A bureau within the U.S. Department of Commerce   
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
Warning Decision Training Division (Click Here to return to WDTB Home.)


Recognizing High Impact Hydro Events

Millington, TN


Flash flooding is the second most deadliest form of severe weather in the United States over the past 70 years. Flash Flood Warnings and their follow-up statements are some of the most visible products issued by the National Weather Service (NWS). Issues with these products can result in confusion on the part of the general public and our partners, and result in increased risk to life and property. Best practices and recommendations have been made based on the assessment of performance and warning practices documented in some of NOAA’s NWS Service Assessments, such as the Southeast United States Floods of September 18-23, 2009 and the Record Floods of Greater Nashville: Including Flooding in Middle Tennessee and Western Kentucky of May 1-4, 2010 assessments.

As part of the FY12 National Strategic Training Educational Plan (NSTEP), the NWS Warning Decision Training Division (WDTD) has developed training on recognizing and forecasting extreme rainfall events. Course material will focus on synoptic pattern recognition and the use of standardized anomalies to assist in forecasting large-scale quantitative precipitation forecasts (QPFs). The lessons from this course are intended to help the warning forecaster with these specific job-related tasks:

Training Implementation Briefing

Description: This presentation is intended to provide guidance to local training officers and regional/national training partners on the purpose and implementation of this course. This course was created in response to Recommendation 12 of the Record Floods of Greater Nashville: Including Flooding in Middle Tennessee and Western Kentucky of May 1-4, 2010 Service Assessment.

Play Presentation

Performance Objectives for Course:

  1. Show how to forecast an event using large scale set-ups from ensemble data, probability of QPF, and meteorological assessment of ingredients.
  2. Demonstrate how to translate huge anomalies to an effective QPF.
  3. Demonstrate how to use a situational awareness approach to increase prediction of extreme flash flood events.

LMS Note to NWS Personnel:

To receive credit for completing the Recognizing High Impact Hydro Events Training, you must complete the course requirements through the NWS Learning Center!

LMS Web Page

Course Completion Instructions:

  1. Complete the pre-requisites for the course:
  2. Review optional material that can better your understanding of QPF, NWP models, precipitation estimation, hydrology, and streamflow prediction. A list of relevant material can be found on the Review Page.
  3. Complete all lessons in Recognizing High Impact Hydro Events course, including the case exercises.
  4. Complete the course assessment on the LMS Web Page.

Course Outline:

Use the tabs below to view the details on each part of this course. You have the ability to view or download the presentations and exercises from here. Remember to login to the LMS to receive credit for the Course and the Case Exercises.

***NEW*** Recognizing High Impact Hydro Events - Webinar
Recorded Live Webinar PLAY Download Best Practices Rationale Lesson(12.6 MB File)
PDF of Webinar Slides Download Best Practices Rationale Lesson(3.7 MB File)

Overall Course Duration: 140 minutes

Part 1: On the Value of Anomalies

Description: This first module on anticipating extreme rainfall with standardized anomalies and ensembles focuses on how anomalies can be used in predicting extreme rainfall events, the limitations of anomalies, and how they can prodive confidence in forecasting significant flood events. The module will also talk about antecedent conditions and their role in predicting high impact flood events.

Duration: 15 minutes

Download Best Practices Rationale Lesson(9.3 MB ZIP File) or Play Presentation

* This module contains flash applications that will launch in a separate window. Check your browser properties if these flash applications do not appear.
Part 2: Ensembles and Anomalies

Description: The second module of this course will focus on how to leverage ensemble and anomaly data when forecasting high impact rainfall and flood events. By using ensemble and anomaly data, you should be able to recognize known heavy rainfall patterns, the persistence of these patterns, and the predictability and probabilities of excessive rainfall.

Duration: 20 minutes

Download Best Practices Rationale Lesson(14.8 MB ZIP File) or Play Presentation

* This module contains flash applications that will launch in a separate window. Check your browser properties if these flash applications do not appear.
Part 3: Case Exercises

Description: This set of two Case Exercises will allow forecasters to analyze a series of datasets (model, anomalies, QPFs, etc.) to gain expertise and confidence in predicting high impact rainfall and flood events. Within each case is a Job Sheet that provides information and asks questions regarding the case data. The Case Exercises are HTML based and can be viewed within any internet browser. You can launch the Case Exercise Interface from this page or you can download it to your local PC. You will need to print our the Job Sheet to complete the Case Exercises.

Case Exercise #1 - Job Sheet
Case Exercise #2 - Job Sheet

Duration: 105 mintues

TASK Case #1 Case #2
Job Sheet 40 min. 40 min.
Debrief 10 min. 15 min.
TOTAL 50 min. 55 min.

Download Limiting the Number of Countiesi in Warnings Lesson(174 MB ZIP File) or Launch Case Exercise Interface

Last Updated: March 7, 2012


If you are having problems launching or downloading the Case Exercise Interface, you can request a CD to be mailed to the office by contacting Steven.Martinaitis@noaa.gov or Bradford.Grant@noaa.gov.

You can access the references and material used for the course modules and case exercises by clicking on this link for the Reference Page.


WDTD welcomes your feedback on how well this training supported your understanding of forecasting high impact hydro events. Please send us your comments! Thanks!

* Image courtesy of NWS-WFO Memphis

WDTB Home!

Department of Commerce
National Oceanic & Atmospheric Administration
National Weather Service
Office of Chief Learning Officer
Web site owner:
Warning Decision Training Division
120 David L. Boren Blvd.
Norman, OK 73072
Page Author: WDTD Webmaster
Page last modified: April 3, 2015 10:05

Privacy Policy
Information Quality

About NWS
Career Opportunities
Strategic Plan
NWS Mission Statement