Meteorology Commons^™

Editorial: Special Issue: Safety & Efficiency Of Civil Aviation: Selected Papers From The World Conferences Of The Air Transport Research Society And The World Conference On Transport Society - 2013, Paul Hooper, Ian Douglas, Chunyan Yu, Stefano Paleari

Chunyan Yu

The Air Transport Research Society (ATRS) is a Special Interest Group (SIG) of the World Conference on Transport Research Society (WCTRS). The ATRS annual World Conference was held at the University of Bergamo, Bergamo, Italy on 26-29 June 2013 and it attracted 266 papers from 37 countries. Also, the WCTRS triennial World Conference was held on 15- 18 July at Rio de Janeiro, Brazil, during which the ATRS organised several sessions devoted to air transport topics. This special issue of the Journal of Air Transport Studies has drawn upon all of this material to present four papers that promote improvements …

General Aviation Weather Encounter Case Studies, John M. Lanicci, Massoud Bazargan, Daniel Halperin, Scott Shappell, Jaclyn Baron, Rebecca Iden, Carla Hackworth, Kali Holcomb

Scott Shappell

This study presents a compilation of 24 cases involving general aviation (GA) pilots’ weather encounters over the continental U.S. The project team interviewed pilots who had experienced a weather encounter, and we examined their backgrounds, flight experience, and weather encounter details. Results from meteorological data analysis for each weather encounter were consistent with findings of larger GA weather accident studies in terms of the types of hazards encountered and flight phase during which the encounters occurred. Investigation of pilot weather products and the sources from which they were obtained revealed a lack of uniformity of pre-flight data sources and underutilization …

Synoptic-Scale Environments Conducive To Orographic Impacts On Cold-Season Surface Wind Regimes At Montreal, Quebec, Alissa Razy, Shawn M. Milrad, Eyad H, Atallah, John R. Gyakum

Shawn M. Milrad

Orographic wind channeling, defined as dynamically and thermally induced processes that force wind to blow along the axis of a valley, is a common occurrence along the St. Lawrence River Valley (SLRV) in Quebec, Canada, and produces substantial observed weather impacts at stations along the valley, including Montreal (CYUL). Cold-season observed north-northeast (n = 55) and south-southeast (n = 16) surface wind events at CYUL are identified from 1979 to 2002. The authors partition the north-northeast wind events into four groups using manual synoptic typing. Types A and D (“inland cyclone” and “northwestern cyclone”) are associated with strong lower-tropospheric geostrophic …

Synoptic-Scale Analysis Of Freezing Rain Events In Montreal, Quebec, Canada, Gina M. Ressler, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum

Shawn M. Milrad

Freezing rain is a major environmental hazard that is especially common along the St. Lawrence River valley (SLRV) in southern Quebec, Canada. For large cities such as Montreal, severe events can have a devastating effect on people, property, and commerce. In this study, a composite analysis of 46 long-duration events for the period 1979–2008 is presented to identify key synoptic-scale structures and precursors of Montreal freezing rain events. Based on the observed structures of the 500-hPa heights, these events are manually partitioned into three types—west, central, and east—depending on the location and tilt of the 500-hPa trough axis. West events …

Synoptic Typing Of Extreme Cool-Season Precipitation Events At St. John's, Newfoundland, 1979-2005, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum

Shawn M. Milrad

Quantitative precipitation forecasting (QPF) continues to be a significant challenge in operational forecasting, particularly in regions susceptible to extreme precipitation events. St. John’s, Newfoundland, Canada (CYYT), is affected frequently by such events, particularly in the cool season (October–April).

The 50 median events in the extreme (>33.78 mm during a 48-h period) precipitation event category are selected for further analysis. A manual synoptic typing is performed on these 50 events, using two separate methodologies to partition events. The first method utilizes a Lagrangian backward air parcel trajectory analysis and the second method utilizes the evolution of dynamically relevant variables, including …

Synoptic-Scale Characteristics And Precursors Of Cool-Season Precipitation Events At St. John's, Newfoundland, 1979-2005, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum

Shawn M. Milrad

The issue of quantitative precipitation forecasting continues to be a significant challenge in operational forecasting, particularly in regions susceptible to frequent and extreme precipitation events. St. John’s, Newfoundland, Canada, is one location affected frequently by such events, particularly in the cool season (October–April). These events can include flooding rains, paralyzing snowfall, and damaging winds.

A precipitation climatology is developed at St. John’s for 1979–2005, based on discrete precipitation events occurring over a time period of up to 48 h. Threshold amounts for three categories of precipitation events (extreme, moderate, and light) are statistically derived and utilized to categorize such events. …

Synoptic-Scale Precursors, Characteristics And Typing Of Nocturnal Mesoscale Convective Complexes In The Great Plains, Shawn M. Milrad, Cailee M. Kelly

Shawn M. Milrad

Mesoscale convective complexes (MCCs) occur frequently during the warm season in the central U.S. and can produce flooding rains, hail and tornadoes. Previous work has found that the synoptic-scale environment can greatly affect, and be affected by, the development and maintenance of MCCs. Ninetytwo MCC cases from 2006–2011 are manually identified using infrared satellite imagery and partitioned into three types (upstream trough, zonal and ridge) using a unique manual synoptic typing based on 500- hPa height patterns. Upstream trough cases feature an amplified longwave 500-hPa trough upstream of the MCC genesis region (GR), while the 500-hPa flow is relatively flat …

The Extratropical Transition Of Tropical Cyclones. Part I: Cyclonic Evolution And Direct Impacts, Clark Evans, Kimberly M. Wood, Sim D. Aberson, Heather M. Archambault, Shawn M. Milrad, Lance F. Bosart, Et Al.

Shawn M. Milrad

Extratropical transition (ET) is the process by which a tropical cyclone, upon encountering a baroclinic environment and reduced sea surface temperature at higher latitudes, transforms into an extratropical cyclone. This process is influenced by, and influences, phenomena from the tropics to the midlatitudes and from the meso- to the planetary scales to extents that vary between individual events. Motivated in part by recent high-impact and/or extensively observed events such as North Atlantic Hurricane Sandy in 2012 and western North Pacific Typhoon Sinlaku in 2008, this review details advances in understanding and predicting ET since the publication of an earlier review …

Mobile Radar As An Undergraduate Education And Research Tool: The Erau C-Breese Field Experience With The Doppler On Wheels, Shawn M. Milrad, Christopher G. Herbster

Shawn M. Milrad

Embry-Riddle Aeronautical University Convective-Boundary Research Engaging Educational Student Experiences (ERAU C-BREESE) was an 18-day National Science Foundation (NSF)-funded educational Doppler on Wheels (DOW) deployment through the Center for Severe Weather Research in May 2015. ERAU C-BREESE had three primary areas of focus: meteorological field observations and research, undergraduate experiential learning, and local community outreach. ERAU undergraduate meteorology students had the unique opportunity to forecast for, collect, and analyze field measurements of sea-breeze processes and convection. The scientific objectives of ERAU C-BREESE were to forecast, observe, and analyze central Florida sea-breeze processes and thunderstorms by combining a DOW with more traditional …

Synoptic Typing And Precursors Of Heavy Warm-Season Precipitation Events At Montreal, Québec, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum, Giselle Dookhie

Shawn M. Milrad

A precipitation climatology is compiled for warm-season events at Montreal, Québec, Canada, using 6-h precipitation data. A total of 1663 events are recorded and partitioned into three intensity categories (heavy, moderate, and light), based on percentile ranges. Heavy (top 10%) precipitation events (n = 166) are partitioned into four types, using a unique manual synoptic typing based on the divergence of Q-vector components. Type A is related to cyclones and strong synoptic-scale quasigeostrophic (QG) forcing for ascent, with high-θe air being advected into the Montreal region from the south. Types B and C are dominated by frontogenesis (mesoscale QG forcing …

On The Dynamics, Thermodynamics, And Forecast Model Evaluation Of Two Snow-Burst Events In Southern Alberta, Shawn M. Milrad, John R. Gyakum, Kelly Lombardo, Eyad H. Atallah

Shawn M. Milrad

Two high-impact convective snowband events (‘‘snow bursts’’) that affected Calgary, Alberta, Canada, are examined to better understand the dynamics and thermodynamics of heavy snowbands not associated with lake effects or the cold conveyor belt of synoptic-scale cyclones. Such events are typically characterized by brief, but heavy, periods of snow; low visibilities; and substantial hazards to automobile and aviation interests. Previous literature on these events has been limited to a few case studies across North America, including near the leeside foothills of the U.S. Rockies. The large-scale dynamics and thermodynamics are investigated using the National Centers for Environmental Prediction (NCEP) North …

Precipitation Modulation By The Saint Lawrence River Valley In Association With Transitioning Tropical Cyclones, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum

Shawn M. Milrad

The St. Lawrence River valley (SLRV) is an important orographic feature in eastern Canada that can affect surface wind patterns and contribute to locally higher amounts of precipitation. The impact of the SLRV on precipitation distributions associated with transitioning, or transitioned, tropical cyclones that approached the region is assessed. Such cases can result in heavy precipitation during the warm season, as during the transition of Hurricane Ike (2008). Thirty-eight tropical cyclones tracked within 500 km of the SLRV from 1979 to 2011. Utilizing the National Centers for Environmental Prediction (NCEP) North American Regional Reanalysis (NARR), 19 of the 38 cases …

A Diagnostic Examination Of Consecutive Extreme Cool-Season Precipitation Events At St. John's, Newfoundland, In December 2008, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum

Shawn M. Milrad

St. John’s, Newfoundland, Canada (CYYT), is frequently affected by extreme precipitation events, particularly in the cool season (October–April). Previous work classified precipitation events at CYYT into categories by precipitation amount and a manual synoptic typing was performed on the 50 median extreme precipitation events, using two separate methods. Here, consecutive extreme precipitation events in December 2008 are analyzed. These events occurred over a 6-day period and produced over 125 mm of precipitation at CYYT. The first manual typing method, using a backward-trajectory analysis, results in both events being classified as “southwest,” which were previously defined as the majority of the …

A Meteorological Analysis Of The 2013 Alberta Flood: Antecendent Large-Scale Flow Pattern And Synoptic-Dynamic Characteristics, Shawn M. Milrad, John R. Gyakum, Eyad H. Atallah

Shawn M. Milrad

The 19–21 June 2013 Alberta flood was the costliest (CAD $6 billion) natural disaster in Canadian history. The flood was caused by a combination of above-normal spring snowmelt in the Canadian Rockies, large antecedent precipitation, and an extreme rainfall event on 19–21 June that produced rainfall totals of 76 mm in Calgary and 91 mm in the foothills. As is typical of flash floods along the Front Range of the Rocky Mountains, rapidly rising streamflow proceeded to move downhill (eastward) into Calgary.

A meteorological analysis traces an antecedent Rossby wave train across the North Pacific Ocean, starting with intense baroclinic …

A Diagnostic Examination Of The Eastern Ontario And Western Quebec Wintertime Convection Event Of 28 January 2010, Shawn M. Milrad, John R. Gyakum, Eyad H. Atallah, Jennifer F. Smith

Shawn M. Milrad

The priority of an operational forecast center is to issue watches, warnings, and advisories to notify the public about the inherent risks and dangers of a particular event. Occasionally, events occur that do not meet advisory or warning criteria, but still have a substantial impact on human life and property. Short-lived snow bursts are a prime example of such a phenomenon. While these events are typically characterized by small snow accumulations, they often cause very low visibilities and rapidly deteriorating road conditions, both of which are a major hazard to motorists. On the afternoon of 28 January 2010, two such …

Dynamical And Precipitation Structures Of Poleward-Moving Tropical Cyclones In Eastern Canada, 1979-2005, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum

Shawn M. Milrad

Tropical cyclones in the western North Atlantic basin are a persistent threat to human interests along the east coast of North America. Occurring mainly during the late summer and early autumn, these storms often cause strong winds and extreme rainfall and can have a large impact on the weather of eastern Canada. From 1979 to 2005, 40 named (by the National Hurricane Center) tropical cyclones tracked over eastern Canada. Based on the time tendency of the low-level (850–700 hPa) vorticity, the storms are partitioned into two groups: ‘‘intensifying’’ and ‘‘decaying.’’ The 16 intensifying and 12 decaying cases are then analyzed …

A Meteorological Analysis Of Important Contributions To The 1999-2005 Canadian Prairie Drought, Lisa M. Hryciw, Eyad H. Atallah, Shawn M. Milrad, John R. Gyakum

Shawn M. Milrad

Drought is a complex natural hazard that is endemic to the Canadian prairies. The 1999–2005 Canadian prairie drought, which had great socioeconomic impacts, was meteorologically unique in that it did not conform to the traditional persistent positive Pacific–North American (PNA) pattern and west coast ridging paradigm normally associated with prairie drought. The purpose of this study is to diagnose the unique synoptic-scale mechanisms responsible for modulating subsidence during this drought. Using 30-day running means of the percent of normal precipitation from station data, key severe dry periods during 1999–2005 are identified. Analysis of the mean fields from reanalysis data shows …

A Thermodynamic Analysis Of An Intense North American Arctic Air Mass, Jessica K. Turner, John Gyakum, Shawn M. Milrad

Shawn M. Milrad

Northwestern Canada is a genesis region of arctic air masses often considered to be formed primarily through radiative processes. However, the details of their life cycle are poorly understood. This paper examines the formation, maintenance, and dissipation of an intense and long-lived arctic air mass, using a thermodynamic budget analysis.

The airmass formation is characterized by a deep-layer, multistage process that begins with snow falling into a nascent air mass. Radiative cooling from cloud tops begins the process. After the snow abates and clear skies are observed, the surface temperature drops rapidly, aided by the high emissivity of fresh snow …

Ctle - Meteorological Sensors Incorporated Into A Uas For Pedagogical Purposes, David Ehrensperger, James Curtis, Dorothea Ivanova, Mark Sinclair, Jacqueline R. Luedtke, Tim Holt, Jennah Perry, Johnny L. Young, Nicholas E. Harris

David Ehrensperger

Drought Impacts On Soil Fertility Management, John E. Sawyer

John E. Sawyer

If crop production was severely reduced because of dry conditions this year, there are a few items you can consider when planning for next year's crop. One, with severely damaged crops and low yields you might credit some of the phosphorus (P) and potassium (K) applied for this year's crop to next year, as much less removal will occur in grain harvest of the lower than expected yield.

Revisiting 3d Stereo Satellite Image Displays, Frederick R. Mosher

Frederick R. Mosher

Over 30 years ago, there were a number of development efforts to display 3D stereo satellite images and associated weather. Dr. Fritz Hasler showed how the GOES-east and west satellites could be remapped to generate true stereo pairs for obtaining cloud heights and he also showed how artificial stereo images could be generated using derived IR cloud heights to generate parallax shifts for the visible or infrared images. While there was a flurry of interest in the 1980s, the techniques had largely fallen from routine usage until recently. However, technology advances in both satellites and display technology has allowed for …

Revisiting 3d Stereo Satellite Image Displays, Frederick R. Mosher

Frederick R. Mosher

Over 30 years ago, there were a number of development efforts to display 3D stereo satellite images and associated weather. Dr. Fritz Hasler showed how the GOES-east and west satellites could be remapped to generate true stereo pairs for obtaining cloud heights and he also showed how artificial stereo images could be generated using derived IR cloud heights to generate parallax shifts for the visible or infrared images. While there was a flurry of interest in the 1980s, the techniques had largely fallen from routine usage until recently. However, technology advances in both satellites and display technology has allowed for …

Revisiting 3d Stereo Satellite Image Displays, Frederick R. Mosher

Frederick R. Mosher

Over 30 years ago, there were a number of development efforts to display 3D stereo satellite images and associated weather. Dr. Fritz Hasler showed how the GOES-east and west satellites could be remapped to generate true stereo pairs for obtaining cloud heights and he also showed how artificial stereo images could be generated using derived IR cloud heights to generate parallax shifts for the visible or infrared images. While there was a flurry of interest in the 1980s, the techniques had largely fallen from routine usage until recently. However, technology advances in both satellites and display technology has allowed for …

Horizontal Phase Speed Distribution Of Gravity Waves Observed In Mesospheric Temperature Maps, Ahmad Talaei, Mike Taylor, Pierre-Dominique Pautet, Yucheng Zhao, Takashi S. Matsuda, Takuji Nakamura

Ahmad Talaei

The goal of the current work is to develop a method suitable for analyzing the horizontal phase speeds of atmospheric gravity waves from an extensive amount of gravity wave data obtained by the USU Advanced Mesospheric Temperature Mapper (AMTM) from Logan, Utah and South Pole, Antarctica. AMTM is a novel infrared digital imaging system that measures selected emission lines in the mesospheric OH (3,1) band to create intensity and temperature maps of the mesosphere. This analysis builds on the recent work by Matsuda et al. using all-sky (180° field-of-view) intensity data to investigate the gravity waves horizontal phase speed distribution. …

The New Aviation Meteorology Specialization In The Graduate Aeronautics Program At Embry-Riddle, John M. Lanicci, Erin A. Roberts

John M Lanicci

The next 12 months will be an exciting time of growth in graduate aviation studies at Embry-Riddle Aeronautical University's Daytona Beach, FL campus. Beginning in Fall Semester 2009, a new Area of Concentration (AOC) in Aviation Meteorology will be added to the Master of Science in Aeronautics (MSA) program, and the new Doctoral program in Aviation will be starting in January 2010. The Aviation Meteorology AOC adds a crucial specialty to the existing MSA options in Air Traffic Management, Aviation/Aerospace Education Technology, Aviation/Aerospace Management, Aviation/Aerospace Operations, and Aviation/Aerospace Safety Systems. The Aviation Meteorology AOC is designed to be a cross-disciplinary …

The Weather And Air Traffic Management Integration Course In The Graduate Aeronautics Program At Embry-Riddle, John Lanicci

John M Lanicci

One year ago, Embry-Riddle Aeronautical University added a new Area of Concentration (AOC) in Aviation Meteorology to the Master of Science in Aeronautics (MSA) program at the Daytona Beach, Florida campus. As part of the preparation for the start of this program, an experimental graduate seminar in Weather and Air Traffic Integration was taught over the summer, which attracted graduate students with backgrounds in commercial and private aviation, applied meteorology, and engineering physics. The purpose of this course was to introduce the students to the concept of weather and air traffic integration as it currently exists and is being planned …

Weather Technology In The Cockpit (Wtic): Concept Of Operations, User Needs, Education, And Training, John Lanicci, L. Kirk, L. Martin, J. Vacek, E. A. Roberts, M. Edwards

John M Lanicci

The FAA, through sponsorship of the Center for General Aviation Research (CGAR), has funded a multi-disciplinary research program on Weather Technology In the Cockpit (WTIC). The CGAR is a consortium of four universities, three of which (Embry-Riddle Aeronautical University, University of North Dakota, University of Alaska-Anchorage) are working together on this program. Each university partner has the lead on a portion of the project: the University of Alaska-Anchorage is the lead on developing the WTIC Concept of Operations (CONOPS); the University of North Dakota is the lead on developing a robust set of WTIC user needs; Embry-Riddle Aeronautical University is …

General Aviation Weather Encounter Case Studies, John Lanicci, Massoud Bazargan, Daniel Halperin, Scott Shappell, Jaclyn Baron, Rebecca Iden, Carla Hackworth, Kali Holcomb

John M Lanicci

This study presents a compilation of 24 cases involving general aviation (GA) pilots’ weather encounters over the continental U.S. The project team interviewed pilots who had experienced a weather encounter, and we examined their backgrounds, flight experience, and weather encounter details. Results from meteorological data analysis for each weather encounter were consistent with findings of larger GA weather accident studies in terms of the types of hazards encountered and flight phase during which the encounters occurred. Investigation of pilot weather products and the sources from which they were obtained revealed a lack of uniformity of pre-flight data sources and underutilization …

Analysis Of Climatological Rainfall Extremes Over The Kennedy Space Center Complex Using A High-Density Observational Network, John Lanicci, Adam Schnapp

John M Lanicci

The use of observational datasets to determine the occurrence frequencies of extreme weather events has gained a lot of recent interest due to concerns about the potential regional impacts from global climate change. Extreme-value theory can quantify the return frequency of the most extreme events using climatologically short data sets and the assumption that such short climatological periods are stationary. However, the resulting analyses must be used with caution since they may not accurately reflect the potential of extreme events in the future due to climate change and variability. Accurately predicting extreme-event likelihood is important for building realistic long-range planning …

Assessing The Effectiveness Of An Education And Training Module For General Aviation Pilots On The Use Of Nexrad-Based Products In The Cockpit, John Lanicci, Erin Roberts, E. Blickensderfer

John M Lanicci

Numerous studies over the years have documented the need to improve meteorological education and training for General Aviation (GA) pilots. With the advent of readily available aviation weather hazard products for real-time pilot use on the flight deck, there is now a lack of education and training on the proper interpretation and usage of these products. Data-linked NEXRAD is a good example of a currently available real-time product that is very popular in the GA community, but lacks a coherent understanding of its proper usage in pre-flight planning and in-flight operation.

Proper usage of NEXRAD in the cockpit should require …