Area Forecast Discussion
Issued by NWS Memphis, TN
Issued by NWS Memphis, TN
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856 FXUS64 KMEG 250432 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1132 PM CDT Fri May 24 2024 ...New AVIATION... .UPDATE... Issued at 950 PM CDT Fri May 24 2024 Evening convection has finally weakened or moved out of the Mid- South leaving a few quiet hours before the next round starts up. Shower and thunderstorms are developing along the I-44 corridor as a cold front presses into the MS River Valley this evening. While that convection approaches from the NW another cluster of storms over southern AR will approach from the west. These clusters of storms will have an unstable and moist airmass to work with across the Mid-South. MLCAPES range from 1500-3000 j/kg with marginal 0-6km shear values of 30-35 kts. This environment could support some severe storms overnight. PWs over 1.5 inches will support locally heavy rain and isolated flash flooding. Latest CAMS indicate that the most active time will be from midnight to 6 am with activity pushing into Middle TN and north AL thereafter. Most of Saturday looks pretty good though redevelopment could occur by late afternoon. && .SYNOPSIS... Issued at 323 PM CDT Fri May 24 2024 Unsettled weather will persist through Memorial Day weekend with multiple rounds of heavy rain anticipated. In addition, severe weather chances will return on Sunday. The main concern at this time will be flooding as elevated rainfall rates accompany storms through Monday morning. Fortunately, dry conditions should return by Wednesday. && .DISCUSSION... (This evening through next Thursday) Issued at 323 PM CDT Fri May 24 2024 3PM radar imagery depicts mostly dry conditions over the Mid- South with a few pop-up thunderstorms forming over portions of north Mississippi. Overall confidence for storm coverage this afternoon and evening is low due to uncertainties regarding how well the environment will recover from this morning`s convection. However, satellite imagery depicts clearing skies over portions of the Mid-South, which may further encourage storm development over the next few hours. If storms do materialize, damaging winds and large hail will be the main concerns. Greater confidence exists overnight for a line of showers and thunderstorms to dive southeast across Missouri, impacting the Mid-South after midnight. The severe weather threat with this line will be low due to the presence of a strong Elevated Mixed Layer. Instead, the greatest concern will be heavy rainfall as precipitable water values are forecast to be around the 99th percentile. Prolific rainfall rates are anticipated overnight, with a few areas forecast to see an additional 1 to 2 inches of rain. Additional precipitation will further aggravate rivers and streams, leading to rises above bankfull. We strongly suggest at this time that you have a flood plan in place through the weekend. A Flood Watch has been issued for the entire Mid-South through Monday morning. A lull in precipitation is possible by midmorning Saturday as the aforementioned line pushes out of the area. There is a chance for thunderstorms to redevelop in northeast Mississippi in the late afternoon hours, but confidence for this remains low. If a storm does develop, it will be capable of damaging winds. Additional severe weather chances appear likely on Sunday as a shortwave trough ejects across the Central Plains. Some model discrepancies are evident for this forecast package, with the ECMWF favoring a more progressive system tracking across southern Missouri. If this solution materializes, severe weather impacts will be more likely across the Mid-South, especially in areas of northwest Tennessee. Timing of severe weather appears to be Sunday evening into the overnight hours. At this time, midlevel lapse rates are forecast to be around 7.5 C/km. In addition, MLCAPE around 2500 J/kg and 0-3 km SRH of 250 m2/s2 are forecast. Therefore, any storm that does develop will be capable of producing all hazards of severe weather. By midweek, upper level ridging should put an end to our unsettled weather pattern with dry conditions returning Wednesday. ANS && .AVIATION... (06Z TAFS) Issued at 1130 PM CDT Fri May 24 2024 CAMs continue in decent disagreement on timing and intensity of convection across each terminal overnight. The line looks to begin impacting JBR/MEM/MKL around 06Z with TEMPO TSRA and reduced visbys with its movement. VFR conditions look to remain across all terminals ahead of a brief period of MVFR at JBR/MKL around 10Z through late morning. PROB30s were added at MKL/TUP tomorrow afternoon into evening to catch a few clusters of convection along a few shortwaves expected to affect said terminals. South/southwest winds are expected to remain at around 4-8kts through the TAF period. AEH && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Flood Watch through Monday morning for ARZ009-018-026>028-035- 036-048-049-058. MO...Flood Watch through Monday morning for MOZ113-115. MS...Flood Watch through Monday morning for MSZ001>017-020>024. TN...Flood Watch through Monday morning for TNZ001>004-019>022- 048>055-088>092. && $$ PUBLIC FORECAST...SJM AVIATION...AEH