Area Forecast Discussion
Issued by NWS Lake Charles, LA
Issued by NWS Lake Charles, LA
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312 FXUS64 KLCH 140942 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA 442 AM CDT Tue May 14 2024 ...New SYNOPSIS, SHORT TERM, LONG TERM, MARINE... .SYNOPSIS... Issued at 425 AM CDT Tue May 14 2024 After a busy past few days, things are finally calming down. KLCH radar shows the last of the convection over our eastern coastal waters zones, weakening as it shifts east. The latest WV imagery and UA analysis shows a pair of vort lobes (the culprits responsible for the intense storms on Monday) translating along the north central Gulf coast, on the southeast flank of low pressure moving toward the mid MS Valley. The main trough axis extends southward into TX, with a sharp moisture gradient preceding this axis as drier advects around the base of the trough. IR satellite imagery shows quite a bit of high cloudiness still streaming north over the region, but the back edge of these clouds are slowly progressing east. As clearing begins, fog is expected to develop and increase in coverage amid the light winds and saturated soils, with periods of dense fog anticipated. A Dense Fog Advisory has been issued for our SE TX Counties. The passage of the convection has left a relatively cooler airmass over the region with temperatures in the middle 60s to around 70 early this morning. 24 && .SHORT TERM... (Today through Thursday night) Issued at 425 AM CDT Tue May 14 2024 A weak cool front will move east across the area this morning, with winds becoming westerly ushering in a drier airmass. Skies are expected to clear today as PWAT values fall below an inch and midlevel rh drops to around 20% or less. Weak ridging aloft and surface high pressure will transit across the area through Wednesday, providing a very nice and much needed break from the recent wet weather. With the drier airmass in place and sufficient insolation expected, temperatures today and Wednesday should easily warm into the middle to upper 80s each afternoon, with highs likely topping out around 90 Wednesday. Overnight lows are expected to fall just a bit below seasonal normals, with minimums ranging from around 60 across central LA to the middle 60s along the I-10 corridor. Patchy to areas of fog will again be possible tonight as winds lighten. The dry break will unfortunately be short-lived as the surface high slides east and another shortwave trough moves into the SW US late Wednesday. A warm and moist advection regime will develop as the LLJ strengthens across TX and translates east Wednesday night into Thursday. Showers and storms will develop across TX Wednesday night and spread east across our area on Thursday, with PoPs sharply ramping up during the day. Another heavy rain scenario will develop as PWATs climb back up to 2 inches or higher within an environment marked by increasing instability and deep layer shear. Most guidance members have been indicating the potential for elevated QPF across portions of the area, although there are some discrepancies regarding placement. A general consensus, supported by NBM probabilistic guidance, suggests that these higher totals could fall across interior SE TX again, which unfortunately is one of the hardest hit regions in recent weeks. In collaboration with WPC, a Moderate Risk for excessive rainfall has been introduced for Day 3 (Thursday) for areas along/north of I-10, with a Slight Risk further south. Some adjustments to the outlook can be expected as the event approaches. While the heavy rainfall and flood risk are the primary concern with this system, there is a non-zero potential for severe weather as well. The latest SPC outlook has a Marginal Risk in place for Thursday, with the expectation that convection that forms across portions of central TX will evolve into a linear mode as it moves east toward SE TX/SW LA. While all modes of severe weather will be possible, the primary threats will be from isolated damaging wind gusts and large hail. 24 && .LONG TERM... (Friday through Tuesday) Issued at 425 AM CDT Tue May 14 2024 Ongoing, potentially heavy, precipitation will start the extended period Friday as a series of upper level disturbances cross the northern gulf coast as they wrap around a broader shortwave moving across the southern plains. This energy will continue to take advantage of abnormally high forecast PWAT values near or above 2 inches to produce high rainfall rates falling on already saturated grounds. Thus, the risk for flash flooding will continue through Friday evening. Precip looks to finally end sometime late Friday evening or early Saturday morning with the passage of a weak frontal boundary. While there will be no appreciable change in surface airmass behind the front, it will scour out most of the moisture aloft. There remains some inter-model variation regarding the timing of the fropa, but better agreement compared to 24 hours ago. Guidance continues to maintain isolated PoPs through the day Saturday for account for wraparound moisture. Maintained isolated wording for now, but thinking that there is unlikely to be enough moisture left behind the front for this to be much of a concern. Clearing skies and surface high pressure building into the region will allow for temperatures to climb to near 90 each afternoon Saturday through Monday with a more extended period of drier weather looking to set up next week. Jones && .AVIATION... (00Z TAFS) Issued at 604 PM CDT Mon May 13 2024 Severe thunderstorm cluster hitting LFT now and ARA within the next half hour. LFT just gusted to 69 kt or 79 mph, expect something similar for ARA within a few minutes. Remainder of forecast will see MVFR ceilings overnight, with MVFR visibility possible for southern sites between 10-14z. Improving conditions expected for Tuesday. 08/DML && .MARINE... Issued at 425 AM CDT Tue May 14 2024 West to northwest winds are expected today with the passage of a weak cold front. Winds will shift northerly tonight then back east to southeast through the day Wednesday as high pressure quickly slides east. Onshore flow will then persist, strengthening slightly, through the end of the week. Exercise caution conditions will be possible at times. Shower and thunderstorm chances will return Thursday as another low pressure system approaches the area. 24 && .PRELIMINARY POINT TEMPS/POPS... AEX 85 60 89 64 / 0 0 0 0 LCH 86 65 89 69 / 0 0 0 10 LFT 88 66 91 69 / 0 0 0 0 BPT 88 65 89 70 / 0 0 0 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...Dense Fog Advisory until 8 AM CDT this morning for TXZ180-201- 259>262-515-516-615-616. GM...None. && $$ SHORT TERM...24 LONG TERM....66 AVIATION...08