# Presentation: 502370

## Warning Methodologies

- A systematic approach to the severe weather warning process

**Presented by **
**the Warning Decision Training Branch**

**Notes:**
Webster’s dictionary defines methodology as “an orderly arrangement, or the branch of logic concerned with the application of the principles of reasoning to scientific and philosophical  inquiry.” Thus, a warning methodology should describe an ordered sequence or process that can help forecasters work through the warning process in a systematic manner, to avoid being haphazard. 

It is difficult to describe the warning process, because as one forecaster commented, it is a fluid process. In addition, there are many details which cannot be written down. Often  due to habits or personal preferences, an ordered, systematic approach is not always applied by the warning forecaster. So, as we venture into this topic try to keep an open mind into the possibilities of the process as a whole and not so much the individual parts. 

## Purpose of Training

- Provide forecasters with methods for environmental assessment, storm scale detection and analysis of hazardous weather types (tornado, hail, damaging winds, and flash flooding).

**Notes:**
The training objective is to provide a systematic approach for developing  severe convective warnings. This approach will address tornado, severe, and flash flood warnings. As this training is fully developed (by 2004), WDTB will provide detailed methodologies for each hazard. This presentation provides an overview of the warning methodology process with emphasis on staffing strategies and storm interrogation process.  
One suggested analogy to warning methodology is medical protocol in an emergency room . There are several prescribed checks and procedures that are  carried out in the emergency room to determine the condition of the patient. These methods are similar to what a warning forecaster may  perform as he/she tries to determine if a storm is severe or not. In addition, just as every person is different, every storm is different in some way, so that even in the same environment, the step-by-step process may change ever-so-slightly  with each warning. The goal, however,  is to provide a  process that can be flexible enough yet sufficiently rigid to thoroughly evaluate the threats associated with each storm and with each situation in a scientific manner. We will not be able to address all situations so application and validation of the methodology is ultimately up to the warning forecaster. To thoroughly evaluate the training, each forecaster will need to complete a simulated severe weather event using the Weather Event Simulator with the local training officer (for ex. SOO).    

## Learning Objectives This session

- Describe 3 of the 4 elements of a Severe Weather Operations Plan (SWOP).
- Identify the 3 factors (the 3 C’s) needed to successfully apply a severe weather operational strategy.
- Identify 2 ways to reduce workload in severe weather warning operations.

**Notes:**
For this particular training session, there are five learning objectives. We will discuss all of these objectives in this instruction.  We have no test to evaluate your learning of these objectives. However, to evaluate your performance in applying these learning objectives on the job at your local forecast, we will supply a evaluation form. Use the form to indicate how well you are able to relate and/or apply the learning objectives to your own warning operations. This will help both trainee and trainer in improving the effectiveness of this training.  

## Training Components

- Severe Weather Staffing Strategies
- Environmental Threat Assessment
- Storm Interrogation Process
- Continual Reassessment

**II**
**III**
**IV**

**Warning Decision**

**I**

**Notes:**
Thus, after identifying the Instructional Component’s learning objectives (slide 4), the training outline was structured based on four principal components of  the an effective warning methodology. This lesson will focus primarily on Part I (staffing strategies) and Part III (the storm interrogation process). More in depth treatment of the other parts of warning methodologies is being developed later in 2003/04. 

Many factors come into play in the warning decision making (WDM) process. Warning methodology training does is not designed to provide instruction on every WDM topic such as situational awareness (although SA is certainly an important aspect to maintain during a warning methodology). Warning methodology training is designed to provide an overview of the warning methodology process, with emphasis on specific job tasks that each and every forecaster can accomplish to improve warning proficiencies.  

## Severe Weather Operations Plan (SWOP)

- Does your office have a *SWOP?*

## Elements of a SWOP

- Common goal (NWS Mission)
- Essential tasks accomplished efficiently
- Staffing levels and assignments appropriate for the severe wx threat
- Evaluation of office performance after each event

**Notes:**
There are at least 5 important elements of an effective SWOP. The first is ensuring that everyone on the warning team has a common goal during operations. This goal should be to provide weather, hydrologic, and climate forecasts and warnings for the United States, its territories, adjacent waters and ocean areas, for the protection of life and property and the enhancement of the national economy (from NWS mission statement). As long as everybody keeps this mind during a severe weather event, and doesn’t worry about other factors (such as verification) the mission will be met. If everybody has a common goal, then it can help the warning team react in the face of difficult or unexpected events Each individual should know what he/she is doing as well as what everybody else is doing. The shift supervisor/event coordinator determines proper staffing levels to accomplish all tasks efficiently and directs the whole operation. The “Severe Weather Team” needs to maintain consistency but also flexibility with the changing weather situation and/or changes to operational demands (asked to provide backup, for ex.). It is important to assign staffing levels based on expected severe weather threat . After every event, the Team should review actions and evaluate performance from an operational standpoint (did the SWOP work as designed?) and a service standpoint (were the objectives of the mission met?).  

In additional, to ensure an effective SWOP, the 3 C’s must be met (more on next slide).

## Factors in an Effective SWOP

**Communicate**

**Cooperate**

**Collaborate**

- J. Eise

**Notes:**
One of the most important factors in a successful severe weather operational strategy is maximizing the three Cs : communication, collaboration, and cooperation. 

The staff must understand their roles and remain focused on severe weather detection, and upon information flow within and out of the office. One of the  severe weather coordinator’s jobs is to make sure the “team” is maintaining this focus and not getting distracted by outside communication. John Eise (MKX) provided this graphic from his presentation. 

## Factors in an Effective SWOP

- Mitigation of negative stress

***Stress/Performance Curve***

***Stress***

***Performance***

**Team Building Associates (1997) **

**Notes:**
Stress, if not managed effectively can have an adverse impact on performance. The impact of excessive stress on teamwork is also harmful, and it can damage: 

individual work performance 
team performance 
working relationships 
cooperation between team members 
team spirit 

The more effort team members have to expend in managing their own stress, the less they have to contribute to teamwork and mutual support. Thus, a good SWOP can act to reduce stress and chaos in a warning situation, which can be a very stressful situation, if not handled properly. 

## Example #1 -  Office Layout

***WS1***

* *

*CRS*

* *

***WS2***

* *

***WS3***

* *

***CRS***

* *

***WS5***

* *

***WS4***

* *

**Long-term**
**(1 Met)**

**QC/River Flood**
**(1 HMT/Intern)**

** **

**Svr Wx Coordinator**
**(1 Met)**

**Short-term**
**(1 Met)**

**Warning **
**(1-2 Mets)**

**HAM (1 Person)**

**Storm Reports**
**(1 HMT/Intern)**

- MKX operations for “light” severe weather

**Notes:**
Most SWOPs recommend staffing levels based upon the severe weather type, coverage or intensity. Essential duties for light events are accomplished by a few staff members or may be split amongst several staff members during severe weather outbreaks. Each person is often assigned to a specific AWIPS workstation, unless the duties do not require use of AWIPS. Rigid workstation assignment is not necessary, since AWIPS workstation are interchangeable and for large events, more than one “position” may end up sharing an AWIPS workstation. The AWIPS workstation positions within the office layout are not as important as the duties and tasks that are identified.  

This is an example of a light to moderate severe weather event setup (for ex., expecting organized convection, but no widespread or significant severe weather) from MKX. Notice that to handle small events such as these, some of the positions combine duties such as QC (Quality control)  and River flooding . One HMT or Intern can usually handle these duties easily. Similarly, for the Warning Meteorologist position,  one to two mets can handle the duties of warning meteorologist (WM) and warning assistant (WA).  That would involve drawing up and submitting all warnings and SVSs in WarnGen. 

In this scenario, the duty of making outgoing calls (to spotters, etc.) would fall to the Severe Weather Coordinator.

## Example #2 – Office Layout

- MKX operations for “outbreak” event

## Example #3 – Office Layout

**WFO DMX severe weather operations layout for “outbreak” events (Note 2 Warning Teams)**

**Notes:**
An alternative office layout showing positions for a potential severe weather outbreak event is from WFO Des Moines (DMX).  Here they have two warning teams at the two primary warning workstations with two people at each. They have LINUX AWIPS machines between the 2 HP workstations so in effect they could have 4 workstations and 4 mice in use. This could accommodate up to 4 warning teams (each sectorized). The mesoanalyst that is employed at DMX would end up sharing a workstation performing other Warning Assistant duties such as writing SVSs. 

## Role of Severe Weather Coordinator

- Does your office use a Severe Weather Coordinator?

**Notes:**
Below are some of the duties of the Event Coordinator (often called the Severe Weather Coordinator). This individual is often the shift supervisor, or lead forecaster as scheduled for that shift, or held over from previous shift. Note that the position of Severe Weather Coordinator, to be effective performing all the listed duties, must not be  required to work at any severe weather position which requires, or may require, sustained dedicated attention (such as warning meteorologist, warning/statement writer, radio operator, etc.). Some of the important duties of the Coordinator include:
	1) Oversees SWOP
	2) Completes svr wx checklists
	3) Assigns duties/positions, staff decisions (granting OT, etc.)
	4) Ensures 3Cs are met
	5) Maintains high SA (team and individually for team members)
	6) Ensures system problems are addressed 
	7) Warning areas clearly defined
	8) QC products; monitors product content (do warnings/statements convey the threat?)
	9)  Ensure coordination with other agencies and partners 

## Roles of a Severe Weather Coordinator

- Oversees SWOP
- Completes severe wx checklists
- Assigns duties/positions, staffing decisions (granting OT, etc.)
- Ensures 3Cs are met during operations
- Maintains high SA
- Ensures system problems are addressed
- Defines/assigns/modifies warning sectors
- QCs products; monitors product content
- Ensure coordination with other agencies and partners

**Notes:**
These are the main roles of the Severe Weather Coordinator. Can you think of any others? 

## Example #3 - The Warning Team(DMX model)

**Warning Met**
- Analyzes data each Volume Scan
- Makes warning decision
- Starts WarnGen process and sends draft warning to Text WS for Assist. WM to complete

**Notes:**
An example of a  “Warning Team from DMX. This model uses a “2-man” approach to accomplish the warning tasks as shown. Note that the DMX Assistant Warning Met handles severe weather  statements (SVS) and finishes all warnings that the Warning Met starts. The advantage of this “configuration” is that the Warning Met is freed from SVS duties and can spend more time on meteorological data/radar interrogation. Note that some offices divvy up the SVS duty to a separate “Statement” position, but this may be difficult and require more communication on storm characteristics, for example whether the storm is still severe and whether the warning is being reissued. 

## The Warning Team (DMX Model)

**Assistant Warning Met**
- Reviews & completes warnings on Text Workstation
- Tracks warnings/storm reports
- Writes SVSs
- Assists WM w/radar and NSE interpretation
- Performs outbound comms

**Notes:**
The role of the Assistant Warning Met. may vary from office to office, but this is what DMX does. Usually, this person would sit right next to the Warning Met.

## Example #4 - The Warning Team(OUN model)

- Warning Met
- Analyzes data each Volume Scan
- Makes warning decision
- Uses end-to-end WarnGen process
- Writes SVSs
- In “sectorized” operations

**Notes:**
In this model, the Warning Meteorologist draws up all warnings and SVSs for his/her assigned area using WarnGen, and finishes the product text.Usually in this model the office tends to “sectorize” their warning area frequently, dividing up the real estate to prevent overload on the Warning Meteorologist.An advantage is that the Warnings and SVSs are issued by a person familiar with all details of their assigned storm sector. A disadvantage is that with a high warning volume, overload may occur and SVSs may not get issued. Also, it will take time spent tracking SVSs, and using WarnGen to draw up SVSs.This is time that may be better spent scouring meteorological/radar data and evaluating storm structure. 

## Sectorizing 

- By geographical area (esp. during outbreak events)
- “I’ll take the metro, you take the west”
- “I’ll take these batch of storms”
- By hazard type
- “You take the flash flood threat”

**Notes:**
One way offices typically reduce duty workload is to divide up the weather in your CWA, by geography, by storm, or by hazard. This is highly recommended when a severe weather outbreak is expected. In this way, you can allow  undivided attention to the most severe storm, or threat for example. The other Warning Team (s) maintains continuous warning service to the other storms or threats.

Other times when sectorization is definitely needed is when you have to provide backup warning operations for another WFO. 

## Sectorizing Needs

- Communication/Cooperation are vital
- Between warning teams
- Make sure statements are not dropped

**Notes:**
Sectorizing warning operations requires good communication as warning forecasters must know precisely which counties or storms they are responsible for.  A lapse in communication could result in a lapse in warning service. All staff must know who is responsible for each sectors so reports aren’t  “dropped” because they were delivered to the wrong team. Also, make sure Severe Weather Statements (SVSs) are consistently prepared to continually convey the threat for each warning. Event coordinators should check on this throughout the event.   

## Sectorizing Example

- _[Click on this text to play the movie](ftp://ftp.roc.noaa.gov/Pub/WDTB/presentations/warnmethods/litsectex.html)_

**Notes:**
Next up is a situation where you might definitely consider sectorizing warning operations. This is a 0.5 degree reflectivity product from KLZK (Little Rock, AR) from 21 January 1999 (a loop will run from 2000z to 2109z ).  The radar indicated multiple supercells aligned SW-NE with high tornadic threats with each storm. 

The question to ask yourself is, “How would you plan on sectorizing warning operations in this case?”

One answer might be to break it up north and south. You probably will need to evaluate the situation after the threat assessment part of the methodology. Even with thorough threat assessment, sectorizing is difficult because storms can evolve quite rapidly.   

## Other Ways to Reduce Workload

- Have another duty position assigned to write Severe Weather Statements (SVSs)
- More people/separate WS needed
- Requires good communication

**Notes:**
The way offices handle SVS writing duties vary. For some, the Warning Meteorologist (WM) draws up all warnings and SVSs for their assigned area using WarnGen, and may even type the text as well.  These offices tend to sectorize to prevent overload on the WM. The advantage is that Warnings and SVSs are issued by a person or team familiar with all details of their assigned area and can handle the entire evolution of the storm with consistency and no coordination is required. One disadvantage is that with a high warning volume (even in sectorized operations) , overload may occur and SVSs may not get issued. Another disadvantage is that time must be spent tracking SVSs, and using WarnGen to draw up SVSs, instead of time that may be  better spent analyzing storm structure. In the DMX model shown earlier, the warning teams use WarnGen to generate warnings only, and the Warning Assistant (WA) uses WarnGen to draw up SVSs. The WA finishes off the text and inserts spotter reports into the text for both warnings and SVSs. The advantage to this tact is that Warnings and SVSs are issued by a team familiar with all details of their assigned area, and the WM is freed from SVS duties to spend more time on meteorological data/radar interrogation. A noted disadvantage is that the WA must have access to D2D and WarnGen in order to draw up SVSs.

 If you designate a separate duty position devoted to SVS development only, this frees the WMs to focus on warning decisions only. This may require less sectorizing, but it requires the SVS writer and WM (s) to coordinate on storm characteristics, for example, is the storm still severe and whether the warning will be reissued.  Another disadvantage is that a dedicated SVS writer needs a Workstation (WS) preferably in close quarters to the WM (s).

## Training Components

- Severe Weather Staffing Strategies
- Environmental Threat Assessment
- Storm Interrogation Process
- Continual Reassessment

**II**
**III**
**IV**

**Warning Decision**

**I**

**Notes:**
We again show our training outline structure based on four principal components of an effective warning methodology. Next we will briefly provide an overview of Part II (Environment Threat Assessment).  More training on specific strategies for threat assessment will be developed in 2004. In the meantime, there is a lot of training for threat assessment already available in PCUs 3 and 4.  See the PDS web site. 

Threat assessment information and forecasts from NWS Forecast Offices can be found textually in the form of regularly scheduled Hazardous Weather Outlooks (HWOs), Short-Term Forecasts (NOWs), and the Area Forecast Discussions (AFDs). 

## Threat Assessment

- Determines what products/procedures will be used
- A factor in establishing mental models for the event
- Sets the tone for awareness (HWO)
- We’re talking the environment!

**Notes:**
Threat assessment, the second part of an effective warning methodology, is important in determining the tone of awareness for the subsequent event. 
This step enables the severe weather warning team to begin to focus on specific threat areas and specific storms within the CWA. By assessing the spatial and temporal evolution of the mesoscale convective environment, forecasters can improve their decision making skills because they can acquire an increasing knowledge of the perceived level of threat for each storm. Threat assessment is a continuous process, not a one-time duty. 

The assessment of potential hazards influences what radar products you might look at and how you will look at them , which is related to interrogation strategies (Step III). One way to think about this is that there is a range of possibilities for all severe weather. After the synoptic and mesoscale assessment, you have narrowed down your expectations. When storms develop and you detect them on radar, you then compare that data to the mental images that have been processed in your brain. Even though the initial expectations provide an important working framework for subsequent warning sequences, individual and collective expectations must be re-evaluated during the event . This is another vital part (Part IV) of warning methodologies.  Specific training on threat assessment for each severe weather hazard will occur during 2004.

## Threat Assessment

- Applies climatology and pattern recognition
- Includes synoptic/mesoscale analysis
- Influences screening & ranking process,  subsequent warning decision
- Several subcomponents to forecast process

**Notes:**
An important aspect of threat assessment is comparing observations to known patterns. The role of climatology is important in recognizing relative seasonal threats.  As you analyze large scale features and make the forecast for potential severe weather, it is important to not get caught up in evolution of details, but try to target relative threats from the potential storm types. Analyze fields of shear, potential buoyancy, movement, and all potential lifting mechanisms to help define the highest threat areas within the CWA. Analyze hourly model forecast  soundings to help you predict convective storm mode and evolution. Compare your local forecast with the SPC outlooks/mesoscale discussions. 

Time and data quality are big factors in this process. How good is the model objective analysis (OA) of thermodynamic and kinematic fields that are displayed on AWIPS? Are there observations to support the analyses? Important questions to ask as this component is performed in the warning methodology. Try to improve your local OA by getting more observations into the analyses. Closer to the event, you will typically be analyzing mesoscale features using observed data and high-resolution models (like the WRF). Remember, this information will help you decide how you will interrogate these storms and can have a very positive effect on how you weigh radar and other information in the eventual warning decision. 

## Threat Assessment

- Location
- Provide detail not in SPC outlooks
- Timing
- When and how much
- Impacts
- Probability of specific hazard occurring

**Notes:**
Proper threat assessment on the mesoscale adds accuracy to the initial convective outlook process. The analysis of mesoscale data helps to determine when and where convection will develop (and possibly intensify), and, on some occasions, will yield clues to the probability of a specific hazard occurring.    

How can forecasters provide useful information in a short-term threat assessment which supports the ongoing warning methodology? There are several ways. 
For example, increasing observations will help forecasters evaluate the usefulness of mesoscale model output. In addition, the use of interactive programs which ingest the latest observations from ACARS, VWP data or profiler data and produce hodographs or soundings could improve our ability to predict the type of severe weather. High-resolution satellite data from GOES-12 can provide critical information on aspects of convective initiation and evolution. There are lots of other ways as technology becomes fused into operations. There is specific training in the AWOC on the latest techniques of severe weather threat assessment. 

## Threat Assessment

- What position regularly performs mesoscale analysis in your office?
- Warning Met, short-term, long-term, dedicated?

## Threat AssessmentSample AWIPS Layout

- Should include the ability to monitor convective storm development & evolution  throughout lifetime of event

**Notes:**
If a dedicated Meso-analyst is not available, we recommend at least one monitor on your AWIPS warning workstation dedicated to mesoanalysis for all situations when severe weather is expected. The Warning Met should utilize some panes on the AWIPS D2D workstation for proper mesoanalysis. In moderate to outbreak severe weather events, an entire AWIPS workstation position may be needed to perform the duties. It depends on staffing strategies, but some offices may combine the Mesoscale Analyst position with other positions (eg., HMT,  long-term, aviation, short-term forecaster, etc.) .  

There is a lot of room for personal preference here, but for any situation , the AWIPS workstation layout should provide the opportunity for the mesoscale analyst position to monitor storm development and evolution. Multiple AWIPS datasets providing routine and continuous analysis of the convective environment include GOES and POES satellite imagery, upper-air data, surface data, profiler data, model data, and radar data. In terms of radar data, the mesoscale threat assessment D2D layout should incorporate a state scale view of the data so the forecaster can keep abreast of the “big picture”. This analysis is important for the warning Met as he/she often loses track of the big picture during the storm scale interrogation process. 

## Training Components

- Severe Weather Staffing Strategies
- Environmental Threat Assessment
- Storm Interrogation Process
- Continual Reassessment

**II**
**III**
**IV**

**Warning Decision**

**I**

**Notes:**
The next step after proper environmental assessment of all hazards is the storm interrogation process. This step combines the use of personal preferences (an art) with application of scientific principals (mostly a science) in the detection  and analysis of severe storm structure. 

Note that reports can enter in at any point in the process. After storm interrogation, an attempt should be made to try and validate what you expect based on the process. But, certainly, a warning decision will need to be made at the conclusion of the process , regardless of whether a report is received or not.

## Storm Interrogation Process

**Report**

**S****creen**

**R****ank**

**I****ndividual  **

**D****ecide**

**T**
** ****I**
**M**
** ****E**

**Notes:**
The storm interrogation process is one of the key components in a warning methodology. As was previously discussed, the process is heavily influenced by the previous threat assessment. The threat assessment and your SWOP actions will facilitate the screening and ranking process. The storm interrogation process is primarily storm-scale analysis via radar data (augmented by spotter reports and other inputs). The process can be remembered as  SRID.  Initially you will screen and then rank storms in your CWA based on potential severity. After this, you can better determine which storms need further investigation. Step 3 is individually interrogating each storm to determine the threat of each hazard.  At step 4  you decide on the type of warning , and begin composing your warning text and finally, send the warning out. 

Note that in the task flowchart a valid report of severe weather could interject (and interrupt) the sequential storm interrogation process. A valid incoming report could lead to a rapid decision (Step 4) which would bypass the steps of screening and ranking. For other storms where no reports have been received, you normally will need to work through these steps to make a good decision. Time and data quality are big factors in this process. Hopefully, the ranking process is already fairly mature by the time a report comes in. If not, the threat assessment and SWOP action would have been off base. 

We’ll break down each step next.

## Screening Process

- Comparative Process
- Does current state fit what you expected from previous analysis?

**Rotation**
**(Strength, Ht, Depth)**

**Updraft strength**
**(Core, Ht)**

**Movement**
**(Duration)**

**Notes:**
Assuming there have been no valid reports of severe weather, and there are no active warnings, the initial step in the storm interrogation process is the screening process. At this juncture, you are likely comparing what you observe with your expectations (based on mental models acquired from the environmental threat assessment) . This is similar to pattern recognition in severe storm forecasting (see Johns and Doswell, 1992). You try to determine which storms need further investigation based on perceived threat (eg., “is this  storm moving into/along a boundary?”) You should evaluate rotation potential and updraft strength (not necessarily in that order) for all storms in your sector. For updraft strength you will need to assess the height of the reflectivity core. This may help as you simultaneously evaluate storm rotation via strength and location of associated shear. In addition, you should evaluate the movement of convective cells; this is very important in assessing storm characteristics (for ex., supercell convection, quasi-stationary convection, etc.).  

The initial screening step can help you as you begin to rank storms according to their severe weather potential. One other aspect that should be noted at this stage is convective initiation mode. In other words, how and where do the storms develop? Do they form along a boundary? In clusters or lines? As isolated cells? The initial convective organization and development often tells a lot about what kind of severe weather will initially occur and provides clues to convective storm/system evolution.

There is more later on the type of products and/or AWIPS D2D layouts to perform these initial screening and ranking steps.

## Screening Process 

- Comparative Process
- What are the characteristics in terms of overall shape of the storm?

## Screening Process

- Used to evaluate immediacy of threat
- What is going to happen?
- Analyze quickly using all radar vantages
- Prepares you in ranking (next step)

**Notes:**
The screening process helps you to determine the initial immediacy of the threats (if any). For example, if several storms were  quickly forming in an area of the highest instability and shear, then that observation would likely determine where you would proceed with the first full-fledged interrogation process for each storm. Storms forming well north of a surface boundary likely will be elevated convection, so you might decide to interrogate those storms in a different manner, focusing on hail threat. Another example, storms that continue to “backbuild” over previous convection (helpful to diagnose with use of forecast propagation vector) might initially prompt the warning team(s) to interrogate flash flooding threats. So, the result of the screening process is like an internal “Nowcast” of convective storm development over the next 30 minutes or so. This could help focus the warning teams to  potential “trouble spots” and help them get ready to begin ranking storms for interrogation and ultimately,  determine which storms need warnings.  

A lot of this screening process is based on the previous meso threat assessment but it will need to be accomplished with the help of all radars to get the full view. 

## Ranking Process(Or, determining which storms need further investigation)

- Depends on the Situation (If ...then)
- Environment Assessment
- Immediacy of Threat
- Is there a warning about to expire?
- Is there a report?
- What storm poses the biggest threat to life and property?

**Notes:**
The ranking process is a step that flows sequentially from the initial screening process. At this juncture, you are trying to determine which storms need further interrogation. Ranking depends of the situation and often is decided based on the previous threat assessment and the initial screening of storms. Hopefully,  you will have decided to sectorize warning operations (and set up a good SWOP) to deal with this event before the ranking step. As was previously discussed,  for large convective outbreak situations, sectorizing will allow the warning team to evaluate all threats. This will preclude an extensive and often,  difficult ranking process. For example, it is much easier to rank 2 or 3 storms in one portion of the CWA, or deal with only one or two types of hazards (tornado and hail, for ex.) with a couple of storms, than to try to rank all storms within your CWA at any given moment, for all threats. Forecasters often rank storms (assuming no history and no prior reports) based on the immediacy of the threat. In this fashion, storms with flash flood warning potential are often ranked last (or perhaps delegated off to a separate “warning team”) due to the fact that the associated damage and any life-threatening aspects are slower evolving that from tornadic storms and/or hail and windstorms. 
If a storm report has been received, most likely that storm will get a #1 ranking at least in terms of initial interrogation order. For ongoing  storms with existing warnings, you still will want to have an ranking order based on threat to life and property, but expiration times will be a ranking factor as well.   
Here are some examples: 
If tornadoes are possible based on the fact that there is a favorable shear environment (and sustained updrafts are noted), and a well defined boundary  is present, then most likely , warning forecasters will likely rank any storms that show supercellular characteristics first. All other storms will be handled next (or handed off to a separate warning team for individual interrogation). On the other hand, another example might be previous convection has produced saturated ground conditions , storms develop in this area, and training is observed. In this case, the warning team might delegate a  person to work on a flash flood warning first, and then the team will deal with the remaining storms next. A third example could be a large, mature MCC rolling through your CWA. The main threat would likely be damaging winds, so storms with highest wind threat will be handled first. The ranking will often change based on changes to storm morphology and storm scale processes. Thus, forecasters will need to update the ranking throughout the warning event. 
One last hypothetical, if you receive a flash flooding report and you are expecting tornadic supercell storms (but the threat is not imminent) , you will likely need to address that report immediately (either get a warning out fast or hand off the warning duties to another forecaster immediately).

The System for Convective Analysis and Nowcasting (SCAN) could be useful in the event of a difficult ranking situation  or in a case where the warning team is “behind the 8-ball” . SCAN can help rank storms by size and estimated updraft strength (ht. of max reflect., VIL, or storm top), or by rotation (via the MESO and TVS height and shear attributes), and even by environment (via the CAPE and Storm-Relative Helicity attributes). To take advantage of the most recent radar data for screening and ranking, warning forecasters should utilize base data initially, but algorithm output (such as what is seen in SCAN) can be useful. SCAN users should also be aware of the time and resource limitations in AWIPS.    

## A Ranking Example

**Notes:**
This is another hypothetical situation where (even if there is only one warning forecaster available) you will not have to spend an inordinate amount of time ranking storms. The strongest storm in terms of the 0.5 deg reflectivity data and velocity data (not shown) is the large storm on the swrn most part of the line. Radar indicates very good structure from even just from one elevation angle. The warning team should concentrate on issues with this storm first, and likely consider the tornado threat first.  

## A Difficult Ranking Example

**Notes:**
This is a much more complicated situation where ranking (and sectorizing) is crucial in dealing with multiple threats in the warning process.  Supercells are possible based on environmental assessment across the entire CWA. After 3 large storms began to develop from SW to NE across the CWA,  they quickly developed supercellular characteristics (hook echoes, shear). These storms would likely be ranked first due to initial development, and then the warning team would investigate tornado , hail, and wind threats with each of these storms. Other storms that were developing across the SE/NE  portions of the CWA were not as organized initially, but due to environment, would still need dedicated attention for supercell characteristics. Flash flood threat initially was perceived to be low (fast-moving storms and high flash flood guidance values), and ranked last. But, due to the observations that storms were tracking over the same region , the threat would need to be considered in the subsequent ranking/storm interrogation process. 

## Ranking Process

**Sample screen layout**** **
- Quickly assess rotation, updraft, and movement
- 5 panes of radar data to assess severe potential
- One hour loop
- Z, SRM, LRM, VIL, STP
- Remember digital VIL

**Notes:**
In order to assess the severe potential of each storm that develops, you need a AWIPS layout that allows you to quickly assess rotation (strength, height, and depth) , updraft strength (including core and depth), and the overall shape and movement.  There are lots of personal preferences here; some forecasters like 3-panes, some use 5 panes, etc.  The main point is to quickly determine what storms need to be considered for interrogation. 

One example is a 5-pane layout using any of the  following radar products: Z, SRM, LRM, VIL, ET, and STP (OHP could also be used). CZ is another option replacing the LRM.  Keep the loops of 12 frames. You could also incorporate 8-bit Z, or V , and/or 8-bit SRM (but know the limitations).

Using digital VIL in place of VIL is good but remember to compare relative intensities of storms.  All of us have little operational experience with interpreting the significance of the absolute numbers since it integrates uncapped reflectivities.

## Ranking Process

**Radar products**
- Include STP/OHP to monitor flash flood potential
- VIL, ET, LRM on bottom panels for comparing storm sizes

**Notes:**
The precipitation estimation products, STP and  OHP could be placed in 2 panes of a 4-panel display with VIL, and ET (or LRM) to quickly compare storm sizes (i.e., which storms have the biggest updrafts and are producing the biggest rainfall?). Reminder , a specific methodology for addressing flash flood threats will be released in 2004. 

You can use the VIL and ET to calculate VIL density but keep in mind that ET values can carry significant errors.

In addition to digital VIL, you can also display the enhanced ET product.  Remember that this product interpolates the ET between observed beam heights.  This interpolation is merely a guess as to the true height of an echo and is not an observation.  In some places this product will give you better height estimations, and in others, a pure guess.  The precision is higher in all areas.

## Storm Interrogation Process

**T**
** ****I**
**M**
** ****E**

**S****creen**

**Notes:**
The storm interrogation process is one of the major components in a warning methodology. The process is heavily influenced by the previous threat assessment. The storm interrogation process is primarily storm-scale analysis via radar data (augmented by spotter reports and other inputs). The process can be remembered as  SRID.  Initially you will screen and then rank storms in your CWA based on potential severity. After this, you can better determine which storms need further investigation. Step 3 is individually interrogating each storm to determine the threat of each hazard.  At step 4  you decide on the type of warning , and begin composing your warning text and finally, send the warning out.  
As you rank storms, determine which radar will offer the best view of the storms – this is important in deciding which procedures you call up to get the 4-dimensional attributes of the storm. If the storms are moving fast and are at least 60 nm away from the radar,  then you will probably want to use a procedure which displays the lowest 4 elevation slices of base Z , SRM, or V in a 4-panel for example. As storms evolve, remember to use alternative radars. 

Note that in the task flowchart a valid report of severe weather will usually lead to a rapid decision (step 4) and bypass the steps of screening and ranking. However, for other storms where no reports have been received,  you will need to go through these steps.  Time and data quality are big factors in this process.  

We’ll break down each step next.

(Note: training on the detailed storm interrogation process for specific hazards will be developed in 2004 as a part of AWOC). 

## Individual Storm Interrogation(Evaluating the potential for the storm to produce...)

**Tornadoes **

**Damaging Winds**

**Hail **

**Flash Flooding **

**Notes:**
Now that you have pinpointed the threat areas , and detected storms that look “suspicious” based on the data, you are going to be investigating each storm for the potential to produce the 4 threats shown here. You will probably start with the highest and most immediate threats to life and property. Again, this could be tornadoes first, if supercells are expected, or it could be hurricane force straight line winds. Or, in another situation, you might start by evaluating hail threat first, if that is the most immediate threat.
Make sure you have products that can assess the primary threats first, but be ready to go back to a “screening & ranking” procedure to assure all threats are assessed. Some threats can be evaluated by the same products (tornadoes and hail, for ex.) . Always know the locations of meteorological boundaries as that information factors into the interrogation and resulting decision process.

## Your turn to decide what it is

- What type of features do you see?
- What are the main threats?
- What warnings do you issue?

## Storm Types/Hazards Table

|  | Dmg winds | Hail | Tornado | FF |
| --- | --- | --- | --- | --- |
| Ordinary cell
(0-6km shear <15 m/s) | Steep LL lapse rates
High LCL, dry midlevels, high DCAPE
Intense elevated core
Descending core bottom
Elevated radial convergence | Cold temps aloft
Large buoyancy ~
-20 C
Intense elevated core ~ -20 C and colder
High VIL density, TBSS | No CIN, steep LL lapse rates
Sharp boundary with LL vertical vorticity
Rapidly growing and new CBs  | high RH in deep layer; deep warm cloud; small mean wind 
Slow storm motion 
Large storm core |
| Super-cell
(0-6km shear > 15 – 20 m/s) | Similar environ as above except for shear and high CAPE & DCAPE, strong 0-1 km shear can assist
In addition to above, LL mesocyclogenesis; developing hook, deep convergence zone | Large buoyancy @ -20 C level, strong 0-6 km shear, stg mid- upper SR flow; 
WER BWER, intense elevated core,
mesocyclone,
TBSS, high VIL density | Strong 0-1km shear in addition to 0-6 km shear; low LCL; low CIN
LL TVS, meso, inflow notch; sign of a hook, strong LL convergence below mesocyclone;BWER | High RH in deep layer; deep warm cloud; small SR anvil flow
Low supercell motion
Not an LP storm |
| Multicell
(organized group of ordinary/supercells) | >40kt 0-6km shear
Strong >30kt 700-500 wind;
Stg leading  Gradient;
Bookend vortex pair;
MARC, deep convergence zone, rear inflow notch | Separated cores; cells exposed to favorable environment | Similar to supercells?  
Mostly left of rear inflow notches along leading edge of core, front inflow notch with WER and vert vorticity | Slow MBE motion; triple pt anchoring; upwind instability, LL jet, high PW, high mean RH
Intrastorm seeding
Echo training, slow motion |

**Source: IC 5.7 Student Guide ****http://www.wdtb.noaa.gov/courses/dloc/topic7/index.html**

**Notes:**
This graphic is from concepts taught in the IC 5.7 Student Guide (for reference only). In this chart, you can see the relationships between typical environmental parameters and radar signatures for various storm hazards for various storm types.