Area Forecast Discussion
Issued by NWS Lake Charles, LA
Issued by NWS Lake Charles, LA
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
922 FXUS64 KLCH 262355 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA 655 PM CDT Sun May 26 2024 ...New AVIATION, CLIMATE... .SHORT TERM... (Tonight through Tuesday night) Issued at 323 PM CDT Sun May 26 2024 Another rather humid for May day across the forecast area with heat index readings around 100F to 105F degrees. Southerly breezes from the pressure gradient between a high near Florida and a low over the Plains has helped keep air temperatures down a bit this afternoon, and a cap in place has helped preclude any significant convection. Will have to watch for any convection that develops later tonight near a surface boundary along the Red River valley as the outflow from this may try to get a few showers going in central Louisiana just before daybreak. Pattern change will begin on tomorrow Memorial Day. The center of the upper level ridge over old Mexico will shift back to the southwest helping to flatten the ridge over the forecast area. This will allow a series of short waves to carve out a trough from the Great Lakes down to the Gulf coast that will help allow northwest flow to develop aloft. The first notice of this pattern change will be a surface boundary will move into the forecast area on Monday afternoon. Before the boundary arrives, lighter south winds and some compression warming ahead of the boundary will allow air temperatures to soar into the mid and possibly upper 90s. Meanwhile, plenty of low level Gulf moisture will be in place with afternoon dew points in the mid 70s. The combination of the 2 will mean max heat index readings or the apparent temperature will soar to near danger levels between 108F and 111F degrees. Therefore, a Heat Advisory will be in effect for the area, with the exception of right along the coast, from Noon to 8 pm CDT. Also, the boundary may combine with the daytime heating to break the cap and kick off thunderstorms. At this point, storm activity is expected to be isolated in nature starting late in the afternoon (like after 3 pm,) then decreasing in the evening with the loss of daytime heating. Despite the activity to remain isolated in nature, strong CAPE values of over 4000 j/kg, 0-6km shear between 40 and 50 knots, favorable mid level lapse rates, and downdraft DAPE (DCAPE) over 1500 j/kg, will bring about a conditional potential of severe storms, with damaging microburst winds the main concern. Due to the factor storms are expected to be limited in nature, a Marginal Risk Potential (level 1 out of 5) will be outlined for the forecast area. The surface boundary will stall over the forecast area on Tuesday, daytime heating and Gulf moisture will combine for a chance of showers or storms. With the northwest flow aloft, will have to watch to see if any short wave energy can make its way into the forecast area and help enhance any storm activity. Dew point will be a little lower on Tuesday, along with a better chance to see clouds and convection keeping air temperature down just a bit, and thus keeping heat index in check that a heat advisory is not anticipated on Tuesday. Rua && .LONG TERM... (Wednesday through next Saturday) Issued at 323 PM CDT Sun May 26 2024 A weak frontal boundary will be located off the coast early Wednesday, while aloft the forecast area will be situated beneath a persistent W to NW flow between troughing to the north and ridging to the south and west. This same general mid/upper level pattern will persist into the weekend, while the surface boundary will gradually lift back inland as a warm front through the later half of the work week. At the same time, a series of weak disturbances will pass overhead in the W/NW flow aloft. The first of these disturbances will arrive Wednesday, inducing scattered showers and thunderstorms by the afternoon hours. Rain chances for Wed are much better today vs. yesterday, with 30-50% POPs now on tap. Thursday through Sunday will bring a fairly repetitive pattern as a few more disturbances slide overhead though the period. Rain chances look to increase each day through the late morning into the afternoon, before tapering off by the evening hours, as a combination of daytime heating and the upper disturbances induce daily showers and thunderstorms. Temperature wise, the entire period will consist of highs in the upper 80s to low 90s, with overnight lows in the upper 60s to mid 70s, which is slightly below seasonal norms. 17 && .AVIATION... (00Z TAFS) Issued at 655 PM CDT Sun May 26 2024 Pretty much a persistence forecast aviation-wise with MVFR ceilings expected to develop this evening with good low-level moisture lingering on persistent srly flow. Restrictions to visibility are not expected to be much of a problem except at KLCH where vis is already down to 4SM in haze and will likely stay there through tonight. As usual, conditions will improve post- sunrise with VFR conditions expected by late morning. With a lesser gradient in place, elevated srly winds like today are not expected on Monday. While there is a slim chance at convection by Monday afternoon, coverage looks minimal to leave out any mentions at this time. 25 && .MARINE... Issued at 323 PM CDT Sun May 26 2024 Modest southerly flow over the coastal waters this afternoon with the pressure gradient between a surface high near Florida and a surface low over the Plains. The low will move further away from the forecast area tonight, and this will help reduce the pressure gradient and lower wind speeds. For Memorial Day through the middle part of the week, the surface high near Florida will weaken some, however still ridge westward into the coastal waters. There, mainly light southerly flow and low seas can be expected. Any shower or thunderstorm activity is expected to stay north of the coastal waters during the period. Rua && .CLIMATE... Issued at 655 PM CDT Sun May 26 2024 All five primary climate sites set/tied record warm low temperature records for 5/26 (assuming nothing odd like an unexpected rapid cooling happens). LCH today`s low: 79 (previous record: 78/2000 & earlier) BPT today`s low: 79 (record: 79/2000) LFT today`s low: 79 (previous record: 77/1909) AEX today`s low: 76 (record: 76/2000) ARA today`s low: 78 (previous record: 77/1989) 25 && .PRELIMINARY POINT TEMPS/POPS... AEX 74 95 70 93 / 20 10 10 20 LCH 78 92 75 92 / 10 20 20 20 LFT 79 94 76 94 / 10 20 20 20 BPT 78 94 75 92 / 0 20 20 20 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...Heat Advisory from noon to 8 PM CDT Monday for LAZ027>033-044- 045-141>143-152-153-241>243. TX...Heat Advisory from noon to 8 PM CDT Monday for TXZ180-201- 259>262-515-516-615-616. GM...None. && $$ SHORT TERM...07 LONG TERM....17 AVIATION...25