Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, 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
305 FXUS64 KLIX 081804 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 104 PM CDT Wed May 8 2024 ...New AVIATION... .SHORT TERM... (Today through Thursday Night) Issued at 330 AM CDT Wed May 8 2024 Today will be a rather dry day across the region with most of the upper support in the active SW flow aloft staying to our north over the Midsouth and Tennessee River Valley. The story already this morning is just how muggy and warm it is outside. At the time of this AFD in the middle of the night, temperatures are still around 80F with dew points of 75F leading to a heat index of 85F...Keeping in mind it`s still early May. Today we should warm a good bit into the lower and middle 90s. Low level flow will remain out of the south today meaning immediate coast will remain slightly cooler than inland zones. On Thursday a strong upper level shortwave will help send a cold front southward toward the region. During the afternoon, in response to a modest impulse over central TX, clusters of showers and thunderstorms are expected to develop along the I35 corridor and slide eastward within the flow that over our location should become more zonal as the parent trough aloft continues to evolve/amplify upstream. These clusters of storms may merge into a QLCS late Thursday and continue downstream across our region. At this juncture, low level shear appears to be very modest, but instability will be on the more moderate to higher end. Globals and mesoscale models have this QLCS moving through in the early morning hours generally along and north of the I-12/10 corridor. This is where SPC has delineated a slight risk of severe thunderstorms (marginal elsewhere) in the SWODY2. Primary concern will be strong gusty winds with bowing signatures where mean flow crosses the QLCS perpendicularly. Additionally, with a bit higher instability, cannot ignore at least a low-end severe hail threat as well but this will likely be a secondary concerns. Finally, given the transient nature of the QLCS, think that flooding potential will be minimal outside of of typical poor drainage areas within Baton Rouge. We`ll also need to watch the cold pool dynamics and how it may impact the speed for the cold front. It wouldn`t be out of the realm of possibility that the cold pool will help motivate the FROPA a bit sooner than currently forecast. (Frye) && .LONG TERM... (Friday through Tuesday) Issued at 330 AM CDT Wed May 8 2024 Any residual shower/storm activity lingering over from the short term period will quickly exit stage east and south. At the surface, the cold front will continue to drop southward as an upper level Canadian trough continues to amplify over the eastern U.S. With lower heights and thicknesses along with low level CAA, temperatures will be slightly cooler on Friday. That said, above average temperatures are anticipated to continue especially closer to the coast. Despite the weak CAA, strong insolation/sun angle will help keep things on the warm side. Going into the weekend, a more progressive pattern takes over. Temperatures start out around average on Saturday and Sunday with a more zonal flow over the region. However, all eyes begin to shift upstream later into Sunday. The next H5 shortwave, this one with Pacific roots, will migrate over the high plains. This will help the front that pushes through late in the short term period or early in the long term period lift back closer toward our region. With surface convergence and perhaps some help from isentropic upglide, POPs increase later into the weekend and especially to start the new workweek. One question is how far north the front will get and how progressive the H5 trough will be. The surface high takes some time to migrate eastward into the Mid Atlantic states this weekend and so return flow will be limited initially. That said, a very moisture rich environment isn`t far and with the front lifting northward it wouldn`t take long to moderate the low level moisture profile. Going deeper into the new workweek next week, it appears that a series of upper level impulses within the flow move over our region leading to perhaps periods of showers and thunderstorm activity. Models are still in a bit of a disagreement with the exact strength of upper level features and any surface trough/low development that takes place across the northern Gulf, but feeling a bit more confident with strong QPF signals despite the slight disagreements amongst the ECM and GFS. Needless to say with the increase in cloudiness and rainfall, temperatures will be held down or more closer to climo norms. (Frye) && .AVIATION... (18Z TAFS) Issued at 1256 PM CDT Wed May 8 2024 Terminals continue to be a mix of VFR and MVFR due to lower ceilings in some areas. These ceilings will start to lower more into this afternoon and evening ahead of an approaching frontal boundary. Most terminals will see MVFR and IFR conditions as the cloud cover moves in. Winds will be slightly gusty gusty, gusting 20-25kts. && .MARINE... Issued at 330 AM CDT Wed May 8 2024 Winds will gradually increase today through Thursday with cautionary headlines needed up until a cold frontal boundary passes through the region early Friday. Behind the front, moderate winds and seas will continue with northerly flow developing. This northerly flow will begin to breakdown quickly going into the upcoming weekend as surface high pressure begins to settle across our local waters. (Frye) && .PRELIMINARY POINT TEMPS/POPS... MCB 72 90 66 82 / 10 20 60 10 BTR 76 94 72 88 / 0 10 30 10 ASD 74 93 71 87 / 10 10 40 20 MSY 77 93 75 86 / 0 10 30 30 GPT 75 89 70 87 / 10 10 40 30 PQL 74 90 69 87 / 10 10 40 30 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...RDF LONG TERM....RDF AVIATION...HL MARINE...RDF