Area Forecast Discussion
Issued by NWS Jackson, MS
Issued by NWS Jackson, MS
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310 FXUS64 KJAN 250246 AAA AFDJAN Area Forecast Discussion...UPDATED National Weather Service Jackson MS 946 PM CDT Tue Sep 24 2024 ...New MESOSCALE UPDATE... .MESOSCALE UPDATE... Issued at 937 PM CDT Tue Sep 24 2024 Local radars continued to show scattered showers and thunderstorms across central and east Mississippi this evening. This activity was southeast of a weak cold front noted near a line from Winnsboro Louisiana to Grenada Mississippi. Satellite imagery showed southwest flow aloft across our CWA around a closed low noted spinning over the mid Mississippi valley. Although the convection ahead of the cold front has shown a decrease in intensity the last couple of hours, additional redevelopment will remain possible into morning as a subtle shortwave within the sw flow aloft moves overhead. There were a few severe storms that developed earlier this evening but the additional convection tonight should remain subsevere. /22/ && .DISCUSSION... Issued at 303 PM CDT Tue Sep 24 2024 Today and Tonight... The forecast remains on track today: Today`s forecast looks to bring rain showers (30-50% coverage) and cloudy conditions along a weak frontal boundary pushing into the area. Current observations establish the boundary through the southeastern corner of Arkansas with surface temperatures and dew points lower in central AR. The upper level dynamics associated with the attendant low have begun to shift northward, cutting off any major support and therefore chances for significant deepening and subsequent strengthening of the feature have diminished. Unsurprisingly, this cut off low, has lost a lot of momentum and is projected to slowly amble its way through the region today. Afternoon heating coupled with an upper level disturbance is expected to provide lift today to support the develop of scattered showers with embedded thunderstorms. The line of showers is not expected to be completely filled in, so some sites may not see any rainfall today. There is a possibility for isolated strong storms due to a combination of instability and deep effective shear of 40- 45kts, which have the potential to produce gusty thunderstorms with small hail. The convective outlook marginal risk area remains just to our north across northeast Mississippi. Another lobe of energy is forecast to pivot through the region during the late parts of tonight and into the early morning tomorrow. Providing us with a substantial increase in overall coverage (35%-70%). There`s some indication of slower propagation of activity during this timeframe which could result in locally higher rain totals of 1-2". This afternoon will be our last bout of temperatures breaking into the low 90s F for the foreseeable feature as the front is expected to bring widespread cloudiness over the CWA for the next few days. The incoming regime will establish a more seasonal temperature profile, with highs in the mid to low 80s F and lows in the low 60s F. The 850mb front is expected to stall out over the region, and with minor overnight retrograding, we will likely see a repeat of today`s weather over the next few days. Tomorrow and Thursday... Light rain showers will be the main topic of discussion as it is projected to dominate throughout the forecast area Wednesday. The intensity and coverage will be less impressive tomorrow, as our major source of ascent will have pivoted around the upstream low and migrated into TN tomorrow. Hourly rain rates are projected to be at or below 0.01/hr for all sites, with the exception of the areas surrounding Winston county which could see totals for the 48 hour period exceeding an inch. Thursday Night through Friday Night... The late week and weekend period will be characterized by an unorthodox Fujiwhara-like intercyclonic setup. While the low associated with the aforementioned stalled out frontal boundary lingers in western TN/central AR, another cyclonic feature, tropical in nature, will make its way ashore near the Florida panhandle from the Gulf of Mexico. This unorthodox interplay will have Helene pull in moisture from the Gulf, rotating around the low before feeding into the Low in western TN/central AR. The moisture transport around the mid latitude will feed into and over Tennessee, before the making its way over the CWA in the form of cloudy residue; since most the moisture will have rained out before reaching us. That being said there looks to be a narrow channel of precipitation that may develop through far east and northern reaches of the area of responsibility, in the lead up to Helene moving into Georgia. Saturday through Tuesday... We look to return to a more typical mid latitude setup as Helene merges with the cut-off low, and upper level dynamics sweep southward and begin to pull the low off towards the mid Atlantic seaboard. A restoration of seasonal weather is in store for the remainder of the forecast, with highs in the mid to low 80s and lows in the mid to low 60s F and stark precipitation chances./OAJ/ && .AVIATION... (00Z TAFS) Issued at 643 PM CDT Tue Sep 24 2024 VFR conditions were observed at all TAF sites at 2330Z and VFR conditions wl prevail at GLH-GWO through the end of the TAF period. Elsewhere a cold front wl sag across the area through Wed aftn and result in isolated to scattered SHRA/TSRA at the TAF sites. MVFR/IFR cigs wl develop by 10Z and prevail until after 15Z. VFR conditions are expected by 16Z and wl continue through the end of the TAF period away from any SHRA/TSRA activity. /22/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 69 82 64 80 / 70 50 20 20 Meridian 68 81 64 79 / 90 60 40 30 Vicksburg 68 83 63 81 / 50 40 10 10 Hattiesburg 71 88 67 83 / 30 50 30 20 Natchez 69 84 64 81 / 40 40 10 10 Greenville 64 80 61 78 / 10 30 10 10 Greenwood 65 81 61 81 / 20 30 10 20 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ /OAJ/22