"THERE SEEMS TO BE SOME CONVECTIVE FEEDBACK IN THE GFS&

[HURAKAN]

SW N ATLANTIC
BIGGEST PROBLEM OVER THE ATLC WATERS IS A BROAD TROUGH EXTENDING
FROM BERMUDA SWD TO CENTRAL CUBA. THE GFS CONTINUES TO DEVELOP
AREAS OF LOW PRESSURE ALONG THIS TROUGH WHICH THEN MOVE NEWD.
WHILE WEAK LOW CENTERS MOVING ALONG THE TROUGH APPEAR REASONABLE
...THERE SEEMS TO BE SOME CONVECTIVE FEEDBACK IN THE GFS
SOLUTION SO WILL HOLD OFF ON CHASING ANY INDIVIDUAL LOW CENTER.
DOING SO WOULD LIKELY RESULT IN A WINDSHIELD WIPER EFFECT AS THE
GFS CONTINUES TO HAVE LARGE RUN TO RUN VARIATION. RATHER...WILL
DELINEATE WINDS E AND W OF TROUGH AXIS AND COVER POSSIBLE HIGHER
CONDITIONS WITH WITH STATEMENT OF "WIND AND SEAS HIGHER IN
SHOWERS AND THUNDERSTORMS." HIGH PRES BUILDS OVER THE AREA MON.
OTHERWISE GENERALLY LIGHT WINDS ACROSS THE ATLC THROUGH THE
PERIOD.

Can anyone explain me what "convective feedback" is or means?

[kevin]

It means the gfs is having a problem in short, with the amount of moisture or something. The pros will elaborate no doubt.

[x-y-no]

Convective feedback is a real-world phenomenon in which the presence of convection modifies the immediate environment. For various reasons, the global models do not represent this effect well, relying on parameterization functions which can at times go haywire.

The bottom line is that while convective flareups in the model runs indicate the potential for something to happen, they can't be counted on to accurately predict such events.

Jan

[MWatkins]

SW N ATLANTIC
BIGGEST PROBLEM OVER THE ATLC WATERS IS A BROAD TROUGH EXTENDING
FROM BERMUDA SWD TO CENTRAL CUBA. THE GFS CONTINUES TO DEVELOP
AREAS OF LOW PRESSURE ALONG THIS TROUGH WHICH THEN MOVE NEWD.
WHILE WEAK LOW CENTERS MOVING ALONG THE TROUGH APPEAR REASONABLE
...THERE SEEMS TO BE SOME CONVECTIVE FEEDBACK IN THE GFS
SOLUTION SO WILL HOLD OFF ON CHASING ANY INDIVIDUAL LOW CENTER.
DOING SO WOULD LIKELY RESULT IN A WINDSHIELD WIPER EFFECT AS THE
GFS CONTINUES TO HAVE LARGE RUN TO RUN VARIATION. RATHER...WILL
DELINEATE WINDS E AND W OF TROUGH AXIS AND COVER POSSIBLE HIGHER
CONDITIONS WITH WITH STATEMENT OF "WIND AND SEAS HIGHER IN
SHOWERS AND THUNDERSTORMS." HIGH PRES BUILDS OVER THE AREA MON.
OTHERWISE GENERALLY LIGHT WINDS ACROSS THE ATLC THROUGH THE
PERIOD.

Can anyone explain me what "convective feedback" is or means?

This has been an ongoing problem with Global Models (especially the GFS), which involves how models handle the way the environment changes as a result of latent heat release and moisture changes in the atmosphere as a result of thunderstorms occuring in the model. Part of this is that the small-scale dynamics are not completely understood, and part of it is that these changes happen on a smaller scale (sometimes) than can be resolved in the grids.

The net impact is that the models, again especially the GFS, tend to overestimate the impact of a paticular area of thunderstorms, keep them going much longer than is realistic, and the net result is spinning up a tropical cyclone over water, for example, from the process...rather than actually forecasting development based on other merits. Convective feedback is the major reason why the GFS spins up so many suprious systems, especially in the extended periods.

MW

[dhweather]

I wonder if my PC has ever had convective feedback?