269 FXUS64 KJAN 171721 AAA AFDJANArea Forecast Discussion...UPDATED National Weather Service Jackson MS 1221 PM CDT Wed Sep 17 2025
...New AVIATION...
.MESOSCALE UPDATE... Issued at 1005 AM CDT Wed Sep 17 2025
The early morning fog has dissipated and under strong insolation, temperatures are warming as expected. Per the 12Z Wed JAN sounding PWATs were still around an inch and a half. With the lower heights overhead due to our troughing aloft from the northeast, daytime heating of our airmass should lead to isolated showers and thunderstorms again this afternoon. Thus, the forecast remains on track. /22/
&&
.DISCUSSION... Issued at 126 AM CDT Wed Sep 17 2025
Today and Tonight...
A few upward adjustments were made to the forecast regarding the convective coverage for our entire CWA later this afternoon, as guidance suggest slightly higher rain chances later today. The center of the upper-level low pressure system over the Northern Rockies and the eastern CONUS will continue to weaken today. As this low continues to weaken, near term guidance shows shortwave trough amplification over a good portion of our forecast area. This combined with southwesterly moisture advection flow will help yield more areal coverage of late afternoon/early evening scattered showers and t-storms across our CWA. A few strong storms with wind gusts up to 40 mph cannot be ruled out. Afternoon highs will peak into the low to mid 90s areawide.
A few lingering showers will be possible later this evening as the upper-level sfc low tracks northward towards the Upper East Coast. Quiet conditions will prevail over our CWA heading into the overnight period. HREF guidance is starting to show low probabilities (around 10-20%) of patchy fog development across our area. Confidence is too low to introduce any fog graphics at this time, however shallow fog will be possible around dawn. Nighttime lows will drop into the upper 60s/low 70s areawide. /CR/
Thursday through Tuesday...
Quiet conditions will prevail across most of our CWA Thursday and Friday, with a slight chance of an isolated shower across portions of southeast AR and a few northeast LA parishes. Rain chances will start to increase across northern portions of our CWA through the weekend as a positively tilted trough axis moves over the southeast CONUS. Late afternoon/early evening showers and t-storms will continue heading into the new work week. /CR/
&&
.AVIATION... (18Z TAFS) Issued at 1217 PM CDT Wed Sep 17 2025
There is a very low chance for -SHRA/-TSRA to come in vcty of the TAF sites 20-24Z. Otherwise, VFR conditions and a light wind will prevail through the TAF period. /22/
&&
.PRELIMINARY POINT TEMPS/POPS... Jackson 92 69 92 69 / 20 20 0 0 Meridian 93 67 93 68 / 10 10 0 0 Vicksburg 93 69 93 68 / 20 20 0 0 Hattiesburg 94 67 94 67 / 10 10 0 0 Natchez 92 68 92 67 / 20 20 0 0 Greenville 94 69 94 68 / 20 20 0 0 Greenwood 94 68 95 68 / 20 20 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. &&
$$
22/CR/22
NWS JAN Office Area Forecast Discussion