All Sky Layered PW

The first 4-panel below shows the GOES layered PWAT products for AR and vicinity. Upper left is total PW, upper right is Sfc-900 mb, lower left is 900-700mb, and lower right is 700-300 mb. (These are actually sigma levels, e.g., .7 to .3)  The latter shows deeper moisture around the MCV over eastern OK and extending into west AR, with drier air aloft farther east. Perhaps a more favorable environment for deep convection and/or heavier rain.

The next image below is the same except for the upper left panel, which shows the GOES derived-product total PWAT. Note there is a lot of blank area or missing data due to cloud cover. In the first image above, these gaps are filled in with data from the latest GFS, to make a smoother and more complete product. Where both sources have data, the values are similar but not exactly the same.

Starting Day3 at LZK

Today, Wednesday May 16, we are "located" at WFO Little Rock (LZK). As of 18Z temps have risen to the mid 80s with dewpts in the mid 60s. MLCAPE is about 1500 to 2000 J/kg. Wind fields are not particularly strong but dynamics are a little stronger due to an MCV moving slowly southeast toward our area from eastern OK. About the western half of the CWA is in a marginal risk area according to SPC.  Showers and a few t-storms have begun to develop over this area but nothing severe yet. A.Cope

Week 3 Day 3 Operations

We will be operating today in the Little Rock, AR and San Angelo, TX CWAs. An MCV is currently moving across Eastern Oklahoma and should spawn some thunderstorms across Arkansas throughout the afternoon with a marginal chance for severe weather. A few storms are also anticipated to develop in west Texas later this afternoon/evening with an opportunity for some severe hail or damaging wind gusts. The overall environment is pretty marginal today.

-Michael

Day 2 Wrap Up and Feedback

Below is the feedback from yesterday provide in this morning's debrief:

NUCAPS

Modified NUCAPS did a pretty good job capturing the surface correction and gave a pretty good

representation of the environment

Liked looking at the gridded lapse rates

There were some gaps in the data the last two days

Gridded CAPE is confusing and doesn’t calculate well

Would rather have some sort of SBCAPE or MLCAPE calculation instead of from pressure levels

It would also probably be better to use the modified soundings especially for CAPE calculations in the
gridded data

Soundings captured the gradient in CAPE values in the Lubbock CWA and predicting how the
convection can evolve

Like having any sounding outside of the normal hours is a good thing

All-Sky LAP

Showed a very distinct moisture boundary in west Texas and delineated between the storms that were
struggling and the ones that took off

The all-sky was extremely important with all of the cloud cover in the northeast, the baseline GOES
were not useful with all of the cloud cover

Having the layered feature is very helpful to see the levels of moisture

Able to distinguish the EML with the upper level layered product in west Texas

Again would be helpful to have maybe a CONUS grid using RAP instead of GFS for better updates.

CI

The highest probabilities weren’t really near where the storms were developing

It would flash spurious higher values for one scan and then go away

The severe CI would spike the most it seemed like

It’s hard to have much confidence in the values when they are jumping around so much

Would want to see a consistent trend in the values to have confidence in the product

Didn’t seem to pick up on any of the storms developing over Virginia

Did seem to do well at the southern end of the squall line in Pennsylvania

GLM

The 2 minute data was helpful in showing a more recent trend and not having the older data hold on
longer can age the data a little more than the 2 minute

Have found the most use out of the flash extent density and flash area. The total energy is also good at
bringing the two together and looking at where the flashes are coming from in the storm

Still a question on whether some type of smoothing should be done to make it a little more pleasing to
the eye but could lose some of the maximum values

The lightning data pulsing within the squall line helped draw attention to the cells that were intensifying

The tracking meteogram actually worked pretty well at showing trends in the flash extent density

The data has more value when you can see the trends

ProbSevere

Came up with some really high values on wind and tor yesterday which was good to see with it being
more calibrated for the different hazards

The first day I thought that the combined was the best, but found the separated hazard models to be
more valuable when looking for the different hazards

It’s especially useful when looking at the Tor

Think it is worth having them separate even in a WFO environment when working warnings

Still trying to figure out the best way to display it

Tried running it on MRMS products instead of base data as it covers up some of the data

Use more on a broad view of data and not on the pane used for interrogation

New Cell and Lightning Trend

I watched a new cell develop over southern NJ.  The main reason this cell stood out was because of a significant increase in Flast Extent Density.  This increase really drew my eye to that part of the line where a cell was rapidly intensifying. 

Fig 1. Flash Extent Density increased rapidly.

Fig 2. Corresponding new cell growth. Note cell in center of image.

This was just another example of the GLM data providing a good overview for situational awareness.

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Erratic CI - Especialy CI Severe

Noticed that the CI probabilities were jumpy with some convective development. This was especially noticeable with the CI Severe, which jumped from less than 30% to 90% or higher, before coming right back down. The regular CI also had jumps, but they were much less dramatic.

CI Severe between about 2130Z & 2300Z

CI between about 2130Z & 2300Z

Alex Brown

Max Values for GLM 5-min FED

Watching the 5-minute GLM Flash Extent Density product, I've noticed that the individual grid values sometimes exceed 100 flashes per 5 minutes in a few of the most vigorous T-storms. The default data range here is 0 to 50, but this might need to be adjusted depending on the amount of lightning activity on a given day.  I think the 0 to 50 range was probably designed for the 1-minute FED. A.Cope

Viewing lightning trends

I've noticed the lightning data go through various cycles throughout the afternoon, ramping up then coming back down. That got me thinking about a way to visualize these trends in AWIPS.

Using the Tracking Meteogram Tool, I was able to create a quick table that displayed GLM activity over a desired time frame (it even tracked the background visible satellite).  I did note that the Flash Area products did not plot like the other GLM fields.

Fig 1. Setting up the Tracking Meteogram Tool

Fig 2. Meteogram information extracted from above.

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NUCAPS Skew-T Near Lubbock

Switched to WFO LBB for rest of this shift. T-storms have formed near southern border of LBB CWA; wondering how they will evolve. Image below shows a 2000z pass NUCAPS sounding from just northeast of KLBB. (Upper left panel shows NUCAPS availability.) The sounding shows a CAPE of about 3000 J/kg and no CINH in area of cumulus. Later satellite imagery at 2200Z  (lower left panel) shows storm moving northeast towards that area and other storms developing to the west of KLBB. Will have to wait and see if that trend persists.
A.Cope

Update: SPC issued a Severe T-storm Watch including the LBB area at 2215z.

CI Product Noise

The CI product has been a little noisy this afternoon along the southern edge of the QLCS. I've noticed relatively large areas of enhanced probabilities (40-50%) that drop in and out over the period of a few scans.

The CI product displaying noisy values near MD-PA border.

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