Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
499 FXUS64 KLIX 050450 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1150 PM CDT Fri Oct 4 2024 ...New AVIATION... .SHORT TERM... (This evening through Saturday night) Issued at 300 PM CDT Fri Oct 4 2024 A weak surface trough and upper impulse over the region is helping generate widespread shower activity generally along the coast...generally along and south of I10/12. This is where the highest QPF values will reside through the short term period. PWATs are at CLIMO record levels...around 2.5" on the 12z sounding. Localized hydro concerns will remain possible, especially urbanized areas. The clouds and rain are helping keep temperatures on the low side with most of the region only warming into the upper 70s or lower 80s. The warmer temps will likely be inland with the lower rain chances. Going into Saturday surface riding will take shape down the spine of the Appalachians and across the northern Gulf Coast. This should help suppress the rainfall just a bit with the best chances being right along the coast or offshore during the day Saturday as the upper trough (TUTT) remains over the region. (Frye) && .LONG TERM... (Sunday through Thursday night) Issued at 300 PM CDT Fri Oct 4 2024 Eyes begin to shift south of our region on Sunday and going into the upcoming workweek. Modest are still struggling to resolve what eventually happens with the CAG and whether or not tropical development takes shape. The recent operational GFS (12z) and ECM (00z) both have a surface low developing across the Bay of Campeche. The upper level trough should then pick up this feature and send it over to Florida by midweek. For our region, a cold frontal boundary will move through the area on Monday. The parent trough will be the responsible player in keeping anything tropical to our south and east through the medium range. As dry air filters into the region behind the front, expect overall a quiet weather pattern. The only highlight of concern with a tightening pressure gradient in the Gulf would be the moderate to strong easterly fetch across the northern Gulf. Over time this will allow water to pile up on eastern facing coastlines. A coastal flood adv may become necessary later this weekend as water level rise allowing for some minor flooding during high tide cycles. Otherwise, temperatures look "fresh" through the medium range with overnight lows mid to late week perhaps dropping into the 50s along and north of I10/12. (Frye) && .AVIATION... (06Z TAFS) Issued at 1146 PM CDT Fri Oct 4 2024 Primary concern will be the development of IFR stratus ranging between 300 and 800 feet at the more inland terminals like MCB, HDC, and BTR as moisture remains trapped beneath a weak inversion layer. At ASD and GPT, the inversion will be weaker, and this will keep prevailing IFR ceilings from developing. However, occasional periods of IFR conditions will develop through 10z and this reflected by a TEMPO group. After 14z, increased mixing of drier air aloft will lead to improved conditions as the inversion lifts. This will result in prevailing VFR conditions at all of the terminals from 15z onward. PG .AVIATION... (00Z TAFS) Issued at 623 PM CDT Fri Oct 4 2024 The atmosphere has stabilized from the previous rainfall and that has resulted in much lighter rainfall and no visibility impacts for the terminals this evening. However, a mix of IFR and MVFR ceilings ranging from 800 to 1500 feet will linger through the overnight hours as deep tropical moisture remains in place beneath a weak elevated temperature inversion near the surface. As the inversion mixes out tomorrow morning, drier air in the mid- levels that is forecast to advect into the area late tonight behind a passing front will begin to mix down to the surface. This will allow cloud bases to rise to between 2500 and 3500 feet after 14z tomorrow, resulting in prevailing MVFR and VFR conditions at all of the terminals. Rain chances will also diminish with this drier air with only the extreme coast of Louisiana and the offshore waters seeing any rainfall that could limit visibilities. PG && .MARINE... Issued at 300 PM CDT Fri Oct 4 2024 Moderate easterly flow will develop this weekend. Cautionary headlines are already out, but SCAs may be required as a broad low pressure across the southern Gulf interacts with high pressure over the Southern Appalachians. With the develop surface low over the gulf and some upper level support from a weak shortwave trough, showers and a couple of thunderstorms will be possible this weekend. A cold front will move through the region early next week, which should push most of the shower and thunderstorm activity to the south. ENE surface winds will increase further behind the front and a continuation of hazardous marine conditions will continue through the end of the forecast period. (Frye) && .PRELIMINARY POINT TEMPS/POPS... MCB 68 87 65 87 / 20 0 0 0 BTR 72 90 70 92 / 20 0 0 0 ASD 71 86 70 88 / 30 10 10 10 MSY 73 84 73 87 / 20 20 10 10 GPT 71 84 70 86 / 40 20 10 10 PQL 72 86 70 89 / 40 20 10 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...RDF LONG TERM....RDF AVIATION...PG MARINE...RDF