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Title: The Impacts of Adjusting Momentum Roughness Length on Strong and Weak Hurricane Forecasts: A Comprehensive Analysis of Weather Simulations and Observations
Abstract The momentum roughness length ( z 0 ) significantly impacts wind predictions in weather and climate models. Nevertheless, the impacts of z 0 parameterizations in different wind regimes and various model configurations on the hurricane size, intensity, and track simulations have not been thoroughly established. To bridge this knowledge gap, a comprehensive analysis of 310 simulations of 10 real hurricanes using the Weather Research and Forecasting (WRF) Model is conducted in comparison with observations. Our results show that the default z 0 parameterizations in WRF perform well for weak (category 1–2) hurricanes; however, they underestimate the intensities of strong (category 3–5) hurricanes. This finding is independent of model resolution or boundary layer schemes. The default values of z 0 in WRF agree with the observational estimates from dropsonde data in weak hurricanes while they are much larger than observations in strong hurricanes regime. Decreasing z 0 close to the values of observational estimates and theoretical hurricane intensity models in high wind regimes (≳45 m s −1 ) led to significant improvements in the intensity forecasts of strong hurricanes. A momentum budget analysis dynamically explained why the reduction of z 0 (decreased surface turbulent stresses) leads to stronger simulated storms.  more » « less
Award ID(s):
2211308 2228299
NSF-PAR ID:
10451811
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
American Meteorological Society
Date Published:
Journal Name:
Monthly Weather Review
Volume:
151
Issue:
5
ISSN:
0027-0644
Page Range / eLocation ID:
1287 to 1302
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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