Origin of Moisture for the Precipitation Produced by the Exceptional Winter Storm Formed over the Gulf of Mexico in March 1993

Abstract

On 12–15 March 1993, a severe winter storm (SC93) formed over the Gulf of Mexico, affecting the Caribbean Islands and the eastern coast of the United States (US) and Canada with a notable amount of precipitation, snow and severe local storms. In this study, we investigate the origin of the precipitation generated by SC93 by applying a widely used Lagrangian moisture source diagnostic method. Our findings revealed that most of the moisture came from the western North Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico. Moreover, the eastern US and Mexico acted as notable terrestrial moisture sources. Overall, the moisture contribution from the oceanic origin was higher than the terrestrial counterpart, and the moisture sources progressively shifted northward as the storm moved. In addition, the moisture uptake mainly occurred in the cyclone–anticyclone interaction region.

Evaluating Changes in the Moisture Sources for Tropical Cyclones Precipitation in the North Atlantic That Underwent Extratropical Transition

“…The previous results are noticeably dependent on TCs locations and their pathways, in agreement with Pérez-Alarcón, Coll-Hidalgo, et al (2022). Note that the highest density of the ET process occurred over the WNATL region (Figure S2a in Supporting Information S1), which explains the highest moisture contribution from the WNATL source.…”

“…We obtained the model output at 6-hourly intervals over a grid of 1° × 1° of horizontal resolution. Previous works have used the FLEXPART model forced with the ERA-Interim for identifying the moisture sources for weather systems, that is, extratropical cyclones (Coll-Hidalgo et al, 2022;Gozzo et al, 2017), atmospheric rivers (Ramos et al, 2016) and TCs (Pérez-Alarcón et al, 2022b, 2022cPérez-Alarcón, Coll-Hidalgo, et al, 2022;. Additionally, Pérez-Alarcón, Coll-Hidalgo, et al (2022) noted that the precipitation of TCs estimated using the Lagrangian moisture tracking approach applied to the outputs of the FLEXPART model forced with the ERA-Interim fitted very well with the TC precipitation from satellite products.…”

“…We obtained the model output at 6‐hourly intervals over a grid of 1° × 1° of horizontal resolution. Previous works have used the FLEXPART model forced with the ERA‐Interim for identifying the moisture sources for weather systems, that is, extratropical cyclones (Coll‐Hidalgo et al., 2022; Gozzo et al., 2017), atmospheric rivers (Ramos et al., 2016) and TCs (Pérez‐Alarcón et al., 2022b, 2022c; Pérez‐Alarcón, Coll‐Hidalgo, et al., 2022; Pérez‐Alarcón, Fernández‐Alvarez, et al., 2022). Additionally, Pérez‐Alarcón, Coll‐Hidalgo, et al.…”

“…Recently, using a Lagrangian moisture source analysis, our group identified the origin of the moisture for the precipitation of TCs during the genesis, the peak of maximum intensification and dissipation stages over the NATL basin, but did not differentiate the spatial extent and magnitude of these sources before and after ET (Pérez-Alarcón et al, 2022c). Likewise, Pérez-Alarcón, Coll-Hidalgo, et al (2022) investigated the moisture sources that supplied the atmospheric humidity for the precipitation of the six major hurricanes (category 3+ on the Saffir-Simpson wind scale) formed in NATL in 2017. Although three of them (hurricanes Harvey, Maria and Ophelia) underwent ET, the authors did not investigate changes in the moisture sources before and after the ET.…”

Moisture Sources for the Precipitation of Tropical-like Cyclones in the Mediterranean Sea: A Case of Study

“…If the condition was not satisfied, the MSLP at 1000 km was the critical value for that leg. Subsequently, the minimum value of all "critical" MSLPs was the last closed isobar, and by interpolating it in each radial leg, we determined the system geometry, the area of which is the sum of the areas of the 36 triangles with vertices in the centre of the system and two adjacent radial legs (see Coll-Hidalgo et al [56] for details). Then, the TLC outer radius was the radius of the virtual circumference centred on the TLC, assuming that the area of the system geometry is approximately the area of that circumference.…”