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Predicting Supercell Motion Using a New Hodograph Technique
FEBRUARY 2000 BUNKERS ET AL. 61 Predicting Supercell Motion Using a New Hodograph Technique MATTHEW J. BUNKERS* AND BRIAN A. KLIMOWSKI NOAA/NWS Weather Forecast Of®ce, Rapid City, South Dakota JON W. Z EITLER NOAA/NWS Houston/Galveston Weather Forecast Of®ce, Dickinson, Texas RICHARD L. THOMPSON NOAA/NWS Storm Prediction Center, Norman, Oklahoma MORRIS L. WEISMAN NCAR/Mesoscale and Microscale Meteorology Division, Boulder, Colorado (Manuscript received 16 December 1998, in ®nal form 13 September 1999) ABSTRACT A physically based, shear-relative, and Galilean invariant method for predicting supercell motion using a hodograph is presented. It is founded on numerous observational and modeling studies since the 1940s, which suggest a consistent pattern to supercell motion exists. Two components are assumed to be largely responsible for supercell motion: (i) advection of the storm by a representative mean wind, and (ii) propagation away from the mean wind either toward the right or toward the left of the vertical wind shearÐdue to internal supercell dynamics. Using 290 supercell hodographs, this new method is shown to be statistically superior to existing methods in predicting supercell motion for both right- and left-moving storms. Other external factors such as interaction with atmospheric boundaries and orography can have a pronounced effect on supercell motion, but these are dif®cult to quantify prior to storm development using only a hodograph. 1. Introduction some form of severe weather (i.e., tornadoes, ¯ash ¯ooding, hail $1.9 cm diameter, wind gusts $25 m s21, a. Background or wind damage) during their lifetime (e.g., Burgess and Although supercells1 have been given considerable Lemon 1991). -
Severe Local Storms Forecasting *
WEATHER AND FORECASTING VOLUME 7 Severe Local Storms Forecasting * ROBERT H. JOHNS National Severe Storms Forecast Center, Kansas City, Missouri CHARLES A. DOSWELL III National Severe Storms Laboratory, Norman, Oklahoma (Manuscript received 11 May 1992, in final form 13 August 1992) ABSTRACT Knowledge of severe local storms has been increasing rapidly in recent years as a result of both observational studies and numerical modeling experiments. This paper reviews that knowledge as it relates to development of new applications for forecasting of severe local storms. Many of these new applications are based on physical understanding of processes taking place on the storm scale and thus allow forecasters to become less dependent on empirical relationships. Refinements in pattern recognition and severe weather climatology continue to be of value to the operational severe local storms forecasters, however. Current methodology for forecasting severe local storms at the National Severe Storms Forecast Center is described. Operational uses of new forecast applications, new “real-time” data sources (such as wind profilers and Doppler radars), and improved numerical model products are discussed. 1. Introduction first part of this forecasting process, focusing on the relationship between the severe local storm and its Convective storms produce a wide variety of weather environment. Since the primary forecast product of SELS phenomena that might be considered “severe” (a hazard is the severe weather watch (see Ostby 1993 for a complete to life and property). For purposes of this discussion, description of SELS forecast products), that is the primary however, only those convectively induced phenomena topic within this paper. Other SELS forecast products will forecast by the Severe Local Storms Unit (SELS) of the be mentioned as well, however. -
PRESIDENT'smessage NWA's 26Th ANNUAL MEETING ANNUAL
NWA NEWSLETTER No. 01-08, 09 Aug-Sep 2001 PRESIDENT’S MESSAGE things and meet new people. We have a great agenda with many interesting and thought provoking A National Tragedy presentations. Nevertheless, we realize that plans can While the tragic events of 11 September 2001 in change and people have different ways of dealing America were not meteorological in nature they with events. Institutional, organizational and affect all of us and our friends and countrymen in a corporate decisions may also lead to changes in travel most profound way. Many of our friends, fellow plans citizens, and perhaps even members’ families have All presenters — Please let me know as soon as suffered or died at the hands of terrorism. Who can possible if your plans change and you are unable to imagine what is in the minds of those that would do attend or have to change your presentation time. such evil acts? I believe that peace will eventually Please be sure to monitor the NWA Web site for the rise from the rubble and from so many innocent latest agenda. Your current date and time for deaths. We are embarking on a long national journey presenting will not change unless I coordinate with of suffering and healing and hopefully great you ahead of time. punishment for those who have done this. I request The WestCoast Ridpath hotel still has rooms at the that each of us make those victims, their families, the National Weather Association Conference discount rescuers and cleanup crews, and our country and its rates. If you haven't reserved a room yet, please do welfare, economic and otherwise, subjects of our so soonest by calling 1-800-325-4000. -
Storm Fury on the Plains Spring Spotter Newsletter P a G E 3
N a t i o n a l Weather Service Storm Fury on the Wichita, KS Inside this issue: Plains Historic 1 Spring Spotter Newsletter A p r i l 2 0 1 3 Snowstorm Buries central and Historic Snowstorm Buries Central and south central Kansas South Central Kansas Annual 4 By: Eric Schminke Tornado Winter 2012-13 had been relatively quiet for central, south central and southeast Information Kansas until February 20th when Old Man Winter and his mythical sidekick, the Meet Jim 6 Abominable Snowman, went into action. Caruso That morning, a strengthening cyclone (Red L in Figure 1) was situated over Fire Weather 7 southern Utah, and Nevada. Information As the day progressed, the winter storm moved slowly east toward then over the Do you know 9 southern Rockies. As time evolved, moisture-rich east southeast flow in the why the lower atmosphere steadily increased, spreading colder, sub-freezing air across sirens sound the Great Plains. As the upper-level cyclone moved east over southern Arizona in your the upper-level directional flow began to diverge over the Central Plains to pro- community? mote increasing deep layer ascent over Oklahoma and southern Kansas. The stage had been set for a winter storm that would prove historic for most of Kan- Despite 10 Recent sas. Precipita- South central Kansas was the first to get snowed upon with 2-4 inch accumula- tion, Drought tions over primarily Harper, Kingman, Sumner, and Sedgwick counties. By late Continues afternoon, the snow had spread due north Winter 15 2012-2013 primarily along and Highlights west of I-135 where accumulations had Severe 18 reached 5 inches in Weather Reporting several locations.