Area Forecast Discussion
Issued by NWS Memphis, TN
Issued by NWS Memphis, TN
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905 FXUS64 KMEG 281148 AAA AFDMEG Area Forecast Discussion...UPDATED National Weather Service Memphis TN 648 AM CDT Sun Apr 28 2024 ...New AVIATION... .SYNOPSIS... Issued at 352 AM CDT Sun Apr 28 2024 A wet and unsettled period for the Mid-South will begin today as showers and thunderstorms return late this evening. Temperatures on Monday will be slightly cooler thanks to increased cloud cover with highs in the mid to upper 70s. However, daily rain chances and temperatures in the 80s will return by Wednesday. && .DISCUSSION... (Today through Saturday) Issued at 352 AM CDT Sun Apr 28 2024 The upper level low responsible for Saturday`s severe weather outbreak in the Plains will push northeast today, ejecting an attendant cold front into western Arkansas. While this boundary appears to washout before reaching the Mid-South, the pressure gradient will tighten later this morning. The WSUP Viewer paints most of northeast Arkansas and the Missouri Bootheel in a 50-70% chance of exceeding Wind Advisory criteria through this afternoon. As such, a Wind Advisory will be in effect from 8AM to 7PM. A limited severe weather threat may materialize for a few hours tonight as a line of showers and thunderstorms pushes into northeast Arkansas and the Missouri Bootheel. Forecast soundings at this time depict bulk shear around 40 kts with mid level lapse rates of 6.5 C/km. Upscale growth of storms will be limited by 2 factors: the first being instability as both GEFS and ECMWF ensembles paint only a 30% chance of > 500 J/kg of SBCAPE. The second limiting factor will be the potential for a capping inversion to develop after sunset. If a severe storm does materialize, the main concern will be damaging winds. A Slight and Marginal Risk for severe storms is in place through Monday morning for areas along and west of the MS River. Precipitable water values through Monday afternoon are forecast to be around 1.6 inches, which is around the 99th percentile for this time of year. Therefore, showers and storms will likely be efficient rainfall producers. Storm total precipitation from now through Monday night will range from 1 - 2 inches, with locally higher amounts possible. As such, a Slight Risk for excessive rainfall is in place across the majority of the Mid-South through Monday. A brief lull in precipitation will occur on Tuesday as quasi- zonal flow aloft returns. By Wednesday, daily rain chances will return as several shortwaves, embedded in zonal flow, transverse the Mid-South. One thing to note: both the GFS and ECMWF depict a negatively tilted trough pushing into the Midwest on Friday. The GFS solution brings this system much further south than the ECMWF. If this southern trend continues, severe weather chances may materialize. However, confidence now remains low for severe weather through the end of the week. ANS && .AVIATION... (12Z TAFS) Issued at 648 AM CDT Sun Apr 28 2024 Surface winds to remain the primary impact today. A few gusts in excess of 30KT cannot be ruled out at JBR this morning, once the mixed layer deepens with daytime heating. A convective cap should limit daytime TSRA chances at JBR, and preclude daytime TSRA at the remaining TAF sites. The cap will weaken with the approach of a midlevel trough by late evening. CAM consensus remains relatively tight with onset TSRA timing, if slightly faster than the Extended TCF. It`s probable that convective outflow will begin to outrun the TSRA after 06Z, with diminishing TSRA coverage thereafter. This may be the reason that the TCF depicts limited TSRA coverage east of MEM after 07Z. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Wind Advisory until 7 PM CDT this evening for ARZ009-018-026>028. MO...Wind Advisory until 7 PM CDT this evening for MOZ113-115. MS...None. TN...Wind Advisory until 7 PM CDT this evening for TNZ001. && $$ PUBLIC FORECAST...ANS AVIATION...PWB