Christopher M. Fuhrmann

Ambient temperature and emergency department visits for heat-related illness in North Carolina, 2007-2008

PURPOSE To estimate the association between environmental temperatures and the occurrence of emergency department visits for heat-related illness in North Carolina, a large Southern state with 85 rural and 15 urban counties; approximately half the states population resides in urban counties. METHODS County-level daily emergency department visit counts and daily mean temperatures for the period 1/1/2007-12/31/2008 were merged to form a time-series data structure. Incidence rates were calculated by sex, age group, region, day of week, and month. Incidence rate ratios were estimated using categorical and linear spline Poisson regression models and heterogeneity of the temperature-emergency department visit association was assessed using product interaction terms in the Poisson models. RESULTS In 2007-2008, there were 2539 emergency department visits with heat-related illness as the primary diagnosis. Incidence rates were highest among young adult males (19-44 year age group), in rural counties, and in the Sandhills region. Incidence rates increased exponentially with temperatures over 15.6 °C (60 °F). The overall incidence rate ratio for each 1 °C increase over 15.6 °C in daily mean temperature was 1.43 (95%CI: 1.41, 1.45); temperature effects were greater for males than females, for 45-64 year olds, and for residents of rural counties than residents of urban counties. CONCLUSIONS As heat response plans are developed, they should incorporate findings on climate effects for both mortality and morbidity. While forecast-triggered heat health warning systems are essential to mitigate the effects of extreme heat events, public health preparedness plans should not ignore the effects of more persistently observed high environmental temperatures like those that occur throughout the warm season in North Carolina.

Ranking of Tornado Outbreaks across the United States and Their Climatological Characteristics

AbstractThe calendar year 2011 was an extraordinary year for tornadoes across the United States, as it marked the second highest annual number of tornadoes since 1950 and was the deadliest tornado year since 1936. Most of the fatalities in 2011 occurred in a series of outbreaks, highlighted by a particularly strong outbreak across the southeastern United States in late April and a series of outbreaks over the Great Plains and Midwest regions in late May, which included a tornado rated as a category 5 event on the enhanced Fujita scale (EF5) that devastated the town of Joplin, Missouri. While most tornado-related fatalities often occur in outbreaks, very few studies have examined the climatological characteristics of outbreaks, particularly those of varying strength. In this study a straightforward metric to assess the strength, or physical magnitude, of tornado outbreaks east of the Rocky Mountains from 1973 to 2010 is developed. This measure of outbreak strength, which integrates the intensity of tornado...

Climatological Perspectives on the Rainfall Characteristics Associated with Landslides in Western North Carolina

Landslides are a significant hazard in the mountains of North Carolina. While previous studies have estimated the critical instantaneous rainfall rates that may trigger a landslide, very little is known about the climatology of rainfall events associated with landslides. The rainfall climatology of a sample of landslide events in western North Carolina from 1950 to 2004 is presented in two parts. First, the two-day concurrent and cumulative antecedent (from 4 to 90 days prior to slope movement) rainfall totals are assessed climatologically by ranking them relative to all heavy precipitation events observed in western North Carolina over a 55-year period. Second, the storm types responsible for the rainfall associated with each landslide event are determined using a manual weather map classification scheme. Forty-seven percent (47%) of the landslide events are connected with concurrent rainfall totals that exceed a one-year return period. In almost half of these cases, the heavy rainfall is associated with a tropical cyclone passing through the region. The other major storm types connected with landslide events (i.e., synoptic and cyclonic-type events) generally display lower rainfall intensities and longer durations compared to tropical cyclones. Landslide activity shows the strongest relationship with antecedent precipitation totals over a 90-day period, which is the longest time period examined in the study. In many cases, a tropical cyclone produced heavy rainfall over the landslide location between 30 and 90 days before the event.

A Climatology of Cold-Season Nonconvective Wind Events in the Great Lakes Region

Abstract A 44-yr climatology of nonconvective wind events (NCWEs) for the Great Lakes region has been created using hourly wind data for 38 first-order weather stations during the months of November through April. The data were analyzed in terms of the two National Weather Service (NWS) criteria for a high-wind watch or warning: sustained winds of at least 18 m s−1 for at least 1 h or a wind gust of at least 26 m s−1 for any duration. The results indicate a pronounced southwest quadrant directional preference for nonconvective high winds in this region. Between 70% and 76% of all occurrences that satisfied the NWS criteria for NCWEs were associated with wind directions from 180° through 270°. Within the southwest quadrant, the west-southwest direction is preferred, with 14%–35% of all NCWEs coming from this particular compass heading. This directional preference is borne out in five out of six stations with high occurrences of cold-season NCWEs (Buffalo, New York; Dayton, Ohio; Lansing, Michigan; Moline, ...

A Trajectory Approach to Analyzing the Ingredients Associated with Heavy Winter Storms in Central North Carolina

AbstractWinter storms, namely snowstorms and ice storms, are a major hazard and forecasting challenge across central North Carolina. This study employed a trajectory approach to analyze the ingredients (i.e., temperature, moisture, and lift) associated with heavy snowstorms and ice storms that occurred within the Raleigh, North Carolina, National Weather Service forecast region from 2000 to 2010. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) tool was used to calculate 72-h backward (i.e., upstream) air parcel trajectories from three critical vertical pressure levels at the time and location of heaviest precipitation for each storm. Analysis of composite trajectories revealed the source regions and meteorological properties of air parcels associated with heavy winter storms. Adiabatic and diabatic contributions to air parcel temperature and moisture content were also estimated along each trajectory to assess the physical processes connected with heavy winter precipitation in the reg...

Airborne pollen characteristics and the influence of temperature and precipitation in Raleigh, North Carolina, USA (1999–2012)

The incidence of allergic diseases has been increasing in recent decades, in part due to increased exposure to aeroallergens, particularly pollen. Allergic diseases have a major burden on the health care system, with annual costs in the USA alone exceeding

The August 2007 Heat Wave in North Carolina: Meteorological Factors and Local Variability

30 billion. There is evidence that the production of aeroallergens, including pollen, is increasing in response to environmental and climatic change, which has important implications for the treatment of allergy sufferers. In this study, pollen data from a Rotorod sampler in Raleigh, North Carolina, was used to characterize and examine trends in the atmospheric pollen seasons for trees, grasses, and weeds over the period 1999–2012. The influence of mean monthly antecedent and concurrent temperature and precipitation on the timing, duration, and severity of the pollen seasons was assessed using Pearson’s product-moment correlation coefficients and multiple linear regression models. An increasing trend was noted in seasonal tree pollen concentrations, while seasonal and peak weed pollen concentrations declined over time. The atmospheric pollen seasons for grasses and weeds trended toward earlier start dates and longer durations, while the tree pollen season trended toward an earlier end date. Peak daily tree pollen concentrations were strongly associated with antecedent temperature and precipitation, while peak daily grass pollen concentrations were strongly associated with concurrent precipitation. The strongest relationships between climate and weed pollen were associated with the timing and duration of the pollen season, with drier antecedent and warmer concurrent conditions tied to longer weed pollen seasons.

Sub-regional snow cover distribution across the southern Appalachian Mountains

August 2007 was an exceptionally warm month across North Carolina. Hundreds of daily maximum and daily high minimum temperature records, as well as numerous all-time temperature records, were either tied or broken during the month. At the same time, a drought of historic proportions overspread much of the Southeast United States. A critical aspect of the August 2007 heat wave was the observed variability in heat and humidity across the different geographic regions of North Carolina. The highest maximum temperatures occurred most frequently in the Piedmont and Sandhills regions, while minimum temperatures were exceptionally high along the coast. The broad-scale pattern of heat can be tied to adiabatic warming associated with subsidence downstream of a persistent upper-level ridge centered over the Mississippi River Valley. Regional to local variations in the heat and humidity across North Carolina are linked to upwind sensible heat fluxes associated with major soil moisture deficits, adiabatic warming connected with downsloping winds off the Appalachian Mountains, and the depth of the mixing layer. Along the coast, the pattern of heat and humidity was tied to the positioning of a mesoscale thermal trough and the presence and strength of the sea-breeze circulation.

Enhancing the Teaching and Learning of Biometeorology in Higher Education

Abstract Snowfall in the Southern Appalachian Mountain region of the eastern US is characterized by much spatiotemporal variability. Annual snowfall totals vary by up to 75 cm, and variations in snowfall intensity can lead to large differences in the local snowfall distribution. Research has shown that the synoptic pattern associated with the snowfall strongly influences the regional-scale distribution of snow cover. However, topographic variability results in locally complex snow cover patterns that are not well understood or documented. In this study, we characterize the snow covered area (SCA) and fractional snow cover associated with different synoptic patterns in 14 individual sub-regions. We analyze 63 snow events using Moderate-resolution Imaging Spectroradiometer standard snow cover products to ascertain both qualitative and quantitative differences in snow cover across sub-regions. Among sub-regions, there is significant variation in the snow cover pattern from individual synoptic classes. Furthermore, the percent SCA follows the regional snowfall climatology, and sub-regions with the highest elevations and northerly latitudes exhibit the greatest variability. Results of the sub-regional analysis provide valuable guidance to forecasters by contributing a deeper understanding of local snow cover patterns and their relationship to synoptic-scale circulation features.

Temporal and spatial variation in personal ambient temperatures for outdoor working populations in the southeastern USA

This meeting was the result of a 2015 proposal to the Tromp Foundation (foundation for biometeorological research) within the International Society of Biometeorology (ISB) where opportunities were identified for gaining critical insight into the prospects of the incorporation of biometeorology into higher education. Specific topics were highlighted regarding how to effectively integrate biometeorological concepts, learning modules, and pedagogical techniques into undergraduate and graduate courses and curricula worldwide—and to learn the best practices by which to do so.