18th Conference on Weather and Forecasting, 14th Conference on Numerical Weather Prediction, and Ninth Conference on Mesoscale Processes

Wednesday, 1 August 2001
The value of realtime upper tropospheric inertial stability measurements on tropical convection forecasts
John R. Mecikalski, Univ. of Wisconsin, Madison, WI
Beginning in early 2001, fields of inertial stability were being produced in realtime at the Cooperative Institute for Meteorological Satellite Studies (CIMSS). These data, combined with GOES-satellite derived winds, visible and infrared imagery from GOES and the Tropical Rainfall Measuring Mission (TRMM) Visible and InfraRed Scanner (VIRS), are used to assess the correlations and influences of inertial stability on the temporal behavior of deep convection. Recent studies have identified the strong influence regions of low upper tropospheric potential vorticity (i.e. low inertial stability) have on the invigoration of deep convection, as well on determining the structural qualities (e.g., momentum transport) of the enhanced convection.

Specifically, this poster will address the following: 1) to assess the correlations between regions of low inertial stability (low potential vorticity; near zero PVU), convective outflows and the intensification of moist convective systems, 2) to understand the effects (both temporally and spatially) a region of low inertial stability has on influencing the outflow characteristics of a tropical cyclone, and 3) to evaluate the value of upper tropospheric (above 30 kPa) isentropic inertial stability for forecasting the behavior, intensity and momentum transports of deep convection in the tropics.

Preliminary results show that regional low inertial stability can be used as to assess when and if deep convection will develop, intensify or expand in coverage. With respect to tropical cyclones, our diagnostics show promise for 0-12 hour nowcasting of storm intensity changes, especially when combined with satellite-derived winds. These will be reported on at the conference.

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