do you think temperatures this summer will be above, near average, or below average?

Have a great day!

Jeremy

False Funnel & T-Storms/Cold Front
May 26, 2010

***Watch WISN 12 News at 5, 6, & 10 p.m. for the latest radar updates!***

Thank you for stopping by the Weather Watch 12 blog!  In today’s blog we will discuss the chance of thunderstorms with a passing cold front, discuss severe weather chances, and also look at a ‘funnel’ cloud from Tuesday evening.

Let’s start with the ‘funnel’ cloud because this is very important.  Tuesday afternoon at 3:53 p.m. a thunderstorm was just west of Waupun in Dodge County.  Local law enforcement called in a report to the National Weather Service of a ‘funnel’ cloud.  The NWS then forwarded this report and made it available to the media and public. 

As a Meteorologist, you always want to pass along this information to viewers, but first you have to do a couple of quick checks to verify if the report is legitimate.  Mark Baden and myself first looked at the radar again, checked the velocity(to see if there was rotation with the storm).  After another quick analysis we thought it would be very difficult for this storm to produce a funnel.

Then, Tuesday evening we received this picture from an experienced storm chaser – Doug Raflik – who was near the Waupun storm within a minute or two of the funnel report.  The report of the funnel, as you can see by the picture below, was very likely a rain shaft and NOT a funnel.

 

The National Weather Service always says, if you are in doubt, please don’t report a funnel or tornado.  There must be rotation for either to occur.  Storm chasing is not easy, and sometimes cloud features and rain shafts can LOOK like funnels or tornadoes.  

For Wednesday afternoon, more thunderstorms are expected across the region.  With a passing cold front nearby, and lots of moisture available, one or two storm may be strong to severe.  While no widespread severe weather outbreak is anticipated, we will watch this very closely! 

Below is the severe weather outlook from the Storm Prediction Center.

The area that says ‘see text’ is over our viewing area.  Here is the text that the SPC included for our area.

SIMILAR REGIME TO TX EXISTS NEAR THE RESIDUAL FRONTAL ZONE FROM
   KS/NEB TO IL/WI. MCV OVER NEB/KS ATTM MAY PROVIDE THE IMPETUS FOR
   MARGINALLY ORGANIZED STORMS…PERHAPS IN CLUSTERS OR BANDS…CAPABLE
   OF LOCALLY DAMAGING WINDS AND PERHAPS SOME HAIL. ANOTHER
   CONCENTRATED AREA OF DEVELOPMENT IN WEAKLY SHEARED FLOW MAY EVOLVE
   ON THE WRN SHORE OF LAKE MI WHERE OLD FRONT WILL MERGE WITH LAKE
   BREEZE DURING PERIOD OF PEAK DESTABILIZATION.

Where the lake breeze sets up, along with the timing of the cold front will go a long way as to where any possible severe weather may develop.  The main concern with the thunderstorms today would be hail, gusty winds, and heavy downpours.  One thing to note, when I was chasing for our 5/6pm newscasts yesterday, north of Oconomowoc there were two soccer fields filled with kids.  A thunderstorm was just a couple of miles away.  If you hear thunder, please move indoors or get in your vehicle!

Remember, when thunderstorms develop there are many ways to stay up-to-date with our forecasts, storm updates, and radar!

  • Interactive Radar www.wisn.com/irad
  • Facebook: WeatherWatch 12
  • Twitter: WISN12News
  • WISN 12 News 5, 6, & 10pm

If you have a storm related picture or storm report please post it to the comments section of WISN.com or email it to mbaden@hearst.com or jdnelson@hearst.com

Have a great day and check back all day for the updates!

Jeremy Nelson

Tracking Thunderstorms & Severe Weather Chances
May 25, 2010

***Watch WISN 12 News at 5, 6, & 10 p.m. for the latest on thunderstorms chances!***

Thank you for stopping by the Weather Watch 12 blog!  Parts of southern Wisconsin woke up to rumbles of thunder and heavy downpours Tuesday morning.  In this blog we will discuss the chances of more thunderstorms for both Tuesday and Wednesday, and also look at the areas that may see severe weather.  Remember, you can track thunderstorms right down to your backyard with our interactive radar!

www.wisn.com/irad

While thunderstorms rumbled over south central and southwest Wisconsin, here in Milwaukee all we saw were dark skies off to the west.  Typically, the weather moves from west to east in our area, and these thunderstorms would have raced in during the morning.  However, the thunderstorms this morning were moving from the south-southeast to the north-northwest.  

Let’s take a few minutes to look at the reason why, and then discuss the possibility of more thunderstorms today, and the areas that could see strong to severe storms. 

First, the visible satellite showed the puffy cumulonimbus clouds very well over southern Wisconsin.  The satellite picture is from around 9:30 a.m.  Just click on the image to enlarge.

Another thing to notice on the satellite picture is the north-south orientation of the clouds.  Just look in central and northern Wisconsin, it is a little easier to see there.

This helps to explain why the thunderstorms did not move toward Milwaukee, but instead moved to the north-northwest.  The upper level winds were blowing from the south-southeast to the north-northwest.  The thunderstorms follow these winds much like your car follows the road.  The winds helped to steer the thunderstorms away from southeast Wisconsin.

Below is the upper level wind field from Tuesday morning.  The wind barb close to Milwaukee shows the wind blowing TOWARD the north-northwest.  The exact direction the thunderstorms were tracking…pretty cool!

Round one of the thunderstorms missed our immediate viewing area this morning.  Another round should develop this afternoon.  Again the best chance of thunderstorms is in south central and southwest Wisconsin the rest of today.  However, isolated thunderstorms are possible anywhere in southwest Wisconsin.  As the lake breeze pushes inland today, it may act as a mini cold front and help to fire a few thunderstorms.  This is a wild card, but on that should not be overlooked.

Along with the highest threat of thunderstorms staying to the west, so will the slight risk of severe weather.  Below is the severe weather outlook from the Storm Prediction Center for today(Tuesday).

The green areas is where the slight risk of severe weather is located, but Milwaukee is in the brown outline, meaning thunderstorms are possible.  We will be tracking the thunderstorms on WISN 12 News at 5, 6, & 10 p.m. so make sure to watch for the latest!  Much like Tuesday, Wednesday will bring another chance of thunderstorms to southern Wisconsin.  The best chance again will be over south central and southwest parts of the state.

Coming up this week, I will go over the Summer Forecast in the blog.  I already discussed our initial thoughts on WISN 12 News last week, but will put some additional thoughts down in writing.

Have a great day!

Jeremy Nelson

Almost 90. Triple “H” Weather
May 24, 2010

Hot, hazy, and humid. Triple “H” is back. We hit 88 degrees today in Milwaukee at 11:00 AM, but because the lake breeze kicked in we did not make it to 90. The record high for today is 90 degrees set back in 1950. When the lake breeze started moving in some weird fog made its way into Downtown. Take a look at a picture from one of my co-workers at WISN-12.

I love this picture because it shows the Hoan bridge and the only building visible in downtown was the top of the U.S. Bank building. That fog cooled it down quickly along the lake, but the fog has not made it much farther than a block or two inland. There is a dense fog advisory over the lake right now. You can see it on a visible satellite image.

The milky white color over Lake Michigan is fog. It is forming because we have a very humid air mass and when the humid air collides with the cool air over the lake the dewpoint is hit and fog forms. Just like yesterday, you can also pick out where the lake breeze is because of the cumulus clouds created by the lift of the cooler air pushing the warm and moist air upward. There is another example of the lake breeze on radar again today.

The lake breeze has made it farther inland today than yesterday, but the warm air mass is still keeping temperatures quite mild. Inland temps are all around 90. Temperatures will be back in the 80s on Tuesday and Wednesday with plenty of humidity. A cold front will arrive late on Wednesday afternoon and that may kick off a few showers and isolated storms. At this point, severe storms are not expected. Get a look at the Wednesday afternoon forecast.

The rain does not look too impressive for us, but if you are hoping to get a little less humid that should happen on Thursday. The early prognostication for the holiday weekend looks very nice with highs around 70 and partly sunny skies. Have a great day.

Mark

Summer Arrives Early
May 23, 2010

Happy Sunday, everyone. What a fantastic day. Summer making an early arrival to our area with almost everyone into the mid 80s today. If you are right next to the lake today it is cooler, but just a block inland is in the 80s. The warm forecast goes on all week. So, why was yesterday so much cooler near the lake, but not today? It has a lot to do with the wind direction. The winds today are more south-southeast as opposed to yesterday with an easterly wind. The lake always has to be factored into our forecasts. Take a look at the current lake temperatures as estimated by satellite.

The lake water is now generally into the 50s and even some pockets of 60s. As the lake warms up, there is less and less of a lake breeze as we move into summer.

I mentioned earlier that almost everyone is enjoying a day in the 80s.

CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS
MILWAUKEE      MOSUNNY   84  68  58 SE14      29.95S HX  87
WAUKESHA       MOSUNNY   84  64  51 S12       29.97S HX  86
MILWAUKEE/TIMM MOSUNNY   84  61  45 S13       29.96R HX  84
RACINE         SUNNY     80  67  64 S17       29.99S HX  82
BURLINGTON     MOSUNNY   86  66  51 S15G21    29.96S HX  88
KENOSHA        MOSUNNY   87  70  56 SE10      29.97S HX  92
FOND DU LAC    PTSUNNY   88  66  48 S14       29.94R HX  90
SHEBOYGAN      MOSUNNY   78  67  68 S13G21    29.96S HX  80
WEST BEND      PTSUNNY   87  66  49 S9        29.95S HX  88
JUNEAU         PTSUNNY   86  64  48 S14G21    29.95S HX  87
$$

LSZ147-162-232100-
LAKE SUPERIOR

STATION/POSITION TIME  TEMP    WIND        PRES    WAVE
                       AIR SEA DIR/SP/G            HT/PER
                 (UTC) (F)     (DEG/KT/KT) (MB)    (FT/S)
W MID LAKE BUOY  2000   53 38  250/  2/  4 1010.1R   1/ 3
DEVILS ISLAND    2000   63      20/  7/  8 1010.0R
PORT WING        2000   51     350/  3/  4 1010.2R
SAXON HARBOR     2000   80     200/ 12/ 17 1009.8R
$$

LMZ867-665-643>646-232100-
LAKE MICHIGAN

STATION/POSITION TIME  TEMP    WIND        PRES    WAVE
                       AIR SEA DIR/SP/G            HT/PER
                 (UTC) (F)     (DEG/KT/KT) (MB)    (FT/S)
N MID LAKE BUOY  2000   54 48  220/ 16/ 17 1015.0F   2/ 4
NORTHPORT PIER   2000   68     150/ 12/ 20   N/A
SISTER BAY       1900   69     160/ 17/ 20   N/A
GREEN BAY ENTRAN 2000   84     180/ 16/ 18   N/A
ALGOMA LAKESHORE 2000          210/ 14/ 16   N/A
KEWAUNEE LAKESHO 2000   54     180/ 12/ 13 1015.6S
SHEBOYGAN LAKESH 2000   54     160/ 10/ 11 1014.4R
PORT WASHINGTON  2000   62     160/  5/  7 1015.2S
S MID LAKE BUOY  2000   54 46  130/ 10/ 12 1015.4F   1
KENOSHA   LAKESH 2000          180/ 13/ 17 1014.2F

The warmest spot in our area at 3PM was 88 degrees in Fond du Lac. The coolest is 54 degrees right next to the lake in Sheboygan. The official temperature in Sheboygan is 78 degrees. That is taken about 3 miles inland. One of the interesting ways to see how far inland the lake breeze has moved is by using NEXRAD radar.

Notice the red line that runs from Sheboygan county through eastern Ozaukee, Milwaukee, Racine, and Kenosha counties. That line is the lake breeze. The NEXRAD radar is so sensitive that it picks up any insects or dust that is picked up along the lake breeze. Yesterday, the lake breeze made it farther inland. So far today, only areas very near the lake have been affected.

One other image to share with you. Another way to see the lake breeze. Check out the visible satellite.

Notice no clouds over the lake with the cold stable air. The lake breeze actually creating clouds inland. The lake will have an influence on the temperatures all week, but it will still be warm everywhere. Enjoy!!

Mark

Lake Fog & Warm Sunday
May 22, 2010

***Watch WISN 12 News for Milwaukee’s most accurate forecast!***

Thank you for spending a few minutes of your weekend on the Weather Watch 12 blog!  Weather conditions have varied greatly across southeast Wisconsin Saturday afternoon.  Areas near Lake Michigan were once again seeing locally dense pockets of lake fog moving inland from time to time.  While inland locations were enjoying a mix of sun and clouds and temps in the 70s!

The fog hang over parts of Downtown Milwaukee have provided some great pictures over the last day.  Our camera network on the weather page of WISN.com is a great place to look at various cameras across our viewing area.  The view below is from our station at 19th and Wells, looking back toward Downtown.  Notice that the US Bank building which is typically very easy to see, is blocked by the fog and low clouds!

Many people have been wondering how and why the fog is forming, and staying so close to the shore.  The main reason the fog is forming is that warm and moist air is flowing over the chilly waters.  Dew points, which are a measure of surface moisture have climbed into the 50s to around 60 in Milwaukee.  Combine this with a light southeast wind, and low clouds and fog are forming over the lake, and pushing near the shore.

The fog has been dense at times, and reduced visibilites to less than an 1/8 of a mile.  Again, most of this fog is within about 1 to 2 miles of the lake.  Below is a surface map showing the wind direction, temps(in red), and dew points(in green) which I discussed above.

 

Once you get slightly inland, the wind direction shift to a more southerly direction.  This halts the fog, along with the sunshine.  The fog needs to hang close to its source region, the lake.  Before we move on to the Sunday forecast, another picture from our camera network.  This one from Racine within about 100 yards of the lake.

The fog should not be a problem on Sunday.  Winds will be much stronger, and turn to a more southerly direction.  This will allow temperatures in all locations to warm into the 80s.  Likely low 80s near the lake, and mid 80s inland.

Below is a temperature forecast for 1 p.m. on Sunday.  This is from the 12Z NAM, one of several computer models we look at when forecasting.

Along with the warm temperatures, it will be humid.  Dew points will likely push into the 60s.  During the late afternoon I still think a couple of isolated showers or thunderstorms may develop.  Best chance of this would be over inland areas away from Lake Michigan.  So don’t be surprised if a couple showers develop later Sunday.

Better rain chances more in with more scattered thunderstorms on Monday and possibly Tuesday.  Until then, enjoy the weekend and early summer preview!

Watch WISN 12 News for the updated forecast all weekend!

Jeremy Nelson