On the morning of 12 May, while discussing the previous day's forecast at the CI desk, we noticed some interesting westward-propagating wave-like features in the observed GOES-13 data over southern Texas. The waves appeared to originate from an MCS in southeast Texas. We then viewed the simulated 6.95 micrometer band from the 11 May model run, and were interested to see that the 30-36 hour forecast also showed similar waves propagating westward. The images above show the simulated and observed WV band at 0600 UTC on 12 May, but the waves are difficult to locate without viewing an entire loop. A few hours later, a storm initiates (in both the observed and the simulated imagery) along the Rio Grande River and might be related to the westward-moving feature. A more thorough analysis of this case is needed.
Thursday, May 12, 2011
Gravity Waves in the Simulated Water Vapor Imagery
On the morning of 12 May, while discussing the previous day's forecast at the CI desk, we noticed some interesting westward-propagating wave-like features in the observed GOES-13 data over southern Texas. The waves appeared to originate from an MCS in southeast Texas. We then viewed the simulated 6.95 micrometer band from the 11 May model run, and were interested to see that the 30-36 hour forecast also showed similar waves propagating westward. The images above show the simulated and observed WV band at 0600 UTC on 12 May, but the waves are difficult to locate without viewing an entire loop. A few hours later, a storm initiates (in both the observed and the simulated imagery) along the Rio Grande River and might be related to the westward-moving feature. A more thorough analysis of this case is needed.
Wednesday, May 11, 2011
Day 3 forecaster interactions...
This morning 3 of the visiting forecasters participated in the EFP's new CI desk. The discussion was based on where they expected new convection to occur within a selected domain encompassing most of OK, the northern half of TX, southern half of KS, and eastern halves of CO and NM. The simulated reflectivity from the NSSL-WRf was examined early during the forecast period to help determine the accuracy of the NSSL-WRF model. While it was decided that the NSSL-WRF didn't capture the early MCS over W. TX and OK, it did show some potential useful information regarding CI forming along the dryline later in the day once the MCS moves on and instability returns. We also examined the 10-12 micron band difference product to help determine specific areas where CI would occur (see below).
NSSL-WRF simulated GOES-R 10-12 micron band difference for 1900 UTC on 11 May, 2011. Arrows indicate areas where low-level moisture is favorable for convective development.
While the group decided collectively on a conditional slight/moderate/high contoured area, individual participants were asked to select a point where they expect the first CI to occur within 25 miles, as well as what time they expect it to occur and their confidence in their forecast. This input helps generate a human based PDF that can be compared to the model generated PDF following the forecast period. I picked a point near Lawton, OK at 2000 UTC with a 30 min +/- window and a 70% confidence... we'll see how I do.
NSSL Scientist Mike Coniglio leading the forecast discussion at the EFP CI desk.
Following the CI desk forecast, invited EWP forecasters began working on an initial AFD on their AWIPS stations. Forecasters are using a combination of operational model field, as well as some experimental data from the Nearcast and the OUN-WRF. Ralph Petersen spent some time with the forecasters to explain how the Nearcast output could help increase their confidence of thunderstorm development. Forecasters have seemed very interested in a strictly observation-based forecast out to 9 hours... some have even asked how to get this data back into their AWIPS at their local WFO.
Ralph Petersen of UW-CIMSS explains the Nearcast product to NWS forecasters during real-time forecast operations.
While the group decided collectively on a conditional slight/moderate/high contoured area, individual participants were asked to select a point where they expect the first CI to occur within 25 miles, as well as what time they expect it to occur and their confidence in their forecast. This input helps generate a human based PDF that can be compared to the model generated PDF following the forecast period. I picked a point near Lawton, OK at 2000 UTC with a 30 min +/- window and a 70% confidence... we'll see how I do.
Following the CI desk forecast, invited EWP forecasters began working on an initial AFD on their AWIPS stations. Forecasters are using a combination of operational model field, as well as some experimental data from the Nearcast and the OUN-WRF. Ralph Petersen spent some time with the forecasters to explain how the Nearcast output could help increase their confidence of thunderstorm development. Forecasters have seemed very interested in a strictly observation-based forecast out to 9 hours... some have even asked how to get this data back into their AWIPS at their local WFO.
EWP discussion 11 May
Following the joint afternoon discussion period with the EFP, the EWP forecasters met for a discussion about the previous day's experience. The forecasters monitored the SATCAST product during the late afternoon period yesterday and offered these comments...
- Fair amount of CI hits, but it didn't seem like many of them would go on to full convection.
- Displaced a little westward from the visible satellite... probably due to the parallax correction.
- What is it's goal? Should I be watching it to stay red (nowcast) or once it goes red should I expect it to verify? It became unusable because it jumped from red (nowcast) to blue (cloud detection) all the time and it wasn't verifying. It seemed like the false alarm was so high that it deterred me from using it.
- I understand that the satellite scan time is an issue scanning every 15 minutes, but if it shows two back to back scans of nowcast, then that's when I would pay attention.
- How should I verify this? Should I look at a 35 dBZ echo at the surface or anywhere in the column, or the first occurrence of lightning? Probably shouldn't use lightning because we only have CG detections now and that may not show all lightning that may be occurring, so it wouldn't be a fair validation. The EFP CI desk is using a 35 dBZ threshold at the -10 C level and we can display that in AWIPS... this is probably the best way.
- Fair amount of CI hits, but it didn't seem like many of them would go on to full convection.
- Displaced a little westward from the visible satellite... probably due to the parallax correction.
- What is it's goal? Should I be watching it to stay red (nowcast) or once it goes red should I expect it to verify? It became unusable because it jumped from red (nowcast) to blue (cloud detection) all the time and it wasn't verifying. It seemed like the false alarm was so high that it deterred me from using it.
- I understand that the satellite scan time is an issue scanning every 15 minutes, but if it shows two back to back scans of nowcast, then that's when I would pay attention.
- How should I verify this? Should I look at a 35 dBZ echo at the surface or anywhere in the column, or the first occurrence of lightning? Probably shouldn't use lightning because we only have CG detections now and that may not show all lightning that may be occurring, so it wouldn't be a fair validation. The EFP CI desk is using a 35 dBZ threshold at the -10 C level and we can display that in AWIPS... this is probably the best way.
UW-Madison CIMSS convective initiation, overshooting-top, and nearcasting update
GOES-R proxy University of Wisconsin convective initiation (UWCI), overshooting-top/enhanced-V, WRF ARW simulated data and nearcasting fields have been flowing in a smooth manner into the EFP via N-AWIPS for forecast discussion integration. UWCI did indicated individual cells developing along north-south boundary in MN yesterday afternoon (10 May 2011).
24-hour UWCI indications, overshooting-tops, and NLDN lightning data from 12 UTC 20110510 - 12 UTC 20110511 below:
Example GOES Sounder nearcasting product within N-AWIPS with radar overlay on top. Red and yellow areas indicate regions of conditional instability.
The usual first week hiccups in GOES-R HWT experiment. Unfortunately the UWCI and Overshooting-top/thermal couplet products are strangely flipped from north to south during GRIB2 to AWIPS netcdf decode at HWT. Jordan Gerth is talking to local AWIPS expertise to resolve the issue however no solution so far. This is preventing evaluation of products within EWP. Nearcasting and WRF simulated data are available.
24-hour UWCI indications, overshooting-tops, and NLDN lightning data from 12 UTC 20110510 - 12 UTC 20110511 below:
Example GOES Sounder nearcasting product within N-AWIPS with radar overlay on top. Red and yellow areas indicate regions of conditional instability.
The usual first week hiccups in GOES-R HWT experiment. Unfortunately the UWCI and Overshooting-top/thermal couplet products are strangely flipped from north to south during GRIB2 to AWIPS netcdf decode at HWT. Jordan Gerth is talking to local AWIPS expertise to resolve the issue however no solution so far. This is preventing evaluation of products within EWP. Nearcasting and WRF simulated data are available.
GOES Hail Probability Product - Day 2
Complementing the blog post below about convective initiation in Minnesota, the image above shows the 21-00 UTC hail probability forecast on 10 May 2011. The units are %, and the small 'a' symbols represent observed hail reports. Note the maximum located in western and central Minnesota; as noted in the other post, storms were just forming at 21 UTC, and proceeded to produce severe hail a little east of their initiation point. Additional hail reports occurred later after 00 UTC. Notice also the maximum in eastern Indiana and western Ohio, and the observed reports there.
First Total Lightning Ops Day
Wednesday is shaping up to be the first ops day to use total lightning data for the Spring Program this year. The main area of focus will be in central Oklahoma using observations from the Oklahoma Lightning Mapping Array.
This year, there will be two additional products added to the lightning product list. In 2010, NASA's Short-term Prediction Research and Transition (SPoRT) program developed the pseudo Geostationary Lightning Mapper (PGLM) product. This was a simple algorithm that could be applied to any ground-based total lightning network. While it is not the official Algorithm Working Group proxy product, it was designed to be used at the Spring Program until the proxy is available. The PGLM is simply a tool to train forecasters about total lightning and the Geostationary Lightning Mapper, and a way to work with forecasters to determine the best way to use the 8 km resolution data. Addtionally, this product gives end users the opportunity to discuss new ways to better visualize these data.
Based on feedback from the 2010 Spring Program and SPoRT's efforts to enhance the visualizations, two new PGLM products have been introduced for 2011. These are the flash initiation density and the maximum flash density (MFD) products. Figure 1 shows the original PGLM (1 minute data, bright color) overlaid with the MFD (60 minute history, faded color). The MFD shows the largest PGLM value for each grid box for either 60 or 120 minutes. It is effective to show a basic trend in lightning activity over time. In Figure 1 below, taken at 1446 UTC on 11 May 2011, the MFD shows a large amount of lightning activity from storms as they entered western Oklahoma. However, the PGLM data show that these storms have greatly diminished in lightning activity. Figure 2 shows the corresponding radar reflectivity from KFDR.
FIGURE 1: The 60 minute maximum flash density (faded color) and the 1 minute pseudo geostationary lightning mapper flash extent density (bright color) taken at 1446 UTC. Note how the PGLM shows that the lightning activity has greatly diminished, both in magnitude and extent.
This year, there will be two additional products added to the lightning product list. In 2010, NASA's Short-term Prediction Research and Transition (SPoRT) program developed the pseudo Geostationary Lightning Mapper (PGLM) product. This was a simple algorithm that could be applied to any ground-based total lightning network. While it is not the official Algorithm Working Group proxy product, it was designed to be used at the Spring Program until the proxy is available. The PGLM is simply a tool to train forecasters about total lightning and the Geostationary Lightning Mapper, and a way to work with forecasters to determine the best way to use the 8 km resolution data. Addtionally, this product gives end users the opportunity to discuss new ways to better visualize these data.
Based on feedback from the 2010 Spring Program and SPoRT's efforts to enhance the visualizations, two new PGLM products have been introduced for 2011. These are the flash initiation density and the maximum flash density (MFD) products. Figure 1 shows the original PGLM (1 minute data, bright color) overlaid with the MFD (60 minute history, faded color). The MFD shows the largest PGLM value for each grid box for either 60 or 120 minutes. It is effective to show a basic trend in lightning activity over time. In Figure 1 below, taken at 1446 UTC on 11 May 2011, the MFD shows a large amount of lightning activity from storms as they entered western Oklahoma. However, the PGLM data show that these storms have greatly diminished in lightning activity. Figure 2 shows the corresponding radar reflectivity from KFDR.
FIGURE 1: The 60 minute maximum flash density (faded color) and the 1 minute pseudo geostationary lightning mapper flash extent density (bright color) taken at 1446 UTC. Note how the PGLM shows that the lightning activity has greatly diminished, both in magnitude and extent.
1.5 Hour Lead Time from UAH CI Algorithm
Figure 1.
UAH CI forecast (red) valid from the 2040 UTC GOES imagery.
Figure 2.
Radar valid at 2042 UTC.
Figure 3.
Radar valid at 2209 UTC.
The UAH CI algorithm forecasted CI (first instance of 35+dBZ radar echo) approximately 1.5 hours before it was detected on radar for this case in western Minnesota (Figures 1 - 3, above). As subsequent GOES imagery rolled in, the algorithm continued to forecast CI down along a line of growing clouds to the south, achieving lead times of around 1 hour. According to the Storm Prediction Center storm reports (see Figure 4, below), this line of storms quickly turned severe and went on to produce several instances of large hail and even a tornado!
Figure 4.
SPC storm reports for 05/10/2011, valid through ~12 UTC on 05/11/2011.
Innovative Methods for Displaying UAH CI Product in AWIPS
Some of the forecasters here in the Experimental Warning Program are finding creative ways to integrate the UAH CI product (GOES-R AWG CI product proxy) into their AWIPS workstations. Above is an excellent example of this. In the top-left display quadrant, the Null (blue) and Positive (red) cloud object CI forecasts are overlaid onto GOES Visible satellite data, with an option to change the transparency of the two integrated data sets at the touch of a button. Similarly, in the top-right display quadrant, the UAH CI product is overlaid onto radar data.... This way the forecasters will know where to focus their attention on the radar for future development, especially in regions where severe weather is expected but not yet initiated.
Tuesday, May 10, 2011
Use of Simulated Imagery for Convective Initiation on Day 1
On Day 1 of the 2011 Spring Experiment, the Convective Initiation forecast desk chose a focus area over northeast Wyoming, western Nebraska and western South Dakota. During the forecast process, we viewed the simulated 6.95 micrometer band based on the NSSL WRF-ARW, and noted during the morning hours that the timing and location of the shortwave trough moving through Utah and entering Colorado was handled quite well by the model (see the top panel of the image above). Later in the forecast, the model generated convection in eastern Wyoming very close to what was observed. This is a nice example of how the simulated imagery is very useful for morning model evaluation.
UAH CI (SATCAST) Now Up and Flowing...
Despite a few early glitches in the product delivery, the UAH CI product is now flowing into the SPC Hazardous Weather Testbed AWIPS and N-AWIPS workstations regularly. The posted pic (above) is the first image that was received for "real-time" display in this year's newly created Convective Initiation desk.
From the time of the first GOES scan line (the image time stamp), it took only 10 minutes for the data to be processed, delivered, and displayed..... This is a significant advantage over the time latency issues the UAH CI product had from last year (our first year of "real-time" processing and evaluation). This is typical for Northern Hemisphere scans from GOES. For pure CONUS scans from GOES, it generally only takes about 8 minutes to accomplish the same process. From the moment the GOES data is downloaded, it takes a mere ~1.5 - 2.5 minutes to process it and produce the CI output forecast.
Day 2... Data Flow
So today marks the first full day of the experiment... The morning started with a few data flow issues... all of which have been resolved. The data flow for the Spring Experiment is now completely up and running...
The morning EWP forecasters have been sitting with the EFP CI desk where they have been looking at the NSSL-WRF simulated satellite imagery as well as the 10-12 micron band difference while deciding what domain they should choose for their forecast.
The EWP morning shift have written their first area forecast discussion (AFD) for where the EWP should operate throughout the afternoon... which they have chosen to be central TX. The EFP will continue to discuss their forecasts until lunch and then we will have our first joint EFP/EWP map discussion at 1pm.
Will update as the day progresses...
The morning EWP forecasters have been sitting with the EFP CI desk where they have been looking at the NSSL-WRF simulated satellite imagery as well as the 10-12 micron band difference while deciding what domain they should choose for their forecast.
The EWP morning shift have written their first area forecast discussion (AFD) for where the EWP should operate throughout the afternoon... which they have chosen to be central TX. The EFP will continue to discuss their forecasts until lunch and then we will have our first joint EFP/EWP map discussion at 1pm.
Will update as the day progresses...
Monday, May 9, 2011
Day 1... Training Day
Today marks the beginning of the 2011 Spring Experiment in the Hazardous Weather Testbed. While the beginning of the day was spent introducing ourselves to... ourselves, we did provide a good deal of forecaster training on the EWP side. EWP forecasters participated in 4 hours of training on the products they would be using throughout the week within their AWIPS systems. Most of the training was given by the visiting scientists via PowerPoint presentation. Each presentation lasted about ~30 minutes, with time afterward for comments a questions.
Geoffrey Stano (NASA SPoRT) provides training on the PGLM to WFO forecasters during EWP training session.
The forecasters were very engaged and often asked how to obtain these products within their local AWIPS at their WFOs. Luckily because of the Proving Ground's emphasis on bringing WFOs experimental GOES-R data, the core cooperative institutes (UW-CIMSS, CIRA and SPoRT) have already prepared for this and it was easy to explain how this could be done. Because of the coordination with theSPC and HWT over the past few years, UW-CIMSS has set up a webpage that has step-by-step instructions for ingesting and displaying their products within any AWIPS system. See... http://cimss.ssec.wisc.edu/goes_r/proving-ground/SPC/SPC.html Kudos!
The forecasters were very engaged and often asked how to obtain these products within their local AWIPS at their WFOs. Luckily because of the Proving Ground's emphasis on bringing WFOs experimental GOES-R data, the core cooperative institutes (UW-CIMSS, CIRA and SPoRT) have already prepared for this and it was easy to explain how this could be done. Because of the coordination with theSPC and HWT over the past few years, UW-CIMSS has set up a webpage that has step-by-step instructions for ingesting and displaying their products within any AWIPS system. See... http://cimss.ssec.wisc.edu/goes_r/proving-ground/SPC/SPC.html Kudos!
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