Looking Into September & Tropical Development

/Looking Into September & Tropical Development

Looking Into September & Tropical Development

Good morning bloggers,

A rather interesting weather pattern is setting up for the first week of September.  There will be a tropical connection forming in the next several days that may end up increasing our chances for rain over the holiday weekend.  The tropics are becoming active as predicted it would be by Weather2020 this week 8 months ago (see the last graphic in this blog).  The peak of hurricane season is approaching and it usually will pick up in activity at this time of the year, and what Weather2020 has shown with this recent prediction is that using the LRC the location of the activity increase is predictable.  More on this below. Here is the 7 PM forecast 500 mb chart from the overnight GFS model:


The 500 mb level is around 18,000 feet above us.  This is around half way up in the atmosphere in weight, is unaffected by surface friction, and is the best level to monitor storm systems.  Tropical storms are warm core systems with the most intense part of the storms near the surface. A reflection of them is easily seen aloft, however, and we can see the development of what will likely become Hurricane Florence over the holiday weekend. There is also a tropical wave near the Bahamas that is being monitored closely.

For Kansas City there is a warm front passing through this morning, and this has triggered thunderstorms, most numerous east of Kansas City. The heat and humidity will be returning big time today with highs jumping to near 90 degrees or higher the next two days.  By Sunday, the flow will be rotating in from the Gulf of Mexico at most levels of the troposphere. This will increase moisture and will likely lead to showers and thunderstorms in Kansas City before the holiday weekend is over.


September is one of the wetter months on average in KC. And, the next 16-day total from this latest GFS model run shows that the first half of the month will be somewhat active with rain chances.


I quickly put this together showing the 8-month prediction made at the AMS conference in January as compared to the 5 and 7 day outlooks that came out the past couple of days.  Weather2020 over the past few years has made these types of predictions accurately for tropical activity, severe weather outbreaks, Arctic outbreaks, winter storms, and more.  As Real Humedude suggested yesterday, it is how it is phrased, how it these predictions are described that will continue to evolve.  This latest example, at 8 months out, we would predict the location and explain how a tropical wave is likely to target this region on the date range predicted.  And, then as we get closer the prediction will become more specific.  Either way, this is a validated LRC prediction, and I am sure most of you would agree.  These other outlooks are strikingly similar to the one that was issued and monitored for 8 months now.  The models are the models, so let’s see if anything intensifies early next week, right on schedule.

Screen Shot 2018-08-31 at 7.25.00 AM

Have a great day and a safe holiday weekend. Go over to the Weather2020 blog and join in the conversation at weather2020.com.  Thank you for sharing in this weather experience.


2018-09-01T09:10:06+00:00August 31st, 2018|General|28 Comments


  1. Michael August 31, 2018 at 8:12 am - Reply

    Here are my August rain totals for Maryville: I recorded 9 rain events through the month. The biggest total was on August 20th, with a total of 2.35″ and the least was on August 24th with a Trace. Things are really getting green again. It’s amazing how some rain helps the lawns. Now all we need is some big rains to fill the ponds. Have a great weekend bloggers!

    • Jim August 31, 2018 at 8:31 am - Reply

      Remember when these events directly hit Kansas City on consecutive days in past cycles of the LRC… yea, me neither.

  2. Tim August 31, 2018 at 8:28 am - Reply

    Come on Gary! Stop milking your LRC tropical prediction. Look you get complete credit that there happened to be a tropical wave in the area predicted 8 months ago, but thats it!!! The environment in the gulf is completely unfavorable for tropical development over the next several days– you know that, the NHC knows that, and all of the current models show that. The only chance this has for development is almost 5-7 days away before a possible texas/mexico landfall (not florida) which will not be Sept 1st as you predicted. Hey you gave it an awesome try – just let it go now.

    • Gary August 31, 2018 at 10:02 am - Reply


      Thanks for your advice. We are not by any means milking anything. It is the part of the pattern that we projected would produce a hurricane in this location, and there is still more to learn. We have been sharing this technology. There are other factors that come into play. Let’s see what happens with this wave as it moves over the warm Gulf of Mexico waters.


  3. Mr. Pete August 31, 2018 at 9:11 am - Reply

    How about a day by day detailed forecast for the holiday weekend in KC? I’m really curious about which day will be the best for rain free outdoor events.

    • Richard August 31, 2018 at 9:50 am - Reply

      This weekend may not be perfectly dry everywhere, but odds are it will be drier for many areas, or not. Depending on where your backyard is and how many trees are in your yard, and whether or not you have an umbrella with you just in case you are outside.
      As for events and festivals they might or might not be safe to go to. Again, depending if you have your umbrella, raincoat and galoshes with you. Oh, and sunscreen. Don’t forget the sunscreen, sun glasses in case the sun is beating down on you without the possibilty of any rain whatsoever.
      Otherwise I would just spend the entire 3 days inside the house watching football, golf, and looking out the window now and then.

      Have a great holiday weekend Pete everyone !

    • Gary August 31, 2018 at 9:51 am - Reply


      I thought I mentioned it. Saturday is likely the best day for outdoors and the lowest chance of rain of the three days.

      • Mr. Pete August 31, 2018 at 10:35 am - Reply

        I must have missed that, sorry!

  4. Real Humedude August 31, 2018 at 9:29 am - Reply

    More backward oriented storms today, must be a signature of next LRC I’m thinking. Its a warm front forcing thing, and warm fronts are also notorious tornado producers so maybe next severe season is something to monitor as we are due for above average tornadic year.
    Totally get Gary’s thinking on his Gulf forecast from 8 months ago, it would be nearing peak hurricane season so this disturbance had a higher chance of being a hurricane so he went that direction going for the gold. He still nailed the disturbance timing and location, just not the intensity. We must understand forecasting a Hurricane in the now is difficult, let alone months in advance. Lets give him some credit, who knows how good they might get at this type of forecast. Heck, in ten or 20 years they might be using LRC extensively in Tropical forecasting and we saw it here in its infancy.

  5. Mason - Basehor August 31, 2018 at 9:52 am - Reply

    Wow — I’m surprised to see you claim victory on this forecast.

    The forecast was not for an area of clouds and some thunderstorms (what will happen in the Gulf next week) but rather it was specifically for a HURRICANE – 75% chance.

    75% chance of hurricane tomorrow:

    90% chance of Florida hurricane landfall:

    To cite to other forecasts from this week (that will pan out to be wrong; there will be no tropical storm or hurricane) as verification is weak.

    The National Hurricane Center puts development in the gulf for the next 48 hours at ‘near 0%”.

    Ask people in Florida if your forecast verified!

  6. hoopsA1 August 31, 2018 at 10:15 am - Reply

    i will give this forecast a B for identifying when and where tropical formation was likely to develop 8 months out. i think the reason why the forecast (may not) verify is that its hard to predict wind sheer and saharian dust inhibition months in advance! Just because you have sufficient sea surface temps wont make a tropical storm or hurricane. i think next LRC he will need to dig deeper into look at the other aspects of the tropics and Africa weather features before making a prediction.

  7. Tim August 31, 2018 at 11:00 am - Reply

    Gary deserves a little credit, but no where did this forecast truly verify. I did go back and look at the NHC outlooks for the last days in august/first days in Sept over the past 4-5 years in the Gulf of Mexico or Florida, and surprisingly there was literally nothing except for Harvey. Had there NOT been strong upper-level winds in the area this would probably be a tropical storm at the very least.

    • Bobbie August 31, 2018 at 11:29 am - Reply

      Yeah this is not an LRC victory whatsoever. Another 3″ in the rain guage is though!

  8. NoBeachHere August 31, 2018 at 12:26 pm - Reply

    If I was looking at odds of a land falling hurricane, Florida at that, I’d give it a 10% chance 8 months out. One who is drivin by what the media says about would be all over it.
    Living on the Emerald Coast for over 10 years, not one major hurricane made landfall. Only two Cat 1 hurricanes made landfall, 1995: Erin and Opal. The next year I can recall a major landfalling hurricane was 2004. So there is a chance lol, a peak around the 10th of September and a 2nd peak around October 12th or so.
    Also as someoywho loves to surf, we surfers loved east of landfallling tropical systems. Clean, big swells to ride. So I’ll give to Gary for a bold forecast that in reality has about a 10% chance of happening. So let’s see what happens and if don’t fall on the 1st or 2nd, please don’t scream scam and it was going to happen anyway. Do some research, for the sake of your own learning, information and if you have a love for meteorology, read multiple sources and then come back with a wealth of info and share it.

  9. Anonymous August 31, 2018 at 12:38 pm - Reply

    I think anything that is a closed low in the Gulf in the next 10 days should qualify as a hit. Waves shouldn’t and as of now nothing has happened to validate the fcst, although the hint of something by the models has been mildly impressive.

    • Gary August 31, 2018 at 1:36 pm - Reply

      Here is the truth bloggers! First of all, the grading early, before mid-next week, is like grading a winter storm forecast five days before it hits or not. Secondly, If there is a hurricane right there, or even a tropical storm right in the predicted spot by Wednesday, would the grade suddenly be an A? Thirdly, if I would have worded it in January that the LRC indicates that there will be a wave tracking into and over that location, would that immediately go to an A grade? The truth is that the LRC is once again producing the predictability of the pattern. It is going to get an A. Now, let’s see what happens, and how to learn from this for our winter forecast, spring forecast, and tropical forecasts. We are sharing a very special thing with the bloggers. The latest Euro just came out and spins up a stronger tropical system again just as it goes over where my vision of this was in January.

      Have a safe holiday weekend.

      • Heat Miser August 31, 2018 at 2:48 pm - Reply

        So it can predict a storm will be in the general vicinity, but not the intensity or the exact location (general location).

        • Heat Miser August 31, 2018 at 2:49 pm - Reply

          If so, I give it a B+ or A- for date and location, F for intensity forecast.

        • Gary August 31, 2018 at 2:58 pm - Reply

          At the very least it provides enough information for a general vicinity and date range. As we have shown many times, it has the potential to be much more specific and there has to be a set of parameters place on the specifics. Somewhat like us predicting 1 to 4 inches of rain in the next week, which is certainly seemingly likely. How specific will we get with a forecast of 1-4 inches of rain? If you say there will be 3″ of rain at your house, and then you only get 1″ of rain, then is that forecast wrong? There is one level saying “1 to 4″ at your location. Then, the next level up saying 3″ will fall at your location within 0.25”. We would say there is a 90% chance of the first general prediction, and perhaps a 40% chance of the more precise prediction? I am just thinking out loud here. So, in the hurricane predition, we could say there is a 75% chance of a tropical wave intensifying right over our targeted spot, with a 25% chance of storm formation. Something like that, at 8 months out.

          • NoBeachHere August 31, 2018 at 3:41 pm - Reply

            I agree . It’s a bold forecast 8 months out.

  10. JoeK August 31, 2018 at 4:29 pm - Reply

    From my prospective, the much larger ( and probably most important) point to the forecast is being overlooked. While many of us weather enthusiasts are very tough on a forecast and understandably so, I believe the LRC forecast made 8 months ago will definitely grab the attention of those in the weather community and more specifically, the NHC. This bold forecast proved what the average person can’t see, that the possibility and set-up for tropical development can be predicted far in advance. if you take a minute and think about the impact this can and will have on the future of forecasting, it has the potential to be groundbreaking. With that said, everybody has their opinion, some valid and some not so much. I am confident that Gary and his team will learn from this and their knowledge of forecasting with the LRC will continue to evolve. Bottom line, it doesn’t matter what we think as we are not the experts. What matters is what this means to the hurricane impacted community. Respectfully,Just my two cents

    • Blue Flash August 31, 2018 at 8:47 pm - Reply

      Well said!

  11. Mike August 31, 2018 at 9:55 pm - Reply

    Super Typhoon has formed in the Pacific. A very active typhoon year in the Pacific.


  12. NoBeachHere September 1, 2018 at 8:01 am - Reply

    Now getting my third thunderstorm this morning. Adding to about 3/4 so far. Love it

  13. Michael Casteel September 1, 2018 at 9:07 am - Reply

    I recorded .78″ up in Maryville, MO this morning! Things are really getting green. Hoping to mow yard before next shot of rain. NOAA got us getting over 2 inches by Monday night! Ponds will be filling up! #DroughtBusted! Have a great weekend Bloggers!

  14. Anonymous September 1, 2018 at 10:47 am - Reply
  15. Anonymous September 1, 2018 at 10:49 am - Reply
    • Anonymous September 1, 2018 at 10:49 am - Reply


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