Evaluating Linkages between Atmospheric Blocking Patterns and Heavy Rainfall Events across the North-Central Mississippi River Valley for Different ENSO Phases

Abstract

Over the last six to seven decades, there has been a substantial increase in atmospheric research to better understand the dynamics and evolution of atmospheric blocking events. It is well known that atmospheric blocking serves as a catalyst for increasing the frequency of atmospheric flow regime stagnation and forecast unpredictability. This study built upon the results of previous work by expanding upon the findings of various climatologies and case studies. This work analyzes specific trends observed in association with atmospheric blocking predominantly across the central and eastern Pacific Ocean. Such trends include the relationship between the size, duration, and onset position of atmospheric blocking events and the frequency, duration, and intensity of heavy rainfall events across the central United States. A strong focus is placed on examining the duration and spatial extent of atmospheric blocking which has been found to influence the intensity of heavy rainfall events. The goal is to further bridge the gap between the location and duration of blocking highs and the intensity, duration, and frequency of heavy rainfall events which occur downstream of such blocking events.

Atmospheric rivers and associated precipitation patterns during the ACLOUD and PASCAL campaigns near Svalbard (May–June 2017): case studies using observations, reanalyses, and a regional climate model

“…S4 and S5 for temporal evolution) shows the mean sea level pressure (MSLP), the geopotential height at 700 hPa, and potential temperature (θ ) at 2 PVU, which is commonly used to define the height of the dynamical tropopause (Hoskins et al, 1985;Juckes, 1994;Wilcox et al, 2012;Woollings et al, 2018), providing an analysis of the upper-level flow. The combination of these variables is used to study the atmospheric blocking, which has previously been associated with ARs (Benedict et al, 2019;Francis et al, 2020;Rabinowitz et al, 2018;Wille et al, 2019). Atmospheric blocking leads to persistent weather conditions, playing an important role in directing ARs poleward.…”

Atmospheric rivers and associated precipitation patterns during the ACLOUD/PASCAL campaigns near Svalbard (May–June 2017): case studies using observations, reanalyses, and a regional climate model

“…S4 and S5 for temporal evolution) shows the mean sea level pressure (MSLP), the geopotential height at 700 hPa and potential temperature (θ) at 2 potential vorticity units (PVU), which is commonly used to define the height of the dynamical tropopause (Hoskins et al, 1985;Juckes, 1994;Wilcox et al, 2012;Woollings et al, 2018) providing an analysis of the upper-level flow. The combination of these variables is usually used to study the atmospheric blocking, which has previously been associated to ARs (Benedict et al, 2019;Francis et al, 2020;Rabinowitz et al, 2018;Wille et al, 2019). The atmospheric blocking leads to persistent weather conditions, playing an important role in directing ARs poleward.…”

Dynamic and Thermodynamic Factors Associated with Different Precipitation Regimes over South China during Pre-Monsoon Season

“…As pointed by Trenberth et al [21], the characteristics of precipitation, i.e., intensity, frequency, and spatial pattern, are as important as the amount. Besides, the precipitation is always related to multiple atmospheric dynamic and thermodynamic factors, and may be related to or modulated by many other systems, such as atmospheric blocking, El Niño/Southern Oscillation, Pacific Decadal Oscillation [3,6,11,[22][23][24]. However, most previous studies on AMJ precipitation over South China only analyzed individual dynamic and thermodynamic factors, which is incomplete for analyzing the relationship between AMJ precipitation and atmospheric dynamic and thermodynamic factors.…”