The Wdss-Ii Supercell Identification and Assessment Algorithm
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23 Public Reaction to Impact Based Warnings During an Extreme Hail Event in Abilene, Texas
23 PUBLIC REACTION TO IMPACT BASED WARNINGS DURING AN EXTREME HAIL EVENT IN ABILENE, TEXAS Mike Johnson, Joel Dunn, Hector Guerrero and Dr. Steve Lyons NOAA, National Weather Service, San Angelo, TX Dr. Laura Myers University of Alabama, Tuscaloosa, AL Dr. Vankita Brown NOAA/National Weather Service Headquarters, Silver Spring, MD 1. INTRODUCTION 3. HOW THE PUBLIC REACTED TO THE WARNINGS A powerful, supercell thunderstorm with hail up to the Of the 324 respondents, 86% were impacted by the size of softballs (>10 cm in diameter) and damaging extreme hail event. Listed below are highlighted winds impacted Abilene, Texas, during the Children's responses to some survey questions. Art and Literacy Festival and parade on June 12, 2014. It caused several minor injuries. This storm produced 3.1 Survey question # 3 widespread damage to vehicles, homes, and businesses, costing an estimated $400 million. More People rely on various sources of information when than 200 city vehicles sustained significant damage and making a decision to prepare for hazardous weather Abilene Fire Station #4 was rendered uninhabitable. events. Please indicate the sources that influenced your Giant hail of this magnitude is a rare phenomenon decisions on how to prepare BEFORE this severe (Blair, et al., 2011), but is responsible for a thunderstorm event occurred. disproportionate amount of damage. 1) Local television In support of a larger National Weather Service 2) Websites/social media (NWS) effort, the San Angelo Texas Weather Forecast 3) Wireless alerts/cell phones -
Winter 2020/2021 Volume 18
NATIONAL WEATHER SERVICE GREEN BAY Winter 2020/2021 Volume 18 Lake Michigan water levels remain near record highs BY: mike cellitti Inside this issue: In December 2012 and January 2013, the Lake Michigan-Huron basin (Lake Michigan and Lake Huron are treated as one lake from a hydrologic perspective) East River Watershed 3 Resiliency Project observed record low water levels, making it the 14th consecutive year of below normal water levels. These record low water levels garnered national attention 2020-21 Winter Forecast 4 raising concerns for the shipping industry, climate impacts, and the long-term future Ambassador of Excellence 6 of the Great Lakes water levels. Since this minimum in water levels 6 years ago, Lake Kotenberg Joins NWS 7 Michigan-Huron has been on the rise, culminating in record high water levels for much of this year (Figure 1). In fact, Lake Michigan-Huron set monthly mean record Severe Weather Spotters 7 high water levels from January to August, peaking in July at greater than 3 inches Thank You Observers! 8 above the previous record. Word Search 9 The water level on the Great Lakes can fluctuate on a monthly, seasonal, and annual basis depending upon a variety of factors including the amount of precipitation, evaporation, and rainfall induced runoff. Precipitation and runoff typically peak in late spring and summer as a result of snowmelt and thunderstorm activity. Although it is difficult to measure, evaporation occurs the most when cold air flows over the relatively warm waters of the Great Lakes during the fall and winter months. East River The record high water levels of Lake Michigan-Huron are largely a result of well Flooding above normal precipitation across the basin over the past 5 years. -
USING a LIGHTNING SAFETY TOOLKIT for OUTDOOR VENUES Charles C
USING A LIGHTNING SAFETY TOOLKIT FOR OUTDOOR VENUES Charles C. Woodrum Meteorologist National Weather Service, NOAA Pittsburgh, Pennsylvania Donna Franklin Office of Climate, Water, and Weather Services National Weather Service, NOAA Silver Spring, Maryland _________________________ Abstract guidelines that are used as a template for creating a new plan or enhancing an existing plan. The toolkit The threat of fatal lightning strikes at outdoor was developed within the framework of NCAA venues continues to be a pressing concern for event Guideline 1d. The NWS used plans from the managers. Several delays were documented in 2010 University of Tampa, the University of Maryland, and and 2011 in which spectators did not have enough time Vanderbilt University along with guidance from to evacuate, or chose to wait out delays in unsafe emergency management at the University of locations. To address this issue, the National Weather Tennessee and Florida State University as assistance Service (NWS) developed a lightning safety toolkit and to develop the toolkit. recognition program to help meteorologists work with venue officials to encourage sound and proactive Guidelines established for venue decisions when thunderstorms threaten their venue. management include: redundant data reception sources; effective decision support standards; 1. Introduction and Background multiple effective communication methods; a public notification plan; protection program with shelters; and Every year, hundreds of outdoor venue education of staff and patrons. The toolkit template managers are challenged to determine when an event safety plan helps venues meet these guidelines by delay is necessary due to thunderstorm hazards. In providing steps to follow before, during, and after the 2000, “ninety-two percent of National Collegiate Athletic event. -
CALIFORNIA STATE UNIVERSITY, NORTHRIDGE FORECASTING CALIFORNIA THUNDERSTORMS a Thesis Submitted in Partial Fulfillment of the Re
CALIFORNIA STATE UNIVERSITY, NORTHRIDGE FORECASTING CALIFORNIA THUNDERSTORMS A thesis submitted in partial fulfillment of the requirements For the degree of Master of Arts in Geography By Ilya Neyman May 2013 The thesis of Ilya Neyman is approved: _______________________ _________________ Dr. Steve LaDochy Date _______________________ _________________ Dr. Ron Davidson Date _______________________ _________________ Dr. James Hayes, Chair Date California State University, Northridge ii TABLE OF CONTENTS SIGNATURE PAGE ii ABSTRACT iv INTRODUCTION 1 THESIS STATEMENT 12 IMPORTANT TERMS AND DEFINITIONS 13 LITERATURE REVIEW 17 APPROACH AND METHODOLOGY 24 TRADITIONALLY RECOGNIZED TORNADIC PARAMETERS 28 CASE STUDY 1: SEPTEMBER 10, 2011 33 CASE STUDY 2: JULY 29, 2003 48 CASE STUDY 3: JANUARY 19, 2010 62 CASE STUDY 4: MAY 22, 2008 91 CONCLUSIONS 111 REFERENCES 116 iii ABSTRACT FORECASTING CALIFORNIA THUNDERSTORMS By Ilya Neyman Master of Arts in Geography Thunderstorms are a significant forecasting concern for southern California. Even though convection across this region is less frequent than in many other parts of the country significant thunderstorm events and occasional severe weather does occur. It has been found that a further challenge in convective forecasting across southern California is due to the variety of sub-regions that exist including coastal plains, inland valleys, mountains and deserts, each of which is associated with different weather conditions and sometimes drastically different convective parameters. In this paper four recent thunderstorm case studies were conducted, with each one representative of a different category of seasonal and synoptic patterns that are known to affect southern California. In addition to supporting points made in prior literature there were numerous new and unique findings that were discovered during the scope of this research and these are discussed as they are investigated in their respective case study as applicable. -
Glossary Compiled with Use of Collier, C
Glossary Compiled with use of Collier, C. (Ed.): Applications of Weather Radar Systems, 2nd Ed., John Wiley, Chichester 1996 Rinehard, R.E.: Radar of Meteorologists, 3rd Ed. Rinehart Publishing, Grand Forks, ND 1997 DoC/NOAA: Fed. Met. Handbook No. 11, Doppler Radar Meteorological Observations, Part A-D, DoC, Washington D.C. 1990-1992 ACU Antenna Control Unit. AID converter ADC. Analog-to-digitl;tl converter. The electronic device which converts the radar receiver analog (voltage) signal into a number (or count or quanta). ADAS ARPS Data Analysis System, where ARPS is Advanced Regional Prediction System. Aliasing The process by which frequencies too high to be analyzed with the given sampling interval appear at a frequency less than the Nyquist frequency. Analog Class of devices in which the output varies continuously as a function of the input. Analysis field Best estimate of the state of the atmosphere at a given time, used as the initial conditions for integrating an NWP model forward in time. Anomalous propagation AP. Anaprop, nonstandard atmospheric temperature or moisture gradients will cause all or part of the radar beam to propagate along a nonnormal path. If the beam is refracted downward (superrefraction) sufficiently, it will illuminate the ground and return signals to the radar from distances further than is normally associated with ground targets. 282 Glossary Antenna A transducer between electromagnetic waves radiated through space and electromagnetic waves contained by a transmission line. Antenna gain The measure of effectiveness of a directional antenna as compared to an isotropic radiator, maximum value is called antenna gain by convention. -
2.3 an Analysis of Lightning Holes in a Dfw Supercell Storm Using Total Lightning and Radar Information
2.3 AN ANALYSIS OF LIGHTNING HOLES IN A DFW SUPERCELL STORM USING TOTAL LIGHTNING AND RADAR INFORMATION Martin J. Murphy* and Nicholas W.S. Demetriades Vaisala Inc., Tucson, Arizona 1. INTRODUCTION simple source density-rate (e.g., number of sources/km2/min) with various grid sizes and A “lightning hole” is a small region within a temporal resolutions. An additional data storm that is relatively free of in-cloud lightning representation method may be obtained by first activity. This feature was first discovered in aggregating the sources according to which severe supercell storms in Oklahoma during branch and flash produced them and then MEaPRS in 1998 (MacGorman et al. 2002). The looking at the number of grid cells “touched” by feature was identified through high-resolution the flash. This concept, which we refer to as three-dimensional observations of total (in-cloud “flash extent density” (see also Lojou and and cloud-to-ground (CG)) lightning activity by Cummins, this conference), is illustrated in the Lightning Mapping Array (LMA; Rison et al. Figure 1. The figure shows the branches of a 1999). It is generally thought that lightning holes flash. At each branch division, as well as at are to lightning information what the bounded each bend or kink in any single branch, a VHF weak echo region (BWER) is to radar data. That source was observed. Rather than counting all is, lightning holes are affiliated with the of the sources within each grid square to extremely strong updrafts unique to severe produce source density, we only count each storms. -
WOIS - Meteorologists
WOIS - Meteorologists http://www.wois.org/use/occs/viewer.cfm?occnum=100014 University of Washington Libraries Meteorologists Occupational Summary At a Glance Meteorologists study the earth's atmosphere and the ways it affects our environment. Many of them forecast Not all forecast the the weather. weather Many specialize in Have you ever wondered why hurricanes receive names? The reason is actually quite simple: there is often one area more than one at a time. Hurricanes can also take days to travel over the ocean, gaining or losing strength. By May work overtime naming them, meteorologists can track them without confusion. They don't waste time coming up with new during weather names, however. Instead, meteorologists use a list of pre-selected names. Only when a storm is particularly big emergencies do they retire a name. Thus, there will never be another Hurricane Andrew or Hurricane Fifi, although there Have good research may be more hurricanes just as powerful. and communication The atmosphere consists of all the air that covers the earth. It also contains the water vapor that turns into rain skills and snow. Meteorologists study what the atmosphere is made of and how it works. They also see how it affects Have at least a the rest of our environment. bachelor's degree Meteorologists usually specialize in one area. Weather forecasting is the best known of these. Meteorologists who forecast the weather are called operational meteorologists. They identify and interpret weather patterns to predict the weather. They try to predict what the weather will be like for a week, a month, or several years. -
Mt417 – Week 10
Mt417 – Week 10 Use of radar for severe weather forecasting Single Cell Storms (pulse severe) • Because the severe weather happens so quickly, these are hard to warn for using radar • Main Radar Signatures: i) Maximum reflectivity core developing at higher levels than other storms ii) Maximum top and maximum reflectivity co- located iii) Rapidly descending core iv) pure divergence or convergence in velocity data Severe cell has its max reflectivity core higher up Z With a descending reflectivity core, you’d see the reds quickly heading down toward the ground with each new scan (typically around 5 minutes apart) Small Scale Winds - Divergence/Convergence - Divergent Signature Often seen at storm top level or near the Note the position of the radar relative to the ground at close velocity signatures. This range to a pulse type is critical for proper storm interpretation of the small scale velocity data. Convergence would show colors reversed Multicells (especially QLCSs– quasi-linear convective systems) • Main Radar Signatures i) Weak echo region (WER) or overhang on inflow side with highest top for the multicell cluster over this area (implies very strong updraft) ii) Strong convergence couplet near inflow boundary Weak Echo Region (left: NWS Western Region; right: NWS JETSTREAM) • Associated with the updraft of a supercell thunderstorm • Strong rising motion with the updraft results in precipitation/ hail echoes being shifted upward • Can be viewed on one radar surface (left) or in the vertical (schematic at right) Crude schematic of -
12.9 Experimental High-Resolution Wsr-88D Measurements in Severe Storms
12.9 EXPERIMENTAL HIGH-RESOLUTION WSR-88D MEASUREMENTS IN SEVERE STORMS Rodger Brown1, Bradley Flickinger1,2, Eddie Forren1,2, David Schultz1,2, Phillip Spencer1,2, Vincent Wood1, and Conrad Ziegler1 1 NOAA, National Severe Storms Laboratory, Norman, OK 2 Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma, Norman, OK 1. INTRODUCTION resolution to current-resolution measurements in mesocyclones, we present some of the simulation Through use of Doppler velocity simulations, results of Wood et al. (2001). A comparison of Wood et al. (2001) and Brown et al. (2002) have simulated Doppler radar scans across a shown that stronger Doppler velocity signatures of mesocyclone for 1.0o and 0.5o azimuthal sampling mesocyclones and tornadoes, respectively, can is shown in Fig. 1. The curves with dots along be obtained when WSR-88D (Weather Surveil- them represent the curves along which Doppler lance Radar–1988 Doppler) measurements are velocity measurements are made. There are two made at azimuthal sampling intervals of 0.5o factors illustrated in Fig. 1 that contribute to instead of the current intervals of 1.0o. In addition, stronger mesocyclone signatures with 0.5o for signatures exceeding a particular Doppler azimuthal sampling. First, the peaks of the meas- velocity threshold, the signatures are detectable urement curve in Fig. 1b are closer to the pointed 50% farther in range using 0.5o azimuthal peaks of the “true” curve being sampled by the sampling. radar than in Fig. 1a. The peaks are closer To help substantiate the simulation results, because the radar beam has to scan only half the the National Severe Storms Laboratory’s (NSSL) distance in azimuth for 0.5o sampling and testbed WSR-88D radar (KOUN) collected high- therefore there is less smearing of the true curve. -
Air Masses , Climate, and Weather
Name: Air Masses, Climate, and Weather Meteorologists are scientists who study the weather and climate in an area. Read the article attached about meteorologists. Then, answer the questions below. 1. Why does Mars have different seasons just like Earth? 2. What type of data does a weather balloon collect? 3. What are air masses? 4. What happens if an air mass doesn’t have the same temperature and humidity as another air mass close by? 5. Imagine that you are a forensic meteorologist and have been called to testify in court. Read about the case on the next page. Should John have to pay the medical bills for the injured runner? Use your knowledge of air masses to back up your decision. Name: Air Masses, Climate, and Weather The Case of the Slippery Sidewalk John sells snow cones at a stand in the park. Every night, John cleans out his ice maker so it can make fresh ice overnight. On Saturday morning, joggers were running through the park. One of the joggers slipped on a puddle of water near John’s stand and broke their arm. The jogger wants John to pay all the medical bills. He claims the puddle of water was from his cart. John claims that there was a sudden down pour the night before, which left puddles of water outside. John claims the jogger slipped in a puddle. Should John have to pay the medical bills? Use the information below about air masses to figure out if John should have to pay the medical bills due to puddles created from his cart! Thursday: hot and dry air mass over area Friday: hot and humid air mass over area Friday night: cold air mass moves into area Saturday: cold air mass stays over area Need help? Remember that changes in air masses causes changes in weather. -
Open Reuille Christina Lostinthefog
THE PENNSYLVANIA STATE UNIVERSITY SCHREYER HONORS COLLEGE DEPARTMENT OF METEOROLOGY LOST IN THE FOG: AN ANALYSIS OF THE DISSEMINATION OF MISLEADING WEATHER INFORMATION ON SOCIAL MEDIA CHRISTINA M. REUILLE FALL 2015 A thesis submitted in partial fulfillment of the requirements for a baccalaureate degree in Meteorology with honors in Meteorology Reviewed and approved* by the following: Dr. Jon Nese Associate Head, Undergraduate Program in Meteorology Senior Lecturer in Meteorology Thesis Supervisor Dr. Yvette Richardson Associate Professor of Meteorology Honors Adviser * Signatures are on file in the Schreyer Honors College. i ABSTRACT The growing popularity of social media has created another avenue of weather communication. Social media can be a constant source of information, including weather information. However, a qualitative analysis of Facebook and Twitter shows that much of the information published confuses and scares consumers, making it ineffective communication that does more harm than good. Vague posts or posts that fail to tell the entire weather story contribute to the ineffective communication on social media platforms, especially on Twitter where posts are limited to 140 characters. By analyzing characteristics of these rogue posts, better social media practices can be deduced. Displaying credentials, explaining posts, and choosing words carefully will help make social media a more effective form of weather communication. ii TABLE OF CONTENTS LIST OF FIGURES .................................................................................................... -
Operational Marine Forecasters
Knowledge and SKill guidelineS for Marine Science and Technology Volume 5 Operational Marine Forecasters Operational Marine Forecasters and the Importance of www.marinetech.org Marine Forecasting C o n t e n t s Operational marine forecast- ers produce forecasts of the marine environment that help Page 1 operational marine Forecasters people operate more effectively and the Importance of marine Fugro GEOS, Inc Forecasting and safely in and near the Page 2: Introduction to mATe’s ocean. These forecasts predict Knowledge and Skills Guidelines many aspects of the marine Page 3: Knowledge and Skills Guidelines environment, including winds for operational marine Forecasters and waves at the ocean surface, Introduction ocean temperature, currents, Occupational Definition tides, surf, sea ice, the propaga- Overview tion of sound through the Page 4: Personal Characteristics ocean, the locations of fish and Occupational Titles marine mammals, harmful algal Page 5: Customers blooms, coastal flooding, and Page 6: Educational Backgrounds the movement of oil spills. A marine forecaster at Fugro GEOS, Inc. prepares a forecast for a client conducting operations in the North Sea. Basic Courses Marine forecasters apply Page 7: Salary Ranges ocean and atmospheric science, Resources knowledge, and skills to pro- ocean forecasters recognized the ocean, winds cause waves, Conferences duce predictions about the state that they could use the lunar ocean circulations make good Professional Societies of the ocean and marine atmo- cycle to predict the time of the feeding grounds for fish, and Page 8: Future Developments sphere. Operational marine month at which the highest earthquakes generate tsunamis. Journals high tides and lowest low tides Data from observing systems Page 9: Job Functions and Tasks forecasters deliver forecasts and would occur.