FXUS64 KLCH 310147 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA 747 PM CST Mon Jan 30 2023 ...New UPDATE... .UPDATE... Issued at 738 PM CST Mon Jan 30 2023 From our 00Z sounding, a sharp inversion can be noted at 950mb. From that point to the surface is almost completely saturated. Visibilities about the CWA have fallen below 5mi, with some as low as 1mi south of the I-10. Outside of the issuance of a Dense Fog Advisory and edits to the weather grids, the rest of the grids were on track with current obs and and model trends. Stigger/87 && .SHORT TERM... (Tonight through Wednesday night) Issued at 345 PM CST Mon Jan 30 2023 Mid-afternoon sfc analysis shows a stalling cool front situated over the sern zones while high pressure is noted over the cntl Plains. Water vapor imagery shows a wswrly flow aloft between ridging over the Gulf and troffing over the nrn Plains/Rockies with an embedded cutoff low moving ashore over srn CA. Within this flow, a series of disturbances were noted. The combo of these features was yielding an overrunning pattern which was keeping all but the extreme sern zones in quite the overcast stratus regime. CAA behind the front was holding temps across primarily sern TX in the upper 40s or 50s. Local 88Ds continued to show a few light returns this afternoon, although these were likely resulting in just light spits of rain as opposed to any true shower activity, which was far more common across nern TX and the ArkLaTex where lift from a departing disturbance was a little greater. Quite the forecast this afternoon with multiple issues to deal with. The old frontal boundary is progged to simply meander across mainly the sern zones or coastal waters throughout the short term while multiple disturbances sweep past the region in the wswrly flow aloft. Ahead of the boundary, areas of dense fog, likely of a hybrid variety, will linger, especially over the near shore waters through tonight and on into tomorrow morning. Some of this fog will quite possibly spill over into lower Acadiana after sunset tonight, with visibilities likely lowering to below a mile after midnight. For now, with some uncertainty remaining, have elected to no issue any advisory for this area for tonight. As far as the remainder of the forecast area goes, patchy fog will be likely, although dense fog is not expected...although it certainly can't be ruled out either given how moist our boundary layer is and is forecast to remain. As far as precip goes, given the very moist antecedent conditions within the overrunning regime and the periodic weak disturbances passing nearby, along with the stationary sfc boundary, widely scattered showers look possible through tonight, with best bets remaining across the nwrn zones where lift is progged to be best with proximity to the weak vorts. This also appears to be the pattern at least into Wednesday, although slim POPs over the sern zones gradually diminish as the weak boundary finally slips out the area while the troffing aloft digs deeper into nrn Mexico, carrying the best lift a little farther nwd. Beginning late Wednesday and especially moving into Wednesday night, the swrn CONUS storm system is progged to fill/eject enewd toward the wrn Gulf region. As it does, a sfc low is expected to develop over the nwrn Gulf/adjacent TX coast which will then sweep newd across the ern portions of the forecast area. With forecast soundings indicating moisture increasing (PWAT values progged to climb to as much as 1.7 inches - well above the 90th percentile per SPC sounding climo), showers are expected to become widespread across all but maybe the sern 1/4 of the forecast area by 12z Thursday. With the boundary situated across the forecast area, temp forecasts are really interesting through the short term, with quite the gradient likely, beginning tonight and tomorrow where 20 (or more) degrees could separate the far nwrn zones from locations closer to the s-cntl LA coast. 25 && .LONG TERM... (Thursday through next Sunday) Issued at 345 PM CST Mon Jan 30 2023 A surface low will lift up the Texas gulf coast Thursday morning into the the very moist environment across the region (forecast PWAT 1.4-1.7) serving as an additional focus for the development of widespread showers and thunderstorms. Meanwhile, a shortwave sliding quickly east across Texas will finally push the long meandering frontal boundary through the area late Thursday night into Friday morning. With soils still largely saturated and many area waterways already in flood, the expected heavy rainfall within some of these storms will have the potential to result in street flooding as well as the exacerbation of already ongoing river flooding. The widespread precipitation should come to an end following fropa Thursday evening.Some ensemble members do show some trailing moisture behind the front that could allow for a few, lighter showers early Friday Friday morning with skies clearing by afternoon. Ridging aloft and high pressure at the surface will maintain clear skies and benign conditions through the weekend with temperatures running slightly below normal Friday and Saturday and then near normal Sunday. Jones && .AVIATION... (00Z TAFS) Issued at 524 PM CST Mon Jan 30 2023 Old frontal surface boundary extending from off the southeast Texas coast to onshore in between KARA and KPTN will move little during the period. Southwest flow above the surface is helping to provide a frontal inversion. This will keep low level moisture trapped with very low ceilings and stratus build down type patchy fog. Therefore, IFR/LIFR conditions are likely to persist during the period at all terminals. Rua && .MARINE... Issued at 345 PM CST Mon Jan 30 2023 Issued another Dense Fog Advisory for the near shore waters beginning now and going through 16z/10L tomorrow morning (and it wouldn't surprise me if it needs to wind up being extended). Fog guidance seems to be in relative agreement that the waters generally east of the sfc boundary where warmer/moister air persists over the cooler shelf waters, will maintain much lower visibilities through tonight. Patchy fog is likely over the remainder of the coastal waters, and although dense fog looks a little more patchier over the wrn-most waters, elected to expand the advisory to cover these waters as well. 25 && .PRELIMINARY POINT TEMPS/POPS... AEX 43 49 35 45 / 10 40 50 40 LCH 53 57 43 52 / 10 30 30 30 LFT 56 60 47 57 / 0 20 20 10 BPT 51 57 45 52 / 10 30 30 30 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...Dense Fog Advisory until 9 AM CST Tuesday for LAZ027>033-041>045- 052>055-073-074. TX...Dense Fog Advisory until 9 AM CST Tuesday for TXZ180-201-215-216- 259>262. GM...Dense Fog Advisory until noon CST Tuesday for GMZ430-432-435-450- 452-455. && $$ SHORT TERM...25 LONG TERM....66 AVIATION...07