Open AccessImpact of Assimilating Preconvective Upsonde Observations on Short-Term Forecasts of Convection Observed during MPEX
Author(s) -
Michael C. Coniglio,
Stacey M. Hitchcock,
Kent H. Knopfmeier
Publication year - 2016
Publication title -
monthly weather review
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.862
H-Index - 179
eISSN - 1520-0493
pISSN - 0027-0644
DOI - 10.1175/mwr-d-16-0091.1
Subject(s) - radiosonde , mesoscale meteorology , convection , depth sounding , meteorology , thunderstorm , data assimilation , climatology , convective inhibition , radar , environmental science , advection , grid , convective available potential energy , term (time) , geology , geography , computer science , physics , geodesy , telecommunications , oceanography , quantum mechanics , natural convection , thermodynamics , combined forced and natural convection
This study examines the impact of assimilating preconvective radiosonde observations obtained by mobile sounding systems on short-term forecasts of convection. Ensemble data assimilation is performed on a mesoscale (15 km) grid and the resulting analyses are downscaled to produce forecasts on a convection-permitting grid (3 km). The ensembles of forecasts are evaluated through their depiction of radar reflectivity compared to observed radar reflectivity. Examination of fractions skill scores over eight cases shows that, for four of the cases, assimilation of radiosonde observations nearby to subsequent convection has a positive impact on the initiation and early evolution during the first 3–4 h of the forecasts, even for the smallest resolvable scales of the 3-km grid. For the four cases in which positive impacts near the smallest resolvable scales of the grid are not seen, analysis of the changes to the preconvective environment suggests that suboptimal locations of the soundings compared to the location of convective initiation are to blame. The aggregate positive impacts on forecasts of convection is more clearly seen when spatial scales larger than individual thunderstorms are examined.