The week in the review

Working with the forecasters this week of Mother's day has been comprised of relative slow weather, at least as defined by people who live for the next severe weather event. Due to the relative calmness of the atmosphere, the visiting forecasters have had the opportunity to really dig into the tools presented to them in cases that most would consider marginal. As such, they each had time to interrogate each of the tools, both to test their individual strengths and weakness, as well as how the tools could be used together to give them a more complete picture of the near storm environment and the elements leading up to each interesting case.

The role of a convective initiation algorithm is to give indications of clouds that are exhibiting signs of growth associated with a developing storm. One that will produce a 35 dBZ radar echo, meaning at least rain, possibly more. The UAH CI product, or SATCAST is designed to give the user information, based on IR brightness temperature tests, of how a tracked cloud has grown/changed since the last satellite image. This signal will precede the radar echo, giving the forecaster knowledge of the environment of interest and, depending on the strength of the signal, and area to focus on. The blog has some great examples of the use of the UAH CI/UW CTC products used in collaboration to highlight areas of interest, to many to mention here, and real, the forecasters have done a fabulous job of describing the different cases presented during the week. Instead, I will focus on the ways the products were used and displayed. 

An obvious choice, placing the CI/CTC product on top of a visible satellite image. Regardless of the level of zoom, this setup allows for the familiar imagery to have a bit more utility. 

Utilizing the 4-panel display allows for the flexibility to view the data sets separately.

ALY - 16May12, 2010z

Some different set ups have included lightning data, radar data, and some of the newer products from the MRMS and Near-Cast suite of tools.

An example of the combination of tools made possible by the AWIPS-2 display, the Merged Reflectivity at the lowest altitude display from  the MRMS with the UAHCI and UW-CTC products overlaid allows one to follow the evolution of a cloud object by the satellite products through to the first radar echoes and beyond.

DVN - 15 May 12 2206z

In some cases, outflow boundaries from the storms would trigger additional satellite CI indications that also progress in time to initiation. The ability for the individual control of the color schemes of each of the products made the visualization of these three products simultaneously possible.

Finally, as day passed into night, overlaying the products over an IR image.

 

17 May 12, 2214z

Although the intent of having the product scientists on hand to answer the questions of the forecasters, in many ways, we spend more time learning from them.  Seeing how each forecaster uses the product, what their expectations are, and tapping into their vast knowledge of the storm environment from the operational perspective forces a different perspective.  One that should result in the fine tuning of the algorithms from something that is "geeky cool" to something that can be used everyday.

EWP end of week 2 debrief

Nearcast
- "Did a good job over FL… the gradient of the theta-e difference really lit up when a boundary hit it."
- "Highlighted well where you had a minima in instability over both ends of the CWA... had confidence that you would have the whole area light up."
- Archive case... "Saw a clearly defined dryline which helped us pick out where the convection was going to occur that day."
- "This CAPE product holds a lot of promise... I don't know about accuracy, but qualitatively it was highlighting the areas of interest."
- "Only having two layers is a drawback for now."
- "I would think that the more negative values would be unstable... That ended up being a source of great confusion for the first day because of what I looked at in the training... having that much variation hurt."
- "Warmer colors would intuitively seem to me as unstable."

SATCAST / UW Cloud-top Cooling
- "Several times the CI worked as it was supposed to, then you would get a strong CTC signal getting up towards -40 C/15 mins... I think it would be a really useful tool in a marine environment."
- "CI started to have a breakup of the signals, less random values popping up... you could see a transition of the signals."
- Archive case... "Saw some CTC hits late on in the event when we expected CI to be over... did see a rapid ramp up in the ongoing storms immediately after on radar."
- "The UAH CI strength of signal is a huge improvement... when I was using it with the CTC, I had to stop myself from comparing it to the signals in CTC because they didn't always match up."
- "Relating the stronger cooling rate to severe weather... I don't have a strong opinion one way or another... but the way it was presented to me I found myself really paying more attention to those stronger CTCs."
- "The CI products is something we are hoping to pull into the pilot project."

Simulated Satellite Imagery
- "Forecasters are just going to have to get used to looking at that... getting used to the display of the data... less blow off from your cloud tops that doesn't match actual satellite data... it's just going to take time to get used to what you're looking at, but it does have an amazing ability to show convection... I think it's a great tool."
- "Useful as a planning tool... trying to figure out where stuff is going to form, the location ended up being spot on."
- "I wonder a little bit would we have made the same decisions just looking at model QPF or other model fields... it was an accessible format being similar to satellite data... does that make it more believable?"
- "The training didn't do an effective job in explaining the difference between the water vapor imagery... only after I came here and talked to Chris did I understand that it was actually a different channel than what we currently have on GOES."
- "I did have some reservations that the color scales looking just like observed data."
- "I can see the channel difference being very useful in briefing non-mets about where the dry/moist air is and it's a quick way to pick out those areas."
- "It would be nice to get this stuff in GFE for sky cover."

PGLM
- "Signals were very weak over the MLB area, didn't really have much impact on decision making for this event."
- "I would like some more training on what we should be looking at in regards to jumps and relating that to what we were seeing on the ground."
- "I think it will be huge when we have it everywhere from a satellite perspective."
- "From a severe weather perspective, it was hard to tell what it was showing me."

Overall / Training
- "What deserves my increased attention is such a challenge to determine when you have to triage data in a warning environment... having some sort of quantifiable way to determine what deserves my attention would be nice to have."
- When under pressure and at first glance of new products... forecasters mentioned that they immediately went to 'warn on red' for the colors in the products... which wasn't the case for some of the 3DVAR and Nearcast products.  Forecasters mentioned it took them some time to remember 'no wait, we need a value of X' and go back and re-evaluate the product's output.
- "An 'all-tilts' display method for 3D gridded data in AWIPS II would be extremely useful."
- "Anything we've seen this week we would like to pull into the pilot project."
- "It was an excellent idea to have the training day before we arrived in the HWT."
- "If we had the training available a little earlier, it would have helped."
- "The training material was a good amount for an 8-hour shift... although the amount in the WES was a little problematic to load."
- "A quick reference guide for the training would have been helpful."
- "We needed that amount of training, but by the end of the day doing it all at once I was left exhausted."

CI & CTC May Provide Lead Time on JAX-area Storm

Forecaster comments from EWP blog...

Another severe thunderstorm warning was recently issued (2148 UTC) for a portion of southeastern Georgia (Appling and Jeff Davis Counties), west of Vidalia.  It’s worth noting that both the UAH CI and the UW CTC products flagged this storm quite some time ago.

The first indication on this cell occurred with a 59 strength-of-signal indication from the UAH CI product.

UAH CI and Visible Satellite valid 2012-05-17 1945 UTC

The SOS increased to 68 on the next satellite scan, then 71 on the subsequent scan (2015 UTC).  The UW CTC flagged the storm for the first time at 2045 UTC with CTC rates of -13 to -14 C/15min, and that decreased to -16 C/15 min on the next image.

 UW CTC and Visible Satellite valid 2012-05-17 2045 UTC

The visible imagery becomes quite impressive with overshooting tops by 2130 UTC.  The SVR was issued at 2148 UTC, based mostly on distant radars.  The 3DVAR analysis domain was just recently expanded to include this area, and MRMS POSH and MEHS were not particularly impressive.

Visible Satellite valid 2012-05-17 2145 UTC

CIMSS Nearcasting: Predicts the convective development pattern in Central Florida

On Thursday morning, May 17, the CIMSS GOES Sounder Nearcasting model indicated that unstable Ɵ_e lapse rates would persist over Central Florida throughout the morning and into the afternoon.  Lapse rates would remain relatively weak, but unstable, with the nearcasting CAPE indicating values of 750 to 1000 joules per kilogram.  At 1400 UTC the CIMSS nearcast products indicated that a minimum of weak instability would persist into the afternoon across Central Florida, along a line extending SSW to ENE, with stronger gradients N and S of the line.   Coverage was good at this time because the region was relatively cloud free.

At 1900 UTC HWT forecasters detected a developing convective cell north of Lake Okeechobee and a weaker line of convection south of Gainsville.  Convection in Central Florida remained suppressed. Forecasters noticed that the development matched the nearcasted dƟ_e gradients quite well.

Shown below is a 5 1/2-hour nearcast of dƟ_e  and CAPE valid 1930 UTC, May 17, 2012.  Also shown is the verifying GOES visible and radar images.  Nearcasted CAPE values were strongest along the southern gradient which is where the strongest convection formed.  The areas east of Tampa remained devoid of strong convection.

 

 

Nearcasting CAPE vs Visible Imagery

The Nearcasting model is an excellent observation-based decision-support product that has been developed by UW-CIMSS.  One of the product's strengths is to forecast where instability is and is not located.  The image below is a 7-h forecast of Nearcasting CAPE (valid at 1900 UTC) with the 1900 UTC Visible imagery and previous hour's lightning observations.  Unstable air is in shades of blue and purple while stable air is in shades of green and brown with the CAPE and Visible images transparent for ease of comparison.

Some things to take away from this figure.

1. The majority of the CU field and convection is to the south of a large-scale midlevel instability gradient that extends from central AR east northeastward into the Mid-Atlantic states.

2. The deeper convection is aligned well with the deeper blues and purples (higher values of CAPE) across northern MS and most of TN, eastern Gulf of Mexico, and across central FL.

3. The most stable air extends from southern MO east northeastward into the eastern Great Lakes and into New England...notice there are very few clouds in this area.

Not only is this product good on the NWS CWA level but also for the analysis of large-scale areas of convection (and lack of convection) that are important for operations at the Storm Prediction Center and the Aviation Weather Center.  The SPC could use the Nearcasting model to assist in their forecasts of the "thunder line" and the AWC could use the output to assist their partners with highlighting which high altitude jet routes are clear for the day (e.g., the NYC to Chicago corridor today).

ThetaE Gradient

Forecaster comments from the EWP blog...

Noticed an interesting diagonal differential heating sort of boundary in across northern Florida where the next round of convection appears to be initiating.  It show up well on the nearcast as s thetaE gradient and is now showing up on Vis and CI products…if this end up being the focus of more critical convection later in the afternoon this could be a really good application the nearcast product.  There was a similar looking (though not sure if it was the same cause) feature when we were MLB two days ago that was where the bigger stuff triggered.  Waiting to see…

GOES sounder nearcasting CAPE

Forecaster comments from EWP blog...

We’ve been keeping an eye on the relationship between the GOES based CAPE field and the coverage of the developing convection over Florida today.  The synthetic satellite imagery has also done a good job on delineating the areal coverage of developing convection.  The four-panel image has actual Infrared imagery on the upper left, synthetic satellite imagery on the upper right, visible satellite and lightning data on the lower left and a layered CAPE field derived from GOES-13 sounder retrieval data.  The highest CAPE values, around 1200 joules/kg, are located just to the northwest of Lake Okeechobee, with an axis of lower CAPEs further to the north.  There is also a subtle increase in CAPE values over northern Florida, where additional convection is developing.  The region with the lower CAPEs has weaker convection at this point.  The synthetic satellite imagery is a 12 hour forecast using the 06z run of the WRF model, valid at 18z.  It also does a nice job depicting less convection in the region of lesser instability.

GOES-15 in Super Rapid Scan

For those of you interested in looking at some GOES-R-like temporal resolution imagery, GOES-15 (GOES-West) is operating in Super Rapid Scan Operations (SRSO) today over eastern CO in support of the DC3 experiment until 2359 UTC.  You can find an imagery loop at the link below (courtesy of Dan Lindsey at CSU)...

http://rammb.cira.colostate.edu/templates/loop_directory.asp?data_folder=dev/lindsey/loops/goes15&image_width=1020&image_height=720

UW-CTC in eastern CO

While the warning teams are keeping an eye on things in FL, thunderstorms have developed in eastern CO associated with a midlevel short wave.  The UW-CTC algorithm detected cloud-top cooling rates in the -25C/15min range with a lead time of approximately 45 minutes on a 50 dBZ echo with the storms.  The storms initiated in juicy air with dewpoints around 35F along the front range of the Rockies.  The images below span an hour between 1815 and 1915 UTC.

NearCasting for JAX

Forecaster comments from EWP blog...

We are focused on the JAX CWA today.  While there is convection ongoing in the extreme northern portion of the area (bordering FFC and CHS), the GOES-R NearCast CAPE (new this week) and vertical theta-e difference suggest that the southern half of the JAX CWA is more conducive for new convection.

The NearCast has been challenging to interpret this week due to interpretation confusion (are negative versus positive theta-e differences indicative of instability) and then a mid-week visualization change in AWIPS 2.  The NearCast shows promise for helping with the tremendously-difficult 1-6 hour timeframe, but the product stability has presented a problem.

EWP daily debrief 5/17

Below is some feedback we captured during today's daily debrief of the EWP forecasters...

SATCAST / UW Cloud-top Cooling
- Burlington, VT CWA... "We were seeing high CI signals to start... but when the storms started growing and pluming out, they became less useful, but it did pick up on some outflow boundaries where more development was occurring."
- Albany, NY CWA... "There were several areas where both algorithms flagged this lonely cell but it ended up falling apart... it had CTCs in the range of -30 C/15 min and it didn't do anything significant based on my expectations from what we should be comparing it to... there were some cells to the southeast, so the inflow may have been interrupted."
- "The CI started with a high signal (red), then the CTC flagged the storm and it became the strongest storm in the line."

Nearcast
- "I don't remember seeing an indication necessarily correlating to a tongue of moisture... I don't think it was really well defined... there was some indications of slightly moister airmass, but nothing significant... I don't know if the nearcast had the resolution to get down to that narrow of a feature."
- "We saw higher theta-e values as well as the new CAPE product over N. AR and that was useful which depicted and area where convection occurred."
- "It was an overall helpful tool... not necessarily picking out where severe occurred, but where convection would occur."

Simulated Satellite
- "On a 23-24 hour forecast, it nailed the location of convection over N. AR... I was impressed at how well it did over the NE as well."
- "I would like the reality and the model to look a little different... maybe a slightly different color table."

Overall / Training
- Trend line displays within AWIPS would be very useful.

Synthetic imagery – verified!

Forecaster comments from the EWP blog...

The synthetic imagery did a nice job of placing convection southward along the cold front through the Ohio and Lower Mississippi Valleys.  Here’s a screen capture from 2300UTC, with the actual IR on the upper left and the model forecast on the upper right.  Visible imagery with lightning is shown in the lower left pane, with the theta-e Nearcast product on the lower right.  All in all, the GOES products did well today depicting where convection would be in relation to the cold front.  This would be an excellent application to the CWSU environment for air traffic planning purposes.

CIMSS Nearcasting: Pushed to the limit - the lower limit!

The past three days have been challenging for the CIMSS nearcasting model since atmospheric conditions have not been favorable for the development of strong convection.  Ɵ_e lapse rates have rarely exceeded 8-9 dƟ_e.  However, forecasters have been able to use the nearcasting guidance, both Ɵ_e and the new CAPE products to correlate where convective development is expected.

 

Shown below is a 4-hour nearcast of dƟ_e  and CAPE valid 22UTC, May 16, 2012.  The nearcast model consistently placed a line of instability along the Ohio River Valley associated with a trailing weak cold front.  At this time convective cells formed in NE Arkansas which matched well with the nearcasted dƟ_e and the nearcasted CAPE.  Also shown below is the verifying GOES IR and radar images.  Although convective cells formed, they were not expected to become severe based on other available guidance.

 

 

 

Quick Glance at SimuSat for Today’s Convection

Forecaster comments from the EWP blog...

Severe thunderstorms kept the WFO ALY team busy today!  With storms in our area diminishing (and moving out), I wanted to check out the CIRA/CIMSS Simulated Satellite Imagery from the NSSL-WRF to see how it compared to the last few hours.  Overall, I’d say quite well, aside from some placement issues, and the extent of the coldest cloud tops (which was to be anticipated).

Convective Initiation – Verified!

Forecaster comments from EWP blog...

This series of images shows an ideal case of the CI product detecting a rapid development of storms along a cold front in northeast Arkansas.  The first image shows a strong CI signal (red) at 19:10.

The second image shows the same area about 10 minutes later at 19:25.  The weird tooth-shaped object is the Cloud Top Cooling rate and this indicated -16 deg/15 min.

Finally, at 21:25, about two hours later, the visible imagery showed a developing storm with an overshooting top.

CI Within Nearcasting Instability Max

UW-CTC is depicting strong cloud-top cooling and convective initiation within an area of higher instability that has been forecast by the UW Nearcast model.  The warning forecasters in ALY are watching this storm as it is isolated and ahead of the main line.

VIS and UW-CTC (top left), ENX Base Reflectivity (top right), Nearcast 780-500mb Cape (bottom left), and Nearcast Thta-E Difference (bottom right).

CI products still useful

Forecaster comments from EWP blog...

After the convection developed rapidly, the CI and CTC products became masked due to the TS plumes.  However, the convection at the north end of the CWA may have kicked out an outflow boundary to cause more development in clear air.  This was picked up by the CI product with an increasing signal in subsequent frames.

A stronger (yellow) signal was evident on the next frame.

The resulting composite reflectivity (upper right image), showing development to 45dbz 15 minutes later.  Comp reflectivity was used here due to beam blockage at 0.5 degrees.

Benefits of pre-operational demonstrations

During yesterday's forecasting exercises, a forecaster captured an event that raised a few questions during the case and in our daily debriefing today regarding the cloud-top cooling rate product.  Below is an excerpt from their EWP blog post, including the images they captured...

"Here is the series of visible and infrared satellite pictures for the storm cell that we issued the tornado warnings.  The Convective Initiation product gave a strong signal as this cell began developing, but the Cloud Top Cooling product never identified this storm.  The infrared pictures are sampled at the coolest part of the cell at each time step, about 5 to 10 minutes.  The storm grew explosively and produced one inch hail along with strong rotation on the radar."

Upon some investigation, it was discovered that the growing cloud in question was being affected by the neighboring mature storm a few pixels away within the cloud-top cooling rate products cloud mask algorithm.  This example has been flagged by the developers as a good case for some potential improvements (which they have already quickly identified) to the way the algorithm classifies the scene in which cloud-top cooling rates are calculated.

This is a good example of why bringing products into a operational-type setting and demonstrating them in an experimental sense is very beneficial towards improvement and a successful transfer from research to operations.  In this case, the developers were able to quickly identify the issue that the forecaster expressed confusion with.  Until products are run in real-time over a large domain, some small events may be missed that are still important to an operational user's perspective.  It is essential to identify and address issues within any experimental product prior to operational implementation.

Nearcasting Forecasts Instability in ALY Area

Storms west of Albany, NY are forecast to move into an area of higher instability that is forecast by the UW-CIMSS Nearcasting Model.  New midlevel (780-500mb) CAPE output is depicting an area of 500-700 J kg-1 as the storms approach from the west.  This would support the storms intensifying and growing in coverage as they continue to move eastward.

VIS (top left), ENX Base Reflectivity (top right), Nearcast 780-500mb Cape (bottom left), and Nearcast Thta-E Difference (bottom right).

EWP daily debrief 5/16

Below is some feedback gathered from today's daily debrief of the EWP forecasters...

SATCAST / UW Cloud-top cooling
- For Davenport, IA CWA... "The strength of signal never really got above yellow (~ 60-70%)... the rest were pretty marginal... there were a few interesting CTC signals up to -22 C/15min... the ones that flagged the strongest would shift around, so it was tough to get a feel for the lead time or false alarms.  The CTC signals would appear once and then go away, so it was hard to get some continuity... generally they were -10 to -15 C/15 mins... so that fit our expectation that it wasn't a very favorable environment for severe weather... collectively they both handled the situation well, but if you handle it on a case by case basis it would have been tougher to judge."
- For the Melbourne, FL CWA... "The two CI hits we had in the red (mid 90s %) had about a 24 minute lead time on when it showed up well on radar and turned out to be the stronger storms.  The CTC didn't get the second storm, but the CI did, and that was the one that had the tornado.  The higher CI probabilities really helped me tell that the storms were intensifying versus what I could already tell on visible."
- "One of the interesting challenges with these CI/CTC algorithms... we've had plenty of training on how these products work, but there are still those moments when we're trying to figure out why something didn't happen... that's something that will come with time and more use."

Nearcast
- For Davenport, IA  CWA... "The theta-e difference was a pretty good indicator that it was going to be a pretty marginal day."
- "The theta-e difference picked up nicely on the fact that there were stronger signals in N. MI and that correlated well to the stronger storms"

PGLM
- For the Melbourne, FL CWA... "It showed some signals, but I'm not sure it would have had much of a role in my warning process yesterday."
- "Another application would be where there isn't much radar data... if I was out west forecasting for a fire where there was no radar coverage, it would be very useful in letting people know where the lightning was."
- "From an aviation perspective, especially with a situation where there is a line of storms, this would be very useful in increasing situational awareness."
- "Lightning could have interesting heavy rain/flash flood impacts as well."

Day 2 at HWT

Although there has been a general lack of wide-spread,exciting, edge-of-your-seat, thunderstorms to warn on this week, forecasters have had plenty of opportunity to play with this year's assortment of experimental weather products. UAHuntsville's convective initiation product, or SATCAST, is sporting it's new "strength of signal" look and functionality. Some successes, watching the development of storms along a frontal boundary stretching through Iowa, UAH SATCAST followed the growing clouds from birth to rain, with values ranging from 20-70 on the strength of signal scale. These clouds went on to produce minimum 35dBZ echoes downstream. Overall, the area did not experience any severe weather, but SATCAST was able to differientiate between the weaker storms and the somewhat stronger storms of the day. (See http://goesrhwt.blogspot.com/2012/05/ci-algorithms-over-iowa.htm for more information). Another success, using SATCAST over the Melbourne, FL warning area, the forecasters report good utility of the strength of signal format indicating the growth of a cloud over subsequent satellite images, one of which resulted in a storm that produced a tornado warning. ( See the post at http://goesrhwt.blogspot.com/2012/05/experimental-warnings-north-of-cape.html). Some not as successful points, working in Roanoke, VA in the early afternoon. Cloud cover and cirrus contamination made using the convective initiation products problematic for the forecasters. (See http://goesrhwt.blogspot.com/2012/05/weak-convection-in-rnk-cwa.html). Although surrounding areas were giving indications of CI, the WFOs remained masked out. Overall, the lack of specific severe weather events monopolizing the time of the forecasters really allowed each of the four participants the time to really dig into the products made available to them this week. One hopes that now that the forecasters are more familiar, the weather will cooperate and give them something a bit more interesting to play with. Time will tell.

CI: day vs. night... advantages of higher resolution data

Forecasters operating over the Davenport, IA CWA area brought up some questions regarding what they were seeing in the UAH-CI SATCAST product's output this evening.  There was some confusion why all of the sudden the amount of objects (and shape of objects) being forecast for CI rapidly increased over one satellite scan.  The forecaster spoke with the UAH visiting scientist about this and it was explained very well to the forecaster that the issue is the switch from the products daytime-only cloud mask to the nighttime cloud mask.

The UAH-CI SATCAST product makes use of the visible data within its cloud mask when it is available to aid in identifying small growing cumulus clouds.  During the day, this is extremely beneficial, but since visible data is not available at night, the product is unable to make such high spatial identifications of growing clouds.  This really shows the benefit of having higher resolution satellite data like that which will be available on GOES-R's ABI during all times of the day.... not only for imagery, but for derived products and decision support tools as well.

 UAH-CI SATCAST in daytime mode.

UAH-CI SATCAST in nighttime mode.

Nearcasting CAPE in response to forecaster comments

Early forecaster comments on the nearcasting revealed a general difficulty comparing the vertical theta-e difference and related algebraic representations of the mid-tropospheric instability forecasts from the Lagrangian trajectory model to other stability parameters and other sources (model forecasts and analyses, etc.).

In response to this, product developers Jordan Gerth (University of Wisconsin) and Robert Aune (NESDIS/STAR/ASPB Madison, WI) participating in the testbed this week formulated a simple convective available potential energy (CAPE) calculation using nearcasting model output with the 780 hPa equivalent potential temperature (theta-e) as the parcel and 500 hPa theta-e as the environment.

With CAPE (units of J/kg or m² s^-2), users can easily understand the physical significance of the information provided by the GOES Sounder and watch the evolution.  It is believed that this will be ideal for following the growth and decay of elevated instability.  Even though this is not a full-profile CAPE calculation, the 780-500 hPa layer potential energy is particularly important for storm development and updraft strength.

The CAPE calculation was recently implemented in AWIPS II for the remainder of this year's Hazardous Weather Testbed.  Furthermore, the new layer CAPE output from the nearcasting model is available online at http://cimss.ssec.wisc.edu/model/nrc/ in the "Under Development" section.  It was recommended that forecasters compare to fields in AWIPS II and on the SPC mesoanalysis web page.

CI algorithms over Iowa

Forecaster comments from the EWP blog...

While thunderstorms have not been as impressive over Iowa, Illinois, and Wisconsin, the UAH convective initiation and UW cloud-top cooling algorithms have been increasingly active over the last hour.  To track their effectiveness compared to radar, I overlaid the MRMS merged reflectivity at lowest altitude product with the UAH CI and UW CTC all on the same image (something that wasn’t available with AWIPS 1).  There was an interesting evolution with the UAH CI starting with the 2132 UTC satellite image, when it flagged an area of CI near West Amana, IA (south of Blairstown) with a 28 on the new Strength of Signal scale.

By 2144 UTC, a 20 dBZ shower had developed with that CI object.  By 2200 UTC, CI was up to 44, and the radar reflectivity was up to 48 dBZ.

Shortly thereafter it maxed out at 63 CI SOS; the cell’s reflectivity maxed out between 2226-2234 UTC at 52 dBZ.

A neighboring storm near Lake Iowa triggered both the UAH (74) and UW (-13 C/15 min) algorithms; it too maxed out around 50 dBZ but was shorter-lived.

Viewing the CI and CTC data simultaneously with radar imagery allows forecasters to make direct comparisons to their most frequently-used warning tool.