How to Effectively Use Weather Radar
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NEWSLETTER National Weather Association No
NEWSLETTER National Weather Association No. 10 – 12 December 2010 Tracking the Storms the PLOWS Way Adverse road conditions as- sociated with winter storms are re- sponsible for a large portion of the nearly 7000 deaths, 600,000 inju- Inside This Edition ries and 1 4. million accidents that occur in the United States each Internet Based GIS year . Improving cool season quan- Remote Sensing and Storm titative precipitation forecasting Chasing . .2 depends largely on developing a greater understanding of the me- President’s Message . .3 soscale structure and dynamics of cyclonic weather systems . The Pro- This C-130 Hercules Aircraft flies PLOWS missions. New Learning Opportunities filing of Winter Storms (PLOWS) project is aimed at doing just that. During the 2008- from the EJOM . 4. 2009 and 2009-2010 winter seasons, the University of Illinois (UI), the University of Alabama at Huntsville (UAH) and the University of Missouri (UM) placed teams of Scholarship Fundraising . 4. researchers in the field to study winter cyclones across the Midwestern United States NWA on Twitter and Facebook . .5 as part of the PLOWS project . PLOWS was designed to be a comprehensive field campaign, with complementary National Academy of Sciences to numerical modeling studies, that will address outstanding scientific questions targeted Study NWS . .7 at improving our understanding of precipitation substructures in the northwest and warm frontal quadrants of continental extratropical cyclones. The field strategy Professional Development was designed to answer questions about the mesoscale structure of winter storms Opportunities . .7 including: • What are the predominant spatial patterns of organized precipitation NWA Mission and Vision substructures, such as bands and generating cells, in these quadrants and how Statements . -
Avoiding the Risks of Deadly Lightning Strikes
Avoiding the Risks of Deadly Lightning Strikes Lightning is one of the most underrated severe weather hazards, yet ranks as the second-leading weather killer in the United States. More deadly than hurricanes or tornadoes, lightning strikes in America each year kill an average of 73 people and injure 300 others, according to NOAA's National Weather Service. How Lightning Works Lightning is caused by the attraction between positive and negative charges in the atmosphere, resulting in the buildup and discharge of electrical energy. This rapid heating and cooling of the air produces the shock wave that results in thunder. During a storm, raindrops can acquire extra electrons, which are negatively charged. These surplus electrons seek out a positive charge from the ground. As they flow from the clouds, they knock other electrons free, creating a conductive path. This path follows a zigzag shape that jumps between randomly distributed clumps of charged particles in the air. When the two charges connect, current surges through that jagged path, creating the lightning bolt. The Warning Signs High winds, rainfall, and a darkening cloud cover are the warning signs for possible cloud-to- ground lightning strikes. While many lightning casualties happen at the beginning of an approaching storm, more than 50 percent of lightning deaths occur after the thunderstorm has passed. The lightning threat diminishes after the last sound of thunder, but may persist for more than 30 minutes. When thunderstorms are in the area, but not overhead, the lightning threat can exist when skies are clear. Safety Precautions While nothing offers absolute safety from lightning, some actions can greatly reduce your risks. -
Chapter-5 Doppler Effect
Chapter-5 Doppler Effect Stationary source Stationary observer Moving source Stationary observer Stationary source Moving observer Moving source Moving observer http://www.astro.ubc.ca/~scharein/a311/Sim/doppler/Doppler.html Doppler Effect The Doppler effect is the apparent change in the frequency of a wave motion when there is relative motion between the source of the waves and the observer. The apparent change in frequency f experienced as a result of the Doppler effect is known as the Doppler shift. The value of the Doppler shift increases as the relative velocity v between the source and the observer increases. The Doppler effect applies to all forms of waves. Doppler Effect (Moving Source) http://www.absorblearning.com/advancedphysics/demo/units/040103.html Suppose the source moves at a steady velocity vs towards a stationary observer. The source emits sound wave with frequency f. From the diagram, we can see that the distance between crests is shortened such that ' vs Since = c/f and = 1/f, We get c c v s f ' f f c vs f ' ( ) f c vs Doppler Effect (Moving Observer) Consider an observer moving with velocity vo toward a stationary source S. The source emits a sound wave with frequency f and wavelength = c/f. The velocity of the sound wave relative to the observer is c + vo. c Doppler Shift Consider a source moving towards an observer, the Doppler shift f is c f f ' f ( ) f f c vs f v s f c v s f v If v <<c, then we get s s f c The above equation also applies to a receding source, with vs taking as negative. -
A Real-Time System to Estimate Weather Conditions at High Resolution
12.1 A Real-Time System to Estimate Weather Conditions at High Resolution Peter P. Neilley1 Weather Services International, Inc. Andover, MA 01810 And Bruce L. Rose The Weather Channel Atlanta, GA the earth’s surface (the so-called current 1. Introduction1 conditions). b) We do not necessarily produce weather The purpose of this paper is to describe an observations on a regular grid, but at an operational system used to estimate current irregular set of arbitrary locations or points weather conditions at arbitrary places in real- that are relevant to the consumers of the time. The system, known as High Resolution information. Assimilation of Data (or HiRAD), is designed to generate synthetic weather observations in a c) In addition to producing quantitative manner equivalent in scope, timeliness and observational elements (e.g. temperature, quality to a arbitrarily dense physical observing pressure and wind speed) our system network. Our approach is, first, to collect produces common, descriptive terminology information from a variety of relevant sources of the sensible weather such as including gridded analyses, traditional surface “Thundershowers”, “Patchy Fog”, and weather reports, radar, satellite and lightning “Snow Flurries”. observations. Then we continuously synthesize these data into weather condition estimates at d) We do not strive to produce a state of the prescribed locations. An operational system atmosphere optimized for fidelity with based on this approach has been built and is Numerical Weather Prediction (NWP) commercially deployed in the United States. models. Instead, the system is optimized to produce the most accurate estimate of the In most regards, our approach is analogous to observed state at the surface that can be modern data assimilation techniques. -
Polarimetric Radar Characteristics of Tornadogenesis Failure in Supercell Thunderstorms
atmosphere Article Polarimetric Radar Characteristics of Tornadogenesis Failure in Supercell Thunderstorms Matthew Van Den Broeke Department of Earth and Atmospheric Sciences, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; [email protected] Abstract: Many nontornadic supercell storms have times when they appear to be moving toward tornadogenesis, including the development of a strong low-level vortex, but never end up producing a tornado. These tornadogenesis failure (TGF) episodes can be a substantial challenge to operational meteorologists. In this study, a sample of 32 pre-tornadic and 36 pre-TGF supercells is examined in the 30 min pre-tornadogenesis or pre-TGF period to explore the feasibility of using polarimetric radar metrics to highlight storms with larger tornadogenesis potential in the near-term. Overall the results indicate few strong distinguishers of pre-tornadic storms. Differential reflectivity (ZDR) arc size and intensity were the most promising metrics examined, with ZDR arc size potentially exhibiting large enough differences between the two storm subsets to be operationally useful. Change in the radar metrics leading up to tornadogenesis or TGF did not exhibit large differences, though most findings were consistent with hypotheses based on prior findings in the literature. Keywords: supercell; nowcasting; tornadogenesis failure; polarimetric radar Citation: Van Den Broeke, M. 1. Introduction Polarimetric Radar Characteristics of Supercell thunderstorms produce most strong tornadoes in North America, moti- Tornadogenesis Failure in Supercell vating study of their radar signatures for the benefit of the operational and research Thunderstorms. Atmosphere 2021, 12, communities. Since the polarimetric upgrade to the national radar network of the United 581. https://doi.org/ States (2011–2013), polarimetric radar signatures of these storms have become well-known, 10.3390/atmos12050581 e.g., [1–5], and many others. -
AMOFSG/10-Sod 19/6/13
AMOFSG/10-SoD 19/6/13 AERODROME METEOROLOGICAL OBSERVATION AND FORECAST STUDY GROUP (AMOFSG) TENTH MEETING Montréal, 17 to 19 June 2013 SUMMARY OF DISCUSSIONS 1. HISTORICAL 1.1 The tenth meeting of the Aerodrome Meteorological Observation and Forecast Study Group (AMOFSG) was held at the Headquarters of the International Civil Aviation Organization (ICAO) in Montréal, Canada, 17 to 19 June 2013. 1.2 The meeting was opened by Mr. Greg Brock, Chief of the Meteorology Section of the Air Navigation Bureau of ICAO, who extended a warm welcome to all the participants. Mr. Brock emphasized that this tenth meeting of the AMOFSG was likely to be the last of the group prior to the convening of an ICAO Meteorology (MET) Divisional Meeting in July 2014, to be held in part conjointly with the Fifteenth Session of the World Meteorological Organization (WMO) Commission for Aeronautical Meteorology (CAeM-XV). For this reason, Mr. Brock underlined the need for the group to work efficiently during its three days of deliberations, with a strong emphasis placed on determining whether proposals arising from each of the topics to be addressed were of sufficient maturity so as to reduce or eliminate entirely the need for significant further work and/or a meeting ahead of the MET Divisional Meeting. 1.3 The names and contact details of the participants are listed in Appendix A . Mr. Bill Maynard was elected Chairman of the meeting. The meeting was served by the Acting Secretary of the AMOFSG, Mr. Greg Brock, Chief, Meteorology Section. 1.4 The meeting considered the following agenda items: Agenda Item 1: Opening of the meeting; Agenda Item 2: Election of Chairman; Agenda Item 3: Adoption of working arrangements; Agenda Item 4: Adoption of the agenda; (41 pages) AMOFSG.10.SoD.en.docx AMOFSG/10-SoD - 2 - Agenda Item 5: Aerodrome observations; Agenda Item 6: Forecasting at the aerodrome and in the terminal area and ATIS requirements; Agenda Item 7: Deliverables; Agenda Item 8: Any other business; and Agenda Item 9: Closure of the meeting. -
Soaring Weather
Chapter 16 SOARING WEATHER While horse racing may be the "Sport of Kings," of the craft depends on the weather and the skill soaring may be considered the "King of Sports." of the pilot. Forward thrust comes from gliding Soaring bears the relationship to flying that sailing downward relative to the air the same as thrust bears to power boating. Soaring has made notable is developed in a power-off glide by a conven contributions to meteorology. For example, soar tional aircraft. Therefore, to gain or maintain ing pilots have probed thunderstorms and moun altitude, the soaring pilot must rely on upward tain waves with findings that have made flying motion of the air. safer for all pilots. However, soaring is primarily To a sailplane pilot, "lift" means the rate of recreational. climb he can achieve in an up-current, while "sink" A sailplane must have auxiliary power to be denotes his rate of descent in a downdraft or in come airborne such as a winch, a ground tow, or neutral air. "Zero sink" means that upward cur a tow by a powered aircraft. Once the sailcraft is rents are just strong enough to enable him to hold airborne and the tow cable released, performance altitude but not to climb. Sailplanes are highly 171 r efficient machines; a sink rate of a mere 2 feet per second. There is no point in trying to soar until second provides an airspeed of about 40 knots, and weather conditions favor vertical speeds greater a sink rate of 6 feet per second gives an airspeed than the minimum sink rate of the aircraft. -
Fire W Eather
Fire Weather Fire Weather Fire weather depends on a combination of wildland fuels and surface weather conditions. Dead and live fuels are assessed weekly from a satellite that determines the greenness of the landscape. Surface weather conditions are monitored every 5-minutes from the Oklahoma Mesonet. This fire weather help page highlights the surface weather ingredients to monitor before wildfires and also includes several products to monitor once wildfires are underway. Fire Weather Ingredients: WRAP While the presence of wildland fuels is one necessary component for wildfires, weather conditions ultimately dictate whether or not a day is primed for wildfires to occur. There are four key fire weather ingredients and they include: high Winds, low Relative humidity, high Air temperature, and no/minimal recent Precipitation (WRAP). High Winds are the second most critical weather ingredient for wildfires. In general, winds of 20 mph or greater 20+ mph winds increase spot fires and make for most of the containment considerably more difficult. state Low Relative humidity is the most 30-40+ critical weather ingredient for wildfires mph winds and is most common in the afternoon when the air temperature is at its warmest. When relative humidity is at or below 20% extreme fire behavior can result and spot fires become freQuent. Watch out for areas of 20% or below relative humidity and 20 mph or higher winds à 20/20 rule! Extremely low relative humidity Warm Air temperatures are another values key weather ingredient for wildfires as warming can lower the relative humidity, reduce moisture for smaller dead fuels, and bring fuels closer to their ignition point. -
Weather Charts Natural History Museum of Utah – Nature Unleashed Stefan Brems
Weather Charts Natural History Museum of Utah – Nature Unleashed Stefan Brems Across the world, many different charts of different formats are used by different governments. These charts can be anything from a simple prognostic chart, used to convey weather forecasts in a simple to read visual manner to the much more complex Wind and Temperature charts used by meteorologists and pilots to determine current and forecast weather conditions at high altitudes. When used properly these charts can be the key to accurately determining the weather conditions in the near future. This Write-Up will provide a brief introduction to several common types of charts. Prognostic Charts To the untrained eye, this chart looks like a strange piece of modern art that an angry mathematician scribbled numbers on. However, this chart is an extremely important resource when evaluating the movement of weather fronts and pressure areas. Fronts Depicted on the chart are weather front combined into four categories; Warm Fronts, Cold Fronts, Stationary Fronts and Occluded Fronts. Warm fronts are depicted by red line with red semi-circles covering one edge. The front movement is indicated by the direction the semi- circles are pointing. The front follows the Semi-Circles. Since the example above has the semi-circles on the top, the front would be indicated as moving up. Cold fronts are depicted as a blue line with blue triangles along one side. Like warm fronts, the direction in which the blue triangles are pointing dictates the direction of the cold front. Stationary fronts are frontal systems which have stalled and are no longer moving. -
The Montague Doppler Radar, an Overview June 2018
ISSUE PAPER SERIES The Montague Doppler Radar, An Overview June 2018 NEW YORK STATE TUG HILL COMMISSION DULLES STATE OFFICE BUILDING · 317 WASHINGTON STREET · WATERTOWN, NY 13601 · (315) 785-2380 · WWW.TUGHILL.ORG The Tug Hill Commission Technical and Issue Paper Series are designed to help local officials and citizens in the Tug Hill region and other rural parts of New York State. The Tech- nical Paper Series provides guidance on procedures based on questions frequently received by the Commis- sion. The Issue Paper Series pro- vides background on key issues facing the region without taking advocacy positions. Other papers in each se- ries are available from the Tug Hill Commission. Please call us or vis- it our website for more information. The Montague Doppler Weather Radar, An Overview Table of Contents Introduction .................................................................................................................................................. 1 Who owns the Montague radar? ................................................................................................................. 1 Who uses the Montague radar? .................................................................................................................. 1 How does the radar system work? .............................................................................................................. 2 How does the radar predict lake-effect snowstorms? ................................................................................ 2 How does the -
90001602.Pdf
Kobe University Repository : Kernel タイトル Prediction of human thermophysiological responses during shower Title bathing 著者 Abdul, Munir / Takada, Satoru / Matsushita, Takayuki / Kubo, Hiroko Author(s) 掲載誌・巻号・ページ International Journal of Biometeorology,54(2):165-178 Citation 刊行日 2010-03 Issue date 資源タイプ Journal Article / 学術雑誌論文 Resource Type 版区分 author Resource Version 権利 Rights DOI 10.1007/s00484-009-0265-9 JaLCDOI URL http://www.lib.kobe-u.ac.jp/handle_kernel/90001602 PDF issue: 2021-09-29 PREDICTION OF HUMAN THERMOPHYSIOLOGICAL RESPONSES DURING SHOWER BATHING Abdul Munir Department of Architecture, Faculty of Engineering, Syiah Kuala University, Darussalam, Banda Aceh 23111, Indonesia Satoru Takada Department of Architecture, Graduate School of Engineering, Kobe University, Rokko, Nada, Kobe 657-8501, Japan Phone: +81 78 803 6038 Fax: +81 78 803 6038 Email: [email protected] Takayuki Matsushita Department of Architecture, Graduate School of Engineering, Kobe University, Rokko, Nada, Kobe 657-8501, Japan Hiroko Kubo Department of Environmental Health, Faculty of Human Life and Environment, Nara Women's University, Kitauoya-nishimachi, Nara 630-8506, Japan ABSTRACT This study develops a model to predict the thermophysiological response of the human body during shower bathing. Despite the needs for the quantitative evaluation of human body response during bathing for thermal comfort and safety, the complicated mechanisms of heat transfer at the skin surface, especially 1 during shower bathing, have disturbed the development of adequate models. In this study, an initial modeling approach is proposed by developing a simple heat transfer model at the skin surface during shower bathing, applied to Stolwijk’s human thermal model. -
Aerodrome Actual Weather – METAR Decode
Aerodrome Actual Weather – METAR decode Code element Example Decode Notes 1 Identification METAR — Meteorological Airfield Report, SPECI — selected special (not from UK civil METAR or SPECI METAR METAR aerodromes) Location indicator EGLL London Heathrow Station four-letter indicator 'ten twenty Zulu on the Date/Time 291020Z 29th' AUTO Metars will only be disseminated when an aerodrome is closed or at H24 aerodromes, A fully automated where the accredited met. observer is on duty break overnight. Users are reminded that reports AUTO report with no human of visibility, present weather and cloud from automated systems should be treated with caution intervention due to the limitations of the sensors themselves and the spatial area sampled by the sensors. 2 Wind 'three one zero Wind degrees, fifteen knots, Max only given if >= 10KT greater than the mean. VRB = variable. 00000KT = calm. 31015G27KT direction/speed max twenty seven Wind direction is given in degrees true. knots' 'varying between two Extreme direction 280V350 eight zero and three Variation given in clockwise direction, but only when mean speed is greater than 3 KT. variance five zero degrees' 3 Visibility 'three thousand two Prevailing visibility 3200 0000 = 'less than 50 metres' 9999 = 'ten kilometres or more'. No direction is required. hundred metres' Minimum visibility 'Twelve hundred The minimum visibility is also included alongside the prevailing visibility when the visibility in one (in addition to the 1200SW metres to the south- direction, which is not the prevailing visibility, is less than 1500 metres or less than 50% of the prevailing visibility west' prevailing visibility. A direction is also added as one of the eight points of the compass.