n tflw bndry, ls knwn s gst frnt, s strm-scl r msscl bndry sprtng thndrstrm-cld r (tflw) frm th srrndng r; smlr n ffct t cld frnt, wth pssg mrkd by wnd shft nd slly drp n tmprtr nd rltd prssr jmp. tflw bndrs cn prsst fr 24 hrs r mr ftr th thndrstrms tht gnrtd thm dsspt, nd cn trvl hndrds f klmtrs frm thr r f rgn. Nw thndrstrms ftn dvlp lng tflw bndrs, spclly nr th pnt f ntrsctn wth nthr bndry (cld frnt, dry ln, nthr tflw bndry, tc.). tflw bndrs cn b sn thr s fn lns n wthr rdr mgry r ls s rcs f lw clds n wthr stllt mgry. Frm th grnd, tflw bndrs cn b c-lctd wth th pprnc f rll clds nd shlf clds.
tflw bndrs crt lw-lvl wnd shr whch cn b hzrds drng rcrft tkffs nd lndngs. f thndrstrm rns nt n tflw bndry, th lw-lvl wnd shr frm th bndry cn cs thndrstrms t xhbt rttn t th bs f th strm, t tms csng trndc ctvty. Strng vrsns f ths ftrs knwn s dwnbrsts cn b gnrtd n nvrnmnts f vrtcl wnd shr nd md-lvl dry r. Mcrbrsts hv dmtr f nflnc lss thn 4 klmtrs (2.5 m), whl mcrbrsts ccr vr dmtr grtr thn 4 klmtrs (2.5 m). Wt mcrbrsts ccr n tmsphrs whr th lw lvls r strtd, whl dry mcrbrsts ccr n drr tmsphrs frm hgh-bsd thndrstrms. Whn n tflw bndry mvs nt mr stbl lw lvl nvrnmnt, sch s nt rgn f clr r r vr rgns f clr wtr tmprtrs t t s, t cn ld t th dvlpmnt f n ndlr br.