237 FXUS64 KMEG 271143 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 543 AM CST Fri Dec 27 2019 .UPDATE... Updated to include 12Z aviation discussion below. && .PREV DISCUSSION... /issued 430 AM CST Fri Dec 27 2019/ DISCUSSION... Currently, the region is dry with high pressure situated over central CONUS. A weak pre-frontal trough can be seen upstream. Satellite imagery shows mostly cloudy skies with patchy fog across the area. Dense fog is mostly observed over eastern AR and the MO Bootheel with some areas seeing visibility drop to 1/4mi or less at times. Temperatures are in the low-to-upper 50s and are expected to only drop a few more degrees with clouds and southerly flow keeping temperatures up. The weak pre-frontal trough will move into the southern portions of the Mid-South later this morning and afternoon which will help produce isolated showers - mainly over northern MS and SE AR. High temperatures are forecast to be in the upper 50s to mid 60s. The upper level-ridge located over eastern CONUS will really begin to break down this weekend as a trough that's currently over southern CA/AZ pushes northeast and deepens as it moves through central and northeastern CONUS. A mature wave will then stack ahead of the upper-level trough with the low pressure center moving through WI; as it occludes, a slow moving cold front will stretch down into the Mid-South and produce persistent rain through the weekend over the region. Isolated strong storms will be possible with a deepening trough, strong jet, high bulk sheer, and 50+kt LLJ. However, the severe potential will be conditional based on how much instability we see. Guidance suggests we'll only max out at around 500 J/kg of CAPE in some locations - mainly over eastern AR, western TN, and western MS, which is where the SPC has placed a Marginal Risk for severe storms. The best chance for seeing strong storms will be Saturday night into Sunday. Damaging winds will be the main threat. Temperatures will be in the low to upper 60s for highs. As we start off the work-week, we'll dry out and see cooler temperatures with westerly/northwesterly flow as a ridge builds over the region. High temperatures will be in the upper 40s/low 50s and lows in the 30s. The next system to bring widespread rain to the area will be on Thursday. KRF && .AVIATION... /12Z TAFs/ Mainly MVFR conds across the area right now...with LIFR conds at JBR due to dense fog and 200 foot CIGs. Conds will be slow to improve this morning, but should return to VFR at all sites by late afternoon. Scattered showers and drizzle are possible again today, but confidence is not high enough to add on station. Winds will remain 5 kts or less from the east through the period. Conds will deteriorate after sundown, with light fog and lower CIGs moving in at all sites. AC3 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Dense Fog Advisory until 9 AM CST this morning for Clay- Craighead-Crittenden-Cross-Greene-Lee AR-Mississippi- Phillips-Poinsett-St. Francis. MO...Dense Fog Advisory until 9 AM CST this morning for Dunklin- Pemiscot. MS...None. TN...None. && $$