Asthma-Related Emergency Department Visits in North Carolina Following Hurricane Irene

Objective: Previous research suggests that people with asthma may experience a worsening of symptoms following hurricanes due to changes in environmental exposures, discontinuity in chronic disease management, and stress. The objective of this study was to estimate changes in asthma-related emergency department (ED) visits in North Carolina following Hurricane Irene, which made landfall in August 2011. Methods: Changes in asthma-related ED visits in September to December of 2010 and 2011 were examined using data from the Healthcare Cost and Utilization Project State Emergency Department and Inpatient Databases. A Poisson generalized linear model was used to estimate the association between Federal Emergency Management Agency disaster declarations following Hurricane Irene and county-level asthma-related ED visits controlling for month, year, and county. Results: Following Hurricane Irene, disaster declarations were made for 38 of 100 counties in North Carolina. In September 2010, the rate of asthma-related ED visits for North Carolina was 6 per 10,000 person-months. In September 2011, rates of asthma-related ED visits were similar in counties with and without disaster declarations (7 and 5 per 10,000 person-months, respectively). When adjusting for covariates, there was little or no difference in the rate of asthma ED visits before and after the hurricane between counties with and without a disaster declaration (rate ratio {RR} [95% confidence interval {CI}] = 1.02[0.97, 1.08]). Conclusions: Although risk factors for asthma exacerbations increase following hurricanes, these results found little evidence of an increase in asthma-related ED visits in North Carolina following Hurricane Irene.

Expecting Mother Nature: Uncertain Hurricane Forecasts Disrupt Prenatal Care and Impair Birth Outcomes

Early forecasts give people in a storm's path time to prepare. Less is known about the cost to society when forecasts are incorrect. We examine over 700,000 births in the path of Hurricane Irene and find exposure led to a decrease in birth weights and increase in preterm and low birth weight outcomes. Additional warning time decreased preterm birth rates for women who experienced intense storm exposures documenting a benefit of avoiding a type II forecasting error. A larger share of this at-risk population experienced a type I forecasting error where severe physical storm impacts were anticipated but not experienced. Disaster anticipation disrupted healthcare services by delaying and canceling prenatal care leading to impaired birth outcomes. Recognizing storm damages depend on human responses to predicted storm paths is critical to supporting the next generation's developmental potential with judicious forecasts that ensure public warning systems mitigate rather than exacerbate climate damages.

WAVE EFFECTS ON STORM SURGE IN A SMALL TWO-INLET BAY

Storm surge resulting from oceanic extreme events, commonly tropical cyclones, is a major contributor to coastal flooding and property damage. Thus, there is significant investment in accurate predictions. However, forecasts of storm surge often are focused on regional scales, and are unable to resolve complex nearshore bathymetry and small tidal inlets (Yin et al. 2016) that can be critical to local surge magnitudes and timing. Here, model simulations with a regional wave-flow coupled model (NACCS), a high bathymetric resolution uncoupled flow model (ADCIRC), and a high resolution coupled model (CSTORM) are compared with observations of storm surge during Hurricane Irene (Atlantic Storm 09, 2011) within Katama Bay, Martha's Vineyard, Massachusetts.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/hKdA2zYWI2Y

Transition of the Hurricane Boundary Layer during the Landfall of Hurricane Irene (2011)

The hurricane boundary layer (HBL) has been observed in great detail through aircraft investigations of tropical cyclones over the open ocean, but the coastal transition of the HBL has been less frequently observed. During the landfall of Hurricane Irene (2011), research and operational aircraft over water sampled the open-ocean HBL simultaneously with ground-based research and operational Doppler radars onshore. The location of the radars afforded 13 h of dual-Doppler analysis over the coastal region. Thus, the HBL from the coastal waterways, through the coastal transition, and onshore was observed in great detail for the first time. Three regimes of HBL structure were found. The outer bands were characterized by temporal perturbations of the HBL structure with attendant low-level wind maxima in the vicinity of rainbands. The inner core, in contrast, did not produce such perturbations, but did see a reduction of the height of the maximum wind and a more jet-like HBL wind profile. In the eyewall, a tangential wind maximum was observed within the HBL over water as in past studies and above the HBL onshore. However, the transition of the tangential wind maximum through the coastal transition showed that the maximum continued to reside in the HBL through 5 km inland, which has not been observed previously. It is shown that the adjustment of the HBL to the coastal surface roughness discontinuity does not immediately mix out the residual high-momentum jet aloft. Thus, communities closest to the coast are likely to experience the strongest winds onshore prior to the complete adjustment of the HBL.

Ensemble Variability in Rainfall Forecasts of Hurricane Irene (2011)

Tropical cyclones (TCs) moving into the midlatitudes can produce extreme precipitation, as was the case with Hurricane Irene (2011). Despite the high-impact nature of these events, relatively few studies have explored the sensitivity of TC precipitation forecasts to model initial conditions. Here, the physical processes that modulate precipitation forecasts over the Northeast United States during Irene are investigated using an 80-member 0.5° Global Forecasting System (GFS) ensemble. The members that forecast the highest total precipitation over the Catskill Mountains in New York (i.e., wet members) are compared with the members that predicted the least precipitation (i.e., dry members). Results indicate that the amount of rainfall is tied to storm track, with the wetter members forecast to move farther west than the dry members. This variability in storm track appears to be associated with variability in analyzed upper-tropospheric potential vorticity (PV), such that the wetter members feature greater cyclonic PV southwest of Irene when Irene is off the Carolina coast. By contrast, the wetter members of a 3-km Weather Research and Forecasting (WRF) Model ensemble, initialized from the same GFS ensemble forecasts, show little sensitivity to track. Instead, the wetter members are characterized by stronger lower-tropospheric winds perpendicular to the eastern face of the Catskills, allowing maximum upslope forcing and horizontal moisture flux convergence during the period of heaviest rainfall. The drier members, on the other hand, have the greatest quasigeostrophic forcing for ascent, implying that the members’ differences in mesoscale topographic forcing are the dominant influence on rainfall rate.

Extratropical Transition of Hurricane Irene (2011) in a Changing Climate

Tropical cyclones (TCs) undergoing strong extratropical transition (ET) can produce adverse societal impacts in areas that rarely experience direct TC impacts. This, in conjunction with projected environmental changes in climatological ET regions, motivates the investigation of possible future changes in ET characteristics. We utilize a small ensemble of numerical model simulations to examine how warming affects the ET of Hurricane Irene. To assess the effects of climate change, we use the pseudo-global warming method in which thermodynamic changes, derived from an ensemble of 20 CMIP5 GCMs, are applied to analyzed initial and lateral boundary conditions of model simulations. We find increased storm intensity in the future simulations, both in reduced minimum sea level pressure and strengthened 10-m wind speed. Storm-centered composites indicate a strengthening of tropospheric potential vorticity near the center of Irene, consistent with enhanced latent heat release. The results also demonstrate that Irene’s precipitation in the warmed simulations increases at a rate that exceeds Clausius–Clapeyron scaling, owing to enhanced moisture flux convergence and an additional contribution from increased surface evaporation. The duration of the transition process increased in the warmed simulations due to a weakened midtropospheric trough and reduced vertical wind shear and meridional SST gradient with a slower northward translation. These results suggest that transitioning storms may exhibit an increased ability to extend TC-like conditions poleward, and motivates additional research.

The Library as Lifeboat

According to Hurricane Katrina: Lessons Learned (2006), emergency management professionals realized first-hand that preplanning and coordination is essential when mounting an effective reaction to natural disasters. This chapter describes how leaders in Chesterfield County, VA learned similar lessons in 2001 during Hurricane Irene. In comparison to Katrina the amount of damage caused by Irene was minimal but the impact on county leaders was severe. Based on lessons learned during Irene and an unexpected wind storm nine months later, Chesterfield County leaders now include the Chesterfield County Public (CCPL) in their official disaster relief plans. When activated, CCPL will serve as an information hub, double as a daytime relief shelter and participate in mass feeding if necessary. Selected library branches are available to be used as overnight relief shelters for mass care when the activation of a standard sized shelter facility is not warranted. These changes have made a notable difference.