TRACKING: Rain Late Tuesday into Wednesday

It has been dry as of late across eastern Iowa.  In fact, the last time we had rain in Waterloo was 8 days ago, and it’s been 7 days since the last measurable rain in Dubuque, Cedar Rapids and Iowa City.  So far this month (through October 23rd), here’s our rainfall departures.

Rain Departures - 4 lines

We will likely get close to where we should be in rainfall later this week, as we are tracking a potent low pressure system that will track through Iowa.

Monday will be seasonable with a mostly sunny sky and temperatures in the upper 50s to lower 60s.

We are tracking a strong storm system that is forecast to track through Iowa Tuesday and Wednesday.  We will have an increase in clouds on Tuesday, with a chance for rain tracking in by late Tuesday afternoon and evening.

The best chance for rain and a few isolated storms will be Tuesday night into Wednesday morning.  Areas north of Highway 30 could see 1-2″ of rain, with local amounts of 3″ not out of question.  South of Highway 30 could potentially see a half inch to 1″+.  This is dependent on the exact track of the low pressure center.

It will also be windy and cool Tuesday and especially Wednesday.  Highs Wednesday will likely range from the upper 40s in northern Iowa, to low 60s in southern Iowa.

MW FutureTrack Rain Accumulation GFS

Stay with KWWL for updates.

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Posted under Forecast Discussion

This post was written by Kyle Kiel on October 23, 2016

Labor Day Weekend Update…And Beyond

We will see a partly cloudy to mostly clear sky during the overnight hours Saturday, with lows dropping to the middle and upper 50s.  Our nice stretch of weather continues as we head into Sunday, although it will be a bit humid.  The wind also picks up out of the southeast 10-15 mph, with highs reaching the upper 70s to near 80°.

Labor Day will be humid, breezy with a slight chance for a few isolated showers and storms in the morning  The best chance would be north of Highway 20, and most of us will not see any rain.

Labor Day - Construction

 

There’s a better chance for storms later Tuesday and Wednesday as a cold front tracks through.  Heavy rain is a potential, and we will continue to keep an eye on the severe weather threat.

Here’s the Storm Prediction Center’s outlook for severe weather on Tuesday:

day4prob

And for Wednesday:

day5prob

Our next system tracks in Friday, bringing another good chance for storms.  Below is the rainfall potential through next Saturday.

p168i

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Posted under Forecast Discussion, Holiday

This post was written by Kyle Kiel on September 3, 2016

Warm, Humid and Storm Chances before Weekend Cooldown

Warm, humid, and a chance for storms.  Sounds like summer in Iowa, doesn’t it?  That’s what we’ve got in the forecast for Tuesday.

A weak storm system will track through, bringing a chance for a few pop-up showers and storms Tuesday afternoon, mainly across the northern half of the viewing area.  Severe weather is not expected, but gusty wind and a heavy downpour are possible in any storm that does develop.

There may be a couple lingering showers early Wednesday, otherwise we stay dry Wednesday and Thursday, ahead of our next chance for storms later on Friday, Friday night and Saturday.

A cold front will be tracking through our warm, humid airmass, and that will lead to the development of showers and thunderstorms late Friday.  The Storm Prediciton Center has the area under a slight risk for severe weather.  Damaging wind, heavy rain and hail would be the primary threat.  This is still a few days away, so this outlook will change.

severe storm track 2

Heavy rainfall of a half inch to an inch (locally higher amounts) are possible as it looks now.

Once the cold front tracks through, cooler, drier air from Canada will track in for the weekend and into next week.

814temp.new

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Posted under Forecast Discussion

This post was written by Kyle Kiel on August 15, 2016

Heavy Rain and Flash Flooding Potential

We are tracking an area of low pressure and a cold front that will move through eastern Iowa Thursday evening and overnight.  As you know, it’s very humid out so there is a lot of moisture available in the atmosphere.  Heavy rain will be the primary threat as these storms move there.  There is a slight risk for severe weather, mainly in western parts of Iowa.  But, as the storms move through, gusty winds are possible.

A Flash Flood Watch is in effect for the KWWL viewing area through Friday morning.

Flash Flood Watch

 

The Weather Prediction Center has eastern Iowa in a Slight to Moderate risk for flash flooding.

 

flooding

Widespread 1-3″ totals are expected, with locally higher amounts.

 

Flash Flood 1

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Posted under Flooding, Forecast Discussion

This post was written by Kyle Kiel on August 11, 2016

More humid Tuesday, Chance of Storms Tuesday Night

After a relatively cool, and comfortable holiday weekend, our weather pattern is going to be a bit more summer-like.

A warm front tracks into the area on Tuesday, not only bringing warmer temperatures, but also an increase in moisture.  It will feel very uncomfortable as we head into Tuesday afternoon as temperatures approach the upper 80s to near 90°.

During the late afternoon and evening hours, rain and thunderstorms are forecast to develop along a cold front from central Minnesota to northwest Iowa.  Some of these storms could turn severe weather damaging wind of 60 mph, quarter size hail or larger, and isolated tornadoes.  As the evening progresses, the tornado threat will go down.  The complex of storms will track to the east/southeast through the KWWL viewing area Tuesday night, mainly after 10 PM.  Damaging wind gusts and large hail will be the primary threat, along with heavy rainfall and lightning.

Severe Wx Risk for web

These storms should move out by early Wednesday morning, and then there is another threat for storms Wednesday night.

This is still a developing situation, so stay tuned to KWWL for further updates.

weather app

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Posted under Forecast Discussion

This post was written by Kyle Kiel on July 4, 2016

Father’s Day Forecast

We’ve had a nice couple days with lower humidity, but the humidity goes up just slightly on Father’s Day.  It will be a hot one, but there is no chance for rain.

Fathers_Day_Ver_A
With plenty of sunshine in the forecast, be sure to have the sunscreen handy throughout the day if you plan on spending an extended period of time outdoors.

DMA 3D FutureTrack SatRad - RPM 4km

 

While the humidity levels won’t be unbearable on Father’s Day, it will still feel slightly humid.  With Temperatures in the upper 80s and lower 90s, it doesn’t take much for it to feel warmer.  Stay hydrated!  A south breeze will bring a little relief.

Comfort Index 2Happy Father’s Day to all the dads out there.

 

 

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Posted under Forecast Discussion

This post was written by Kyle Kiel on June 18, 2016

Storms and Higher Humidity Ahead

The weather lately has been comfortable and dry. Temperatures have been cooler than normal through much of May. All of this is about to change starting Monday. The humidity level increases (it will be humid next week) with a chance of rain/storms each day.

The chart below shows different computer model plots of forecast dew point temperatures. The green, straight horizontal, line marks the dew point temperature of 60 degrees. Once we start to see this value and above it is uncomfortable to some degree. The higher it is the more uncomfortable you will feel. This past week and this weekend to come, the dew point have been low…dry atmosphere. The change comes Monday. A south and southwest flow will bring more moisture north Monday and increase the humidity level. It remains humid all week until, potentially, next weekend.

1

The dew points of 60+ degrees will be the first time this year that threshold has been reached. The chart below shows the high and low dew point for each day so far this year. The lines in red are the days (8 days) where the dew-points has been 55 degrees or higher. It has not reached 60 degrees yet. So enjoy the comfortable humidity levels this weekend since it will be more humid all of next week.

2

Now that there is more moisture in the air, we have a better chance of getting thunderstorms through Iowa compared to recently. There is a front to our west most of the week. The map below shows the position of the front Wednesday morning.

6

More moisture in the atmosphere means heavier rainfall amounts are possible. We could be dealing with a few rounds of storms this week dropping locally heavy rain.
3

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Posted under Forecast Discussion

This post was written by Schnack on May 20, 2016

Snow Wednesday Night

We are tracking light snow forecast to move through the area tonight bringing most locations 1-3” of new snow. The wind tonight and Thursday will be 10-15 mph. Blowing snow will be minimal. The snow tapers off around 4 or 5 AM. The roads will be slick tonight into early Thursday morning. High temperatures Thursday will reach the low and mid 30s, but there are much warmer days ahead.

Snow Forecast DMA Hand

 

A stray rain or snow shower is possible Friday afternoon with the best chance in far northeast Iowa. Expect dry weather this weekend with sunshine as temperatures warm into the 40s Saturday and 50s Sunday. A lot of snow will melt this weekend.

The warm weather doesn’t stop there. Highs will be in the 60s Monday and Tuesday. This comes with a gusty wind and a chance of rain both days. We might even have a thunderstorm Tuesday.

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Posted under Forecast Discussion, Winter Weather

This post was written by Schnack on March 2, 2016

Tracking Wintry Weather Monday Night/Tuesday

After a very nice weekend of mild temperatures (aside from the wind), we are in store for some changes in the week ahead.

Monday is a tricky temperature forecast, as another cold front will track through the area.  Before that, temperatures will warm up quickly to the south with temperatures in the mid 50s.  However, the north will see temperatures in the lower to middle 40s before the front moves through.  Clouds will increase throughout the day.

All eyes turn to late Monday evening through Tuesday.

lowtrack_circles

The guidance coming in late Sunday evening are showing the best chance for accumulation north of the Highway 30 corridor.  South of Highway 30 is where we have the best chance for a wintry mix of freezing rain, sleet and/or snow, before changing to snow late Monday night.  We have to take into account the very warm temperatures we’ve had over the last several days.  The snow will likely melt on the ground as it falls, initially.  Also, with the warmer temperatures the snow to liquid ratio (SLR) will likely be lower, which means the snow won’t accumulate as quickly as if the temperatures were in the lower to middle 20s.

The forecast calls for a Trace to 3″ of snow, with locally higher amounts.  Those higher amounts are more likely to occur north of Highway 30, and more east.

Snow Forecast DMA Hand

 

Here are the probability maps for 1 inch or more of snow, 2″ or more of snow, and 4″ or more of snow.  Notice, according to the Weather Prediction Center, the heavier snowfall is forecast to fall east of us in eastern Iowa.  This, as of Sunday evening.

snow 1

snow 2

snow 4

 

This is all dependent on the exact track of the area of low pressure.  Computer model guidance are still not in agreement with one another.

Stay tuned for further forecast updates.

 

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Posted under Forecast Discussion, Winter Weather

This post was written by Kyle Kiel on February 28, 2016

Possible Snow Tuesday

After a warm weekend there is potential for a storm to bring snow to Iowa. The model guidance has changed with every update from location of snow and amount of snow. At one point one model had 36” of snow for parts of eastern Iowa and the next update it was lowered to 7”. At the same time the other long range model had nothing when the first one mentioned had 36”. So as you can see the model guidance has not been very helpful.

As Meteorologists we like to see consistency in the long range models from update to update. That has not been the case in the last 6 days. As we get closer to next Tuesday the hope is for some similarity. At least by the weekend the short term models will add some insight as to what might happen on Tuesday.

With that said, here is the latest model guidance showing where the best chance of snow to fall. Notice the big difference on location of the snow. These maps are most likely going to change with each update. One of the model updates 4 times a day so expect a lot of changes until we get closer.

1

 

The National Weather Service is also looking at the potential for snow and possibly heavy across Iowa Tuesday.

2

We will continue track the developments through the warm weekend. The weekend weather throws a wrench in this storm as well. The ground is going to be very warm after three days with temperatures near or into the 50s. So for the snow to accumulate it would have to come down pretty fast. The storm also will start out as rain with temperatures near 40. There is a lot to iron out so the best advice is to check back for updates as there will be changes.

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Posted under Forecast Discussion

This post was written by Schnack on February 25, 2016