"Tales from the Testbed" Webinar

Today marks our first ever "Tales from the Testbed" weekly webinar.  This webinar is available to outside participants and is lead by the forecasters visiting this week.  Each forecaster was asked to put together a 5-minute presentation on something that they took away from their time in the HWT throughout the week.

A couple comments from the forecasters during the webinar...

"Based on the environment and the ongoing supercell activity, I issued the warning as soon as I saw the CTC... Without the CTC product, I may have issued the warning a scan or two later... which lead to a greater warning issuance lead time."

"Synthetic WRF imagery can enhance forecasts by providing model data in a familiar satellite format which makes model analysis, model comparison to obs and model forecast projections easier to visualize and understand."

One of the forecasters even mentioned that some of the GOES-R Proving Ground products are currently available for demonstration to the broader community via website or LDM in real-time.

EWP end of week 1 debrief

Prior to our "Tales from the Testbed" webinar that begins at noon, we had the opportunity to sit down with the visiting forecasters and discuss their experiences over the past week regarding individual products and overall training/demonstration effectiveness.

SATCAST / UW Cloud-top Cooling
- "We were looking at the CI/CTC quite often and there were some areas that were quite ahead of time where enhanced updraft potential was taking place." (Thursday's event)
- "We saw a lot of the SATCAST along the boundary, but not as much of the CTC... which did make sense because we did see a lot of enhanced cu, but not a lot of really strong storms." (Thursday's event)
- "It (SATCAST) really helped to focus in on the area with the lower probability threshold and then once it transitioned into 50 or above, that's when the strong storms started to develop... very consistently too."
- "I never felt like during the experiment that it (SATCAST) was giving me too much information, like too many false alarms or anything... the strength of signal really helped correspond to what was happening."
- "It (SATCAST) was a great move to go with the strength of signal... it provided information instead of the yes or no... you can compare it to your level of confidence in terms of development."
- "It was definitely important to stress to look at the environment first with these products, especially with the SATCAST product which helped me handle any false alarms."
- "It was nice to match up the CTC with things like the 3D-VAR updraft strength."
- "I only say one high confidence false alarm over the whole week... other than that, when you saw red, you could count on it seeing 30 dBZ or higher." (SATCAST)
- Would you like to see a completely data-fused product with model data or would it be helpful to provide the product by itself as well?  "If you could provide both, that would be really useful because sometimes the model is completely wrong."
- Any other potential uses for this (SATCAST) product?  "Boundary identifier definitely... you can really pick out areas where instability is increasing."
- "With the CTC, the storm was generally already ongoing... we could use the two products to somehow put an initial lower probability."
- Would you like to see any big changes in the SATCAST product? "I would like to see some studies done on the threshold on the signal strengths."  "I would like to see a readout of the background fields."
- "It (CI) enhances the total observations network... I would like to play with it some more."
- Did you like the color scheme for SATCAST? "I liked it... it worked great."
- "I love that product (CTC)... yeah you can look at the IR imagery and figure it out, but why do that extra work... have the algorithm do it for you.  It really helped as a situational awareness tool."
- "I issued a warning on the CTC... obviously you have be aware of the situation and the environment."
- Was it obvious every time it happened? "I think it was enough, you could overlay it on visible or radar and then use the accumulated to get a longer picture of what has happened."
- "I'd like to see a longer accumulation product (CTC)... sometimes it was a much longer period between the initial growth before it became strong."
- "Maybe an alarm of a CTC threshold like -10 or -20 C/15 min would be useful."

Nearcast
- "It was picking up a surge of theta-e that was over the eastern-most counties over our CWA, which pointed out an area of enhanced tornadic threat later in the day." (Thursday's event)
- "Near storm environment... specifically the theta-e difference product... you can see the instability extending all the way off shore... you could tell that storm would keep going and going."
- A lot of the time you would have missing data, but specifically with the isolated storms you could really get an idea of where the instability would be."
- "Useful in finding the cold front and relatively stable air... you could see the cold airmass moving in."
- "If there weren't clouds moving in...  I wonder if we would have seen cooler more stable air moving in at the 500mb level that would have suppressed convection.  It would have been nice to use the different levels more often, but there was a lot going on."
- "We added the synthetic IR to the 4-panel with the nearcast theta-a difference and levels to get an overall picture of what could evolve."
- "Instead of seeing the holes from cloud cover... maybe you could add in some model data to fill the gaps."

Simulated Satellite
- "The simulated imagery really helped depict boundaries where storms would form, and also had a good handle on the mode of the convection." (Thursday's event)
- "Maintaining situational awareness, getting the impression that the short wave was moving in and the moisture coming in to the area, it was great to see how the environment was changing."
- "Potential for convective initiation was brought out... makes those spots look hot on a quick large scale glance"
- "I can easily compare WRF IR to observed IR... it was really simple to do."

Overall / Training
- "Between the satellite stuff and the 3D-VAR, you're really getting a good start on warn-on-forecast... putting it all together would really be very useful."
- "I really felt like I was a warning forecaster during the event... and that is key to a good experiment."
- "The cheat sheets you made for each of the products, how to load them and use them, were really useful."
- A few of the forecasters have asked us to provide them with either a website or some way to bring some of the products into their operations... specifically the simulated satellite imagery and band differences data, as well as the SATCAST and UW cloud-top cooling products.  POC information will be provided to the forecasters for each of the products within an end of the week thank you email.
- "Having the forecasters blog really helps you all see if we are 'getting it'."
- How much should we interrupt you during operations?  Could you have used more conversation from the PIs? "I thought it was perfect"
- "Not having the pressure to have to 'catch every warning' and having the freedom to test things was very useful in getting some quality feedback."
- "The addition of the extra day on Monday was very helpful in setting up a rhythm."
- Was the pace of the training good? Was it too much? "I thought it was fine... you covered all the products."  "I think it's important to emphasize the first training shift at the WFO to come in up to speed... the more emphasis the better... If everyone could get that done ahead of time you could really hit the ground running when you came in."
- Did the job sheets introduce the products well? "They were great."
- "The format you put the WES case in was very compatible to the various PCs we had available... I know I'm going to go back and give a seminar on how we should package our training."

BRO MESO Desk @ 0010Z

EXPERIMENTAL forecaster discussion from EWP blog...

NearCAST guidance continues to support the enhancement of thunderstorm development from Jim Hogg and Starr counties.  It’s appears the model indicated a weak disturbance increasing Theta E across forecast area between 01Z and 04Z, which will add to the existing unstable conditions.  Severe thunderstorm potential remains high.  Emergency managers and other decision makers are strongly encouraged to prepare for the threat of severe weather through 05Z.  Isolated tornadoes are still possible.

EWP: EXPERIMENTAL Severe Thunderstorm Warning Based on UW-CTC and Environmental Parameters

Another thunderstorm was developing along an outflow boundary over southern Texas.  The NWS forecaster working the KCRP WFO made note of the UW-CTC  -20 K / 15 min at 2310 UTC 10 May 2012 on the newly developing thunderstorm.  Given the experiment is designed for out-of-routine thinking, he decided to issue a severe thunderstorm warning "a radar volume scan earlier" based upon the mesoscale environment, previous thunderstorm development along the boundary, and the fact the storm was exhibiting cooling rates in the strong category from the UW-CTC vs. NEXRAD study presented for training.

Figure 1.  Valid 2310 UTC 10 May 2012.  The UW-CTC rate of ~ -20 K / 15 min (top right panel) combined with the environmental conditions and previous thunderstorm development in the vicinity allowed for an experimental severe thunderstorm warning at EWP/HWT (bottom left panel).  **NOTE THIS IS AN EXPERIMENTAL WARNING**

We are continuing to monitor the storm via the KCRP radar for further intensification.
UPDATE 1:  2340 UTC 10 May 2012 - radar is estimating just over 1.00" hail (severe hail threshold); for a 30 minute lead-time for UW-CTC.

UPDATE 2:  2350 UTC 10 May 2012 - the NWS forecaster has upgraded the severe thunderstorm warning to an EXPERIMENTAL tornado warning, 40 minutes after the intense UW-CTC signal.   The radar estimated hail size has increased to 1.40".  The storm is highlighted in the image below.

Figure 2.  Valid 2350 UTC 10 May 2012.  The storm warned on in Figure 1, now upgraded to an EXPERIMENTAL tornado warning highlighted by the red circle.

EWP: UAH SATCAST and UW-CTC Provides 40-50 minute lead time on EXPERIMENTAL Severe Warning

Thunderstorms continued to develop along an outflow boundary over southern Texas Thursday afternoon.  The satellite-based convective support algorithms (UAH SATCAST and UW-CTC) captured the early growth of the latest thunderstorm along the outflow boundary.  Shown in the figures below, SATCAST and UW-CTC provided 40-50 minutes of lead-time ahead of severe thunderstorm issuance and approximately 1 hour ahead of tornado warning issuance.  Additionally golf ball size hail was reported with this storm 1.5 hours later.

Figure 1.  Valid 2140 UTC 10 May 2012.  The UAH CI Strength of Signal product detects early rapid growth on a newly developing storm in south Texas (top-left pane).

Figure 2.  Valid 2145 UTC 10 May 2012.  The UW-CTC algorithm identifies the same developing storm with cooling rates of approximately -12 K / 15 min (top-right pane).

Figure 3. Valid 2155 UTC 10 May 2012.  The UAH CI Strength of Signal product continues to indicate rapid redevelopment on the tail end of the existing thunderstorm complex (top-left pane).

Figure 4. Valid 2229 UTC 10 May 2012.  The base reflectivity from KCRP with severe thunderstorm warning polygon issued by NWS forecasters at the EWP/HWT.  This warning was later upgraded to a tornado waring at the EWP/HWT.  **NOTE THIS IS AN EXPERIMENTAL WARNING**

Sieglaff/CIMSS
Walker/UAH
Barnes/WFO OUN

BRO/CRP West Radar Analysis 2240Z

Forecaster comments from EWP blog...

CI continues to show promising results in terms of providing significant lead for strong/severe t-storms.

The first image below at 2115Z shows a strength of signal around 99 (red) in UAH-CI in the upper left pane for a developing storm west of Laredo.

 The next image at 2125Z depicts -14C/15 min UW-CI (lower left) for the developing storm.

Radar imagery continued to show storm growth and the storm reached 50 to 55 dbz at 2208Z as shown in the upper right pane of the image below.  Also, MESH reached 1.18 inches at this time as well.

With these figures in mind, the lead time from initial CI detection on UAH-CI was around 55 min. and the lead time from UW-CI was around 45 min.  It would be great to put a product out conveying the possibility of strong storms when we first see these CI signals with an actual warning coming later.

BRO MESO Desk @ 2250Z

Forecaster comments from EWP blog...

We noticed a good comparison of the CTC at 2210Z occurring 18 minutes before the 1″ hail indication by MESH.

BRO/CRP West Meso Desk @ 2220Z

Forecaster comments from EWP blog...

Focusing on the newly developed storms over Mexico and west of Laredo, the synthetic satellite appeared to capture the progression of these storms as they move east.  Projections have these storms moving into Texas between 00Z-01Z.  Latest radar trends may be a bit faster though.

MESO Desk update @ 2150Z

Forecaster comments from the EWP blog...

These two nearCast screen captures depict the main axis of theta e/PW that was translating east of the BRO.  Ample moisture remains over the eastern and southern parts of the BRO CWA and support thunderstorm development.  Sadly, convection continues to be inhibited and is reflected on the 3DVAR sim. comp. reflectivity.

 

Mexico! CTC shows a rapidly developing thunderstorm

Forecaster comments from the EWP blog...

Top image – IR Satellite with CTC rates of -40C/15 min (dark looking region) ~25 minutes before
+60 dBZ @ ~32Kft (bottom image) were observed.

BRO Meso Analysis with Nearcast/Sythetic WRF at 2030Z

Forecaster comments from the EWP blog...

The below image at 22Z depicts nearcast theta-e at 780 mb in the upper left pane, synthetic WRF IR in the upper right, nearcast theta-e at 500 mb in the lower left, and nearcast vertical theta-e difference in the bottom right.

Looking at the 780 mb theta-e, it shows areas in yellow of best moisture/instability predicted for this afternoon which matches up with storms predict in synthetic IR imagery.  Because the 2 products derived off of different model projections are in decent agreement, this lends more confidence to this convective scenario for this afternoon.

 

BRO MESO Desk @ 20Z

Forecaster comments from EWP blog...

The following four screen captures depict several favored areas of UAH-CI strength of signal along the outflow boundaries that exist immediately north of CWA and north-south along a line from Los Angeles-Realitos-Encino-Raymondville.   Knowing were the boundaries were located,  UAH strength of signal allowed us to focus on the most favored areas between 20Z-21Z.   (Synthetic Sat showed the most likely CI would take place between 20-21Z, particularly with storms along the Rio Grande.  It didn’t capture any activity over the northern extent of the outflow boundary.)

BRO Afternoon Forecast 1920Z

Forecaster comments from the EWP blog...

Synthetic WRF imagery was useful in making a convective forecast for Brownsville this afternoon.  At 13Z, the synthetic WRF depicted two areas of convection over TX with the south complex near Brownsville being slightly displaced to the south in location.  This convection was occurring in an area of high shear ahead of an upper level low progress slowly across the southwest U.S. (seen in synthetic and observed imagery).

13Z Synthetic:

13Z Observed IR/WV (top 2 panes):

At 19Z synthetic and observed IR/WV imagery matched up well with the southern complex, but over did convection to the south of the northern complex in TX.  Over Brownsville area, visible satellite imagery depicted a low broken cu field at 1914Z which matches low clouds in the synthetic IR imagery.

19Z Synthetic:

19Z Observed IR/WV (top 2 panes):

1914Z Visible Sat:

Conclusion:  The Synthetic WRF model seems to be doing an OK job overall so far today with a few issues.  However, it depicts the upper low driving convection today as well as 2 distinct areas of convection over TX.

For Brownsville area for the rest of the afternoon, synthetic images below predict convective initiation around 20Z with convection strengthening through the afternoon hours (22Z image), and then beginning to decrease in strength at 0Z.

20Z Synthetic:

22Z Synthetic:

0Z Synthetic:

BRO MESO desk @ 1834Z

Forecaster comments from EWP blog...

A few towering cu were present across BRO.   CTC centriods were present in LaSalle county (CRP) an immediately south of Starr county.  In fact, the LaSalle county CTC also showed a high strength of signal on the UAH-CI.

EWP: UW-CTC 45 minute lead-time on severe hail

Another day at HWT we are focusing on southern Texas.  An upper level low over northern Mexico is finally beginning to move eastward, this combined with humid low-level flow off the Gulf of Mexico is setting the stage for severe thunderstorms over southern Texas today.  There were numerous severe thunderstorms ongoing as of late morning.  One of the most recent developing storms is showcased below.  At 1632 UTC 10 May 2012, the UW-CTC product showed cloud-top cooling rates of ~ -6K / 15 min.  The following satellite scan at 1645 UTC the UW-CTC increased substantially to over -20 K / 15 min.  Later images of radar-based maximum expected hail size show estimated severe hail occurring at 1715 UTC and significant hail in excess of 3.00" at 1725 UTC. 

Figure 1.  Valid 1632 UTC 10 May 2012.  The UW-CTC product indicates initial substantial vertical growth of a developing thunderstorm (red circle).

Figure 2.  Valid 1645 UTC 10 May 2012.  The UW-CTC rate on the developing storm explodes into the strong category with cooling rates near -23 K / 15 min (red circle).

Figure 3.  Valid 1715 UTC 10 May 2012.  The bottom right panel shows radar-based maximum expected hail size exceeding severe thresholds (1.00", red circle), 45 minutes after the initial UW-CTC signal.

Figure 4.  Valid 1725 UTC 10 May 2012.  The bottom right panel shows radar-based maximum expected hail size of over 3.00 (red circle)", 55 minutes after the initial UW-CTC signal and 40 minute after the maximum UW-CTC signal.

Another CI success story @ 2032z

Forecaster comments from the EWP blog...

At 2032z…storm was pushing offshore from St Johns County in Fl.  The CTC product indicated strong cooling rates approaching -20 DegC/15 minutes associated with that storm.  There was a short period of time when we did not receive any products.  However…the radar showed a stronger storm with increased lightning activity by 2112z.

EWP: GOES optical depth retrieval enhances UW-CTC

The inability for the UW-CTC algorithm to detect newly developing convection beneath thin cirrus clouds was the primary deficiency identified by forecasters in previous experiments.  In response to forecaster feedback, a recent proposal was awarded to UW/CIMSS to include GOES optical depth retrievals into the UW-CTC algorithm for the purpose of detecting these type of developing thunderstorms.  Thin cirrus clouds are frequently present related to anvil blow off of nearby storms, decayed convection from previous days, and related to jet streaks.  Figure 1 below provides another example of detecting a newly developing convective cloud in areas of thin cirrus.  The UW-CTC value is ~ -9K /15 min and the tower beneath the thin cirrus clouds can be seen in the upper right panel highlighted by the red circle.  Since this storm was out of our focus domain, radar data is not available, but NLDN detected the first lightning strike about 10 minutes later.

Figure 1.  Valid 2115 UTC 09 May 2012.  Note the developing thunderstorm beneath cirrus blow-off from storms to the south (red circle, top left panel).  The corresponding UW-CTC was ~ -9 K /15 min.  The bottom right panel shows the UW-CTC ice mask, which shows areas where detection was not possible prior to the inclusion of GOES optical depth retrievals.

CHS Desk – UAH CI product/Visible-Radar 2014Z

Forecaster comments from EWP blog...

Two images are shown here.  On the left, a line of storms extends along the South Carolina coast and into portions of southern Georgia at 2014Z. Earlier at 1945Z, on the right, the UAH Convective Initiation product showed 3 areas of 60%.  Initiation was predicted along and just ahead of an outflow boundary, and just off the coast oriented west southwest to east northeast.  The product performed very well, with around 30 minutes of lead team for the updrafts that exhibited +35dBZ.

JAX Cloud To Cloud Lightning near MLB 2035Z

Forecaster comment from EWP blog...

Cloud to cloud lightning was observed in a very weak storm in Osceola County.  pGLM flash rates are observed in the upper right and lower left images depicting the cloud to cloud lightning.  Cloud to ground lightning was not observed with this storm as depicted by the absence of strikes in the lower right panel.  This data proves that this weak storm had an updraft strong enough to produce cloud to cloud lightning but not cloud to ground lightning.

I feel that adding cloud to cloud lightning data will really help storm warnings, fire weather applications, aviation forecasts, etc. if added as a baseline product for WFOs because we’re obviously missing a lot of lightning data not only in weak convection as this example shows but in strong/severe storms as well.

EFP simulated satellite evaluation

Part of this year's EFP portion of the Spring Experiment is to examine simulated satellite imagery from the CAPS ensemble.  The goal of this project is to determine how differences in the microphysics schemes in the different model runs produce different cloud objects and features in the simulated imagery.  While this is not directly related to GOES-R, it is exposing the modeling community to satellite techniques and radiative transfer.  The group asked me to help them explain why different clouds seemed "cooler" in the simulated imagery and how features of clouds (such as ice particle concentration, height and optical depth) would affect what an actual satellite would "see".  I was able to alleviate some confusion amongst the participants regarding whether the standard IR window was seeing a layer or more of a surface when it came to different cloud features, such as an optically thick storm updraft core versus a relatively optically thin cirrus cloud associated with an anvil.  It is good to see some of the non-satellite community actively trying to better understand how satellite observations are made.

UAH CI Product Achieves 1.5 hour Lead Time in Tropical Florida Environment

One of the places in which the old version of the UAH SATCAST CI product used to suffer was in the tropical environment of the Gulf Coast with relatively low PODs and shorter lead-times.  Shown below is an example of an output CI forecast that was able to produce a lead time of 1.5 hours over radar (Figures 1 and 2).

Several improvements have been made to the algorithm since its debut as a "cloud object tracking CI product" 2 years ago (Spring 2010). With a newly defined future path as a "doubly data fused" algorithm (using short-term NWP environmental forecasts as input --and-- CI forecast output as NWP assimilated input), the best way to gauge performance is to make sure we are thoroughly bench-marking and improving its accuracy and usefulness as a Decision Support System (DSS).  Otherwise, using it as input into NWP models will prove much less effective. 

Figure 1.  SATCAST Strength of Signal CI product produces forecast output of 70+ index value (on scale from 0-100), valid from 1315 UTC (Left).  The storm motion is to the ENE.  Note the lack of any radar echoes at the time (Right).

Figure 2.  By 1445 UTC (1.5 hours after the above CI forecast in Figure 1), the first 35+ dBZ echo is finally detected by the radar (Right).

JAX Meso Update 1940Z

Forecaster comments from the EWP blog...

Nearcast data shows favorable conditions for convective initiation and maintenance through mid afternoon.  The first 2 images of nearcast at 19Z and 20Z show good theta-e values (yellows) at 780 mb (upper left) with a slightly cooler drier environment aloft (greens) at 500 mb (lower left).  Bright greens over central and eastern portions of JAX area support a favorable convective environment.   This analysis combined with soundings and other environment data are supportive of small hail with storms early this afternoon.

19Z:

20Z:

In the later 2 images below at 21Z and 22Z, the environment becomes less favorable for convection as we can see less of a threat of convection as the brighter yellows at 780 mb (upper left) begin to move off shore (a cold front enters the area).  Also at 500 mb (lower left), brighter yellows are observed moving into JAX central and eastern portions of the area indicating more warm/moist mid levels which would be less supportive of small hail and more supportive of heavy rainers given the environment conditions.  The theta-e difference (lower right) depicts most unstable/moist environment (bright greens) moving off shore as well.

21Z:

22Z: