LRC - Surface Analysis carryover discussion?

Thought I would offer this space for continued discussion away from the KSHB blog. Very good and spirited discussion!

Severe Weather?

I heard from Devin Lucie from KCTV [TV left on from March Madness] last night that "severe" weather may be possible on Thursday.

Quite a claim 5 days out. I think I see some potential, but I am not going out on that limb yet.

Some folks have asked what I look at when I determine severe outlooks…this blog will walk you through it.

Here are some details to the setup....

Here is what the SPC is already graphing…


Here is the key to this storm for this area, I believe…

“STRONGEST OF WHICH MAY CROSS NRN ROCKIES D -AY-4/26TH-27TH...THEN N-CENTRAL PLAINS AND UPPER MS VALLEY DAY5/27TH-28TH. ECMWF/UKMET ARE VERY SIMILAR WITH THIS EVOLUTION AND RESULTANT SFC FEATURES...WHEREAS MORE DISPARATE GFS RUNS FROM DETERMINISTIC AND MREFS APPEAR TO BE LOWER CONFIDENCE SOLUTIONS. UPPER PATTERN MOST PROBABLE FOR DAY-4 SHOULD RESULT IN INCREASINGLY WELL DEFINED SFC DRYLINE CENTRAL/SRN PLAINS...BUT ALSO ROBUST ELEVATED MIXED LAYER WITH ATTENDANT CAPPING CONCERNS...AND STRONGEST MOISTURE RETURN DISPLACED HORIZONTALLY FROM MOST FAVORABLE LOW LEVEL LIFT.”

So as seen above, I check the SPC and see what they got. Second, I look at the GFS for that time period…

I have pulled up the 2m map for day 4 first. 90hr. I have drawn in the front with warm front and what I think is the dryline. [bare with me..still learning synoptic scale drawing]


So..as you can see..we are right on the warm front in this picture.

The 700 mb does not show much of any moisture, so I would expect little clouds at this level for this day.

We may have an opportunity for some convection would be my thought. So, let’s check out the forecast sounding…



This is not a pretty skew T for severe weather. Yuck.

Little CAPE, CINH [cap] is abundant, and we are seeing little of any surface based convection. Warm air aloft is evident at the 800mb level of this graph. This is the “capping” mechanism. Surface heat and convection would need to exceed this at the surface to bust it, or we will need some lifting from upper air forcing.

Unfortunately, the 500mb vorts are in N. Nebraska..so I am not feeling there will be enough forcing yet to bust this cap. So..I would say atleast for Thurs..there is little chance right now of severe weather in the metro.

This is the same analysis I would do for Friday.

I would look at each level of the atmosphere.

500 – for lift and possible PVA. Also, how much moisture is it bringing with it?

700 – How much moisture is there? Are we overcovered with moisture. This may be an indication of cloudy skies. Could we get enough convection? Or is this an elevated scenario?

850 – Where is the frontgenesis…if any? Where is the front? Is there an 850 low that may give some lift?

Surface – What are the 2M temps? Where are the winds coming from? What are the surface features. Is there a low, dryline, cold front, or warm front near by? Where is it expected to track?

Skew – Inversion? CAPE? CINH? LI? Does the sounding give us a handgun shape? Many other parameters as well…when we get closer, satellite, WV, mesoanalysis tools, etc will come in useful.

This is just a glimpse into the analysis that I do going into a severe setup….

Fun, huh? Then..once the scenerio is locked in to strong potential..then you have to go out and catch one of those crazy storms...

I am ready for Spring!

For Grins - Another chart

Ok..I still have alot of work to do on my charts, but I posted one about a week ago, and had no response. Here is another using some of the same data..but presenting it a bit differently.


This is a graph for the precip trends this year set up on a 54 day cycle.

Here is what I did...


1. Took actual precip data from KMCI from August 1st, 2007 to a few days ago. The is the F6 product information.


2. I assigned values to ranges of precipitation.

For T-.25 I assigned a value of 1
For .25-.75 I assigned a value of 2 and
For >.75 I assigned a value of 3.


Then I charted the data in a bar chart for each cycle duration. In this case, there were four cycles. Then I applied a 3 day moving average trendline to each cycle graph.


At this point, I removed the bar charts leaving each graph with the trendlines to help smooth out some of the anomolies and to show the overall trending.


I took each of the cycle trendlines and overlayed them on one another. This is what you see above.


I painted in the common cycle as I see it. Others may interpret it differently. I am confident with the first part of the cycle duration, while seeing that the back end is a bit more variable.


More cycle data will help with determining if the backend of the cycle has more definite traits.

Dare I ask what you think? Is there a better way to show this stuff?

I will work a bit more on the temp one...that is a bit tougher, but I am going to try the same method with it as well.

Administration Change

Due to the potential name stealing of anonymous comments, I have re-enabled login registration.

Sorry for the inconvienece, but seems to be the most fair way to create accountability and reduce confusion or imposters.

If you are a regular poster, you will take the time to do the very quick registration.

Thanks.

A bit about soundings

Folks, I am not an expert on soundings, but I do use them during spring time analysis for severe weather.

I will not be the all telling source as how to use them. I do not use all the info available. Much of it is helpful, but without other sources...its hard to get a true sense of the environment from just one site.

That said..what is a sounding?

A sounding is a recording of atmospheric conditions from a weather balloon launch. Often times, they are sent up at 0Z and 12Z daily from a weather office. During potentially severe days, you may see several instances of soundings.

A sounding provides a great deal of information. I use a sounding for a couple things.

1. Lapse rates. How much does the temperature change with height? This gives an indicating of lift.

2. CAPE - measurement of instability. How unstable is the environment? Where is it unstable?

I won't go into this much as books likely are written on instability.

3. CINH - what kind of inhabition is there to development? This is a good indicator of capping.

4. PW - Precipable water. How much moisture is available in the atmosphere?

5. Sheer - how much sheer is available, and at what level? Is there veering with height?

Here is a great page for more detail....

http://www.spc.noaa.gov/exper/soundings/help/index.html
also this...
http://www.theweatherprediction.com/thermo/parameters/

Soundings can be represented several ways, but the one I use is skew-Ts. The definition and differences can be found in the links above...no need to rewrite it.

There are two sites I use for sounding data...

1. http://www.spc.noaa.gov/exper/soundings/
2. http://rucsoundings.noaa.gov

Knowing basics of soundings will give you an idea of what you are looking for in the atmosphere in upper and mid level data. Also, it gives clues about how the future atmosphere will respond to the upper levels.

A sounding was useful already this Winter for me when looking for ice storms or what kind of precip would be falling. By looking at the moisture profile and where it was in relationship to the temp gradient, one could tell where in the atmosphere it might warm above freezing or refreeze.

Anyway..enough for now...hope you liked it!

Spring Forecast

Anyone want to see this?

RE: March 13th and some fun

Another quick verification…

Initially posted Jan 13th. Date of storm changed two days forward on Feb 17th.

All before model data was available.

“The second week of March will bring a quick shortwave through around the 13th. Expect precipitation to be light based on location and the progressive nature of the storm. Expect temps to be cooler than mean for the early part of the week warming up toward the end.”

First, lets look at the quick shortwave.

Check.

Second, lets look at the precip amount.

Trace recorded at KMCI. Those who read regularly know that is the point where I am basing the cycle upon for F6 data.

Check.

Third, lets look above at the temps through the 7-14th [second week of March]

Check.

Darn good forecast.

So..lets have some fun with analogies. Sometimes these are good to illustrate a point.

Lets consider that we can break down this forecast into four elements:

Quick shortwave
Light Precipitation
Cooler in the early week
Warmer in the later week.

So, someone might think that each of these could be considered a 50/50 proposition disregarding the cycle concept all together.

Ok. So…another similar comparison of a 50/50 bet would be a coin flip. But in this case, it would be four coin tosses all needing to be – say- heads. Assuming coincidence in verifying my forecast…I can see this analogy being plausible?

So..what is the odds of hitting four out of four in a 50/50 prop? 1/16

6.25%

This would indicate by chance, 93.75% of the time some other combination would occur.

LOL.

Anyway…. I am sure some will take this too serious, but I am having a bit of fun. Did I revolutionalize the wheel by predicting a small storm of little significance? No.

But..all the same, I did forecast a series of events for a given time period in a somewhat finite range far ahead of any model data. I think that must count for style points…

Ha.

So, upcoming week…here is what I had.

“The third week of March brings one of the stronger matches for a storm on March 23rd. Expect this storm to pack a punch. This will be another potential for severe weather. Expect half an inch to an inch of rain, quick moving, but having a large temperature gradient. Warm up a day or two before the storm will enhance the convective potential. This will align with a powerful cold front. The air behind the front will bring very cool air below normal mean temperatures.”

Right now the storm in question is showing up on the GFS for March 22nd. We will see what happens. The GFS is notoriously biased to be fast in long range. But..too far to tell right now. Still a fantasy in the models.

What Next?

So..what do you all want to see now? I can go into my Norman trip, I can do some more cycle graphs, I can do some other information such as satellite analysis/presentations...

What do you all think? I think probably most folks are burned out on cycle analysis for now...give me some ideas of what you want to see.

If you don't comment, I won't know. Just drop a line.

LRC Margin Propagation Thoughts

Repost from KSHB blog:

I understand that the patterns have some variability. I have seen it. I think my concern is two fold.

We hear this cycle "averages" about 50 days. It can be 47 or up to 56 days. Let me propose a scenario.

Cycle 1 – First event on the first day or DAY 1 cycle 1

Cycle 2 – Repeat of first event one day later than 50 days. 51 days.

Cycle 3 – Repeat of second event four days later than 50 days. 55 days.

Cycle 4 – Repeat of third event two days sooner than 50 days. 52 days

Cycle 5 – Repeat of forth event 7 days later than 50 days. 59 days.

So…what was the event starting on the first day of the first cycle now would show up as the same event on day nine of the fifth cycle. Nine days out of sync.

Look at this very real scenario – Help me understand two questions….

Based on the variability, what could be predicted for Cycle 6? Based on the calculations and extension of the variability, it would be about nine days off the “average” cycle, but within the range presented of 47-56 days. Unless you are keeping a total of plus or minus days as a running count cycle to cycle, you would never be able to related the event of the fifth cycle to that of the first. Without explaining this method, people would think you would be nuts to assert it is the same event with an average cycle duration. Maps would not verify.

So, this answers the question that Notes presents: “Why not run out the forecast 6 months if the cycle is known?” For this very reason. The extension of a variable into subsequent cycles makes longer range forecasting problematic based on this method as the variability range would continue to broaden further and further beyond any usefulness.

This is why Gary goes no further out than 45 days. Within that range, you are dealing with a much smaller error propagation since the time duration is within one cycle’s time.

Second – How do you prove out with maps this event with each cycle? You will have problems. Because you have a nine day variability with this cycle event, the margin of error is too great to have statistical significance. Because map analysis is somewhat subjective to start, adding in a range of nine days to find a similar subjective pattern in each cycle position is not good enough to prove this out.

This said, based on this method of analysis, it will be very difficult to prove. However, from a broader perspective in pattern recognition, if you see an event [any event..not just weather] that proves to have specific characteristics that can be identified – happening every 50-59 days – this is enough to provide evidence of a pattern or cycle.

I think the question becomes – how do you prove this, and how do you make it operationally effective in long range forecasting? I think Gary is showing how it can be used in a 45 day window, but because of the variability and seasonal changes – there is a reason why the forecast is somewhat vague and cannot go further out.

I think the critics wanting to push out the forecast even longer or with more detail is somewhat baiting based on the thoughts above. I-for one- have fallen into the trap; hook, line and sinker. I thought initially it should be easy to run out forecasts if the cycle was tighter. I have had marginal success. I don’t think the cycle has as much variability as Gary does, but I still run into the same problems because of the granularity I go to.

All said, I guess it depends on what you want to do with the cycle. If you need trends – this is a great tool. If you are seeking statistical proof of the cycle’s existence…you will need to wait awhile as the current method does not seem robust enough yet to provide that data.

Perhaps further analysis, surface trend blending and other methods could be used to bring numerical proof.

Maybe.

BUST! - The rest of March

Folks - I blew it! Here is what I had for the first week of March into the second week.

"The first week of March will carry on the warm trend of 5-10 degrees above mean. Expect the first big storm around the 10th/11th. Temperatures right before the front will be very warm. I would not be surprised to see mean temperatures 15-25 degrees above mean. This means we could get near 80. As the front passes, expect potential thunderstorms and a potential of severe weather. The temperature gradient with this storm looks potent. Looks to be enough precipitation available per the trend to give half an inch. Following this front, expect the second week to drop 5-10 degrees below mean."

While I had two days way above normal for the 1/2nd, the rest of the week has been way below normal. I am trying to figure out where this cold spell came from. It doesn't match. Is it early, is it late, is the cycle off?

Dunno. I have to research it. I think the cycle is still good as the precip for forecasted in the next two weeks looks very strong. The 13/14th and the 23/24th look good on models.

Lets talk about the 10th. I missed it. I was expecting a repeat of January 16th with moisture this time. I added in what I thought would be the setup for March, and just plain blew it.

Back to more analysis. Given the forecast was put out about 2 month ago, I am not going to beat myself up too much. Also, because the precip is still in line...I wonder if it is possible that the precip and the temp cycles could be different? Dunno, but I cannot rule it out.

So, here is the rest of what I have for March:

{{{{{{Remember..this was done on JANUARY 13TH!}}}}}}

"The second week of March will bring a quick shortwave through around the 13th. Expect precipitation to be light based on location and the progressive nature of the storm. Expect temps to be cooler than mean for the early part of the week warming up toward the end.

[note - thus far the temp part of the second week looks about right]

The third week of March brings one of the stronger matches for a storm on March 23rd. Expect this storm to pack a punch. This will be another potential for severe weather. Expect half an inch to an inch of rain, having a large temperature gradient. Warm up a day or two before the storm will enhance the convective potential. This will align with a powerful cold front. The air behind the front will bring very cool air below normal mean temperatures.

The forth week will be soggy. Expect several days of rain. Temps will be cool and vorts swinging through will give a feel of uneasiness regarding thunderstorms. While severe potential is not evident through regular frontogenesis, forcing will be available with a very active vorticity stream from the SW. Will have to keep an eye on this. Expect temps to swing a bit as each storm comes through, but temps will average below mean norms.”

So - critics...I did loudly announce the BUST...but, do you throw the baby out with the bath water?

First Shot at Graphical Cycle Analysis

So, this will be an interesting entry. I expect some - well pointed feedback.

LOL

I have been working in the last two weeks on putting together some more statistical data in a graphical format to show the cycle.

This is not as easy as I thought it would be.

But - that said here is the first attempt. I am going to work on other ways to do this as well.
So, let me set up the graph. Here is what I did to make this a bit easier to look at. As I recorded the actually precip totals from KMCI, I alligned the days to a 54 day cycle which I believe exists.
So far, pretty straight forward. Nothing funny with doing that. The second thing I did was assign a value range to the precip amounts. Below is the criteria I applied:

T - .50 inches - 1
.51 inches to .99 inches - 2
1 inch or over - 3

In doing this, I am able to show in a blocky manner where precip existed and at the same time provide some measure to show the intensities of the event. I chose this method as it made it easier to see via this method.

Before I get hammered on this, I am sure there are other methods, and I welcome all suggestions on how to show it. This is the first attempt.

So, without futher ado, here is the graph.

In the notes below on the graph, I try to explain what I see. Here is some further thoughts...

There are two pieces of the cycle that show a very strong trend, A and B. If you look at the color matches of each cycle, the intensity of the results, and compared to the rest of the cycle, you see evidence of a match.

C,D, and E are weaker matches. These would not be the events I would choose to prove the cycle, but I do consider these as weaker matches when forecasting the next cycle. Because of a loose match of either some but not all of prior cycles matching, or a wide variance of precip that was recorded, I keep it in mind as a potential.

It is usually in these types of weaker matches, that I compare to temp matches to see if I can get a feel for setup. For example, if I were looking at E that shows 2 out of 4 cycle matches and similar precip amounts, I would look at the temp trends too see if I have a warm to cold transition in that time.

If so, then I might presume this to be frontal type storm. Factoring in time of year and jet location, I would begin to formulate a forecast for this storm potential.
If I found a constant or non descript temp trend, I would consider it to be more of a shortwave type set up. For that, I would greatly minimize potential, but would still mention its possible arrival.

Does any of this make sense? Am I the mad scientist that is speaking crazy talk?

Dunno, it seems valid. I will continue on with other ways to show this. I have the temp trends done, but am trying to find the best way to show it in a graphical method. Right now, I have it as moving average trendlines to show the movement up and down within the cycle.

I see some strong trends, but because of the fluxuations, I don't feel it is ready to show without some manual intervention. I will continue to work on it.

Again, any suggestions would be appreciated!

Ok...have at it.

;-)

National Severe Storm Workshop - 2008

Well, I am half way through at this writing. The first day was very insightful. For those wanting to learn more about weather, I would almost consider this a better investment than spending money on chases or other activities.

Perhaps I should qualify that. For tactical awareness, spotting and chasing is probably better, though this workshop has an awesome spotting class taught by folks from the SPC.

This workshop focuses on three aspects. First, the building of relationships between media, NWS/SPC/NOAA, and the EMS workers. This is a central focus. The second is some specific detail to upcoming projects, current projects, and some detailed explanations of basics that are used by forecasters such as model analysis, radar analysis, and satellite analysis. Third, you have a great opportunity to talk with a great cross section of people that share a similar interest.

I think the sharing of information by the NWS/NOAA/SPC and the different cross sections of folks is the most beneficial.

I have learned a great deal again this year. Good discussion on dual pole doppler, phased array, and a very nice presentation/discussion on mesoscale tools and modeling. This last feature will help me greatly as we continue into the Spring. Much like learning about how to detect sheer from last year, detecting CAPE, cap, and sheer is very timely.

I have met many folks...spotters from SGF, Austin and OKC, many NOAA folks that are both national and regional leads, and many EMS folks.

Definitely worthwhile.

Well..time to jump off...discussion from Les Lemon coming up.

More later.

50 day cycle..really?

Ok, as I have some time to kill, here is one of the blog entries promised before.

How long is this year’s cycle? Really? Is it 47 days? Is it 50 days? Is it 54 days?

Seems like a fair question…but it seems with the variability that has been presented by others, it allows way too much wiggle room for my liking.

So, here is the deal. March 2nd, we had a storm come through the KC viewing area. It seemed like we had seen this type of setup not too long ago. I am continually reminded that we are in a 50ish day cycle, so I decided to look it up. It would have been Jan 11/12th.

Um…hmmm…ok

Here is the 500 mb chart for March 2nd to use to compare.


Notice a couple of features…first, I have marked the trough and ridge axis locations as well as the upper level low

Ok…here is the 850 mb chart for March 2nd to use to compare:

Notice the 850 mb low, the frontal boundary in black and the moisture stream in green

Groovy, so, what does this mean. Nothing yet. But it will matter now as we show Jan 8th vs. Jan 11th.

Look at the 8th compared to March 2nd. While the January version did not quite show the upper level low, the trough and ridge axis are very similar.

Here is Jan 8th 500 mb

Here is Jan 8th 850 mb.


Look at the 850mb, similar location of the 850 low, same moisture stream and a similar frontal boundary.

Is it perfect? No. Does it exactly match March 2nd? No. Is it very close, and 53-54 days apart? Yes.

Now, look below at Jan 11th, and see how different it is. The flow entering the US is flatter, the upper level low in the Great Lakes dominates..no ridging, and look at the 850 mb. Not even close.


Here is Jan 11th 500 mb.

Here is Jan 11th 850 mb.

Here is a comment that was made about this observation on March 3rd..

“Once again, we completely disagree with you. Last week's storm was the 7th/8th. Then, this is the 11th/12th and we are right on schedule. Just look at what is happening now.. There is no doubt to us. “

What do you think?

New Entries coming soon...

Folks, this week I am going to the National Severe Storm Seminar in Norman. I am really looking forward to this as there is going to be many sessions in which to learn from.

I am looking forward to the satellite and radar presentations.

So, I will be doing some updates after each night later this week with some observations. In addition, I will be doing a blog on the comparisons of Jan 7th and March 2nd. These were very similar storms.

And last but not least, I am putting togeter a powerpoint for my cycle analsyis. I have some data charted now and it looks very interesting. It looks a bit different than what I thought it might look, and for that I have learned...but not because the cycle isn't there, but because of how it can be shown numerically!

Anyway, thanks for checking in..and this week should have quite a few blog entries, so check in regularly from Wed night through Sat.