Area Forecast Discussion
Issued by NWS Lake Charles, LA
Issued by NWS Lake Charles, LA
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818 FXUS64 KLCH 260809 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA 309 AM CDT Sun May 26 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Today through Tuesday night) Issued at 306 AM CDT Sun May 26 2024 The forecast for the Memorial Day holiday weekend remains unchanged, with high pressure remaining the dominant feature in our forecast. This ridge is centered over Mexico and is unusually strong for this time of year, with heights in the 97th percentile. This sinking air from the ridge will keep our skies mostly clear, enhancing the diurnal heating. The subsidence associated with the trough will also add to the already hot conditions. At the surface, the high pressure is to our east, which is causing consistent southern flow. This pattern will produce highs in the low-to-mid 90s across the CWA, with heat index values just below the criteria today with values around 107. Monday will see the pattern reach its peak, with actual temperatures in the high 90s across central Louisiana and southeast Texas. We could even see a few isolated spots reach triple digits. With the abundance of low-level moisture, heat index values will soar well above the 108 criteria, especially in the interior of southeast Texas. A Heat Advisory will be issued for inland counties and parishes on Monday afternoon. During the afternoon/evening on Monday, the ridge will begin to retreat. During this time, a short-wave trough will dip into the southeast. This feature will produce some decent rain chances in the evening, with PoPs around 20%. While widespread showers are unlikely, favorable CAPE, shear, and lapse rates provide a high ceiling for any thunderstorms that do manage to form. The SPC has placed parts of Rapides and Avoyelles under a Slight Risk (2/5) while the rest of the region is under a Marginal Risk (1/5) for severe weather. The main threat will be strong downbursts and large hail. In particular, the downburst threat will be one to watch closely, with DCAPE averaging over 1000 J/kg for Monday afternoon and the MBURST index going above 9, indicating that storms that do form could produce damaging winds. Tuesday will see more widespread cloud cover as the ridge continues to retreat and a weak boundary moves across the CWA. This will lead to sporadic showers and thunderstorm activity, but shear and CAPE will be less favorable. Still, the SPC has placed us under a Marginal Risk (1/5) for Tuesday. The boundary will also provide us with a nice shot of drier and cooler air, with temperatures dropping back into the low 90s and Heat Index values around 100. && .LONG TERM... (Wednesday through Sunday) Issued at 306 AM CDT Sun May 26 2024 Large mid to upper level trough over the Eastern U.S. with ridging aloft over Mexico expected to amplify Wednesday through next weekend. This will generally keep a west northwest to northwest flow aloft over the region during this period. Southeast winds expected to keep increased low level moisture across the area. This, combined with periodic weak upper level disturbances within the northwest flow aloft, should be enough to generate isolated to scattered afternoon showers and thunderstorms across the area. Blended guidance generally shows a 20-40% range each afternoon. Lows each morning in the upper 60s to near 70 north of I-10, lower 70s further south. Afternoon highs in the upper 80s to near 90. 08/DML && .AVIATION... (06Z TAFS) Issued at 1150 PM CDT Sat May 25 2024 No changes to previous TAF thinking... (Previous discussion) Sfc obs indicate VFR conditions ongoing while visible imagery shows afternoon cu on the wane as heating relaxes. With such moist low-levels in place, expect MVFR ceilings to develop by the overnight hours across the entire area. Guidance indicates some potential for light fog towards daybreak, particularly where winds are lighter...should these conditions develop, they should improve after sunrise. Thereafter, ceilings will rise/scatter with VFR conditions forecasted again by noon. Southerly winds will increase to rather brisk values by afternoon thanks to a tighter gradient with lower pressures over the srn Plains. 25 && .MARINE... Issued at 306 AM CDT Sun May 26 2024 ASCAT imagery from this evening shows winds between 10 and 15 knots across our waters, with a fetch of slightly higher winds in the western Gulf. Because of this the Caution Statement for small craft will be allowed to expire this afternoon. Buoys and Altimery show waves around 4 feet with a period of around 6 seconds. Waves will be higher in the western waters of the CWA, with waves reaching 6 feet. Starting on Monday evening, the high pressure to our east will become weaker, which will reduce our PGF, which will turn decrease our winds. From Tuesday through the end of the week, sea conditions will be benign, with wave heights below 5 feet and winds less than 15 knots. Little to no convection is expected this week in our waters. && .PRELIMINARY POINT TEMPS/POPS... AEX 93 74 95 70 / 0 10 10 10 LCH 88 78 93 75 / 0 10 10 0 LFT 91 78 94 76 / 0 10 20 10 BPT 90 78 94 76 / 0 0 10 0 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...Heat Advisory from noon to 8 PM CDT Monday for LAZ027>033-044- 045. TX...Heat Advisory from noon to 8 PM CDT Monday for TXZ180-201- 259>262. GM...None. && $$ SHORT TERM...14 LONG TERM....08 AVIATION...25