EFP simulated satellite evaluation

EFP QPF group discussing simulated WV imagery from the 00Z run of the NSSL-WRF on 17 June 2010
Today in the EFP's QPF group Dan Lindsey led a discussion on the comparison of the simulated satellite imagery from the NSSL-WRF to that which was observed over the past few hours (see image above). They used this simulated satellite imagery to determine the accuracy of the current 00Z NSSL-WRF model run for the day. It was determined that is is missing some convective development down near NE and IA, but that the main threat area up near MN is being captured fairly well. This provides them with confidence that the model should handle the rest of the day's development fairly well.

EWP real-time IOP CI feedback

Today's IOP focused over the DCLMA domain to get some real-time PGLM experience. The forecasters broke up into two groups and localized over the Sterling, VA and State College, PA WFOs. The Sterling WFO group have been issuing severe thunderstorm warnings based on PGLM and MRMS products over the past couple hours. I was sitting with the State College WFO group as they were focusing on the UWCI products, watching for convective initiation over their area. One of the forecasters had multiple GOES-R Proving Ground products (UWCI, cloud-top cooling, overshooting top, and thermal couplet) into a 4-panel display and mentioned to me that this display strategy would be extremely useful as a situational awareness tool for monitoring satellite convective information.



GOES-13 IR imagery for 1832 (top left), 1845 (top right), 1902 (bottom left) and 1915 UTC (bottom right) on 16 June 2010. Area of interest noted by green circle.
We noticed an area of obvious convective development that was not detected by the UWCI product on the WV/VA border at 1915 UTC and the forecaster asked me to explain why no CI nowcast was made. Looking at the IR, you could see significant cooling occurring from 1832 and 1915 UTC (see above), but still no signals were seen. Jordan Gerth and I looked at the cloud typing output to see if we could draw any conclusions from that to determine what was going on (see below). Most of the area was covered by cloud types identified as 'water' or 'mixed phase'. However, there were a few spots of 'cirrus' classification over WV nearby where the CI nowcast should have been made. It seemed on visible and IR satellite that this may not have been the case, but this is hard to determine for sure. Jordan suggested that because there were these spots nearby that they may have been contaminating the spatial tests required by the algorithm to flag an area as filtered cloud-top cooling, and thus not allow for a CI nowcast to be made. This may be a fluke case where nothing can be done, but it may be useful to examine this in more detail to see if something can be improved.



UW-CIMSS Cloud typing product for 1832 (top left), 1845 (top right), 1902 (bottom left), and 1915 UTC (bottom right) on 16 June 2010. Area of interest noted by red circle.

Results from Tuesday's EFP forecast

Following up Tuesday's post on the use of simulated imagery, the low cloud deck turned out to be quite important for the storm evolution. Above is the observed GOES-East visible image from 1845UTC. The stratus deck had burned off between 15-18 UTC, and a cumulus cloud/no-cloud boundary was clearly evident in the visible image across southern Indiana and central Illinois. This boundary presumably resulted from the differential heating resulting from the morning clouds. Also note the storm which had formed on the boundary in eastern Illinois, and the multiple storms in southeast Missouri. These progressed to the east-northeast and subsequently grew upscale into a bowing MCS. The severe reports are below.

The blue dots represent severe wind reports. It's interesting that the northern boundary of the wind reports across central Illinois and Indiana corresponds quite well with the cumulus cloud boundary noted above. Most of the high-res models, including the NSSL WRF (for which we looked at the simulated imagery yesterday) had a bowing MCS further north. It turned out that the low clouds limited the instability further north, and the severe weather was confined to the south where more heating had occurred. This was a nice example of how the simulated imagery might be used to diagnose the model's treatment of morning clouds.

EWP daily briefing... 6/15/2010

Psuedo-GLM total lightning flash extent density overlaid with OKLMA flash contours and associated radar reflectivity for the OKC flood event at 1100 UTC on 15 June 2010.
During today's EWP briefing we discussed the previous day's flooding event over OKC from a PGLM perspective. Unfortunately the event unfolded in the morning hours when the EWP was not operating, so we were unable to view the data in real-time. Kristin Kuhlman presented the archived data and discussed with the forecasters what the PGLM showed during the event. She also overlaid the OKLMA flash contours to show how the PGLM relates to what was actually occurring (see above), which really helped the forecasters get a grasp over what the PGLM was showing them. They noted that the lightning seemed to be mainly focused with convection developing on the backside of the system and that this would help radar operators focus on which areas had continued development and represented an increased threat for flooding and severe weather in the future.



24-hour UWCI detections (top left), overshooting top detections (top right), thermal couplet dtetections (bottom left), and SPC severe reports (bottom right) from 14 June 2010
Jordan Gerth showed the UWCI and OTTC products over the past 24 hours in comparison to the severe reports from the same time period (see above). He pointed out the the UWCI had a lot of hits over the southeast with the diurnal convection that was not necessarily severe. He was unsure about how the UWCI performed with the the widespread swatch of wind reports through NC, but it is highly possible that the mass of UWCI signals in WV may be in initiation point for this convection... but we would need to do an in depth analysis of the event to determine this. Also, the numerous severe reports over southern IN seemed to have no UWCI detections associated with them. We suspected this was due to the presence of cirrus over the area. Jordan also noted the high density of overshooting top detections over OK with very few severe reports. He made sure to mention that the overshooting top detections are not necessarily associated with severe weather at the surface, as they are more of an indication of turbulence and lightning threats. There were only a few thermal couplet detections, which are highly linked to severe weather. The three located over TX seemed to be the best examples for this day. Jordan also did a quick introduction to the UW-CIMSS Nearcasting product for the EWP forecasters and showed a couple case examples in addition to the output for today to show areas of convective destabilizations associated with differential theta-e and precipitable water fields. Unfortunately we were unable to establish data flow for this product in time for this Spring Experiment, but we do plan on having it for future experiments.

SPC Day-1 outlook for 15 June 2010
The plan for the day is to once again start early and operate over the SPC moderate risk area in southern IL/IN to examine the GOES-R Proving Ground products prior to warning operations. With a relatively cirrus free sky, it should be a good event to demonstrate the UWCI. However, some storms are currently ongoing and are possibly severe, so we are hoping for some new development further south and west of the ongoing convection. The WFO's localized for the start of the IOP will be Indianapolis, IN and Louisville, KY.

Simulated satellite imagery in the EFP

On Tuesday morning, the Ohio valley region has been chosen for the daily forecast. The left image above is the 4-km NSSL WRF-ARW simulated 10.35 micron channel valid at 15 Z, and the image on the right is the observed GOES-East image from 1515 UTC. One of the biggest advantages of the GOES-R simulated imagery is the ability to evaluate the model's representation of morning clouds. In this case, the model appears to have a pretty good handle on the cold cloud placement. A more subtle but relevant feature is the low clouds across central and northern Indiana. These clouds may inhibit heating and limit the destabilization. At 15 UTC, the model has burned off the low cloud layer across central Indiana, but the observations show that the cloud deck is still present.

The image above shows the simulated band 13 image valid at 18 UTC. Note that the model has formed a new storm in southern Illinois which is moving into the area in question in Indiana. It will be interesting to see whether such a storm forms, and how it evolves as it moves into Indiana.

Hail Probability Product

Data from yesterday's probability of severe hail product was examined. The image above shows the probability forecast (%) from 20 UTC, valid from 20-23 UTC. Also plotted are the severe reports, where hail reports are denoted by 'a'. NAWIPS requires all reports from 18-00 UTC to be plotted at the same time, so not all of the reports above occurred during the 20-23 UTC forecast period. Specifically, the 3 southernmost reports occurred after 23 UTC.

Cold cloud tops from GOES-East dominated the input parameters, but the instability from the SPC mesoanalysis and the RUC forecast contributed. Note that the majority of the hail reports fell within the 1% contour in west Texas, although not specifically within the maximum probability area. The second max across Oklahoma saw no reports; this is a weakness of the product....if cold cloud tops are observed over regions of moderate instability, as was in the case in Oklahoma, higher probabilities will result. I looked at earlier forecasts, and on this particular day the product did not provide a significant lead-time prior to the development of storms.

Real-time PGLM operations

The forecasters are now engaged in a real-time IOP over Norman, OK and Lubbock, TX. Luckily the OKLMA became operational once again right before the dinner break so we are able to get the forecasters familiar with the PGLM product. The first two forecasters to look at the PGLM data had some interesting comments regarding the product's potential uses and performance. One of the forecasters mentioned how useful the product would be in the case of being overloaded with radar information. For instance, during weak cap, high instability days when storms cover the entire radar area a radar operator can get 'tunnel vision' on a couple storms they initially think are the most important and forget about the rest. She said that a GLM product would be very useful in getting you 'back to reality' when you get overwhelmed and help you identify the cells which are most important at that time. Also, the same forecaster mentioned how they would use this in situations when they are bordering on issuing a severe warning. When the radar information is ambiguous or unchanging, the GLM would help determine whether or not to issue the warning based on any dramatic increases seen in the number of total flashes in the cell.

In one case during the IOP we saw the first occurrence of flashes from the PGLM occurring with a growing cell near the center of the OKLMA network 40 minutes prior to the first CG. Flash rates reaching 25 flashes / 8 km / min occurred 25 minutes prior to the first CG for the same cell. She mentioned that this would be extremely helpful in determining whether the cell was actually a 'thunderstorm' and something to watch out for, stating that a lot of forecasters use the first occurrence of a CG to start thinking about the possibility of that cell ever becoming severe. This would provide a much heightened level of situational awareness, especially when storms can rapidly produce tornadoes, severe hail and/or winds with little warning.

EWP daily plan

Following the training sessions for the GOES-R UWCI, OTTC and PGLM products we had planned to move into an immediate IOP focusing over the Norman, OK WFO to get some exposure for the PGLM product with the chance of severe weather entering the area. Unfortunately as we were finishing the training we had heard that some of the OKLMA stations went down due to the heavy flooding occurring in central OK. Therefore, we decided that the current plan should be to move the domain towards the VORTEX-II domain south of Lubbock, TX following the MRMS training for some severe weather applications for the remainder of the evening.

Missing data... now partially restored

Sometime last week, changes were made to the experiment's NAWIPS systems and the GOES-R Proving Ground Products SATCAST and Probability of Severe Hail were removed by an unknown party. I worked with the SPC IT staff to reincorporate the missing data into the NAWIPS systems... The Probability of Severe Hail is back up, but we are still trying to get SATCAST back up and running. The simulated satellite imagery, lightning threat, UWCI and OTTC products remained unharmed. Will keep an eye on this and work on getting the SATCAST back up and running.

The final week begins...

Today marks the start of the final week of the Spring Experiment (it's gone by so fast). This week we will once again be participating in both programs, which means back to the 14 hour days. Our visitors this week include Jim Gurka and Bonnie Reed from the GOES-R Program Office, Dan Lindsey from CIRA and Jordan Gerth from UW-CIMSS. Jordan will be our resident expert within the EWP because he is directly tied to the UWCI and OTTC products, so he will be providing the training and expertise during real-time IOPs.

This morning begins with around the room introductions and an overview of the project...