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Showing results for tags 'squall line'.
For the Tuesday update I would lift the slight into West Kentucky and get the ENH into northern Mississippi - perhaps Memphis. Warm front WF will probably get into West Tenn. Might make it to West Ky. Severe parameters including a screaming low level jet will augment the squall line from the WF south. Upper winds may be less backed than forecast if a lead wave can eject ahead of the bowling ball. A couple leading edge tornadoes would not surprise me. Unfortunately it may be after dark east of the Mississippi River. I'm expecting several to numerous damaging straight line reports, esp if some line echo wave patterns LEWPs can establish. Looks like a set-up favorable to LEWPs esp after dark. Good news farther east is relatively more stable air should keep Alabama, Mid and East Tennessee safe.
Severe weather outbreak looking more and more possible across portions of the lower Mississippi Valley and deep south tomorrow and tomorrow night. This evening the culprit low is located across western Kansas with a warm front stretching along the Kansas border and into northern Missouri. The dryline is located from west of KICT down through western Oklahoma and Texas … roughly along a line from Altus, OK to Sweetwater, Texas and then southwest from there. The cold front is lagging behind in far western Kansas and eastern New Mexico. A fairly large moist warm sector has developed thanks to an extended period of southerly winds off the Gulf. Dew points in the 50s extend almost up to the Missouri/Iowa line ahead of dryline/cold front and will generate instability on the order of around 750j/kg despite clouds and lack of strong radiational heating of the boundary layer. As forcing increase aloft and steeper lapse rates move in, atmosphere will likely pop along/ahead of the dryline as it punches into eastern Texas. Models hinting at two potential dryline bulges north and south of Austin, Texas. This will have to monitored for possible initiation areas as the morning/afternoon progresses. Low level storm relative winds on the order of 20-40 knts and upper/mid level storm relative winds parallel to dry line/initiation axis will promote uniform gust front lifting and upscale growth into a squall line/QLCS structures with damaging winds being the primary threat. Convection will move East with the evening and overnight hours. As it does, shear will increase across Arkansas, Louisiana, Western Tennessee, and Mississippi and hodographs are expected to become open and elongated. Thus, the tornado threat will likely increase as we approach dark and persist into the overnight … especially if more QLCS type structures can be maintained though the time period. Couple this with low LCLs under 500 meters and there could be a strong tornado somewhere tomorrow night … again if semi-discrete QLCS structures persist. Folks across southern Arkansas, northern Louisiana, and western Mississippi definitely need to monitor this situation closely.
An area of low pressure with move out of the plains and up to our Northwest. As it passes by, it will drag a fairly healthy cold front across the area Wednesday afternoon/evening. It is only January but strong winds just off the surface leading to strong shear, a good quality warm sector, and linear forcing with the front may be enough to trigger a strong to severe line of forced convection along the cold front. The primary threat would be damaging winds and heavy rainfall with PWATS possibly exceeding 1.5".