Description |
The storm interrogation IC contains 26 lessons covering 6 storm interrogation topics, and an overview lesson that discusses each of the 26 lessons breifly. At least 6 lessons are required and may be assigned by your training facilitator. The overview lesson is available mainly for the training facilitator to browse the objectives and some of the material from each lesson. However, everyone is encouraged to view the overview lesson, but it is not required. If you wish, you can take any or all of the lessons listed below in IC Severe 3 in addition to the 6 assigned by your training facilitator. The 6 storm interpretation topics are:
- Updraft Location (ICSvr 3-I) - 4 lessons
- Updraft Strength (ICSvr 3-II) - 5 lessons
- Tornado Warning Guidance (ICSvr 3-III) - 7 lessons
- Flash Flood Warning Guidance (ICSvr 3-IV) - 3 lessons
- Large Hail Signatures (ICSvr 3-V) - 4 lessons
- Damaging Wind Indicators (ICSvr 3-VII) - 3 lessons
Note that topic 6 is purposely mislabeled 'VII' to reflect the mislabeling in the presentations. The lengths of the lessons range from 8 to 30 slides, most of them being between 15 and 20 slides. Each lesson on the web contains objectives, core material, and a summary. The overview lesson contains the objectives and summaries of all the lessons, and designed to give the training faciliator an idea of what to expect from each lesson. The training facilitator
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Lesson 1:
ICSvr 3-I-A Location of Weakly Sheared Updrafts
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Description |
This lesson describes techniques for locating the updraft horizontally and vertically through different stages of a weakly sheared convective cell. This lesson is primarily intended for review, however, some of the techniques for updraft location may interest you. |
Estimated Completion Time |
24 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes and still images of the lesson |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 2:
ICSvr 3-I-B: Updraft location in a sheared convective Cell
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Description |
This lesson builds on lesson 1 to show storm structure signatures to determine where the updraft is most likely located, and also its shape, for sheared convection. We use both reflectivity, velocity, and environmental shear direction to produce a three-dimensional map of the updraft. The case that is used to illustrate this is a rather interesting event with an unusual hodograph. |
Estimated Completion Time |
20 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 3:
ICSvr 3-I-C: The nature of the weak echo region (WER)
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Description |
We look for the WER to give us guidance on the strength of the updraft and yet the WER is not always updraft. In this lesson, Jim LaDue has the honor of talking with Les Lemon, a renowned resource on severe weather and radar, about the nature of the Weak Echo Region (WER) in severe storms. The WER is analyzed with new insight on how a convective cell creates this well known feature. |
Estimated Completion Time |
15 min |
Delivery Method |
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| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
handout speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
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Recommended |
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Lesson 4:
ICSvr 3-I-D: Updraft Location of a Sheared Cell by Satellite
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Description |
If there is a situation in which radar data is unavailable, and you need to know the location of the thunderstorm updraft after dark, satellite data offers an excellent backup. Unfortunately, the updraft summit is not always where the coldest cloud top temperatures are located. This lesson explores why this is the case and how you can account for the phasing differences between updraft summit and brightness temperature minima. |
Estimated Completion Time |
20 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
List required reading.
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Recommended |
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Lesson 5:
ICSvr 3-II-A: Upper Level Reflectivity core height and intensity
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Description |
Numerous techniques abound for estimating updraft strength based on the vertical reflectivity profile of a convective cell including the height of strong reflectivity isosurfaces, VIL, VIL density, and using the HDA output. Many of these techniques have particular attributes that make them useful but they're also saddled by limitations. This lesson promotes the technique of evaluating updraft intensity in a similar way to that of the HDA through the evaluation of the reflectivity profile strength in the cold regions of a convective cell. This technique is applied to several unique cases and compares the VIL, VIL density, and aspects of the HDA to the intensity of the storms with respect to the severe weather reports received. You will see an application of the HDA, VIL toolkit made available for you on this website which you may try yourself with an accompanying exercise job sheet. |
Estimated Completion Time |
20 min |
Delivery Method |
|
| Resources |
Exercises |
|
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
A highly informative job sheet is available for download on the WDTB website HERE. This job sheet helps the student dig into the heart of the radar algorithms (VIL, HDA) for assessing hail threat for a particular storm.
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Recommended |
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Lesson 6:
ICSvr 3-II-B: Updraft strength from low-level Convergence
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Description |
On occasion, severe organized convection is able to persist even when entering a region devoid of significant CAPE. This lesson gives you an appreciation as to the contribution low-level convergence may have in the overall updraft strength derived from buoyancy. We provide examples where convergence across boundaries is calculated after using the Vr shear tool, and the updraft speed is estimated through a simple use of the continuity equation. After viewing this lesson, you may have an increased appreciation for why a population of cells can have such a wide variety of intensities when your analysis of instability and windshear appear so homogeneous. |
Estimated Completion Time |
18 min |
Delivery Method |
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| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 7:
ICSvr 3-II-C: Severe Updraft Storm Structure Signatures
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Description |
We revise the classic Lemon (1977) diagrams of storm structure vs. severity of convection in sheared environments. Afterwards, several examples show the variations found in the severe convection updraft signatures ranging from the classic deep supercell with a normal size BWER, to that of a relatively low topped supercell with a wide BWER, and then a quasi linear convective system (QLCS). We ask how the Lemon diagram can be applied to a QLCS and supply conceptual models showing the difference between a severe and nonsevere QLCS. |
Estimated Completion Time |
20 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
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Recommended |
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Lesson 8:
ICSvr 3-II-D: Estimating Updraft Intensity with Satellite: Part 1
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Description |
In case you lose radar data, or a storm is out of adequate sampling, or simply as a confirming piece of evidence, here is a lesson that shows a few techniques for qualitatively estimating the updraft strength from satellite data. The first technique is an application of research by Adler and Mack in the mid 1980s where the time trend of cloud top temperature is converted to updraft strength and compared to those satellite updraft strengths associated with severe weather. Here, we apply the AWIPS cloud top height algorithm directly to examples to estimate relative updraft strength between storms. Another method of estimating updraft strength simply comes from a good estimate of anvil top temperatures in the relatively flat regions surrounding the overshooting top and comparing the temperatures to a representative sounding equilibrium level temperature and height. This second technique can tell you if the convection is realizing the full CAPE available in the sounding. |
Estimated Completion Time |
25 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 9:
ICSvr 3-II-E: Estimating Updraft Intensity with Satellite: Part 2
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Description |
This lesson makes a nice summary of ICSvr 3-II in that a single convective cell udraft is qualitatively estimated by radar and satellite to estimate its updraft strength and overall severity. This cell presents some unique challenges to the simple conceptual models of storm severity already presented here. The decision-making process here is likely to be similar to that of any storm that does not fit the classic model. |
Estimated Completion Time |
12 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
ICSvr 3-II-D: Updraft Strength Signatures in Satellite Data
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Recommended |
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Lesson 10:
ICSvr 3-III-A: Tornado Warning Guidance - Mesocyclone Analysis and sampling
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Description |
While this lesson starts out as a review of mesocyclone structure, it dives into the considerations of how radar sampling affects the analysis of trends in rotational velocity. Two examples are shown, one a distant large mesocyclone, the other, a nearby small mesocyclone in the attempt of finding a real vs. artificial trends in strength. We provide some guidance to help discriminate a real trend in mesocyclone strength.
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Estimated Completion Time |
20 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 11:
ICSvr 3-III-B: An overview of storm scale signatures considered in tornado warnings
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Description |
A variety of signatures favorable for indicating a tornado are presented here as a review. An interesting side note to this review is that we relate these signatures to their role in providing for the ingredients for tornadogenesis. We also provide information on the performance of the TVS as a tornado discriminator based on a study with NSSL in 2001. |
Estimated Completion Time |
25 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 12:
ICSvr 3-III-C: Tornado Warning Guidance--Storm Scale induced storm relative helicity signatures
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Description |
We describe the storm-induced mechanisms that can produce higher values of Storm Relative
Helicity (SRH) within the inflow region of a supercell. Also presented are interesting
results from a numerical modeling experiment showing the magnitude of change to a
hodograph as a supercell approaches a point. This lesson will give you an appreciation
for when to look for significant SRH enhancement, and also how far from a supercell you
need to be in order to be free from its effects on the environment.
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Estimated Completion Time |
15 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 13:
ICSvr 3-III-D: part 1: Near range tornadogenesis signatures viewed by the WSR-88D
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Description |
Mesocyclones appear radically different at close ranges. A TVS appearing in moderate ranges may not show up as one at close ranges. These and other interesting differences between a tornadic cell at close ranges vs. greater ranges are examined in this lesson using the WSR-88D. We present two cases to show you what you would see in the evolution of storm scale signatures leading to tornadogenesis when the radar is nearby. |
Estimated Completion Time |
20 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 14:
ICSvr 3-III-E: part 2: Near range tornadogenesis signatures Viewed by the TDWR
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Description |
To followup ICSvr 3-III-D, one of the same cases is presented again with TDWR data to show you the strengths and limitations of a dataset that will be made available to those of you that have such a radar in your CWA. This lesson provides you a short tour of the strengths and limitations of the TDWR for your warning operations. |
Estimated Completion Time |
15 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
ICSvr 3-III-D: Near range tornadogenesis signatures part1: from the WSR-88D
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Recommended |
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Lesson 15:
ICSvr 3-III-F: Non-mesocyclonic tornadoes
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Description |
These types of tornadoes are the ones that one has little hope of detecting precursor signatures by radar alone. Yet, there are environmental and storm scale signatures that do provide evidence that tornadogenesis ingredients are coming together. This lesson shows you how to analysis background low-level vorticity beyond that of simple gridded analysis, how to estimate if a young updraft may reside on a source of lifting given its motion and the boundary motion, and when the superposition of tornado ingredients is most likely to occur. While this lesson may not help detect specific times and locations of nonmesocylonic tornadoes, it can help give you insight into defining a threat area. |
Estimated Completion Time |
13 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 16:
ICSvr 3-III-G: Quasi-Linear Convective System tornadoes
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Description |
Quasi Linear Convective System (QLCS) tornadoes, their near storm environments, and storm scale signatures are being studied more frequently than anytime in the past. Ron Przybylinski, the SOO at WFO St. Louis and WDTB present interesting results into the origins of low-level vorticity, storm scale signatures, and near storm environment signatures for these kinds of events. Part of the work is based on the results from BAMEX, and more is sure to follow shortly. |
Estimated Completion Time |
15 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
Ketcham and Przybylinski, 2002: The 29 June 1998 tornadic squall line.
Atkins and Przybylinski, 2002: The 27 May 2000 Tornadic Derecho Event.
Trapp et al. 1999: Descending and Nondescending Tornadic Vortex Signatures Detected by WSR-88Ds. Wea. and Forecasting., 14, 625-639.
Weisman and Trapp, 2003: Low-Level Mesovortices within Squall Lines and Bow Echoes. Part I: Overview and
Dependence on Environmental Shear. Mon. Wea. Rev., 131, 2779-2803.
Trapp and Weisman, 2003: Low-Level Mesovortices within Squall Lines and Bow Echoes. Part II: Their Genesis
and Implications. Mon. Wea. Rev., 131, 2804-2823.
Link to all IC Severe 3 References (PDF format)
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Lesson 17:
ICSvr 3-IV-A:
Flash Flood Guidance (FFG) modification
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Description |
Bob Davis, forecaster at Pittsburgh WFO and author of the "Flash Flood Forecast and Detection Models" chapter in the AMS Severe Convective Storms Monograph, presents this lesson on the drawbacks of flash flood guidance (FFG). With several case studies, he provides convincing evidence that modifying FFG to better reflect hydrological conditions prior to the onset of flooding rainfall can help detect flash flood severity. |
Estimated Completion Time |
15 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
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Recommended |
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Lesson 18:
ICSvr 3-IV-B: Effective Use of Flash Flood Monitoring and Prediction (FFMP)
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Description |
FFMP is the most valuable tool available to determine the threat of flash flooding in real-time. This lesson describes the best ways to utilize FFMP, and highlights the potential problems that can arise, such as hail contamination, inaccurate Z/R relationships, etc. |
Estimated Completion Time |
15 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 19:
ICSvr 3-IV-C:
Radar rainfall Estimation
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Description |
Choosing a tropical Z/R relationship is not an easy decision outside of tropical storms but could mean the difference between detecting and not detecting a flash flood. This lesson will help you understand how to identify signatures of warm rain process-dominant convection, with the help of several case studies. One particular example shows how switching to tropical Z/R would have resulted in an accurate detection of a flash flood. |
Estimated Completion Time |
20 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 20:
ICSvr 3-V-A:
Three Body scatter spike (TBSS)
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Description |
This lesson provides an in depth look at precisely what causes a hail spike and how it affects radar data. A thorough discussion of what the TBSS means is included along with several recent examples. Guest commentary is provided by Les Lemon, author of several landmark AMS articles on the TBSS and other convective storm signatures. |
Estimated Completion Time |
15 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 21:
ICSvr 3-V-B:
VIL and VIL density
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Description |
VIL and VIL density has been used over the years as a hail forecasting tool. This lesson shows how VIL is calculated and limitations to its usefulness as a hail detection parameter. A description of the new product, Digital VIL is also provided. |
Estimated Completion Time |
15 min |
Delivery Method |
|
| Resources |
Exercises |
Job sheet for the HDA-VIL toolkit: A highly informative job sheet is available for download on the WDTB website. This job sheet helps the student dig into the heart of the radar algorithms (VIL, HDA) for assessing hail threat for a particular storm. This job sheet will give you a good understanding of how VIL is calculated and how VIL density can vary . |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
Job sheet for the HDA-VIL toolkit: A highly informative job sheet is available for download on the WDTB website. This job sheet helps the student dig into the heart of the radar algorithms (VIL, HDA) for assessing hail threat for a particular storm. This job sheet will give you a visualization of how the HDA actually works.
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Recommended |
Edwards, Roger and Thompson, Richard L. 1998: Nationwide Comparisons of Hail Size with WSR-88D Vertically Integrated Liquid Water and Derived Thermodynamic Sounding Data. Weather and Forecasting: 13, 277–285.
Amburn, Steve A., and Peter L. Wolf, 1997: VIL Density as a Hail Indicator. Weather and Forecasting, 12, 473-478.
Link to all IC Severe 3 References (PDF format)
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Lesson 22:
ICSvr 3-V-C:
the hail diagnosis algorithm (HDA)
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Description |
The Hail Diagnosis Algorithm (HDA) (formely "Detection") is a complex algorithm that does a good job of assisting forecasters in a warning decision environment. This lesson describes how the HDA computes severe hail probabilities and maximum expected hail size. Ways to beat the HDA are provided. |
Estimated Completion Time |
15 min |
Delivery Method |
|
| Resources |
Exercises |
Job sheet for the HDA-VIL toolkit: A highly informative job sheet is available for download on the WDTB website. This job sheet helps the student dig into the heart of the radar algorithms (VIL, HDA) for assessing hail threat for a particular storm. This job sheet will give you a visualization of how the HDA actually works. |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
Job sheet for the HDA-VIL toolkit: A highly informative job sheet is available for download on the WDTB website. This job sheet helps the student dig into the heart of the radar algorithms (VIL, HDA) for assessing hail threat for a particular storm. This job sheet will give you a visualization of how the HDA actually works.
|
Recommended |
Witt, Arthur, Eilts, Michael D., Stumpf, Gregory J., Johnson, J. T., Mitchell, E. DeWayne, Thomas, Kevin W. 1998: An Enhanced Hail Detection Algorithm for the WSR-88D. Weather and
Forecasting, 13, 286–303.
Link to all IC Severe 3 References (PDF format)
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Lesson 23:
iC3-V-D:
Hailstorm characteristics
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Description |
This lesson describes common radar characteristics of severe hail storms using several examples from recent hail storms. It describes how to interrogate a storm for hail threat using just base data radar products, and discusses the important features of storms that are likely to contain severe hail. |
Estimated Completion Time |
20 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 24:
iC3-VII-A:
Hybrid/Wet Microburst detection
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Description |
This lesson is an overview of environmental and storm scale precursor signatures of hybrid and wet microbursts. We promote using DCAPE instead of other environmental parameters to assess microburst risk. In so doing, we provide a simple way of estimating DCAPE from a an analysis of an AWIPS skewt plot and the theta-w difference from surface to midlevels. We show three cases to highlight the order and expected ranges of lead times for different microburst precursor signatures. |
Estimated Completion Time |
27 min |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 25:
ICSvr 3-VII-B: Convergent wind Signature prior to Organized Convective wind events (MARC)
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Description |
This lesson gives an overview of the Mid Altitude Radial Convergence Signature (MARC) as in the context of organized severe wind events. We describe the details of the MARC and the magnitudes of convergence that are often associated with severe weather. Gary Schmocker of WFO St. Louis, MO graciously contributed much of the material for this lesson. |
Estimated Completion Time |
10 min. |
Delivery Method |
|
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 26:
ICSvr 3-VII-C:
Extreme Non-tornadic wind Damage Events
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Description |
This lesson describes the most common storm scale signatures associated with wind events in excess of 80 kts or at least F2 damage from organized MCSs. Many of these extreme wind events are a result of more than a simple short-lived downburst and outflow paradigm with some sustaining themselves over the same geographic area for extended time periods. This lesson is a contribution from Dan Miller, WFO Norman, OK. |
Estimated Completion Time |
25 min |
Delivery Method |
online |
| Resources |
Exercises |
none |
Review Sheets / Hand Outs |
speaker notes |
Student Guide |
none |
| Reading Material |
Required |
none
|
Recommended |
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Lesson 27:
ICSvr3: Storm interrogation Overview
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Description |
This provides an overview of each of the 26 other lessons that make up IC Severe 3. This lesson is designed to give the training facilitator a quick overview of the objectives and summary of each lesson. However, anyone can take this lesson if they so choose. |
Estimated Completion Time |
30 min |
Delivery Method |
|
| Resources |
Exercises |
None |
Review Sheets / Hand Outs |
None |
Student Guide |
None |
| Reading Material |
Required |
None
|
Recommended |
|
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