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Show Area Forecast Discussion - New Orelans, LA (LIX) (New Orleans, LA Area) Selection: |
| #1210482 (Received by flhurricane at: 6:06 AM 03.Dec.2024) AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 447 AM CST Tue Dec 3 2024 ...New AVIATION... .SHORT TERM... (Today through Wednesday) Issued at 333 AM CST Tue Dec 3 2024 Upper trough remains along the East Coast this morning, with ridging from New Mexico to British Columbia. A trough was off the California coast to the west of the ridge. At the surface, high pressure extended from Iowa to the northern Gulf of Mexico. There were a few reports of fog near water sources, but this doesn`t seem to be widespread at this time. Temperatures at 3 AM CST were generally from the mid 30s to lower 40s, except Lakefront Airport (56F), where the warmer water of Lake Pontchartrain held the temperatures up. The high pressure over Iowa this morning will sink southeastward to Florida by Wednesday afternoon. This will keep winds northerly to northeasterly today and most of tonight. By midday Wednesday, surface flow will become southeasterly, allowing moisture to finally return to the area. Precipitable water values were near 0.30 inches on the 00z LIX sounding, and those values won`t change much until the daytime hours on Wednesday. We`ll start to see mid-level (near 700 mb) clouds arrive prior to sunrise Wednesday, gradually saturating the lower levels during the daytime hours with precipitable water values climbing to about 1.5 inches. Could see a few patches of light rain or showers arrive in northwest areas, west of McComb and Baton Rouge prior to sunset Wednesday. Forecast temperatures don`t look unreasonable. Cold advection will hold temperatures down from yesterday`s levels today. Overnight lows will be chilly again with a few of the normally colder spots potentially hitting freezing again. The mid level clouds could mean temperatures starting to rise shortly before sunrise Wednesday, depending on just how quickly they arrive. Warm advection on Wednesday will bring warmer temperatures to the area with most locations in the 60s. && .LONG TERM... (Wednesday night through Monday) Issued at 333 AM CST Tue Dec 3 2024 A southern stream shortwave will move across the area Wednesday night and Thursday, aided by the East Coast trough. This will push a cold front across the area Thursday, arriving in the northwestern portions of the area around sunrise, and moving into Alabama around midday. Rain and a few elevated thunderstorms will accompany the front. While the shear would be sufficient for severe weather, instability is almost non-existent. Rain amounts of 1 to 2 inches will be possible with this system, mainly in northwestern portions of the CWA. The medium range modeling continues to struggle with just how far offshore the frontal boundary makes it on Thursday. The ECMWF runs have been pretty consistent in pushing the front well offshore, while the GFS has trended close enough to the Louisiana coast to hold the potential for at least some rain over the local area for Friday and Saturday. The ECMWF has essentially a dry forecast for the area from Thursday afternoon into the daytime hours on Sunday. This will also have a significant effect on temperatures, as the drier solution also means more cold air advection across the area. Regardless, high temperatures Thursday are likely to occur prior to noon. Thursday night through Friday night temperatures will be tied to the progression of the front. If the ECMWF verifies, sub- freezing temperatures will be possible across a significant portion of the area both Friday and Saturday mornings. The GFS solutions are 10-15 degrees warmer due to cloud cover. The NBM deterministic is essentially a compromise between the two, but would expect that those numbers will start drifting toward the preferred modeling over the next couple days. Highs on Friday will also be a struggle, but would note that the GFSBufr soundings would actually be somewhat more appropriate for the ECMWF solution, with most of the area not getting much warmer than 52-53F at best, and some may not get out of the 40s. Saturday should see some improvement in temperatures, getting into the 60s. High pressure will be off to the east of the area by Saturday night and Sunday with winds gradually turning onshore as a southern stream shortwave (the one off the West Coast now) approaches the area. The GFS is considerably quicker with this system, with some light precipitation possibly arriving prior to sunrise Sunday, while the ECMWF solution is more like Sunday night. Of course, at that time range, the NBM deterministic is somewhat of a compromise, and would expect PoPs to eventually focus on a shorter time span for precipitation chances. We`ll have to keep an eye on that system for excessive rainfall, as the medium range models indicate a very moist airmass with dew points in the mid 60s, and GFSBufr soundings show anomalously high precipitable water values between 1.75 and 2 inches Sunday night through Monday night. Temperatures from Sunday until frontal passage, which could be as late as next Wednesday (12/11) will likely get into the 70s for highs, normal is mid 60s. Overnight lows could be as much as 15 to 20F above normal. && .AVIATION... (12Z TAFS) Issued at 446 AM CST Tue Dec 3 2024 VFR conditions expected through the forecast period. We could start to see some ceilings around FL100 toward sunrise Wednesday as moisture arrives ahead of the next weather system. && .MARINE... Issued at 333 AM CST Tue Dec 3 2024 Will carry Small Craft Exercise Caution headlines for the far western waters today. Wind field should relax later this evening through the daytime hours Thursday. Cold advection behind the front may necessitate Small Craft Advisories Thursday night into Friday, especially if the farther south solution for the frontal position in the ECMWF operational verifies. && .PRELIMINARY POINT TEMPS/POPS... MCB 56 31 62 51 / 0 0 20 90 BTR 64 39 68 58 / 0 0 20 90 ASD 61 36 67 57 / 0 0 0 60 MSY 61 45 67 60 / 0 0 0 60 GPT 59 37 64 57 / 0 0 0 60 PQL 62 31 67 55 / 0 0 0 50 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ |
| #1210476 (Received by flhurricane at: 4:48 AM 03.Dec.2024) AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 337 AM CST Tue Dec 3 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Today through Wednesday) Issued at 333 AM CST Tue Dec 3 2024 Upper trough remains along the East Coast this morning, with ridging from New Mexico to British Columbia. A trough was off the California coast to the west of the ridge. At the surface, high pressure extended from Iowa to the northern Gulf of Mexico. There were a few reports of fog near water sources, but this doesn`t seem to be widespread at this time. Temperatures at 3 AM CST were generally from the mid 30s to lower 40s, except Lakefront Airport (56F), where the warmer water of Lake Pontchartrain held the temperatures up. The high pressure over Iowa this morning will sink southeastward to Florida by Wednesday afternoon. This will keep winds northerly to northeasterly today and most of tonight. By midday Wednesday, surface flow will become southeasterly, allowing moisture to finally return to the area. Precipitable water values were near 0.30 inches on the 00z LIX sounding, and those values won`t change much until the daytime hours on Wednesday. We`ll start to see mid-level (near 700 mb) clouds arrive prior to sunrise Wednesday, gradually saturating the lower levels during the daytime hours with precipitable water values climbing to about 1.5 inches. Could see a few patches of light rain or showers arrive in northwest areas, west of McComb and Baton Rouge prior to sunset Wednesday. Forecast temperatures don`t look unreasonable. Cold advection will hold temperatures down from yesterday`s levels today. Overnight lows will be chilly again with a few of the normally colder spots potentially hitting freezing again. The mid level clouds could mean temperatures starting to rise shortly before sunrise Wednesday, depending on just how quickly they arrive. Warm advection on Wednesday will bring warmer temperatures to the area with most locations in the 60s. && .LONG TERM... (Wednesday night through Monday) Issued at 333 AM CST Tue Dec 3 2024 A southern stream shortwave will move across the area Wednesday night and Thursday, aided by the East Coast trough. This will push a cold front across the area Thursday, arriving in the northwestern portions of the area around sunrise, and moving into Alabama around midday. Rain and a few elevated thunderstorms will accompany the front. While the shear would be sufficient for severe weather, instability is almost non-existent. Rain amounts of 1 to 2 inches will be possible with this system, mainly in northwestern portions of the CWA. The medium range modeling continues to struggle with just how far offshore the frontal boundary makes it on Thursday. The ECMWF runs have been pretty consistent in pushing the front well offshore, while the GFS has trended close enough to the Louisiana coast to hold the potential for at least some rain over the local area for Friday and Saturday. The ECMWF has essentially a dry forecast for the area from Thursday afternoon into the daytime hours on Sunday. This will also have a significant effect on temperatures, as the drier solution also means more cold air advection across the area. Regardless, high temperatures Thursday are likely to occur prior to noon. Thursday night through Friday night temperatures will be tied to the progression of the front. If the ECMWF verifies, sub- freezing temperatures will be possible across a significant portion of the area both Friday and Saturday mornings. The GFS solutions are 10-15 degrees warmer due to cloud cover. The NBM deterministic is essentially a compromise between the two, but would expect that those numbers will start drifting toward the preferred modeling over the next couple days. Highs on Friday will also be a struggle, but would note that the GFSBufr soundings would actually be somewhat more appropriate for the ECMWF solution, with most of the area not getting much warmer than 52-53F at best, and some may not get out of the 40s. Saturday should see some improvement in temperatures, getting into the 60s. High pressure will be off to the east of the area by Saturday night and Sunday with winds gradually turning onshore as a southern stream shortwave (the one off the West Coast now) approaches the area. The GFS is considerably quicker with this system, with some light precipitation possibly arriving prior to sunrise Sunday, while the ECMWF solution is more like Sunday night. Of course, at that time range, the NBM deterministic is somewhat of a compromise, and would expect PoPs to eventually focus on a shorter time span for precipitation chances. We`ll have to keep an eye on that system for excessive rainfall, as the medium range models indicate a very moist airmass with dew points in the mid 60s, and GFSBufr soundings show anomalously high precipitable water values between 1.75 and 2 inches Sunday night through Monday night. Temperatures from Sunday until frontal passage, which could be as late as next Wednesday (12/11) will likely get into the 70s for highs, normal is mid 60s. Overnight lows could be as much as 15 to 20F above normal. && .AVIATION... (06Z TAFS) Issued at 1143 PM CST Mon Dec 2 2024 VFR conditions at all terminals and that is likely to remain through the forecast period. Winds will be light and variable overnight with clear skies outside of some thin cirrus. && .MARINE... Issued at 333 AM CST Tue Dec 3 2024 Will carry Small Craft Exercise Caution headlines for the far western waters today. Wind field should relax later this evening through the daytime hours Thursday. Cold advection behind the front may necessitate Small Craft Advisories Thursday night into Friday, especially if the farther south solution for the frontal position in the ECMWF operational verifies. && .PRELIMINARY POINT TEMPS/POPS... MCB 56 31 62 51 / 0 0 20 90 BTR 64 39 68 58 / 0 0 20 90 ASD 61 36 67 57 / 0 0 0 60 MSY 61 45 67 60 / 0 0 0 60 GPT 59 37 64 57 / 0 0 0 60 PQL 62 31 67 55 / 0 0 0 50 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ |
| #1210457 (Received by flhurricane at: 12:48 AM 03.Dec.2024) AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1144 PM CST Mon Dec 2 2024 ...New AVIATION... .SHORT TERM... (This evening through Tuesday night) Issued at 342 PM CST Mon Dec 2 2024 A deep longwave upper level trough encompasses the entire eastern half of the country with the N/S apex roughly lined up with Florida. The 12Z LIX sounding showed a PW of close to 0.25". Thus, absolutely zero chance of rain in the short term forecast. Slightly warmer temps expected overnight due to both an incremental increase in 500mb heights and thin cirrus deck moving across the southern half of LA. A shortwave tracking through the western side of the upper trough will drive a reinforcing cold front through the CWA Tuesday morning. Cold air advection from a ~1040mb surface ridge will definitely put a damper on warming. Expect SW and Coastal MS to struggle to exceed mid 50s and only lower 60s south of there. && .LONG TERM... (Wednesday through Sunday night) Issued at 342 PM CST Mon Dec 2 2024 Rain chances look to return to the area the second half of this week. As the upper trough to the east lifts northeast, an upper ridge will follow in its footsteps. In doing so, moisture will get drawn northward across east Texas Wednesday morning before spreading east late in the day. Could see light showers accompany this moisture but impacts should be relatively minimal. An upper level low diving south across the Great Lakes around this time will send a cold front towards the Gulf Coast. As this boundary collides with increasing moisture, could see a few thunderstorms develop over the CWA on Thursday. The potentially more impactful system of the next 7 days may be late this upcoming weekend. Global models suggest a more southern stream trough digging well into south Texas will be the main source of this weather. A track that far south will bring jet dynamics needed for more vigorous storms at least close enough for that possibility. The challenge at this time is forecasting how far north the warm sector reaches. That`s still an unknown and thus just will have to monitor future model solutions for more clarity. && .AVIATION... (06Z TAFS) Issued at 1143 PM CST Mon Dec 2 2024 VFR conditions at all terminals and that is likely to remain through the forecast period. Winds will be light and variable overnight with clear skies outside of some thin cirrus. && .MARINE... Issued at 342 PM CST Mon Dec 2 2024 Persistent cold air advection continues to support elevated northerly winds. Based on marine wind obs this morning, have expanded the Exercise Caution headline to all local coastal waters through the rest of this afternoon. High pressure will build into the local waters from the north through tomorrow before sliding east Wednesday. At the same time, a weak low pressure is forecast to develop along the southern TX coast and track northward. Winds will turn onshore Wednesday, gradually becoming southwesterly into Thursday. The frontal passage comes later in the week and winds become offshore again into next weekend. && .PRELIMINARY POINT TEMPS/POPS... MCB 34 55 32 61 / 0 0 0 30 BTR 40 63 39 68 / 0 0 0 20 ASD 38 61 36 67 / 0 0 0 10 MSY 45 59 46 68 / 0 0 0 10 GPT 39 58 37 66 / 0 0 0 0 PQL 34 61 34 68 / 0 0 0 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ |
