Blizzard or Near Blizzard Conditions

Blizzard or near blizzard conditions are possible Sunday afternoon into Monday afternoon in eastern Iowa. Right now a Blizzard Watch is in effect for north central and northwest Iowa. This area could be expanded farther east as we get closer. Light snow is forecast to fall (1-2”)..that is not the big story. The bigger concern is the strong wind (gusts to 45 mph) Sunday afternoon through Monday afternoon. The snow that fell early this week and the additional 1-2” expected to fall will cause hazardous travel conditions. Again this is for Sunday afternoon through Monday afternoon.

 MW WatchesWarningsAdvisories Blizzard Watch

The area of concern for the significant blowing snow will be in locations where the deeper snow pack is. The map below shows the snow depth across the area as of Friday.

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Definition Blizzard

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Posted under Forecast Discussion

This post was written by Schnack on February 5, 2016

TRACKING Potential Blizzard Conditions for Tuesday

DMA WatchesWarningsAdvisories

Heavy snow and strong winds are expected to create hazardous travel conditions over the KWWL viewing area, as well as much of the Midwest, late Monday night through Wednesday. Blizzard conditions would be most likely in our viewing area Tuesday morning through Wednesday afternoon. This means that winds will be over 35 mph and visibilities will be less than a quarter mile for over 3 hours.

You’ll want to stay ahead of this winter storm.

Winter Storm Planner

Snow Forecast DMA Hand

Now that the storm is on the mainland of the United States, our weather balloon network is able to gather important data that feeds our computer model guidance.  Some of the early runs Sunday evening are keeping a heavy band of snow in our far northwestern counties, and points to the northwest. This is where 8 to 12 inches of snow is expected, with isolated higher amounts possible.  In the central part of the area, there will be 6 to 9 inches of snow.  The southeastern part of the area will see a sharp cutoff in snow totals.  This is due to those areas being closer to the track of the low pressure, and the fact that warm air may work in late Tuesday morning or early afternoon, mixing the snow with sleet and rain.  There may be a brief changeover to all rain around Iowa City and Washington.  We’re also keeping an eye on the potential for dry air to wrap into the system.

Storm Impacts

The winds will be very strong with this system, kicking in late Tuesday morning and will be the strongest Tuesday afternoon and night. Gusts could be as high as 45 mph.

A Blizzard Watch is in effect for Tuesday and Wednesday for Black Hawk, Bremer, Butler, Chickasaw, Fayette, Grundy, and Winneshiek counties.  A Winter Storm Watch is in effect for Tuesday and Wednesday for Allamakee, Benton, Buchanan, Clayton, Delaware, Dubuque, Iowa, Jones, Linn and Tama counties.  The remainder of the KWWL viewing is not under a winter weather alert as of Sunday afternoon.

CAUCUS NIGHT: Scattered snow showers or flurries may track in around 10 PM, but the real issues don’t arrive until after Midnight Monday night.
Caucus Night Forecast

Stay tuned to KWWL for further updates.

 

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Posted under Forecast Discussion, Winter Weather

This post was written by Kyle Kiel on January 31, 2016

Friday Afternoon Storm Update

We are still tracking a major winter storm to begin late Monday night. The storm is located north of Hawaii this afternoon. As it moves on shore later this weekend there will be a lot more data put into the computer models. This will help increase our confidence on the the track of the storm. The model guidance so far has been pretty consistent…we like that as forecasters. The recent updates take the storm northeast between the Quad Cities and St. Louis. The heaviest snow falls on the northwest side of the storm track putting Iowa in the “bulls eye” at this point.

Early indications show there is about 1” of liquid available to be changed to snow across Iowa with this storm.

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There may be some adjustments in the track and available moisture as we get closer to Tuesday, but at this point 6-12” of snow is likely across the KWWL viewing area. Snow moves into the area from the southwest late Monday night, after midnight. The heaviest of the snow will fall all day Tuesday and then gradually taper off Wednesday morning.

Not only will there be a lot of snow, the wind will be very strong. The winds will be sustained at 20-40 mph with gusts to near 50 mph. Considerable blowing and drifting snow is expected Tuesday and Wednesday.

Plan accordingly if you have any travel plans Tuesday and Wednesday.

Caucus Night Weather: the snow would not start in eastern Iowa until late Monday night…after midnight. So if you have any plans Monday evening, travel should not be a problem.

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Check back for further updates as we continue to track this major winter storm.

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Posted under Forecast Discussion

This post was written by Schnack on January 29, 2016

Tracking a Major Winter Storm

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We are still tracking the potential for a major winter storm to bring snow and strong winds to Iowa and the Midwest. Early indications show the snow beginning late Monday night through Wednesday morning in eastern Iowa. The latest model guidance shows the low tracking a little farther northwest. This track would pull some warm air into eastern Iowa Tuesday. The result will be a rain/snow mix for a few hours lowering snow totals in southeast Iowa.

The map in this post shows (in white) where the most likely area is to receive snow. There will be a band of heavy snow somewhere within the outlined area. Exactly where will depend on the track and we still are still early on that front. The low is currently in the northern Pacific Ocean and has not gotten into the upper air network to be sampled as well as the lack of surface observations. When that happens, this weekend, it will show its true colors and we will have a better handle on the track.

Here is the forecast position of the storm Tuesday morning by one model.

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The placement of the heavy snow as well as type of precipitation is dependent on where the track of the storm will be. Here are two computer models suggestion as to where the heavier snow would fall.

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A strong wind around this storm will have gusts around 45 mph Tuesday and Wednesday. Once the low moves east of Iowa, the wind shifts to the northwest and pulls in colder air for Wednesday with highs in the teens. The strong wind 20-40 mph) will cause blowing and drifting snow making travel hazardous Tuesday and Wednesday. Plan accordingly.

Caucus Night Weather: the snow would not start in eastern Iowa until late Monday night…after midnight. So if you have any plans Monday evening, travel should not be a problem.
Caucus Night Forecast

Check back for further updates as we continue to track this major winter storm from the northern Pacific Ocean across the Midwest.

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This post was written by Schnack on January 28, 2016

Quick Storm Update For Early Next Week

Here is what we know at this point:

What: Snow (possibly heavy 6″+) and windy
When: Monday night through Wednesday
Where: Iowa and much of the Midwest

We will have more specifics on the storm as it gets closer.

Model guidance is still showing a large storm across the middle of the country with areas on the northwest side of the track with the potential for heavy snow and strong winds. At this point the precipitation is forecast to begin Monday night and not impact the Caucus Monday evening.

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The amount of liquid possible in this winter storm could be more than 1″.

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Posted under Forecast Discussion

This post was written by Schnack on January 27, 2016

Storm Possible Next Week

We are tracking the potential for a large storm in the middle of the country next week.

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This post was written by Schnack on January 26, 2016

Wednesday Evening Forecast Update

Rain will change to light snow across parts of eastern Iowa this evening. Any accumulation will be less than 1”. Most locations won’t have any snow accumulation. The light snow/flurries will end before midnight.

KWWL 2015 MAX Storm ED

Another round of light snow or flurries moves back in Thursday morning and tapering off during the mid to late afternoon. Any snow accumulation again will be less than 1”. A few wet snowflakes or rain drops are possible across the southern counties as high temperatures will be in the mid 30s. 

DMA 3D PM FutureTrack SatRad - RPM 4km

Friday will be mostly cloudy and mild with highs near 40.

Christmas House_NO SNOW

The next round of moisture will be in the form of a wintry mix Saturday morning before temperatures warm up and the mix changes to rain by mid to late morning. The rain tapers off during the early afternoon. The map below is the GFS model showing the rain during the morning.

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Sunday turns windy with gusts of 30+ mph with a mostly cloudy sky.

Monday is the next storm and snow is the more likely precipitation type at this point. It may start as a rain/snow mix as some warm air wraps in as the precipitation starts in the afternoon. Then as the low moves northeast and it gets colder during the evening it changes to all snow. Snow continue through the night with most of the accumulation. Light snow or flurries at this point Tuesday and Wednesday. The map below is for Monday night after the precipitation has turned to all snow.

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Keep in mind this is still a long way out there and the output from the model guidance has been a little different in what will happen and when with each update. We will continue to track the potential accumulating snow Monday/Monday night.

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This post was written by Schnack on December 23, 2015

A Few Rounds of Precipitation

We are tracking three chances of precipitation through early next week. The first storm arrives early Wednesday morning. Here is the forecast map for early afternoon.

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Rain begins between 4-6 AM Wednesday then transitions to light snow between 6-10 PM. It all tapers off by midnight. Rain amounts range from 0.50” to 1.00”. Don’t be surprised to hear thunder areas near Cedar Rapids and south.  The snow amounts will be up to 0.5″. The timing of the snow is not good since there will be more people on the road during the evening commute. So use caution on the roads Wednesday evening.

Thursday a light snow shower or flurries are possible…then a dry Friday.

The next chance of precipitation will be here Saturday with chance of rain and snow. Amounts of either will be light. There is a chance of some sleet mixed in across the northern counties in the morning.  Here is a look GFS model for Saturday morning.
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There is a large storm forecast to move across the Midwest Monday with rain , snow and windy conditions. The track of the storm might come across Iowa. Exactly where is unknown at this point. The track will have a huge impact on precipitation type. At this time model guidance has been back and forth between rain and snow for us. We will continue to track the possible storm for Monday.

The map below is just one solution from the GFS for Monday evening. As mentioned above, the track has been back and forth across Iowa during the last few runs. What we do know is that there is a big storm across the Midwest with wind, rain and snow. Exactly where and how much of that will fall is unknown. Stay tuned as we get more information.

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Here is another look at the storm Monday morning from the NWS.

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Posted under Forecast Discussion

This post was written by Schnack on December 22, 2015

Light Rain to Scattered Light Snow

It has been a cold light rain on and off most of today. Temperatures remain above freezing in most locations this evening to keep the precipitation mainly rain.

DMA 3D PM FutureTrack SatRad - RPM 4km

Light rain transitions to light snow and flurries after midnight as temperatures drop below freezing. Most of the moisture will be north of Iowa tonight and Tuesday so light scattered showers or flurries are expected tonight through Tuesday night. Any accumulation will be minor…most locations a trace to 1” with an isolated 2” near and northwest of New Hampton.

Snow Forecast DMA Hand

The clouds linger through early Wednesday afternoon with slow clearing after that. The first week of December is dry with above normal temperatures. Those above normal temperatures are forecast to linger through the middle of December. Actually the whole month of December is likely to have above normal temperatures. 

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This post was written by Schnack on November 30, 2015

Thanksgiving Day Storm

We are tracking a winter storm forecast to cause all kinds of travel headaches west of the Mississippi River Thursday and Thursday night. Here is the position of the storm this evening.

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In eastern Iowa, light rain and drizzle this evening will continue through the overnight. Widespread rain will be heavy at times during the afternoon and evening. Colder air will start to change the rain over to freezing rain during the evening hours (pink color on the maps below) across our northwestern counties. As the storm moves east, so does the precipitation and the colder air. This will result in the freezing rain to change over to light snow before it ends after midnight from west to east.

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The heavy rain could exceed 2″ in some locations. Localized minor flooding is possible since 6-12″ of snow just melted in the last 3-4 days. Anything more than 1″ of rain across eastern Iowa will make this the wettest Thanksgiving on record.
Rain Forecast DMA Only
Again during the evening, there will be a few hours where some of the rain will be freezing as it reaches the ground. Areas along and north of a Waterloo to Elkader line will be the favored areas for this to happen. We don’t expect a thick coat of ice, but it doesn’t take a lot to cause big problems on the roads.
Ice Forecast DMA Only

Once the air gets cold enough, all the way to the ground, is when all the precipitation turns to snow. Keep in mind this is going to be mainly north of Highway 20 and northwest of the line previously mentioned. A light rain/snow mix may occur near Dubuque around midnight, but no accumulation is expected.

Snow Forecast DMA Only

Now because of the above mentioned snow/ice combination there is a Winter Weather Advisory in effect tomorrow afternoon/evening for our northwestern counties that will be most impacted ice/snow combination.

Winter Weather Advis

The clouds clear Friday with cooler temperatures as you head out to do your holiday shopping.

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Posted under Forecast Discussion

This post was written by Schnack on November 25, 2015