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The Gary Lezak Weather Blog

Another Rain Event Moving Across The Plains

Happy Friday Weather2020 Bloggers,

The next storm is moving out of the western states and into the Rocky Mountains and plains states.  This would usually be a set-up for severe thunderstorms, but instead is mostly going to be a generous rain producer and right over that developing drought area that the Climate Prediction Center had placed weeks ago. It has been obliterated. It’s gone. The drought monitor will likely fizzle it away in the next update or two. It has rained too much. Look at this rainfall forecast over Kansas, Nebraska, Oklahoma and east into Arkansas and Missouri:

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The blocking pattern continues. The upper high over Greenland is filling an falling apart. A new high over low blocking pattern is developing today over the western half of North America as you can see below. Look a the 564 line that goes around both upper lows and then up and over the upper high north of North Dakota:

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A wave of energy will rotate through tonight.  On Saturday the lead upper low will likely begin weakening and this is why the severe weather risk is much lower than would be the case in any other year with a pattern like this. There is still a risk today and tomorrow.

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Have a great day, and thank you for participating in the LRC Forecast Experience Blog. I will write up a new blog entry later in the day on Saturday.

Gary

Thanksgiving In April: The Incredible Cycling Pattern

Good morning Weather2020 bloggers,

The active week of weather that is tracking across the United States has not calmed down yet.  Another storm is moving into the western states and out into the plains this weekend. We are experiencing a weather pattern that has never happened before in the history of Earth.  This is one of the major aspects of the LRC which is a unique pattern sets up every year in the fall, cycles, and continues through the rest of fall, winter, spring, and summer before a new and unique pattern sets up again the next fall. We are currently in the fifth cycle of this year’s pattern.

State of the LRC

Screen Shot 2016-04-28 at 7.22.55 AM

We are currently cycling through what we named “The Thanksgiving Weekend Part Of The Cycling Pattern” in LRC Cycle 2.  I numbered the similar features from April 27th and November 30th.  Remember, we have been showcasing the 47 – 52 day cycle since it set up last fall, centered on 49.5 days. What is 49.5 times 3?  The answer is 148.5. And, these two maps are 149 days apart. And, incredibly, 1/2 day later, in that first cycle, the features lined up even more perfectly.  Look at the rainfall from each cycle in Kansas City. This five day total was 19% above the entire monthly average for November and 22% above the entire April monthly average in just five days in LRC Cycle 5.

There are seasonal differences. And, in this cycle there is a big block over Greenland which has forced the storms to stay farther south as you can see below:

LRC Cycle 5 April 27 GFS. F

The upper high that formed over Greenland, which didn’t quite happen during the winter, even though it tried a few times, has forced the jet stream to be a bit stronger and farther south than normal for late April.  But, realistically as I showed in the comparison this morning, it is really just the same pattern, but just a seasonal difference. It has benefitted Kansas City by bringing some badly needed rainfall. It’s too bad it never happened during the winter.  I did get soaked on Thanksgiving Day during the soggy Plaza Lighting Ceremony, however.

Okay, that took me two hours to analyze and put together. Now, what is next? We are still in this Thanksgiving week part of the cycling pattern. If you remember, that lasted more than just these five days of stormy weather. It was around a ten day stretch in November, and it isn’t over yet.

day1otlk_1200 (1)

There is a risk of severe thunderstorms from the weakening storm over North Carolina, and from the new storm system near the Red River valley of Texas and Oklahoma where I am sure storm chasers are heading.

By Friday, the surface gets a little more menacing, what the storm chasers want it to look like.  Because of the blocking, mentioned above, a cool late April/early May pattern is now in full force.  This is the set-up for Friday:

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The surface low, triple point, will be just northwest of Childress, TX and the target chase areas will be ahead of the dry line where there will be adequate moisture and warm air available for super cell thunderstorms.

Now, remember every year’s pattern is unique, and what happens next to this storm is really going to be interesting to watch happen. It is actually somewhat similar to what happened to the storm yesterday, but this time it’s even cooler farther north and this will mess with the surface set-up for Saturday:

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I am telling you, I have never, ever, seen any pattern do this type of evolution. Oh, maybe there have been similar patterns in the past, but not quite like this. Let’s see how this evolves. The warm air will get separated from the storm, so the severe weather risks will weaken as we move through the weekend and they will most likely stay south.

Storm chasers better get out there, because after this goes by, there will be a break just like after the Thanksgiving part of the cycling pattern. It will take around a week, but then we can look for the “signature” part of the pattern, yes that big storm that has produced major snows in Colorado in the last three cycles. That is due back in here around the second week of May.

Thank you for participating and learning more about the LRC. Yes, I have been working on this since the 1980s, but we learn more every day.  Let us know if you have any questions or comments.

Gary

 

Recap Of Severe Weather Tuesday & A Look Ahead

Good morning Weather2020 bloggers,

Well, it’s about time. A wide spread rainfall event finally hit the Kansas City viewing area for the first time in quite some time.  Now it still mostly missed areas just three counties east in Sedalia with 0.28″ and Chillicothe, MO with only 0.58″.  Look at what fell around Kansas City:

rain gauge2

This rain gauge was posted by Trevor McDowell in south Independence, MO where over 3″ accumulated at his house.  Over 4″ fell at KCI Airport and there has been some flooding.  KCI Airport is suddenly up to over 6″ of rain for the month, and above average for the year.  Weather2020 forecasted that this pattern just had to start producing, and it took a very long time, but it now has!

The severe weather outbreak did materialize, but it just wasn’t a tornado outbreak. Why weren’t there many tornadoes?  The shear, the changing of winds in height, was weak in directional shear, but strong in vertical speed wind shear. What do I mean? The hodographs didn’t have a lot of turning, which means we had a south wind near the surface with also a south wind higher up in the atmosphere, so there wasn’t a lot of turning of the winds aloft as usually happens in the bigger tornado outbreaks. This limited the potential for super cell development, and increased the potential for training echoes and heavy rain. The vertical speed wind shear was strong, however and this is also a very important factor. The winds speed increase as you went 6,000 feet to 30,000 feet up was quite strong and this helped produce some broader rotation to the thunderstorms and helped with the updrafts to produce some of the hail that fell.

Severe weather reports yesterday:

today

As you can see, there were 458 total severe weather reports, but only 5 tornado reports.  Now, this storm isn’t quite done yet. Let’s look into today’s set-up.

Today’s pattern

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There is a slight risk of severe thunderstorms from southern Iowa extending south to the Gulf coast of Louisiana.  This water vapor satellite picture, enhanced with the colors showing the most water vapor and the highest cloud tops, shows this storm quite well this morning:

SAT_EUS_WVENH

A surface low is occluding as this storm drifts across Kansas and Nebraska. We will be monitoring disturbances rotating around the main storm for what may end up being an interesting band of convective showers and thunderstorms this afternoon.

We will look ahead to the weekend storm in tomorrow’s blog.  Thank you participating in the LRC Forecast Experience Blog. Let us know if you have any questions and have a great Wednesday.

Gary

Severe Weather Risk Increases

5:52 PM Update

Topeka is about to get another one. This is the third cell to come over this area, and this one is a strong line. Kansas City has to wait another few hours…….again.  Michael, and other Topeka residents, let us know how much rain you receive.

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4 PM update:

Strong thunderstorms are approaching. You can watch us live at kshb.com or on 41 Action News. The risk of severe weather is increasing. I won’t be able to check in for a while! Stay safe everyone!

Previous entry below:

Good morning again Weather2020 bloggers,

Look at this hail stone that fell over Kansas City this morning. You can see the original raindrop that froze, and then the violent process to create the layers. There are at least four layers, which means this hailstone went up and down inside the turbulent updraft which was likely right next to the downdraft. It got caught in it and formed into this quarter sized hail stone:

Hail Layers

How to report hail? Use this chart:

Hail

The risk of severe thunderstorms is increasing across the plains today. There is a chance of a significant to major severe weather outbreak. In big outbreaks morning thunderstorms that happen early and then move off are showing some of the cards that will be in play later in the day. The fact that these thunderstorms are moving towards Kansas City this morning indicates that there is a good chance they will target this area again this evening.

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Sunny The Weather Dog is showing the big cumulonimbus cloud building over her head. Could the “ice” finally be breaking on the overall drier pattern. We have had adequate rains, but nothing wide spread.  This could be changing in the next ten days with a series of storm systems moving out into the plains.  Sunny looks wet and sad because she really didn’t like posing in the chair, and she had just ran through some sprinklers. Now, on truly breaking the “ice”, areas just southwest of this complex of thunderstorms are still quite dry.

Screen Shot 2016-04-26 at 7.16.02 AM

These thunderstorms were already producing some large hail as of 7:30 AM.  That big thunderstorm complex northwest of KC is turning southeast. This has to be watched closely for a bowing out and possible high wind event. So far there hasn’t been much wind, mostly hail.

Severe Weather Set-up For Later Today

There is a good chance of a major severe weather outbreak today. The largest risk appears to be setting up from the Nebraska/Kansas border south through Wichita, KS and down through the middle of Oklahoma.  This is targeting the traditional tornado alley region:

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The yellow hatched area indicates a 10% chance of a strong tornado within 25 miles of any point. This is pretty strong, but not the highest category. Kansas City is still in the 5% chance of a tornado within 25 miles of any spot.  Everyone should be monitoring this very closely. I will be quite distracted at 41 Action News tonight and I will check into the blog from time to time if I even get a chance.  We will also be updating the KSHB blog as well.

The morning thunderstorms may affect the afternoon set-up. But, it also may just strengthen the warm front and make it even more threatening. I am not sure yet. I will analyze the new data and finish this blog by noon today, so  check back in….

After analysis of the 12 PM surface map, the warm front and outflow boundary have made it to Emporia where it is now stalling. It will likely begin drifting north.  The surface pattern is just now beginning to reorganize. The moderate risk is still in place, in the same spot as earlier. We are expecting explosive development of thunderstorms later this afternoon and evening and this activity would then move north to northeast as a strong wave rotates around the base of the upper level storm.

There is another interesting setup for Wednesday, and then another outbreak look to around Saturday. Let’s stick to today for now.

Thank you for participating in the LRC Forecast Experience Blog. Have a great evening and stay safe!

Gary

Severe Weather Outbreak Possible Tuesday

Good morning bloggers,

The weather pattern continues to cycle according to the LRC. I will show you where we are in a minute, but let’s begin with the day 2 severe weather risk from the Storm Prediction Center:

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The SPC has already placed a large moderate risk area from Nebraska south across central Kansas into Oklahoma.  Conditions are coming together that may result in a major severe weather outbreak tomorrow.  Here is a picture of some large hail the fell over Kansas yesterday. Carl Hobi, one of the 41 Action News storm chasers, experienced this. I doubt his car is in good shape:

hail

Tuesday’s Set-up:

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The Convective Available Potential Energy (CAPE) is forecast to be very high along and ahead of the dry line, and near the warm front and triple point.  This is a lot of energy that would be released if thunderstorms form, when thunderstorms form.

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This is a rather complex set-up for Tuesday into Tuesday night.  Just like the LRC, every pattern is unique each year, and every severe weather set-up is unique. This one features a low pressure area forecast to be near the Colorado/Kansas border near Goodland, KS.  A warm front extends out across northern Kansas into northern Missouri near Kansas City.  And, there is a dry line that will be interesting to plot as we move through the day Tuesday.  Where these features are located will be important for the initial thunderstorm development.

Here is what the SPC wrote up in their day 2 outlook:

“SIGNIFICANT SEVERE THUNDERSTORMS WILL BE POSSIBLE ACROSS PARTS OF
THE SOUTHERN AND CENTRAL GREAT PLAINS TUESDAY AFTERNOON INTO THE
NIGHTTIME HOURS. TORNADOES…SOME STRONG…WILL BE POSSIBLE…IN
ADDITION TO VERY LARGE HAIL AND DAMAGING WINDS. ADDITIONAL ISOLATED
STRONG STORMS ARE POSSIBLE ACROSS PARTS OF THE OHIO VALLEY TO THE
MIDDLE ATLANTIC COAST REGION.

…CENTRAL AND SOUTHERN PLAINS…

…FORECAST PARAMETERS CONTINUE CONSISTENT SIGNAL FOR POTENTIAL
SEVERE WEATHER OUTBREAK ACROSS PORTIONS OF THE CENTRAL/SOUTHERN
PLAINS ON TUESDAY AFTERNOON/EVENING…

DETERMINISTIC AND ENSEMBLE GUIDANCE CONTINUES TO BE CONSISTENT WITH
BRINGING A NEGATIVELY TILTED TROUGH INTO THE PLAINS DURING THE
AFTERNOON/EVENING ON TUESDAY. A 60+ KT SOUTHWESTERLY MIDLEVEL JET
WILL OVERSPREAD TX INTO OK/KS BY EARLY AFTERNOON WITH STRONG DCVA.
THIS WILL BE ALIGNED WITH A SURFACE DRYLINE STRETCHING S/SW FROM
ROUGHLY CNTRL KS…WRN OK AND W-CNTRL TX BY 00Z/WED. THERE IS STILL
SOME VARIABILITY IN GUIDANCE WITH REGARDS TO THE SURFACE LOW
POSITION…BUT EXPECT THIS TO BE SOMEWHERE NEAR THE KS/NEB BORDER
WITH THE ATTENDANT WARM FRONT STRETCHING W-E NEAR/JUST NORTH OF THE
KS BORDER AT 00Z. RICH BOUNDARY LAYER MOISTURE WILL RESIDE ACROSS
THE WARM SECTOR WITH DEWPOINTS IN THE MID 60S TO NEAR 70 AS FAR
NORTH AS S-CNTRL/SE NEB. STRONG INSTABILITY AND VERY STEEP MIDLEVEL
LAPSE RATES WILL BE IN PLACE BY AFTERNOON…AND STRONG HEATING NEAR
THE DRYLINE SHOULD RESULT IN CONVECTIVE INITIATION BY LATE
AFTERNOON.

CONCERNING CONVECTIVE COVERAGE…UNCERTAINTY INCREASES WITH
SOUTHWARD EXTENT ACROSS OK INTO N TX. DEPENDING ON YOUR FAVORED
MODEL DEPICTION…A BI-MODAL COVERAGE PATTERN IS POSSIBLE WITH THE
INITIAL VORT MAX EJECTING NORTHEAST ACROSS N-CNTRL OK INTO KS AND
S-CNTRL NEB. ANOTHER VORT MAX WILL EJECT FURTHER SOUTH ACROSS
CNTRL/NRN TX LATER IN THE EVENING. THIS COULD LEAD TO A RELATIVE MIN
SOMEWHERE…BUT WHERE THIS IS REMAINS UNCLEAR AT THIS TIME.
REGARDLESS…AT LEAST ISOLATED TO WIDELY SCATTERED INTENSE
SUPERCELLS ARE EXPECTED ALONG THE DRYLINE…WITH GREATER COVERAGE IN
THE VICINITY OF THE TRIPLE POINT WHERE FORCING AND SHEAR WILL BE
MAXIMIZED. STRONG /POTENTIALLY LONG-TRACK/ TORNADOES…VERY LARGE
/PERHAPS GIANT/ HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE WITH
ANY STORM THAT DEVELOPS ACROSS THE WARM SECTOR. AFOREMENTIONED
COVERAGE CONCERNS WILL PRECLUDE A HIGH RISK AT THIS TIME.

DURING THE EVENING INTO THE OVERNIGHT…STORMS MAY GROW UPSCALE INTO
AN MCS OR BOWING SEGMENTS ACROSS ERN KS INTO MO. WHILE A TORNADO
THREAT WILL LINGER NEAR THE WARM FRONT…A TRANSITION TOWARD MAINLY
A LARGE-HAIL AND DAMAGING-WIND THREAT IS EXPECTED WITH EASTWARD
EXTENT OVERNIGHT. ACROSS NRN/CNTRL TX…STRONGER FORCING WILL ARRIVE
DURING THE EVENING INTO THE OVERNIGHT HOURS AND SUPERCELLS MAY
DEVELOP LATER THAN FURTHER NORTH. THIS COULD LEAD TO A NIGHTTIME
TORNADO RISK BEFORE STORMS POTENTIALLY GROW UPSCALE AS THEY APPROACH
NORTHEAST TX. ADDITIONALLY…VERY LARGE HAIL AND DAMAGING WINDS WILL
BE POSSIBLE.”

That is one rather strongly worded discussion. Let’s see how the models come in this morning.  The first thunderstorm development from this storm may occur early in the day, and this is something to watch. On outbreak days, there are often morning strong to severe thunderstorms that showcase where the best parameters may line up later in the afternoon. Some of the models ignite thunderstorms around 5 AM over eastern Kansas, so let’s see if this materializes and shows up on the new model runs.

Weather Time-line for Kansas City

  • 5 AM – Noon: A few thunderstorms, high based, may produce severe hail and possibly damaging winds in isolated spots in the morning. The tornado risk is low
  • Noon – 6 PM: Most likely dry as we wait for the thunderstorm development.
  • 6 PM – 2 AM: This is the most likely window for the worst of the severe weather. There is still some uncertainty over which area will be targeted.


The LRC

Are you ready to open your minds? There are around 1,00o of you that read this blog every day, not bad really. One thousand of you, and I appreciate every one of you.  What I am about to explain and show you will take a few minutes for you to seriously look at these first two maps.  We are currently in the Thanksgiving weekend part of the pattern, a part of the pattern that actually had a series of storm systems drop into the western states.  This series of storm systems produced a, what is called a long-term long wave trough, trough in the the western states that took a week to move east.

LRC beginning of Cycle 2:  November 30, 2015    150 days before April 28, 2016, LRC Cycle 5

LRC Cycle 2 November 30

LRC Cycle 5 April 28 NAM

Look at the high over southwestern Canada on the top map.  And, take a look at the 558 line that dips south over Seattle, and then goes up and over western Canada.  The same pattern is cycling through now, and these two maps just happen to be 150 days apart, November 30th on the top 500 mb verification chart from the beginning of LRC Cycle 2, and April 28th, from the beginning of LRC Cycle 5. It’s the same pattern! But, of course due to the seasonal affects, a bit different.

And, maybe you are hearing we are rapidly changing to La Niña from El Niño, well…..this is not the case. We are still in a strong El Niño, but it is gradually weakening. The same pattern continues regardless of the ENSO conditions.  This is an influence, but something bigger is going on, and the LRC is the centerpiece of this big difference.

Have a great day!!!!

Gary