Area Forecast Discussion
Issued by NWS Memphis, TN
Issued by NWS Memphis, TN
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096 FXUS64 KMEG 211150 AAA AFDMEG Area Forecast Discussion...UPDATED National Weather Service Memphis TN 650 AM CDT Tue May 21 2024 ...New AVIATION... .SYNOPSIS... Issued at 302 AM CDT Tue May 21 2024 An unsettled weather pattern kicks off tonight as several systems will cross the Mid-South. Wednesday night into Thursday is currently the highest chance of severe weather. Temperatures will continue to be near to above normal through the forecast period. Rain chances are highest along and north of Interstate 40 with forecast precipitation amounts of 4 to 6 inches over the next 7 days. && .DISCUSSION... (Today through Monday) Issued at 302 AM CDT Tue May 21 2024 High pressure will continue to be pushed east by a complex of thunderstorms as a low pressure system ejects from the four corners region. An MCS is likely to decay as a very dry air is depicted aloft on water vapor satellite imagery. A Marginal Risk is in effect tonight for northeast Arkansas and a portion of the Missouri Bootheel. If a bowing segment is able to materialize, the forecast environment may possess around 40kts of 0-6km bulk shear for a damaging wind threat. As the cluster decays, it will be a race against time due to diurnal stability trends. Confidence is low in severe weather materializing, but a few storms could bring some gusty winds and maybe small hail. Tonight kicks off an unsettled weather pattern. NBM Thunderstorm probabilities hang around the 30-60% range beginning Wednesday afternoon through Monday. The attention does shift to Wednesday afternoon into evening where an Enhanced Risk for severe weather has been introduced. Southwesterly flow will surge a moisture plume and bring dewpoints into the 70s ahead of a strong cold front. Deterministic soundings are indicative of a damaging wind and large hail as the primary threats. Inverted V soundings will provide excellent mixing with around 50kts of effective shear. Unstable lapse rates (~7 C/km) through the column with MLCAPE ~2500 J/kg may bring large, to very large hail mainly to northeast Arkansas and the Missouri Bootheel. On a positive note, 0-1km and 0-3km SRH values are low which keeps the tornadic threat low compared to the wind and hail threats. PWs are hanging in the 90th percentile or higher, meaning locally heavy rainfall is possible. Particularly with any strong updrafts could lead to localized flooding. Current QPF values are highest along and north of I-40. A Flood Watch may be needed if QPF continues to trend upward. While it will not rain or thunderstorm the entire forecast period (some areas may have breaks), another cluster of thunderstorms will move through Thursday night into Friday. Several series of systems continue to cross each night until dry conditions return Tuesday evening. This active pattern is a result of the a heat dome over Mexico making the Mid-South and adjacent areas susceptible to an active weather pattern. QPF for the next 7 days range from 4-6" along and north of I-40 and areas like Aberdeen, MS may only see an inch. We will keep an eye on this active weather pattern and monitor any severe potential in the coming days. DNM && .AVIATION... (12Z TAFS) Issued at 650 AM CDT Tue May 21 2024 Wind will remain the primary concern today. KNQA VAD wind profiler shows 25-30KT in the lowest 3 gates, will will likely be near the peak surface gust potential through mid-afternoon. Scattered TSRA will roll into northeast AR late this evening, then into west TN overnight. 06Z HRRR depicts weaker mixed layer instability east of the MS River, with perhaps lower lightning coverage around MEM. For now, will maintain a PROB30 in the MEM TAF, in-line with the Extended TCF. Increased TSRA chances appear in store after 18Z Wednesday, beyond the 30 hour MEM TAF. This TSRA will hold the potential for more impactful winds, owing to greater daytime convective instability. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...DNM AVIATION...PWB