WEEK 3 FEEDBACK (including Day 4)

Day 1, 2 and 3 Feedback is included in the respective Daily Summery posts. This post includes feedback from the Week 3 final debrief.

-Bill Line

Simulated Satellite Imagery

- Maybe for last week, show nssl wrf reflectivity as well and show things that you can see in the synthetic sat imagery that you cant in reflectivity

- I like it, I used it every day. 

- Model issues

    o It was off with strength of storm, position, timing sometimes. 

    o Cirrus and low clouds often out

- The technique is great, to be able to visualize what the satellite would look like if this model were to pan out. I use nam in my office. It is nice to show low clouds and cirrus shields in the model. if you come out on day shift and it is showing supercells later in day, I would look at early part of forecast to give me more or less confidence in later forecast

NearCast

- I think it is a benefit to have

- I think at the very least it helped to visualize moisture and instability very well

- How to use it from day to day changed. First day, storms initiated as theta-e tongue came in. Next day, theta-e was feeding directly into storm, and it popped up. Next over DC, entire theta-e field, storms followed along with the movement of theta-e

- Go to product between warnings, see what the environment is. Continues to tell you if storm is gonna be in field where it continues to explode, or will it move out of it. 

- I can see it being useful as I come in in morning, it fills gap in sounding data, gives you idea of scope of convective instability.

- Its observed data so I really like it

- I though the model forecasts did well too when there wasn’t missing data.

- Forecasters agreed it would be neat to see winds plotted

GOES-R CI

- I agree it would be very useful in non-severe situations.

- It had its hits and misses

- If doing esta update, might be good to say precip chances might be increased in a certain region

- I couldn't get a handle on a threshold where this is when convection would go. I couldn't rely on it

- I think it would work for SPC mesoscale forecaster

- Instead of individual colors for each object, highlight a general area of interest where convection is more likely to go.

- It is a good situational awareness tool

- Neighborhood approach, larger spatial probabilities might be a good idea. Instead of showing probs for each individual object

Prob Severe

- I like it: I used it every day. The trends were very useful. I liked seeing the data when I sampled (I looked at trends in the numbers). It helped me to zone in on certain storms (broadcaster)

- Yesterday I used it fairly heavily.  Storms moving form KY to TN, what happened was because it was multicellular, there was an adjacent storm that prob severe latched on to, and the product took over that other cell too. So it was then difficult to key in on that particular storm. I wanted to increase lead time, but I wasn't able to in this particular instance. There was some lag time too

- A way to have a sub-scale tracking to make sure to track individual cells to try alleviate merge issue

- Would you use in your office: All yes

- It at least brings your attention to storms to watch

- You start with all tilts. From a spatial awareness perspective. Id be worried about new forecasters getting lazy, relying on these derived products. You still need to get them used to using the base products. Similar to other products.

- But I think it could be treated as any other algorithm I don’t think that ^ is a problem

- There have been times im interrogating a storm in base data, this algorithm would point out a storm that I should look at. It catches things the human would miss.

- What would you like to see added: you don’t want it to get too cluttered. I like the compactness of it. Other environmental attributes could  help that would tell you what type of severe. DCAPE

- I would like to see effective SRH added. 

- Would you like to see probs of individual hazards: all yes

- I could envision a 4 panel. Over all prob severe, prob tor, prob wind, prob hail.

    o And have different fields under each

OTD

- I really tried to use it yesterday. One of limitations was the 15-30 min updates. It wasn't terribly useful in the hot seat. Might be better for mesoscale forecaster.

- I see this being most used in places where you don’t have radar. Oceans, aviation even more so (route planes around this). 

- I see it being much more useful, viable with higher temperal, spatial resolution. (super rapid scan with goes-r)

PGLM and LJ

- It was very useful in Denver day. Seeing total lightning and LJ

- I could see myself using it in warning operations. Monitoring health of updraft

- Pulse. In OK you see storms pulsing. Total lightning showed this. within 10-30 min I can guarantee something will happened

- In W Texas, severe winds were reported. Cell merger > LJ > wind

- LJ twice in a row, prob severe was trending up, I warned, big jump on warning

- Because it is one minute data, I was able to see jump before next radar scan

- I view storms as how much energy they can output, lightning kind of gauges how much energy is in the storm > hail, wind, etc. Updraft > more ice, static electricity, lightning.

- As a broadcaster, it would be nice to have total lightning, because it shows more than just CG.

- LJ display: I was fine with it, I was fine with sigma jumps

Tracking Tool

- I think it has a lot of potential, I was excited to use it, but it dissipated me.

- I like that you have a graph that pops up. I prefer it to be side by side

- If you close it, it would be nice to be able to pull the box back up

- I would like the ability to take the box out, I like screen real estate. 

- I think this type of tool (to show meteogram) is useful. I like the circles. I think it would be useful to track many different fields

- I prefer when you clear, for box to go away.

- In warning mode, I could see myself using this. 

- Its awesome to be able to use the individual points without having to move the whole track

SRSOR

- Do you see it having an impact on my decision making process (4 yes’s).

- Watching area, I could see growth in the 1-minute data, it helped to gain more confidence, I need to pay attention to this area

- In office, many times waiting 15 minutes for next scan. With 1 minute data, you can see convective attempts, failures, dead anvils.

- Would you be disappointed if goes-r was launched and we did not get 1-minute data? (all yes’s)

Daily Summary: Week 3, Day 4 (May 22nd, 2014)

Another solid day in the HWT as our forecasters remained in LWX and OHX for the duration of their shift. All experimental products (yes! even OUNWRF) were evaluated today.

Our LWX team was able to evaluate pre-CI potential using GOES-R CI, LAPS, NearCast, and ProbSevere. When storms got close to LWX our team (Grant and Danielle) were able to use DCLMA network to evaluate total lightning and lightning jumps. The were several preliminary reports of hail and wind damage in the region passed along by our volunteers which helped forecasters validate what they were seeing in the experimental datasets.

2_Large_GIFS

Our OHX team waited anxiously as slow moving storms fired in the LMK and PAH CWAs with NW flow pushing slowly into the CWA. Once again, forecasters had some time pre-CI to get a feel for how the GOES-R and LAPS products were able to diagnose areas of instability and identify storm growth and intensity. The Overshooting Top Detection product was evaluated frequently in conjunction with the Super-Rapid Scan imagery in this domain with a fair amount of detections occurring today.

Furthermore, our visiting forecaster from the Air Force Weather Agency, James McCormick, worked with Gabe to thoroughly evaluate OUNWRF across the entire domain. Many thanks to him for giving us a focused set of eyes on this!

-Darrel Kingfield
EWP Week 3 Coordinator

While not necessarily in my area of interest today, my attention was drawn to PAH’s CWA at around 22Z when the CI product indicated a 70% probability of convection initiating. Admittedly, I didn’t place too much stock in it as there have been false probabilities showing up this afternoon (plus it is outside of my area of focus). However, within the next half hour, convection developed in the same area.

SRSOR_CI_GIF

~Linda

ProbSVR Showed Downward Trend

With a significant increase in ProbSvr and good environmental conditions Linda issued a severe thunderstorm warning for a storm in northern TN. ProbSvr at this time was near 90% at this time.

Two volume scans later, while the reflectivity was still fairly significant the ProbSvr dropped to 48 percent. Two more volume scans later the reflectivity looked like the above image where the storm was obviously weak. This downward trend in ProbSvr was great since it was near the southern end of the severe thunderstorm warning and another warning decision was near.

-JB

Simulated Satellite this afternoon

When looking back at Simulated Satellite today and seeing how it performed, it actually did very well.  It was on point with the timing of initiation of convection and the location of the start of the storm as well as how they moved.  The only thing it really lacked was the strength of the storm.  I would use this product for forecasting purposes! ~Vollmar

Experimental warning issued based on…

…the prob. severe model and SRSOR as well as radar interrogation. The prob. severe model latched on to a storm near the intersection of Sumner, Trousdale, and Macon counties at 2212Z but I wasn’t able to view the actual prob. severe model product until after 2217Z, leading to the warning not being issued with even greater lead time, as I had hoped to be able to do. While waiting for the updated prob. severe model product to come in, I analyzed the super rapid scan imagery and noticed the growing cloud tops between approximately 2207Z through ~2223Z. After the warning was issued, I re-analyzed SRSOR and an OT was detected in the vicinity of the cluster of storms.

~Linda

SRSOR_OT_GIF

Convection Moving Along Theta-E Gradient

Convection continues to develop and move southeast out of KY into TN. The strongest storms are moving southeast within the greatest convective instability indicated on the NearCast model. Although the model has holes across the OH and TN Valleys, extrapolation of the southern gradient of the instability axis indicates that the storms on the western side of the line may be in a less favorable environment for strong updrafts. Radar supports that storms are weaker in this area as well.

-JB

First Experimental SVR for OHX

I issued the first OHX experimental severe thunderstorm warning for the day, based primarily on traditional radar analysis and utilizing the prob. severe model. When two cells merged at the Monroe/Barren/Allen county borders in LMK’s CWA, the prob. severe model indicated an 81% chance of severe and then one volume scan later, the probability jumped up to 97%.

While I didn’t use these products as the basis for my warning, I went back to look at the SRSOR and OTD products. They clearly show the cell merger and significant updraft growth over the course of the last hour.

SRSOR_OTD_LOOP.GIF

~Linda

**Update: Trees were reported down in Clay County, TN.

*** Just a note, the OTD’s appear shifted to the west (and only appear every several minutes) because these detections are from GOES-East, while the satellite imagery in this animation is 1-minute GOES-14. – BL

Lightning Jump Really Helps!

I once again was watching a cluster of storms and the lightning jump turned to red.  I immediately started to monitor that storm and started to see flash extent density increased.  Then Prob Severe started to jump and I actually issued it before it turned hot pink.  I will have to see if this verifies but I think I got a jump by at least 15 minutes or so about issuing a warning! ~ Vollmar

Update it did produce wind damage! WICKED AWESOME!

Using GOES-R product together

It has been beneficial to view multiple GOES-R demonstration products in one AWIPS-II display during the Spring Experiment. This trend was especially evident today as  we were able to use the lightning products in the Sterling CWA. Below is a gif animation of a 4 panel display showing how these products can be used together (sorry about the change in domain in middle of loop).

In the upper left panel, the NearCast (observation-based) analysis theta-e difference (instability) field showed copious amounts of instability in the region. This was due to a plume of high theta-e air below much drier air aloft (see other posts for details). Meanwhile, by 1815 UTC the GOES-R Convective Initiation product (upper-right panel) gave a cloud object an 81% probability of initiating. Given the relative high CI probability in an unstable environment, the forecasters keyed in on this area. At 1830 UTC, it was obvious that this object was indeed growing upscale. At this point, the ProbSevere (lower left panel) product started tracking this cell.

At 1852 UTC, the ProbSevere product gave it's first probability greater than 70%, indicating a relatively high likelihood that this particular radar object would produce severe weather. The probability would actually dip down, before surging up again. This was likely due to an influence of a nearby storm. Shortly after 1900 UTC, total lightning started being detected, seen in the lower right panel as PGLM flash extent density. A 2-sigma lightning jump occurred with this cell at 1959 UTC, indicating an uptick in storm strength. This particular cell went on to produce hail shortly thereafter.

Aside from this 4-panel type of display, forecasters have been finding other unique ways to blend these various datasets together in AWIPS-II (overlays, various 4-panels, etc)

-Bill Line, SPC/HWT Satellite Liaison

NearCast Verifies with Radar

I already blogged about NearCast earlier today, but I wanted to show how it actually verified.  Storms initiated on the boundary and as they moved into the unstable air, they became stronger as the followed the unstable air.  Also, the storms that formed in the lighter blue actually began to weaken as more stable air moved in.  The storms moved like this model showed from NW to SE.  I would use this for storm motion for sure! ~Vollmar

Tracking Tool, Lightning Jumps and Storm Evolution

Above are two examples using the Tracking Meteogram tool and Flash Initiation Density to build flash rates of two individual storms near Washington D.C.    Rapid increases in total lightning signalled the onset of storm intensification in both cases, and multiple lightning jumps were observed as each storm developed and moved across the DC and Baltimore Metro areas. Hail to the size of golfballs was observed in the top storm with the first 1 inch hail reports falling at 1939 UTC.  At the time of this post, the southern storm produced hail to the size of quarters at 2035 UTC.

Chris S.

Storms across the Potomac

Maryland isn't the only state in the mid-Atlantic with potent storms. In Virginia, more storms have had strong ProbSevere signals (with strong satellite growth rates and moderate to large MESH). Severe hail was later recorded northwest of Richmond.

Closer to the Potomac, a storm with moderate to strong satellite growth (~30 minutes prior) increased in probability of severe from 37% to 65% to 85% over the course of six minutes (from 20:26 to 20:32 UTC). This explosively growing storm was warned by the NWS at 20:30 UTC. One inch hail was recorded at 20:36 UTC.

-Cintineo/Sieglaff

An OTD Appears!

At 2030Z, an OTD appears in PAH’s southwestern portion of the CWA. Unfortunately, a jump in the data occurs between 2011Z and 2030Z in the SRSOR imagery. Around the same time as the detection, some hail reports were disseminated from the PAH WFO but nothing over severe criteria.

Some times you just have to sit back and laugh.

So some of this may have been AWIPs 2 some of this may have been alternate issues.

Chris was behind me as we were researching the LJDA components to things. When we noticed the one minute CG data disappeared…. then the 5 minute CG data disappeared. However the LJDA maps/shape files continued to work.  Whalla! a 5 and 6 sigma jump occurred successively over 2 minutes. It was time to warn.

So, I went over to radar base products on another CAVE windows to issue the warning over the base all tilts reflectivity.  Loaded Warngen to find that the old radar display controls from yesterday were still controlling the flow of the storms today 240 when I wanted roughly 320. I immediately attempted to to change the flow and redraw the box. Except now the box refused ro redraw in the southwest direction and immedately insisted on the northwest direction…. fine I’ll attempt to track the ball backward and force a redraw of the box in that direction…. Done. Who Hoo… that wasn’t  hard.

then i went to redraw the verticies….. after clicking on the first vertex the whole screen proceeds to move on me. … “Maybe I missed it” goes through my mind…. and click again…. “nope missed again”… click again…. “okay this is not cool”.  So, I permanently right click down to find a window to edit the vertices. “YAY alternative.”  Next I discover that the one vertex I’m moving is now permanently attached to the mouse icon….. “GAAAHAHHAHAHAHA!!!!!!!”

As i step back and look at it, someone out there of importance could be dead right now. But in this case I’d like to think it was Barney… Because personally I want that fat purple dinosaur to die. Thankfully this is an experiment and i’m happy nobody died… except for that awful singing dinosaur.

Grant H.

When I decided to issue a warning

As the storms to began to break out, I used the prob severe tool in combination with the total lightning initiation and total lightning extent and lightning jump and based on how they all came together, I felt comfortable issuing the warning.  About 15 minutes later, golf ball size hail was reported so with this particular t’storm these products did well together. ~Vollmar

Hagerstown, MD

A storm that developed in southcentral PA had a ProbSevere value of 72%, with moderate satellite growth and nearly 1" of MESH at 18:36 UTC. The probability of severe fluctuated to 45-50%, and then came back up to around 80%. An NWS warning was issued on this storm at 18:57 UTC. Severe hail and wind reports were recorded at 19:02 UTC, in Hagerstown, MD.

When speaking with a forecaster, she noted that she liked to see some sustained signal (several scans of high ProbSevere) before issuing a warning. This underscores that perhaps a forecaster shouldn't necessarily issue a warning as soon as there is a high probability, but that they should perhaps take notice and interrogate the storm further.

-Cintineo

Starting the day in OHX

Since convection has not fired up yet in the Tennessee/Ohio Valleys, I was able to spend some time analyzing the pre-storm environment with the products we’re testing this week. The first on the list is the NSSL-WRF simulated IR/WV satellite product; I pulled up a four-panel with simulated on the left and actual on the right (below). As of ~1845Z-19Z, the simulated imagery was depicting isolated convection across southern KY and middle TN too soon but not necessarily entirely inaccurate. It is accurately honing in on the cloud cluster centered over IN-IL-IA/MO border, albeit overdoing the coverage and coolness of the cloud temps, as has been observed all this week. Interestingly, it is not picking up on the cirrus overspreading the Ohio Valley and into TN. Accounting for all of this, I can adjust accordingly and remain confident in using this product to develop a mesoscale forecast.

Moving to the next item on the list, I pulled up a four-panel of the NearCast analysis products with 500mb theta-e in the top left, 780mb theta-e in the bottom left, theta-e difference in the top right, and 900-700mb PW in the bottom right (below). A surge of mid-level instability can be seen diving into TN and is also evident in the difference product with the gradient diagonally stretched from the NW corner of TN to the SE corner. PW values/moisture surge matches with where storms are quickly firing up in western and south-central KY. When analysis data is available for these NearCast products, I really like to use these to diagnose and forecast.



Next, I loaded the same four-panel with the NearCast forecast and took a screen shot of the 2-hour forecast (21Z, below). Unfortunately, missing data over the region of interest exists with the 500mb theta-e and theta-e difference products. However, I can still see the lower-level instability and moisture axis draped across western KY into TN in the 780mb theta-e and 900-700mb PW, respectively. Given the success of these products so far, I have good confidence in utilizing the forecasts to accurately predict where the greatest threat will be, given other atmospheric conditions line up for convection as well.



Looking at GOES-14 SRSOR vis imagery and overlaying the CI product, a 60% probability popped up in western KY (below) and within a half hour, storms developed in the vicinity. There was a false alarm 60% probability just to the west of Paducah, KY, probably due to the thin cirrus streaming over a CU field there. In OHX’s CWA, no reliable indications of convective initiation has appeared yet. As for the SRSOR product, I am once again very pleased to have this data available to more accurately assess and see the evolution of the regional atmosphere.



Below, I overlaid OTD on IR SRSOR imagery and thus far, no detections.



~Linda

Lightning Jump

I finally got to see lightning jump data and it was so helpful.  At this frame you can it has the brown color and then as I continued the loop it went to a green color.  It indicated to me that this storm was intensifying and definitely got my attention.  It also was trending up on the Prob Severe so at this point I would probably issue a warning. ~Vollmar

Development of storms in LWX

The forecasters are concentrating on the Sterling WFO and Nashville WFO today. Initiation has already occurred across LWX with the GOES-R CI algorithm picking up pretty well on the initiation. Below are two loops featuring the GOES-R CI product and the subsequent development of radar echoes at the -10 C isotherm. Apologies for the fast loops as the AWIPS tool created these automatically. However, you can see the warmer colors across the LWX CWA develop into radar echoes 10-15 minutes later. The first lightning strike

GOES-R CI product from 1715 -1830 UTC

MRMS -10 C reflectivity from 1828 to 1906 UTC

Simulated Satellite WRF. Cirrus/Insolation issues leading to convection.

Decided to through in a pre-enviornment blog about convection over southern West Virginia and far southwestern Virginia. In this case a plume of cirrus/ cirro-stratus is not showing up in the WRF. Normally that would be rather benign.  However in this case that cirrus is blocking just  enough isolation to prevent storm development over both areas which is keeping storms from popping and having the time to hit the equilibrium level.

Grant H.

Prob Severe Lagging Radar Today

I have been closely monitoring the ProbSvr product today as storms have initially developed over parts of western KY. Analysis of the radar data from the OHX radar data indicates that severe weather would be likely from the storm near Fryer, but the ProbSvr to this point only has around 60% chances.

-JB

Northeast convection

We're operating in Sterling, Virginia, to begin today, but storms fired in Pennsylvania and New York before our shift began. The NOAA/CIMSS ProbSevere model was able to pick up on some of these storms. We can see a cluster of storms below, in Pennsylvania. The featured storm (with the scroll-over) exceeded 50% probability of severe when moderate to strong satellite growth rates were observed (17:54 UTC). The storm was warned by the NWS at 18:08 UTC, when the probability of severe was 97%. A storm to the northwest fluctuated in the 20-35% range before being warned by the NWS. The ProbSevere value then jumped to about 65% soon after the warning. This shows that ProbSevere may give increased confidence and lead time to some storms --- not every storm.

-Cintineo/Sieglaff

NearCast Data Today

If you are following NearCast today, it shows the the Diff. Med Low Theta E that the unstable environment would start over western MD and move across the state into the Delmarva Peninsula.  Behind it some more stable air will move in.  It will be interesting to see if storms follow this track and move from NW to SE along the area and at the same time. ~Vollmar

Got the chance with CI today. YAY!

First chance to really play with the CI tool today in a  partially pre-convective environment. Attempted to grab a gif, but it moves a little too fast. I’ll attempt to write through what I’m seeing here anyways.

At the beginning of these frames the CI tool grabs onto a series of storms across far western NY around 15:15Z. These storms fire and immediately move into north central Pennsylvania Probs with these were roughly 86 to 60%. Good job.  Once the storms fire the CI tool lets go of them almost immediately.

focus then shifts south to 1745Z-1815Z where the colors on the CI then begin to resemble a bowl of fruit loops.  We even get a 91% at 1815 over southeastern Pennsylvania that is moving into th New Jersey and the Delmarva.

This tool seems very good for the synoptic level viewing…. but maybe less so on the mesoscale, as there seems to be a lot of noise above  probability of about 40%. The fact that it leaves fired convection behind and moves onto the new area of interest rapidly might make this tool more useful to SPC than to a WFO by redrawing the attention away from the current convection and towards the next problem area. This could help break a natural psychology problem where/when a forecaster would want to obsess over the current convection and may neglect other developing areas for it. .

Also I would like to add that a graduation of the color on the scale may be better than the current discrete 10% breaks built into the color bar.  I noticed that Percent probs were in increments smaller than 10%. This may help to focus the fruit loop bowl effect more. then again it may not but its worth a try.

Grant H.

Low CI (east) With Initial Activity

Looking at the CI product from GOES-E and it appears to have a marginal handle on the CI ongoing over western KY at the moment. In the loop below the values before CI only reached 45% before a 35 dbz echo was detected by radar. In the last frame of the loop there is a 64% noted within the line of CU, though this has not developed on radar. It will be interesting to see if there is soon higher reflectivitiese in this area.

-JB

GFS Difference in Theta-E and NowCast

Today again appears to be a day where the NearCast model is being degraded by a significant amount of cloud cover over the CWA. I have loaded the difference in theta-e fields from the GFS model to fill in some of the gaps in the model. This appears to do well as a proxi for areas of convective instability in the NearCast model. Using the model difference fields in conjunction with the NearCast can help to fill in areas and allow you to get an idea if the model has a good handle on the situation and provides confidence for later in the day.

-JB

Simulated Satellite Vs. IR Sat

I was analyzing the NSSL-WRF simulated satellite versus the actual IR satellite and as you can see it is missing the cirrus cloud deck over the VA peninsula and eastern VA.  It also is missing the cirrus cloud deck over eastern West VA which may hamper or at least slow convection start today.



In one hour it is trying to already form storms over parts that are covered by the cirrus blanket so I wonder if this won’t happen since it hasn’t accounted for it. We shall see. ~ Vollmar

Simulated Satellite to Early

Was comparing the simulated satellite to observations to attempt to get a handle on the pre-convective environment. It appears that the simulated satellite today is to quick in developing convection from southern KY into TN. It also is not handling the convection that is developing over eastern KS well. Finally it has convection developing over southwest KS that is not there in reality. This lowers the confidence in the forecast of this model for later in the day.

-JB

EWP Operations Update – Thursday 5/22 – 1:10pm

Our forecasters are set up in Baltimore/Washington D.C. (LWX) to take advantage of the DCLMA as this region currently has relatively few clouds conducive to stronger surface heating than previously anticipated. Adjusted 12z sounding with current surface temperatures show a large region in LWX with minimal CIN to hinder further convective development.


Super-Rapid Scan visible imagery from 1706z-1820z over the East/Central US.

Our second team is currently situated in Nashville, TN (OHX) as we wait for the remaining cap to erode over this area in the next few hours. We only anticipate isolated severe storms in the northern part of the CWA but would like to use this opportunity to really look at some of the GOES-R pre-CI products to see how they fare in a still capped area. On the plus side, if storms do fire here and move to the southeast, we may get some activity in the NALMA. On our final day of Super-Rapid Scan operations, we also wanted to get both of our forecaster teams in domains where they could leverage these data.

12z ROAB sounding from Nashville, TN.

We’re watching the WTLMA and COLMA regions closely as well and are ready to jump out west if absolutely necessary.

-Darrel Kingfield
EWP Week 3 Coordinator

Daily Summary: Week 3, Day 3 (May 21th, 2014)

Another productive day in the HWT! We ended up operating in three domains today, Denver/Boulder, CO (BOU), Indianapolis, IN (IND), and Lubbock, TX (LUB). For most of the day we had two forecasters in the BOU and IND CWAs but moved IND to LUB within the final two hours when most of the severe convection moved out of the CWA. A weak mid-level impulse and steep lapse rates supported initiation along the TX/NM border and provided both teams of forecasters to look at the PGLM products and utilize the tracking meteogram tool with these datasets.

Our BOU team remained in their CWA and mainly tracked what will likely be called the “Denver Metro Area Supercell of May 21, 2014″ for years to come (this title may need to be shortened…) All GOES-R, several LAPS 3D analysis products (from the 200×200 domain), MR/MS, and Super-Rapid Scan imagery were utilized in performing mesoscale and nowcasting analyses as well as warning issuance. Preliminary reports are coming in on the spatial extent of the main rain-wrapped tornado produced by this storm around 2000z.


0.5 reflectivity from KFTG on May 21, 2014.

Our IND team faced another training sequence of convective cells that came out of the northwest into the CWA. Numerous severe hail and wind reports through the central/southern parts of the CWA. The LAPS 800×800 domain was situated over this area of complex convection, providing 2D analyses and forecasts that our participants compared to MR/MS and other observational products.



Feedback (BL)

Simulated Satellite Imagery
- Indy cwa, it was pretty good with where storms would pop timing wise. Timing a bit off.
- Boulder – convection and cells in correct spots, timing a bit off. 30 min to an hour fast.

NearCast

- Lots of blank spots. It would be nice to blend nwp model data

- An on off toggle with model data might be neat

- Boulder – pw difference with evolution of storm. With discrete cell,m there was a narrow tounge of moisture feeding. A wall of moisture was moving into area. As wall moved in, storms formed along the boundary. I could have got change from discrete to cell.

- A little difficult to use today due to missing data from cloud cover.

GOES-R CI

- It did alright.

- In INDy One cell in particular, ci showed 90%, convection fired about hour later, it was hard to tell if convection was actually associated with it.

- In Denver it did quite well with main Denver cell it had >70% 

- GOES west not doing as well as east

Prob Severe

- Did well in high plains

- In the diminishing phases is was useful in keeping me from warning on a couple storms

- Lots of pink in Indiana (>85). Many of these storms produced severe.

- I warned one based on an upward trend, then it died, lots of storms were doing this

OTD

- In NE Colorado later, the Colorado storm weaked, but still had great OTs, so still intense rainfall. Even though storm isn’t severe, updrafts could still be strong enough to produce heavy rain

- In texas, it showed up nicely, it made me focus on it, hled it for 4 or 5 scans, then it fizzled and the storm weaked. 

- Perfect for overnight convection

PGLM

- Impressed, by overlaying the different products, I issused a warning off of it, it hit a sigma of 3 and I pulled the trigger. Inch hail a few minutes later. 

- Flash extent and initiation. Max did not work. I thought it was great. Watching a storm merger in Lubbock. Initiation density really lit up on front end of merger. A few minutes later extent density lit up as well.

- CG’s do not tell the whole picture at all, so the total lightning was helpful

- Provided lead time over radar.

LJ

- The larger scale one would sometimes try to combine cells. So I would go to smaller one and it would be better at identifying the individual cells

- I did get the bit towards the end of day when it was nice

SRSOR

- It helped me in radar down experiment. It helped to identify boundary that was feeding into storm. It would have taken a little longer to piece in my mind what was going on in the 15 minute scan mode.

-Darrel Kingfield
EWP Week 3 Coordinator

Switching to West Texas…

Excitingly, we’ve switched over to a region that is covered by GOES-14 SRSOR, so I pulled up the visible imagery and overlaid the overshooting top detection product. Interestingly, we noticed a very slow-moving storm in south-central AMA’s CWA that erupted on vis satellite and consequently, the OTD picked up on it. Additionally, a weak but still present enhanced V was observed with this storm on SRSOR’s IR imagery.

Now to center on LUB, I overlaid SPoRT’s Flash Initiation Density product on KLBB 0.5Z and observed an increase in the initial density as a cell merger occurred in northern Lamb County, TX. This increase was evident for a few minutes and then simmered down. What’s particularly important is that the SPoRT data, since it is coming in every minute, indicated this “jump” before the next volume scan came in on radar.



In the next loop (below), I did a similar setup with 0.5 reflectivity, SPoRT’s Flash Extent Density product, and included a 1-minute CG lightning plot as well. As anticipated, flash density responded similarly to the cell merger by showing an increase.



At around the same time, WFO LUB received wind/wind damage reports in the area.

Having the 1-minute total lightning data was very helpful in being able to see the response of the cell merger and give a couple minutes more lead time to anticipate what was to come. While CGs can provide great information, having total lightning to get a better idea of what is going on is exponentially more valuable.

~Linda

Negating false positive/problems from larger LJDA scales.

With the image above I just wanted to show that sometime the LJDA can combine storms and trigger a larger sigma warning than seems realistic. Especially when the storms seem to barely touch on radar. In this case it was a 2-3 Sigma jump in Yellow which would prep the forecaster to think about warning.

This false positive can be fixed by overlaying a smaller scale LJDA over a larger one to potentially split the storms and break the sigma back down to a more realistic approximation that would not trigger a reason for warning (after suspecting it to be a false positive).

Grant H.

Over-Shooting Top and Heavy Rain

Been watching the convection over northeast CO, and although the general trend of the severity of the convection is downward, the over-shooting top algorithm continues to ping over this area. This highlights that although the storms may not be producing severe weather, i.e. hail and/or wind, they could be significant rain producers and should continue to be monitored.

-JB

Total Lightning to forecast strengthening storm

I have been watching the Total Lightning product over the developing storm and it shows both flash initiation density and flash extent density that have been increasing over the last 30 minutes.  That coupled with the increase on the Prob Severe, would lead me to believe this is nearing severe limits and I would then issue a warning.  I really like these products because it shows where the updraft is developing and also where hail would be found. ~ Vollmar

Prob Severe and Demise of Storms

Watching trends in the probability of severe over northeast CO indicates a significant downward trend in prob severe with the low-lived storm that went through DEN. This occurred as the local office allowed the warning expire and the reflectivity signatures were decreasing as well. Provided confidence in letting the warnings expire.

-JB

A CI Update

Remember that screen capture of the 90% probability of convective initiation over Lawrence County, IN at 2130Z? By 2248Z, a decent cell had popped up in the NE corner of the county. Not sure if this necessarily verifies the product or not (after talking with the product’s contact here), but it does instill some confidence on using this product in the future.

~Linda