Details:

Journal Title:
Monthly Weather Review
Personal Author:
LaFleur, Allison T. ; Tanamachi, Robin L. ; Dawson, Daniel T. ; Turner, David D.
LaFleur, Allison T. ; Tanamachi, Robin L. ; Dawson, Daniel T. ; Turner, David D. Less -
NOAA Program & Office:
OAR (Oceanic and Atmospheric Research) ; GSL (Global Systems Laboratory)
OAR (Oceanic and Atmospheric Research) ; GSL (Global Systems Laboratory) Less -
Description:
In this study, we analyze various sources of CAPE in the environment and their contributions to its time tendency that will complement forecast models and operational analyses that are relatively temporally (∼1 h) coarse. As a case study, the relative roles of direct insolation and near-surface moisture advection in the recovery CAPE on 31 March 2016 in northern Alabama are examined using VORTEX-Southeast (VORTEX-SE) observations and numerical simulations. In between rounds of nontornadic morning storms and tornadic evening storms, CAPE over the VORTEX-SE domain increased from near zero to at least 500 J kg−1. A timeline of the day’s events is provided with a focus on the evolution of the lower levels of the atmosphere. We focus on its responses to solar insolation and moisture advection, which we hypothesize as the main mechanisms behind the recovery of CAPE. Data from the University of Massachusetts S-Band frequency-modulated, continuous-wave (FMCW) radar and NOAA National Severe Storms Laboratory (NSSL) Collaborative Lower Atmospheric Mobile Profiling System (CLAMPS), and high-resolution EnKF analyses from the Advanced Regional Prediction System (ARPS) are used to characterize the boundary layer evolution in the pre-tornadic storm environment. It is found that insolation-driven surface diabatic heating was the primary driver of rapid CAPE recovery on this day. The methodology developed in this case can be applied in other scenarios to diagnose the primary drivers of CAPE development. Significance Statement The mechanisms by which atmospheric instability recovers can vary widely and are often a source of uncertainty in forecasting. We want to understand how and why the environment destabilized enough to produce an evening tornado following morning storms on 31 March 2016. To do this, we used model data and observations from a collocated radar and profiler. It was found that heating from the sun at the surface was the primary cause of destabilization in the environment.
Keywords:
[+]
Atmospheric Science
Source:
Monthly Weather Review, 151(6), 1459-1477
DOI:
https://doi.org/10.1175/mwr-d-22-0051.1
ISSN:
0027-0644;1520-0493;
Format:
PDF
Publisher:
American Meteorological Society
Document Type:
Journal Article
Funding:
Grant no. NA15OAR4590231
Rights Information:
Other
Compliance:
Library
Main Document Checksum:
[+]
urn:sha256:6eab8ad89fd3953e4c4e3d946a16535cf8a1c3270ec026522e131ba3e10c0444
Download URL:
https://repository.library.noaa.gov/view/noaa/53740/noaa_53740_DS1.pdf
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