450 FXUS64 KMEG 110901 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 401 AM CDT Fri Aug 11 2023 ...New UPDATE... .UPDATE... Issued at 400 AM CDT Fri Aug 11 2023 Updated to expand the Dense Fog Advisory. && .SYNOPSIS... Issued at 249 AM CDT Fri Aug 11 2023 Today through the weekend, excessive rain and thunderstorms should not be as widespread as we have seen for the past few days, but August heat is returning. We will likely need Heat Advisories and possibly Excessive Heat Warnings through the weekend and maybe on Monday before cooler temperatures return to the Midsouth. We should see mostly dry conditions Tuesday through Friday with high temperatures in the middle 80s to low 90s. && .DISCUSSION... (Today through Thursday) Issued at 249 AM CDT Fri Aug 11 2023 Abundant ground moisture from recent heavy rain, light wind, and mainly clear skies above ~2,000 feet have resulted in prime conditions for fog across the Midsouth. Visibilities below 1/4 of a mile have already been observed at many locations and will likely only become more widespread through sunrise. A Dense Fog Advisory has been issues for most of the Midsouth and may need to be expanded area wide now that clouds have moved out of northeast Mississippi. After sunrise, fog and low clouds should dissipate quickly and temperatures will skyrocket. A Heat Advisory has been issued for east Arkansas, the Missouri Bootheel, Shelby county Tennessee, and portions of north Mississippi. Heat indices may approach 110 degrees. We remain under weak northwest flow with a ridge building over east Texas and Louisiana. The strengthening ridge will result in much warmer conditions today through the weekend. Today should be mostly dry, but we may still see a round or two of thunderstorms. Thunderstorms should be mainly mainly confined to northern and especially northeastern portions of the Midsouth tonight, Saturday and Sunday as weak impulses track across Missouri and northern portions of west Tennessee. A few strong to severe thunderstorms are possible, but widespread hazardous conditions are not expected. The higher likelihood of severe thunderstorms should remain to our north where shear is stronger. The primary threat for any severe storms in the Midsouth would be from damaging wind and large hail today through the weekend. Sunday into Monday, a deep midlevel trough will track out of the northern Rockies and across the central Plains. This feature will become oriented from the Great Lakes into the southern Plains by Midday Monday. At the surface, an attendant cold front will move quickly across the Midsouth on Monday. We could still see heat advisory conditions(105-109 heat index) in north Mississippi and east central Arkansas Monday afternoon ahead of the front, but cooler conditions should arrive to all of the Midsouth by Tuesday. Several days of mostly dry conditions is expected next week beginning Tuesday. Below normal temperatures are expected Tuesday and Wednesday. Expect highs mostly in the 80s and lows in the 60s. As the ridge restrengthens to our southwest, gradual warming will take place Thursday and Friday with high temperatures returning to the 90s. 30/Sirmon && .AVIATION... (06Z TAFS) Issued at 115 1153 PM CDT Thu Aug 10 2023 IFR/LIFR visibilities appear on track to form through the overnight, north of a stationary surface boundary extending from near UTA eastward to between TUP and CRX. MEM may stay altitude more mixed, with low stratus deck more elevated in nature, with LIFR ceilings and IFR visibility. Occasional LIFR, in any case. Conditions should rapidly improve after 15Z, with the onset of stronger surface heating. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Dense Fog Advisory until 8 AM CDT this morning for ARZ009-018- 026>028-035-036-048-049-058. Heat Advisory from noon today to 8 PM CDT this evening for ARZ009-018-026>028-035-036-048-049-058. MO...Dense Fog Advisory until 8 AM CDT this morning for MOZ113-115. Heat Advisory from noon today to 8 PM CDT this evening for MOZ113-115. MS...Dense Fog Advisory until 8 AM CDT this morning for MSZ001>017- 020>024. Heat Advisory from noon today to 8 PM CDT this evening for MSZ001-007-008-010>012-016-017-020>024. TN...Dense Fog Advisory until 8 AM CDT this morning for TNZ001>004- 019>022-048>055-088>092. Heat Advisory from noon today to 8 PM CDT this evening for TNZ088. && $$ PUBLIC FORECAST...JDS AVIATION...PWB