237 FXUS64 KLCH 210940 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA 340 AM CST Tue Jan 21 2020 .DISCUSSION... Early morning sfc analysis shows high pressure centered over the Missouri Valley ridging swd, providing a light nerly flow over the forecast area. Water vapor imagery shows troffing in place over the ern CONUS with ridging developing behind it over the Plains/lee of the Rockies...this is resulting in a dry nwrly flow aloft over the region. Other than a little cirrus spilling over the ridge and spreading over the area at this time, skies are clear thanks to a general lack of moisture through the column per regional 00z soundings with PWATs running below climo normals and MRH values running about 30-50 percent of normal. As expected, regional 88Ds are PPINE this morning. Main issue this morning is the likelihood of frost, especially across the nrn zones where temps have fallen to the lower/mid 30s (KESF has dropped all the way 28F at 09z) with calm winds. No problems anticipated in the short-term with dry high pressure holding on for at least the first period. As we move into tonight, the sfc high shifts ewd, allowing a bit of a low-level return flow to set up, especially over the far wrn zones. After our cool start, temps will run a bit cooler than Monday, especially the swrn zones where highs ran a little higher than expected yesterday. Mins tonight should be a few degrees warmer than this morning. Deeper moisture begins to spread over the forecast area tomorrow with the sfc high now east of the region and the initial disturbance rounding an approaching trof axis brings in Gulf moisture aloft. The combo of these features should allow for the onset of shower development in the morning over the far wrn zones, with an ewd progression through the afternoon (perhaps holding off til the evening for the Atchafalaya Basin for now). An approaching upper-level speed max and a developing sfc low over sern TX/nwrn Gulf will enhance lift starting Wednesday evening, with much of the area under categorical POPs for the night and on into Thursday morning. As of now, best instability is progged to remain closer to or off the coast although with the sfc low eventually expected to move newd across the forecast area, instability may be sufficient enough, along with good mid-level lapse rates/shear, to produce a few storms mainly Thursday. As the trof axis/sfc boundary sweep ewd through the area accompanied by much drier air, expect the showers/storms to gradually end from west to east late Thursday afternoon and evening. Dry conditions look on tap for Friday and Saturday as sfc high pressure and wrly flow aloft briefly settle over the area. Friday and Friday night look seasonal temp-wise before the high moves east in our progressive pattern and a slight warmup commences. Some subtle differences are noted again in the models this morning pertaining to another weak system impacting the area late in the weekend, thus slim POPs are being carried in the interim. The period ends on a dry note for Monday/Monday night as this feature slips past the region and drier air on sfc high pressure/ridging aloft returns. && .MARINE... Extended the caution headlines for the outer waters into the afternoon as guidance paints winds slowly falling through the 15-20 knot range. After a brief diminishing of winds for tonight, caution conditions look likely again for Wednesday as the gradient tightens with low pressure deepening over the Plains. Winds continue to strengthen through Wednesday night with SCA conditions likely as sfc low pressure develops nearby. Once the whole mess moves out on Thursday, a brief period of elevated offshore flow can be expected in its wake. && .PRELIMINARY POINT TEMPS/POPS... AEX 49 31 48 42 / 0 0 30 80 LCH 52 36 52 49 / 0 0 60 80 LFT 50 35 54 49 / 0 0 10 60 BPT 54 40 55 53 / 0 10 80 90 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...Small Craft Exercise Caution through this afternoon for GMZ470- 472-475. Small Craft Exercise Caution until 6 AM CST early this morning for GMZ450-452-455. && $$ 25