Using NRCAST Vertical Theta-e Diff

A 5 hour NRCAST vertical theta-e difference is shown to the left. The gradients between unstable values (greens, yellows, and reds) and stable values (blues) are marked by the white lines. The stronger gradient is along the solid line as a weak cold front pushed southward through the area. A weaker gradient extends to the south.

Observed radar is shown to the left along with the 5-hour theta-e gradient forecast. Note that the stronger storms formed generally along the gradient, rather then in the middle of the unstable area. Additionally, showers were generally confined to the unstable areas. If a general convective initiation time is known, this gradient forecast could be useful in locating the areas where storms will fire. With virtually no precip in the stable areas, this product would also be useful in short term precip probability forecasts.

Denny VanCleve NWS/MKX

Robert Aune NOAA/ASPB, Jordan Gerth UW/CIMSS

NSSL 4km WRF Simulated Satellite imagery

Advanced Baseline Imager bands 8 through 16 are available for the NSSL 4km WRF output.

In this example a 16 hour forecast of band 9 (6.95 um, top image) is compared with the current WV imagery (bottom image) depicting an upper low over the Northern Great Lakes. Band 9 correctly depicts the location and orientation of the upper low and the associated dry slot and cloud regions. Farther to the south over AR, TN, and MS, band 9 is slow in the evolution of a MCS. The various bands of the WRF would be beneficial to forecasters to assess the model evolution of the environment and aid the forecaster in the progression as well.

Mark Gehring NWS/MKX

Justin Sieglaff UW/CIMSS

Fog/Stratus California Coast

The GOES-W MVFR Fog Probability 4km does a fairly nice job assigning high MVFR probabilities to stratus and fog off the coast of CA but also depicts the clearer area over Channel Islands National Park. It does assign only low probabilities to the MVFR-IFR conditions along the coastline however. Could this possibly be due to a thinner depth to the stratus field, assuming it is actually thinner? Farther to the west beyond the various islands the Fog Probability shows an area of "no data" due to clear areas that are present and sct-bkn cloud cover versus the bkn-ovc cloud cover to the east.

Mark Gehring NWS/MKX
Justin Sieglaff UW/CIMSS

CIMSS-MKX Local Area Testbed Beginning Soon

This summer the Hazardous Weather Testbed concept will be expanded to the National Weather Service forecast office in Sullivan, Wisconsin (MKX). Cooperating with the Cooperative Institute for Meteorological Satellite Studies (CIMSS) and Advanced Satellite Products Branch (ASPB), this Local Area Testbed will focus on evaluating GOES-R Algorithm Working Group (AWG) cloud type and mask products, fog probabilities, and simulated ABI longwave bands weekly.

Stay tuned to this blog for exciting posts on how NWS forecasters envision these new products will be used in future forecast operations to improve our assessment of the atmosphere.

J. Gerth

End of the experiment...

Well, the 2011 Spring Experiment is now officially over. Ironically I just made some major facelifts to the blog, including a "follow by email" tool on the right-hand side. I would encourage everyone to follow this blog throughout the year as it is likely to be used by the UW-CIMSS local testbed with the Milwaukee/Sullivan WFO. We may also have an informal late summer experiment here in the HWT regarding fire weather that may have some interesting results.

I would like to thank everyone that visited this year and participated in our activities. Without visiting scientists, the feedback gained and interactions with the forecasters would have been greatly reduced. I would also especially like to thank everyone who helped set up and run the Spring Experiment this year. There are too many to list here, but without their efforts the Spring Experiment would not have happened.

Thank you all!
-Chris Siewert

EWP end of week debrief... 10 June

Today marks the last day of the last week of the experiment. As is tradition, we debriefed the EWP visiting forecasters on their experiences throughout the week...

Convective Initiation

- (Thursday event - N.E.) Cloud-top cooling products seemed to work in diagnosing the strength of storms on the southwest edge of the line that were newly developing.

- Even though CI didn't always occur... false hits were useful in identifying clouds trying to break the cap.

- Forecasters not interested in seeing a binary yes/no output.

- "There were instances where similar looking clumps of Cu that one would flag for CI but the other wouldn't... so I wasn't sure how to interpret that other than maybe this area was more conducive to further development."

- There are lots of products that provide you lead time on CI, the real question would be on the consistency of the output.

- "I would definitely look at this in my WFO... especially the cooling-tops product gave me a lot of information on the relative strengths of the storms."

- "If both groups could work together and come up with a probabilistic product that combined the strengths of the UAH and the UWCI products, that would be very useful."

- "I think from a purely public forecast perspective, especially this time of year where we get convection every day, it would help you identify when exactly CI will occur."

- Would be very valuable for nocturnal CI.

Nearcast

- (Thursday event - N.E.) "I didn't see a whole lot of trend in terms of gradients developing, but all the sudden on the back side of the squall-line we lost data rapidly, probably due to cloud cover... compared to the other days, I didn't see any real patterns."

- (Thursday event - KS/OK) Showed an arch of destabilization between 2200-0300 across the eastern halves of OK and KS... storms formed on the western edge of this gradient and forecaster did not expect the storms to diminish anytime soon and thus increased warning confidence... stronger wording regarding hail/wind potential in warning was issued.

- There seemed to be small scale features in the fields, areas of relative maximum that were moving around... would be nice to compare to radar evolution and see how those areas affected the storm structure.

- Helped understand why convection occurred and where it would occur... definitely the 1-6 or 1-9 hour timeframe was the most useful aspect of it.

- Having a 4-panel set up of the individual layers in addition to the difference field to help increase the understanding of the product.

- The color-table in AWIPS was poor... Also, the values were reversed from those in NAWIPS and on the web. The individual layers of PW were also not available in AWIPS.

Would it be useful to extend the Nearcast another 3 hours, even if that meant smoother fields?

- "I like the high resolution out to whenever we can have it... it seemed that there was definitely information within the gradients... of course if you add 3 hours, we will definitely take that."

Would you have used the observations without it being advected forward?

- Wouldn't have been as useful... It helped determine the evolution of the environment... The forecast parts tended to build areas of increased instability that helped provide guidance on what was going to happen later on.

Overshooting-top / Thermal Couplet

- (Thursday event - KS/OK) None were detected when forecasters expected to see detections, so was not used, especially with the rapid updates of radar data.

- Need to remember to turn icon density to "MAX" within AWIPS or some detections will be lost.

- Looked at pretty much every day... for the most part, operator identified OTs occurred before the algorithm did.

Pseudo-GLM

- (Thursday event - OK) Some of the storms to the east had higher flash rates, but this was an artifact of the LMA network's detection efficiencies.

- (Thursday event - OK) Flash rates would pick up a short time before increases in reflectivity.

- Was useful for diagnosing lightning danger... get a lot of calls from the public regarding that within the WFO.

Overall

- Would definitely help to have some pre-configured procedures before forecasters arrived... forecasters used the "ultimate CI" procedure heavily and liked to see what we think they should be combining to help enhance the utility of the products. Forecasters can then adjust the color-scales for their own preferences.

- "I liked the morning/evening shift idea... that was nice... got to experience something different everyday."

- Sometimes the forecasters would get to tied into warning operations mode and forget to look at the experimental products... would be nice to make sure that the forecasters understand that there is no real pressure and to take their time to examine all of the experimental stuff.

- Would have been useful to provide the forecasters with the training via visitview prior to arrival, as well as some cases that the forecasters could use to get familiar with the products and decrease spin-up time... This would have to be done very far in advance.

- Interaction with the EFP CI desk was not done because there were so many participants over in the area.

- EFP/EWP daily briefing was seen to be repetitive between all the groups and not very "brief" as one forecaster stated. Also, the information being provided was more academic than pure weather discussion.

- WE NEED MORE CHAIRS!

Overshooting-top/thermal couplets over Wichita, KS not detected

AWIPS 4-panel with satellite IR window (top left), visible (top right), overshooting-top detection (bottom left) and NLDN lightning detection (bottom right) for 2345 UTC on 9 June 2011.
EWP forecasters are in the act of warning on storms across KS and OK. One of the more notable storms this evening formed west of Wichita, KS and began moving east towards the northern part of the city. The storm had a very nice hook echo and many reports of funnel clouds and large hail. The forecasters were asked to examine the overshooting-top / thermal couplet products while they were making their warnings. Unfortunately no overshooting-tops were detected... which means there was no chance of detecting a thermal couplet because it requires an overshooting-top detection. Starting from top left and moving clockwise the image above shows the standard IR window, visible, overshooting-top magnitude and NLDN lightning detections within the 4-panel AWIPS D2D display. While it is fairly clear in the IR window and visible imagery at 2345 UTC that there is an overshooting-top, as well as a nice wake signature in the visible, no overshooting-top was detected. At the time of this blog post the storm still has not had an overshooting-top detection.

It was hypothesized that initially the minimum IR brightness temperature requirement for the overshooting-top product was not reached early on. Then once the storm continued to grow, the spatial tests to identify isolated areas of relatively cold cloud tops associated with an overshooting-top failed because cold cloud top temperatures were too close together. These problems are likely due to the relatively poor spatial resolution of the GOES-13 imager and the product would be much improved if resolutions were similar to what will be available on ABI.

Some oberservations on my last day of observations

Today was an active day for observing CI across the country today. The initiation over the North East this morning had people scurrying to get AFD's, projected areas of interest, and survey's out in time to observe the storms. Hey, that is the point of testing experimental data, to see if it works.

For SATCAST, we picked up the first of the big convective storms moving across New York this morning with about 15-20 minutes of lead time. The UWCI product picked it up as well, just one satellite image later. Unfortunately, the storms started to fire, so time spent looking at CI products pretty much ended right then. Watching online using the research display, SATCAST looked to be doing pretty well picking out the new convection south of the line as it developed.

Watching again this afternoon over the dryline area over Texas, Oklahoma, and Kansas, SATCAST was putting up sporadic flags of CI in the late afternoon. In the early ones, the environment was not letting much grow, so the early flags didn't verify. SATCAST and UWCI put up flags simultaneously on the storm that became the large system that kept forecasters busy in the Wichita area. Before the forecasters switched their displays, SATCAST was flagging the convection that appeared about 20-30 minutes later in the southwest corner of Texas moving from LUB forecaster area to the OUN area.

Of course, the forecasters are now focused on tracking storms, putting out warnings, and using the other experimental products such as 3DVAR, the PGLM Lighting information, and the UW cloud top cooling rates, overshooting tops, and thermal couplet data to help them do it. This week's experience with the tools presented, how they were used, as well as interpreted, has provided both the forecasters and scientist with new ways to play with the data. SATCAST has performed well this week, maybe not perfect in some people's eyes, but well. It will be interesting to see where all of the tools presented go from here.

Utilizing PGLM and Nearcast in warning ops

Nearcast differential theta-e and PGLM instantaneous flash extent density within AWIPS D2D during warning operations on 9 June 2011.
Forecasters are once again engaged in warning operations within the EWP's evening activities. Bill Bunting (MIC DFW) is currently using the PGLM instantaneous flash extent density, as well as the Nearcast differential theta-e products while issuing warnings for storms over NW OK (see image above). Like forecasters from previous weeks, the Nearcast differential theta-e field provides information on near-storm convective instability and can provide the forecaster with confidence on whether or not the storms are expected to intensify or dissipate. Currently the PGLM is showing healthy flash densities, while the NLDN is only showing sparse CG activity within the storms.

Integrating CI information into a single situational awareness tool

Discussions with forecasters throughout this year's Spring Experiment have raised an interesting topic regarding how to supply information without overwhelming forecasters during forecast and warning operations. In particular, forecasters have expressed interest in looking at all of the background interest fields from the UAH SATCAST product, which is currently being used as a proxy for the GOES-R CI product. The official GOES-R CI product will have 12 interest fields, all with a unique piece of information about the growth of a cumulus cloud object. As defined within the current GOES-R Algorithm Working Group (AWG) requirements, the CI product will only provide the forecasters with a binary yes/no output. Currently being provided within AWIPS/NAWIPS during the Spring Experiment, SATCAST has 6 interest fields that determine whether or not a cloud object is expected to convectively initiate within the next 0-2 hour time-frame. Forecasters have expressed some displeasure with only being provided a yes/no field to help them determine whether CI will occur. Some ideas have been offered that include providing a probabilistic CI nowcast, similar to what UWCI provides, or providing them with all of the CI interest fields individually in addition to the yes/no nowcast. Providing the forecasters with all of the interest fields and expecting them to look at them within their AWIPS/NAWIPS display is not feasible as it will be extremely distracting and time consuming. The problem with providing a probabilistic approach is that you are removing the detailed information that the forecasters would like to see but currently do not have to time to look at. So what do we do?

An interesting solution to this problem arose during a car ride on the way to pick up dinner this evening during a break in EWP operations. Why not provide a display that looks similar to a binary yes/no product, but be able to (on mouse-over perhaps) interrogate all of the interest field information? Currently within AWIPS you are able to do this for a single field. For instance, you can display radar reflectivity and interrogate the actual dBZ value on mouse-over. What if it were possible to provide information from multiple fields on mouse-over in this similar manner while still providing a simple to understand one-size-fits-all display for the product? Some food for thought.