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precipitation. These effects are especially evident during the cool season, when the occurrence of snowbands often results in intense snowfall and extreme snowfall gradients ( Kocin and Uccellini 2004 , 177–186). Therefore, improving understanding of the structural and dynamical evolution of cool-season mesoscale bands can advance cool-season QPF skill. Cool-season banded precipitation occurs in a variety of types (e.g., Houze et al. 1976 ; Browning 1990 ; Hobbs et al. 1996 ). In a cool
precipitation. These effects are especially evident during the cool season, when the occurrence of snowbands often results in intense snowfall and extreme snowfall gradients ( Kocin and Uccellini 2004 , 177–186). Therefore, improving understanding of the structural and dynamical evolution of cool-season mesoscale bands can advance cool-season QPF skill. Cool-season banded precipitation occurs in a variety of types (e.g., Houze et al. 1976 ; Browning 1990 ; Hobbs et al. 1996 ). In a cool
Connecticut and Long Island. Much of the heavy snow fell within a mesoscale snowband within the comma head of the cyclone with 7.5–10 cm h −1 (3–4 in. h −1 ) snow rates reported within the band and radar reflectivities exceeding 55 dB Z ( Picca et al. 2014 ). Fig . 1. (a) Storm total snowfall accumulation for 8–9 Feb 2013. (b) Topographic map showing the locations of Stony Brook University (SBNY); KOKX dual-polarized radar and upper-air site (KOKX); Chatham, MA, upper-air site (KCHH); KBOX dual
Connecticut and Long Island. Much of the heavy snow fell within a mesoscale snowband within the comma head of the cyclone with 7.5–10 cm h −1 (3–4 in. h −1 ) snow rates reported within the band and radar reflectivities exceeding 55 dB Z ( Picca et al. 2014 ). Fig . 1. (a) Storm total snowfall accumulation for 8–9 Feb 2013. (b) Topographic map showing the locations of Stony Brook University (SBNY); KOKX dual-polarized radar and upper-air site (KOKX); Chatham, MA, upper-air site (KCHH); KBOX dual
majority of bands in the northwest quadrants of cyclones exhibited a distinct “pivot point,” with the bands pivoting as they translated with the parent system, and this pivot point was found to be a favored region for heavy precipitation accumulation. Furthermore, bands in other quadrants tended to move with the mean low- to midlevel flow in the vicinity of the band. In a recent study of northeast U.S. winter storms, Ganetis et al. (2018) found that mesoscale snowbands exhibiting along-axis motion
majority of bands in the northwest quadrants of cyclones exhibited a distinct “pivot point,” with the bands pivoting as they translated with the parent system, and this pivot point was found to be a favored region for heavy precipitation accumulation. Furthermore, bands in other quadrants tended to move with the mean low- to midlevel flow in the vicinity of the band. In a recent study of northeast U.S. winter storms, Ganetis et al. (2018) found that mesoscale snowbands exhibiting along-axis motion
majority of bands in the northwest quadrants of cyclones exhibited a distinct “pivot point,” with the bands pivoting as they translated with the parent system, and this pivot point was found to be a favored region for heavy precipitation accumulation. Furthermore, bands in other quadrants tended to move with the mean low- to midlevel flow in the vicinity of the band. In a recent study of northeast U.S. winter storms, Ganetis et al. (2018) found that mesoscale snowbands exhibiting along-axis motion
majority of bands in the northwest quadrants of cyclones exhibited a distinct “pivot point,” with the bands pivoting as they translated with the parent system, and this pivot point was found to be a favored region for heavy precipitation accumulation. Furthermore, bands in other quadrants tended to move with the mean low- to midlevel flow in the vicinity of the band. In a recent study of northeast U.S. winter storms, Ganetis et al. (2018) found that mesoscale snowbands exhibiting along-axis motion
1. Introduction Some of the world’s most intense lake-effect snow events occur downstream of the North American Great Lakes. Lake-effect snow events often only impact a relatively small area, but, within that narrow corridor, snowfall amounts and rates can be substantial. Lake-effect snowbands are relatively shallow, ~2–3 km deep, and, consequently, Weather Surveillance Radar-1988 Doppler (WRS-88D) coverage of these events from long ranges can be insufficient to capture many of the small
1. Introduction Some of the world’s most intense lake-effect snow events occur downstream of the North American Great Lakes. Lake-effect snow events often only impact a relatively small area, but, within that narrow corridor, snowfall amounts and rates can be substantial. Lake-effect snowbands are relatively shallow, ~2–3 km deep, and, consequently, Weather Surveillance Radar-1988 Doppler (WRS-88D) coverage of these events from long ranges can be insufficient to capture many of the small
1. Introduction Mesoscale snowbands are narrow regions of locally enhanced snowfall rates, most commonly forced by midlevel frontogenesis below a layer of reduced static stability ( Nicosia and Grumm 1999 ; Novak et al. 2004 ; Baxter and Schumacher 2017 ). Snowbands occur frequently within midlatitude cyclones and have the potential to cause significant societal impacts but are challenging to forecast due to their small scale and forcings, with widths generally between 20 and 100 km
1. Introduction Mesoscale snowbands are narrow regions of locally enhanced snowfall rates, most commonly forced by midlevel frontogenesis below a layer of reduced static stability ( Nicosia and Grumm 1999 ; Novak et al. 2004 ; Baxter and Schumacher 2017 ). Snowbands occur frequently within midlatitude cyclones and have the potential to cause significant societal impacts but are challenging to forecast due to their small scale and forcings, with widths generally between 20 and 100 km
1. Introduction Mesoscale snowbands are commonly observed embedded within the stratiform precipitation shield of extratropical cyclones ( Novak et al. 2004 ; Baxter and Schumacher 2017 ). These narrow bands are associated with heightened snowfall rates, leading to significant and highly heterogeneous snowfall accumulations and reduced visibility. Furthermore, the small scale of these bands can result in rapid and oftentimes unexpected onsets, causing major traffic disruptions and other
1. Introduction Mesoscale snowbands are commonly observed embedded within the stratiform precipitation shield of extratropical cyclones ( Novak et al. 2004 ; Baxter and Schumacher 2017 ). These narrow bands are associated with heightened snowfall rates, leading to significant and highly heterogeneous snowfall accumulations and reduced visibility. Furthermore, the small scale of these bands can result in rapid and oftentimes unexpected onsets, causing major traffic disruptions and other
) the stability below (above) the level of maximum heating, and induce a horizontal circulation that may be frontogenetical. Although this feedback is presumably active within a snowband of an extratropical cyclone, the role of the band’s latent heating on its own evolution has not been quantified. It is also not apparent if or how this feedback is disrupted during band dissipation. The vertical and horizontal distribution of moisture may also play a critical role in band evolution by modifying the
) the stability below (above) the level of maximum heating, and induce a horizontal circulation that may be frontogenetical. Although this feedback is presumably active within a snowband of an extratropical cyclone, the role of the band’s latent heating on its own evolution has not been quantified. It is also not apparent if or how this feedback is disrupted during band dissipation. The vertical and horizontal distribution of moisture may also play a critical role in band evolution by modifying the
% chance of rain and snow for Cheyenne and a 30% chance of rain showers, snow showers, and thunderstorms in Fort Collins. The purpose of this paper is to understand the processes that led to the development of convection and to its organization into bands of two sizes (major and minor). The remainder of this article is organized as follows. In section 2 of this article, observations of the 16–17 February 2007 snowband event are presented, highlighting the environmental conditions leading to the
% chance of rain and snow for Cheyenne and a 30% chance of rain showers, snow showers, and thunderstorms in Fort Collins. The purpose of this paper is to understand the processes that led to the development of convection and to its organization into bands of two sizes (major and minor). The remainder of this article is organized as follows. In section 2 of this article, observations of the 16–17 February 2007 snowband event are presented, highlighting the environmental conditions leading to the
1971 ). The fetch over the lake and the alignment with the lakes’ long axis helps determine the morphology and intensity of snowbands that develop ( Wiggin 1950 ; Lavoie 1972 ; Hjelmfelt 1990 ; Niziol et al. 1995 ). Under larger fetch conditions where the mean boundary layer flow is closely aligned with the long axis of a lake (in particular, the rather long and narrow eastern Great Lakes, Erie and Ontario), LE convection will typically organize into one long and often intense band oriented
1971 ). The fetch over the lake and the alignment with the lakes’ long axis helps determine the morphology and intensity of snowbands that develop ( Wiggin 1950 ; Lavoie 1972 ; Hjelmfelt 1990 ; Niziol et al. 1995 ). Under larger fetch conditions where the mean boundary layer flow is closely aligned with the long axis of a lake (in particular, the rather long and narrow eastern Great Lakes, Erie and Ontario), LE convection will typically organize into one long and often intense band oriented
