Area Forecast Discussion
Issued by NWS Shreveport, LA
Issued by NWS Shreveport, LA
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871 FXUS64 KSHV 100330 AFDSHV Area Forecast Discussion National Weather Service Shreveport LA 930 PM CST Sat Nov 9 2024 ...New UPDATE... .UPDATE... Issued at 919 PM CST Sat Nov 9 2024 With the stalled surface boundary having retrograded slightly westward this afternoon and evening, currently draped along a north-south axis across east Texas, stubborn low cloud cover looks to prevent overnight cooling more significantly than model guidance initially targeted. Scattered clearing of skies may manage to occur, but not over a widespread enough area nor long enough duration to cool as much as initially projected. Meanwhile, elevated dewpoint reinforced by ample tropical moisture look to physically prevent much cooling. Using ShortBlend guidance as a starting point, elevated lows to the mid to upper 60s east and middle 50s to lower 60s west. Otherwise, the afternoon forecast package grids look to be on track. Ingested the latest several hours of temperature and dew point obs, and interpolated through to 15Z. SP && .SHORT TERM... (This evening through Sunday Night) Issued at 238 PM CST Sat Nov 9 2024 A dynamic heavy rainfall event is ongoing across north-central Louisiana this afternoon as an axis of deeply rooted gulf moisture along a stalled frontal boundary and lifting warm front, supported by additional moisture availability from TC Rafael in the central GoM, has resulted in a flash flood threat. Training showers and thunderstorms are slowly moving across the SE zones of the SHV CWA, and will continue to do so through the late afternoon and evening. Present thinking is that on top of the general 2-4 inches that have already fallen across the Flood Watch area, an additional 1-3 inches are expected with locally higher amounts possible under the heaviest reflectivity returns and rainfall rates. It is no surprise that this scenario has evolved as it has given the perfect positioning of TC Rafael for extra moisture propagation, while a stalled frontal axis lingers across western Louisiana. As mentioned, the heavy rainfall threat will continue into the evening and likely the early stages of the overnight period before a gradual weakening trend begins. Thinking is that the stalled boundary will begin to move east as surface high pressure builds in from the west. Hi-res solutions seem to be in pretty good agreement that as the boundary moves east through the mid to late morning and early afternoon of Sunday, a few showers and an isolated thunderstorm or two may be possible. By the evening, the majority of the CWA will be rain free, as the boundary works closer to the LA/MS line. Temperature forecast remains tricky, citing heavy cloud coverage, frontal influence and PoPs. A range of 70`s to near 80 deg F will be possible tomorrow after starting in the 50`s and 60`s during the morning. With the passing front, much of the region should see mid to upper 50`s heading into Monday morning. KNAPP && .LONG TERM... (Monday through next Friday) Issued at 238 PM CST Sat Nov 9 2024 When compared to the short term package, the long term appears rather benign. That being said, still trending above average for temperatures through the week as daily max temps approach the upper 70`s to near 80 deg F. Deterministic guidance looks to be coming into more agreement synoptically through mid-week with upper ridging moving across the southern CONUS ahead of troughing by Wednesday. This will work to swing a cold front into the region once again, with long range deterministic output across both the GFS and ECMWF advertising the chance for showers and maybe a few thunderstorms. Again, this is still deep into the forecast package so monitoring trends in the coming days will help increase confidence moving forward. KNAPP && .AVIATION... (00Z TAFS) Issued at 552 PM CST Sat Nov 9 2024 For the 10/00Z TAF period, IFR/LIFR cigs continue to plague most of our terminals this evening with patchy fog and drizzle reducing vsbys as well. Pockets of light to moderate rain will also impact KMLU as a stationary boundary lingers across North Louisiana and South Arkansas. Expect slow but gradual improvement in cigs/vsbys during the latter half of the TAF period on Sunday with MVFR to low VFR cigs by late morning through the afternoon hours. Light and variable winds will be common overnight before trending more NW on Sunday at around 5 kts or less. /19/ && .PRELIMINARY POINT TEMPS/POPS... SHV 67 78 59 77 / 20 20 10 0 MLU 67 78 60 76 / 80 40 20 10 DEQ 56 75 47 73 / 0 0 0 0 TXK 62 76 52 74 / 10 10 0 0 ELD 66 77 54 76 / 40 30 10 0 TYR 63 79 55 76 / 0 0 0 0 GGG 63 77 55 76 / 0 0 0 0 LFK 66 79 59 78 / 20 10 0 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...Flood Watch until 6 AM CST Sunday for LAZ013-014-018>022. OK...None. TX...None. && $$ SHORT TERM...26 LONG TERM....53 AVIATION...19