Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
617 FXUS64 KLIX 030507 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1207 AM CDT Wed Sep 3 2025 ...New SHORT TERM, LONG TERM, AVIATION, MARINE... .SHORT TERM... (Today through Thursday) Issued at 1204 AM CDT Wed Sep 3 2025 Upper ridging from the Four Corners area to British Columbia. A large upper trough was over the eastern half of the country, with multiple shortwaves rotating through the trough. One such shortwave was near Interstate 40 during the late afternoon hours. This has kept the local area in a very persistent northwesterly mid-level flow. At the surface, weak low pressure centers were noted over Kentucky and northern Arkansas. Most of the evening regional upper air soundings reported precipitable water values in the 1.3 to 1.5 range, which is near or below the 25th percentile climatologically. Even at the surface, mid afternoon dew points were in the lower and middle 60s for much of the area. There were some isolated showers and thunderstorms near Interstate 20 after sunset, but they were weakening quickly. There were also a few showers over the far southwestern coastal waters. Another shortwave will be rotating into the base of the main trough over the next 18-24 hours. There will not be much of a surface pressure reflection associated with this shortwave, and moisture will be very sparse. Anything more than an isolated shower or storm would be unexpected, and that would primarily be near and northwest of a Baton Rouge to McComb line. Conditions will be even less favorable for measurable precipitation on Thursday, as any significant shortwave energy will be well northeast of the area. While high temperatures will be near to above normal, upper 80s to middle 90s, dew points mainly in the 60s should keep heat index values well below advisory criteria. Overnight lows should be near, or perhaps slightly below normal. && .LONG TERM... (Thursday night through Tuesday) Issued at 1204 AM CDT Wed Sep 3 2025 As we get into Friday, the mean upper trough will be weakening on the southern end, with the upper flow being a bit more zonal across the northern Gulf Coast. A southern stream shortwave will be moving across Texas on Friday, but isn`t expected to be close enough to impact the weather that day, even if we had sufficient moisture. Highs in the lower to middle 90s will remain in place for Friday and maybe only a couple degrees cooler on Saturday. Low level flow will start to turn onshore by late Saturday, and moisture levels should start to increase. By midday Sunday, moisture levels should be in the 1.7 to 2.0 range for much of the area, a more normal level for early September. Monday and Tuesday, much of the area will have precipitable water values in excess of 2 inches, generally near or above the 90th percentile. With the upper trough re-establishing itself over the Lower Mississippi River Valley, we`ll see a return to the daily threat for showers and thunderstorms for Sunday through Tuesday, especially during the afternoon and early evening hours. More clouds and precipitation will hold high temperatures in the 80s for those 3 days. Any threat of locally heavy rainfall probably won`t start to increase until perhaps Sunday night or Monday. At that point, most of the local area will be approaching 10 days of dry weather. Forecast rain amounts don`t look sufficient to produce any widespread issues through the end of the forecast period. && .AVIATION... (06Z TAFS) Issued at 1204 AM CDT Wed Sep 3 2025 Generally VFR conditions expected through the forecast period. Have seen brief CIGs around FL060 at northwestern airports over the last few hours. If there`s going to be any significant precipitation impacting a terminal, it would be KMCB or perhaps KBTR during the late afternoon. At this point, the probability is too low to justify anything more than a PROB30 at KMCB, and won`t mention at KBTR right now, although the threat is non-zero. && .MARINE... Issued at 1204 AM CDT Wed Sep 3 2025 Overall, no major impacts to maritime operations are expected through the weekend. Through tonight, a weak frontal boundary will remain stalled off the coast of Louisiana. Scattered thunderstorm activity and east winds of 10 to 15 knots are expected over the far offshore waters with this boundary in place. A drier surface high will settle in for Thursday and Friday with very low rain chances, light winds, and nearly calm seas. This high will begin to move to the east on Saturday allowing for a light southerly flow to develop. Offshore shower and thunderstorm activity will also increase as moisture feeds back into the area over the weekend. && .PRELIMINARY POINT TEMPS/POPS... MCB 88 69 91 70 / 30 10 0 0 BTR 91 71 93 72 / 20 10 10 0 ASD 90 69 91 70 / 10 0 0 0 MSY 92 74 93 75 / 0 0 10 0 GPT 89 71 89 72 / 0 0 0 0 PQL 90 68 91 70 / 0 0 0 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...RW LONG TERM....RW AVIATION...RW MARINE...RW