Beau Dodson's WeatherTalk Blog

Morning and early afternoon update

Saturday, April 29, 2017: Severe Weather Update.

 

10 AM through 3 PM Update

 

Additional severe weather possible over the next 48 hours. Then a break from storms on Monday.

Synopsis:

 

1. Yesterday’s forecast turned out almost perfect. Typically, severe weather days can be full of surprises. The forecast for the Bootheel into KY/TN event was all or nothing. If the CAP didn’t break then there would be no severe weather. That is what happened.

 

Heaviest rains of 3 to 6 inches+ were forecast to fall over MO/IL/NW KY. That is what happened.

 

Extensive flooding today across parts of southeast Missouri into southern Illinois and then northeast from there. Many roads are impassable. Homes flooded. Businesses flooded. Some are saying it is one of the bigger flash flood events they have witnessed.

 

More than six inches of rain fell in some areas. Amazing totals in a short amount of time. Seems to be the new norm over the past decade.

 

When thunderstorms train over the same areas you can receive a lot of rain in a short amount of time. There was an amazing amount of moisture in the atmosphere last night.

 

2. Storms (sub-severe) are ongoing across portions of the area. A very warm and moist atmosphere blankets the area. Severe storms could redevelop later this afternoon into tonight. Heavy rain, a few reports of hail, high winds, and QLCS tornadoes are possible.

 

3. Another round of storms likely on Sunday as the cold front sweeps through the area and brings all of this to an end.

 

Forecast:

 

Woosh it has been a long few days. Leading up to this event we knew it was going to be a rough one. It has proven itself already.

 

The NWS and media encourages everyone to stay out of the flooded areas. Avoid flooded roads. Some roads may have washed away. You don’t know what is under that water. Don’t become part of the problem. /end nanny speech

 

If you have stepped outside this morning, across portions of the region, you will know that it feels like August. Incredibly high dew points blanket the area. Some are reporting dew points in the lower 70’s. Those are amazing numbers in the dead of summer, let alone in spring. Rare to experience these type of dew points in April.

 

Makes me wonder if these are record high dew points for April. It certainly has to be close.

 

This is a lot of fuel for additional storms later today and tonight.

 

Unknowns:

 

How unstable the atmosphere will be come timing. Does the sun come out and pop temperatures higher? Do we remain mostly cloudy?

 

What I know:

 

Today is probably not an all or nothing day. I suspect a line of storms will advance through the region later this afternoon and evening. It does not appear that the CAP will play as big of role today as it did yesterday.

 

It won’t take much sun today to cause an already unstable atmosphere to become even more unstable. We are currently capped across much of the area.

 

If the sun comes out today then this will make the threat for additional severe weather higher.

 

What I am anticipating is a squall line to develop over Missouri and Arkansas between 2 PM and 6 PM. That line would then sweep eastward into our region between 5 PM and 11 PM.

 

There remains some questions as to how intense the line will be.

 

Any bowing segments (where storms bow outward) could produce 60 mph winds or higher and isolated QLCS tornadoes.

 

QLCS tornadoes are the most common type of tornado in our region. We have had plenty of them over the past two months.

 

The Perryville, MO tornado was a supercell tornado. The Cuba, Kentucky tornado was QLCS.

 

They are the ones that are extremely hard to warn on. They last seconds to minutes. They can be five feet wide to several hundred feet wide. They can stay on the ground for a matter of feet to a matter of miles.

 

They typically only show up in one or two radar scans. They then disappear.

 

That is why when I tell there that a storm has rotation, you should take necessary precautions for your safety. You don’t need the National Weather Service, media, or myself to tell you to seek shelter. If you feel threatened by a storm then seek shelter until it passes.

 

Have multiple ways to receive weather information. I encourage people to have three to five ways of receiving information.

 

Please utilize the Apple and Android apps for your text messages.  It has come to our attention that ATT and Verizon can be slow in delivering your text messages.  The app is INSTANT. I barely take my finger off the enter button and my phone dings.  Here is the Apple link https://itunes.apple.com/us/app/id1190136514

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Here is the Android app link https://play.google.com/store/apps/details?id=com.weathertalk.beaudodsonweather.android

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Need to track the rain?

Interactive Weather Radar Page.  Choose the city nearest your location:  Click this link—

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This forecast update covers far southern Illinois, far southeast Missouri, and far western Kentucky. See the coverage map on the right side of the blog

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Friday night
Forecast: Flash flood watch.   Cloudy.  Breezy.  Thunderstorms possible.  Some storms could be severe.  Widespread heavy rain developing along and north of the front.  Best chance for storms will be over southeast Missouri and southern Illinois.  Northwest Kentucky, as well.  The placement of the front is key to where the heaviest rain falls.  Training storms likely with this event.  Flash flooding concerns are high.  Scattered severe storms possible along the front.   Rainfall totals of greater than three inches likely in some counties.  Avoid flooded roadways.  Wide temperature range from north to south.
Temperatures:  MO ~ 60 to 72   IL ~ 60 to 72     KY ~ 68 to 74     TN ~ 70 to 70
Winds: South winds south of the front at 15 to 30 mph.  Variable winds north of the front at 7 to 14 mph.
My confidence in the forecast verifying: Low.  Significant adjustments possible.
What impacts are anticipated from the weather?  Lightning.  Gusty winds.  Wet roadways.  Flash flooding.  Large hail.  Damaging winds.  Isolated tornadoes.  Severe weather threat is low if the CAP does not break.  If the CAP breaks then severe weather will occur.
Is severe weather expected?  Yes.  Severe weather is possible IF the CAP breaks.
The NWS defines severe weather as 58 mph winds or great, 1″ hail or larger, and/or tornadoes
What is the chance of precipitation?  MO ~ 80%  IL ~ 80%    KY ~ 30%   TN ~ 30%
Coverage of precipitation: Scattered south of the front and widespread along and north of the front.
Should I cancel my outdoor plans?  Have a plan B.  Monitor updated forecasts.  Some storms are possible Friday night.

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April 29, 2017
Saturday Forecast Details
Forecast:  Flash flood watch.  Partly to mostly cloudy.  Some breaks in the clouds possible south of the front.  Showers and thunderstorms possible.  Again, frontal boundary placement is key to the forecast.  It is possible that the greatest coverage of rain and storms, during the morning hours, will be over Missouri and Illinois on Saturday.  Then a squall line or additional storms may move into the rest of the area during the afternoon and evening.  Heavy rain possible.  A few storms could be severe.  Locally heavy rain possible.  A wide temperature range from north to south.
Temperatures:   MO ~  64 to 82  IL ~ 84 to 78     KY ~ 74 to 80     TN ~ 76 to 82
Winds:  South of the front the winds will be from the south at 6 to 12 mph with gusts to 35 mph.  Variable winds north of the front at 7 to 14 mph.
What impacts are anticipated from the weather? Lightning.  Wet roadways.  Flash flooding.  Some storms could be severe with hail and high winds.  Isolated tornado risk, as well.
My confidence in the forecast verifying: Low.  Significant adjustments are possible.
Is severe weather expected?  Possibly.
The NWS defines severe weather as 58 mph winds or great, 1″ hail or larger, and/or tornadoes
What is the chance of precipitation?  MO ~ 70%    IL ~ 70%    KY ~ 40%    TN ~ 40%
Coverage of precipitation: Scattered to widespread.
Should I cancel my outdoor plans?  Have a plan B.  Rain is possible.

Saturday Night Forecast Details:
Forecast: Flash flood watch.  Mostly cloudy.  Showers and thunderstorms likely.  A few storm could be severe.  Locally heavy rain possible.
Temperatures:  MO ~ 65 to 74   IL ~ 65 to 72     KY ~ 68 to 74     TN ~ 68 to 74
Winds: South winds at 6 to 12 mph with gusts to 30 mph.
My confidence in the forecast verifying: Medium.  Some adjustments are possible.
What impacts are anticipated from the weather?  Lightning.  Gusty winds.  Wet roadways.  Some storms could be severe with hail, damaging winds, and isolated tornadoes.  Monitor updates.
Is severe weather expected?  Monitor updates.
The NWS defines severe weather as 58 mph winds or great, 1″ hail or larger, and/or tornadoes
What is the chance of precipitation?  MO ~ 60%  IL ~ 60%    KY ~ 60%   TN ~ 60%
Coverage of precipitation: Scattered to perhaps widespread.
Should I cancel my outdoor plans?  have a plan B, in case it rains.

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April 30, 2017
Sunday Forecast Details
Forecast:  Windy.  Partly to mostly cloudy.  Showers and thunderstorms possible.  Some storms could be heavy.  Some severe storms possible.
Temperatures:   MO ~  76 to 82  IL ~ 76 to 82     KY ~ 76 to 82     TN ~ 76 to 82
Winds:  South winds at 15 to 30 mph with gusts to 45 mph
What impacts are anticipated from the weather? Lightning.  Wet roadways.  Some storms could become severe with hail and damaging winds.  A non-zero tornado risk, as well.  Heavy rain possible.
My confidence in the forecast verifying: Medium.  Some adjustments are possible.
Is severe weather expected?  Monitor updates.  Some storms could be severe.
The NWS defines severe weather as 58 mph winds or great, 1″ hail or larger, and/or tornadoes
What is the chance of precipitation?  MO ~ 70%    IL ~ 70%    KY ~ 70%    TN ~ 70%
Coverage of precipitation: Increasing coverage from west to east.
Should I cancel my outdoor plans?  Have a plan B.

Sunday Night Forecast Details:
Forecast: Showers likely.  Some evening thunderstorms possible.  Cooler.  Rain and storms ending west to east.  Windy.
Temperatures:  MO ~ 48 to 54   IL ~ 48 to 54     KY ~ 50 to 55     TN ~ 50 to 55
Winds: Winds becoming west and northwest behind the front at 10 to 25 mph with gusts to 38 mph.
My confidence in the forecast verifying: Medium.  Some adjustments are possible.
What impacts are anticipated from the weather?  Evening storms could be strong with lightning, gusty winds, and hail.  Once the main line passes then just remaining showers.
Is severe weather expected?  Perhaps early.  This will depend on how fast the front moves through the region.
The NWS defines severe weather as 58 mph winds or great, 1″ hail or larger, and/or tornadoes
What is the chance of precipitation?  MO ~ 60%  IL ~ 70%    KY ~ 70%   TN ~ 70%
Coverage of precipitation: Widespread ahead of the front.  Becoming scattered as the night wears on.
Should I cancel my outdoor plans?  Have a plan B.

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May 1, 2017
Monday Forecast Details
Forecast:  Mostly sunny and cooler.  Windy.
Temperatures:   MO ~  64 to 68  IL ~ 64 to 68     KY ~ 64 to 68     TN ~ 64 to 68
Winds:  West and southwest winds at 15 to 35 mph and gusty
What impacts are anticipated from the weather? None.
My confidence in the forecast verifying: High.  This forecast should verify.
Is severe weather expected?  No.
The NWS defines severe weather as 58 mph winds or great, 1″ hail or larger, and/or tornadoes
What is the chance of precipitation?  MO ~ 0%    IL ~ 0%    KY ~ 0%    TN ~ 0%
Coverage of precipitation: None.
Should I cancel my outdoor plans?  No

Monday Night Forecast Details:
Forecast: Mostly clear and cool.
Temperatures:  MO ~ 45 to 50   IL ~ 45 to 50     KY ~ 45 to 50    TN ~ 45 to 50
Winds: West winds at 4 to 8 mph
My confidence in the forecast verifying: High.  This forecast should verify.
What impacts are anticipated from the weather?  None.
Is severe weather expected?  No
The NWS defines severe weather as 58 mph winds or great, 1″ hail or larger, and/or tornadoes
What is the chance of precipitation?  MO ~ 0%  IL ~ 0%    KY ~ 0%   TN ~ 0%
Coverage of precipitation: None
Should I cancel my outdoor plans?  No

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May 2, 2017
Tuesday Forecast Details
Forecast:  Partly sunny.
Temperatures:   MO ~  70 to 75  IL ~ 70 to 75     KY ~ 70 to 75     TN ~ 70 to 75
Winds:  Southwest and west winds at 6 to 12 mph with gusts to 15 mph
What impacts are anticipated from the weather?  None
My confidence in the forecast verifying: High.  This forecast should verify.
Is severe weather expected?  No.
The NWS defines severe weather as 58 mph winds or great, 1″ hail or larger, and/or tornadoes
What is the chance of precipitation?  MO ~ 10%    IL ~ 10%    KY ~ 0%    TN ~ 0%
Coverage of precipitation: None
Should I cancel my outdoor plans?  No

Tuesday Night Forecast Details:
Forecast: Some clouds.  A shower or thunderstorm possible.
Temperatures:  MO ~ 50 to 55   IL ~ 50 to 55     KY ~ 50 to 55     TN ~ 50 to 55
Winds: Variable winds at 5 to 10 mph
My confidence in the forecast verifying: Low.  Significant adjustments are possible.
What impacts are anticipated from the weather?
Is severe weather expected?  No
The NWS defines severe weather as 58 mph winds or great, 1″ hail or larger, and/or tornadoes
What is the chance of precipitation?  MO ~ 30%  IL ~ 30%    KY ~ 30%   TN ~ 30%
Coverage of precipitation:
Should I cancel my outdoor plans?  No

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May 2, 2017
Tuesday Forecast Details
Forecast:  Partly sunny.
Temperatures:   MO ~  70 to 75  IL ~ 70 to 75     KY ~ 70 to 75     TN ~ 70 to 75
Winds:  Southwest and west winds at 6 to 12 mph with gusts to 15 mph
What impacts are anticipated from the weather?  None
My confidence in the forecast verifying: High.  This forecast should verify.
Is severe weather expected?  No.
The NWS defines severe weather as 58 mph winds or great, 1″ hail or larger, and/or tornadoes
What is the chance of precipitation?  MO ~ 10%    IL ~ 10%    KY ~ 0%    TN ~ 0%
Coverage of precipitation: None
Should I cancel my outdoor plans?  No

Tuesday Night Forecast Details:
Forecast: Some clouds.  A shower or thunderstorm possible.
Temperatures:  MO ~ 50 to 55   IL ~ 50 to 55     KY ~ 50 to 55     TN ~ 50 to 55
Winds: Variable winds at 5 to 10 mph
My confidence in the forecast verifying: Low.  Significant adjustments are possible.
What impacts are anticipated from the weather?
Is severe weather expected?  No
The NWS defines severe weather as 58 mph winds or great, 1″ hail or larger, and/or tornadoes
What is the chance of precipitation?  MO ~ 30%  IL ~ 30%    KY ~ 30%   TN ~ 30%
Coverage of precipitation:
Should I cancel my outdoor plans?  No

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Don’t forget to check out the Southern Illinois Weather Observatory web-site for weather maps, tower cams, scanner feeds, radars, and much more!  Click here

An explanation of what is happening in the atmosphere over the coming day

Severe thunderstorm outlook.

Remember that a severe thunderstorm is defined as a thunderstorm that produces 60 mph winds or higher, quarter size hail or larger, and/or a tornado.

Friday night:  Thunderstorms are likely tonight.  Some storms will produce hail and high winds.  Isolated tornadoes are possible.  Very heavy rain along and north of the warm front.

There will be a CAP on the atmosphere most of Friday.  A CAP is a warm layer aloft.  This keeps thunderstorms from forming.  IF the CAP breaks then severe weather is likely to occur.  The greatest risk will be from 4 pm Friday through 5 am Saturday morning.

Very heavy rain is likely along and north of the front.  Some areas could receive 3 to 5 inches of rain on Friday night.  Thunderstorms training over the same areas will be the cause of the large rainfall totals.  Flash flooding is possible on Friday night/Saturday morning.

Monitor updates.  I am not overly confident as to where the front become stationary.  That is key to the forecast at your house.

Saturday and Saturday night:

At least some chance for storms on Saturday.  If the front pushes far enough north then our rain chances would diminish.  Plan on some showers and storms Saturday.  I will need to fine tune the forecast moving forward.

Perhaps the greatest coverage on Saturday will be over Missouri and Illinois.  Again, low confidence.

If storms do form on Saturday/Saturday night then they could produce heavy rain.  There is also a risk for a few severe thunderstorms.

Sunday into Monday:  A cold front will enter the region on Sunday and Sunday night.  A band of showers and thunderstorms will accompany the front.  Severe weather is possible.  Monitor updates.

Weather analysis for the next few days:

Short update.

The entire focus is on the flash flood threat and severe weather threat.

Storms between now and Sunday afternoon could produce very heavy rains.  Storms that train along the warm front could easily produce flash flooding.  In addition to this, there should be several rounds of heavy thunderstorms Saturday and Sunday.

There should be several lulls in the precipitation over far southeast Missouri, extreme southern Illinois, western Kentucky, and NW Tennessee.  Areas further north and west may not have much of a break.

The atmosphere will be unstable.  I can’t rule out storms forming at any given point between now and Sunday afternoon.

The cold front arrives on Sunday.  That will bring an end to showers and storms.

Strong and gusty winds this weekend into Monday.  Winds on Sunday night and Monday may gust above 40 mph.  Gradient winds behind the cold front.

Monitor all watches and warnings this weekend.  I am sure I will be sending out several texts via the texting service.  You can sign up at www.beaudodsonweather.com

Here is the future-cast radar.  This is guidance and not gospel.  That means it is the model’s opinion.

HRRR shows severe storms forming this afternoon and evening.   Heavy rain overnight.

Here is the future-cast radar.  Time stamp is at the top of each graphic on the left.

You get the generally idea.  The potential for storms is high.

Additional storms are likely on Saturday and Sunday

This is for 7 PM Saturday

Again, no way of knowing how accurate this model will or won’t be.  Take the general idea that more storms could occur.

10 PM Saturday

1 PM Sunday

Monitor updates frequently through the weekend.

Avoid flooded roadways.

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