Lub tshuab faib kua dej ua los ntawm cov av nplaum muaj qhov tsis zoo thiab tsis sib xws, nrog ntau qhov loj me ntawm 6 txog 10 millimeters. Cov khoom yog lub tais zoo li lub tais, nrog rau qhov cua nkag hauv nruab nrab ntawm lub tshuab faib thiab qhov convection nyob ib puag ncig qhov cua nkag. Lub qhov dej ntws tawm tau teeb tsa rau ntawm qhov kawg sab saud ntawm cov qhov convection, thiab lub qhov thaiv dej ntws tau teeb tsa rau ntawm qhov kawg qis ntawm lub tshuab faib ntawm qhov chaw peripheral ntawm cov qhov convection. Qhov siab ntawm qhov dej ntws tawm yuav tsum tsis pub tshaj ib feem peb ntawm qhov siab ntawm lub qhov convection.
Thaum cov kua dej ntws nrawm heev, txhawm rau kom ntseeg tau tias muaj kev faib tawm ntawm cov roj-kua convection hauv qhov convection thiabtswj qhov siab ntawm cov kua, qhov chaw nres nkoj puv tau teeb tsa rau ntawm qhov kawg ntawm lub qhov convection kom ntseeg tau tias sib xwskev faib tawm ntawm cov roj-kua convection tuaj yeem tswj tau hauv lub pej thuam ntim khoom. Thaum lub tshuab faib kua raug tso rautsis sib npaug, ib qho groove thaiv kev ntws tau teeb tsa rau ntawm qhov kawg ntawm lub cev faib khoom nyob ib puag ncig lub qhov convection kom tiv thaiv cov kua dej ntws hauv qab ntawm lub cev faib khoom.