Area Forecast Discussion
Issued by NWS Jackson, MS
Issued by NWS Jackson, MS
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940 FXUS64 KJAN 241715 AAB AFDJAN Area Forecast Discussion...UPDATED National Weather Service Jackson MS 1215 PM CDT Tue Sep 24 2024 ...New AVIATION... .MESOSCALE UPDATE... Issued at 1002 AM CDT Tue Sep 24 2024 Today`s forecast looks to bring rain showers (30-50%) and cloudy conditions associated with a weak frontal boundary pushing into the area. Current observations distinguish the weak boundary laying through the southeastern corner of Arkansas with temperatures and dew points trending 4F lower behind it. 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 remain limited. Unsurprisingly, this cut off low, has lost a lot of momentum and is projected to slowly amble its way through the region today Daytime heating is expected to provide just enough lift this afternoon to begin to precipitate out the Mississippi moisture profile, with current HRRR/GFS runs depicting rain totals averaging under half an inch along the front as it meanders through this afternoon. The line of showers is not expected to be completely filled in, so some sites may not see any rainfall today. This line will be located in the northwest quadrant and propagate through the southeast by midnight. There is a possibility for isolated thunderstorms embedded in the overall line of showers, but lapse rates look to be generally unfavorable for widespread development. 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 with less coverage and intensity./OAJ/ && .DISCUSSION... Issued at 343 AM CDT Tue Sep 24 2024 Through tonight: A cold front is currently making rather slow progress into the region and will continue to do so through tonight. Ahead of this front, scattered showers have been moving across northeast LA and the ArkLaMiss Delta early this morning. This activity is expected to lose steam as daybreak approaches. However, with diurnal heating, redevelopment of showers is expected ahead of the front this afternoon. Marginally supportive bulk shear and sufficient instability will exist for isolated storms to develop. However, relatively weak forcing, marginal mid level lapse rates, and largely boundary-parallel flow should help temper intensity. Tonight, a more vigorous upper disturbance is on track to move across the area as it rounds a cutoff upper low pivoting into the Mid-Mississippi Valley. Increased forcing associated with this feature should yield greater coverage of showers and embedded thunderstorms along and ahead of the front, even as we head into the overnight. While rainfall amounts will average below a half inch in most areas, locally higher amounts will be possible with HREF LPMM suggesting max localized totals in the 2-4" range. Given current ground conditions with these amounts, flooding is not a concern at this time. Cooler and somewhat drier air will begin to move in from the north tonight behind the front, with airmass change becoming more noticeable in the following days. /DL/ Wednesday through Monday: Extended forecast remains on track as a stalled frontal boundary keeps wet conditions across the area and Potential Tropical Cyclone Nine (PTC 9) moves northward into the southern Gulf of Mexico. Thanks to both the stalled frontal boundary and increased cloud cover from the tropical system, slightly below to near average high/low temps are expected. A slow-moving closed low forms over the Ozarks/ArkLaTex region as a blocking pattern comes into place and a stalled frontal boundary is expected to remain situated over the CWA, continuing rain chances (25-60%) for the area. Turning to the tropics: a tropical disturbance (now PTC 9) is expected to migrate northwards toward the Gulf of Mexico. Models are in agreement in tracking and strengthening the system into a hurricane in the eastern Gulf, affecting FL panhandle near Thursday. Interaction between the closed-low and tropical cyclone is expected to bring abundant moisture to the region. IVT and PW values are expected to be near the 99th and maximum percentile, resulting in possible heavy rainfall across the area through Friday, especially in eastern and northern parts of the CWA. As the remnants of the tropical cyclone absorb into the main flow and the closed low moves out of the area, rain chances will begin to decrease for majority of the area this weekend. Continue to check back for updates as the event gets closer. /SW/ && .AVIATION... (18Z TAFS) Issued at 1213 PM CDT Tue Sep 24 2024 VFR flight conditions will persist across all sites for the beginning of the TAF period. Expect southeasterly winds between 5-10 kts. -RA/VCTS will be possible this afternoon and evening. As a result, MVFR/IFR flight categories will be possible towards the end of the TAF period. /OAJ/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 68 83 64 80 / 60 50 30 30 Meridian 68 83 64 80 / 50 60 50 50 Vicksburg 68 83 62 80 / 50 30 20 20 Hattiesburg 70 88 68 83 / 20 50 40 40 Natchez 69 83 63 80 / 40 40 10 10 Greenville 64 79 60 78 / 10 30 10 20 Greenwood 65 81 61 80 / 20 30 20 30 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ OAJ/SW/OAJ