Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
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589 FXUS64 KLIX 090809 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 309 AM CDT Thu May 9 2024 ...NEW SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Today through Friday) Issued at 305 AM CDT Thu May 9 2024 Another very muggy night tonight across the CWFA. Here at ASD the temps are still in the lower 80s and dewpoints are quite juicy sitting around 76F. Outside of the muggy feels right now, eyes are certainly looking north with the frontal boundary stretching from northeast Texas through the Mid South and TN River Valley. Through the short term period, this front will make its way southward to our region and eventually through the area early Friday morning. Before we get into potential convective impacts, it should also be mentioned that Thursday should be the warmest day for most of the forecast area with lower and middle 90s anticipated for most land locations away from the coast. Okay, so convection. First things first this morning it appears there could be a few isolated low topped showers develop with the initial impulse moving into NW Louisiana at the time of this discussion. The 09/00z RAOB from out back here shows a stout EML, which should put the cap on anything from growing too much vertically. Although one outlier CAM did indicate convection refiring around sunrise from a previous round that has yet to materialize upstream, so we`ll discount that for now. Through the day the surface cold front will slide southward over central MS and AL...which is in line with the mean upper flow slowing the forward progression just a bit by afternoon. A cluster of convection is forecast to initiate up stream along the front over northeast TX by Thursday afternoon. This complex moves quickly eastward into northern Louisiana and into southern and central MS during the overnight and predawn hours Friday. Among the globals and CAM guidance, there is some lowered confidence in terms of where this cluster or eventual complex winds up. Most global and CAM guidance has the complex or cluster just north of the CWFA or across the SW MS Counties. We will continue to monitor the overall trends and hopefully increase confidence on exactly where this complex of storms will go. Now, how severe? Taking a look at the parameters, Instability will not be a problem anywhere within our forecast area. The question will be where is the best lift with the H5 impulse and locations of the front. With roughly 3500 J/KG plus of MLCAPE, hail potential will be there. The main story will likely be strong damaging wind gusts especially with bowing segments of the line. Speaking of, a mesovort or two wouldn`t be impossible with somewhat favorable 0-3km line normal bulk shear present, but overall given the likely orientation of the MCS the potential would likely be on the lower side...not zero but low. PWATs around 2.0" or so will also be present, but hydro concerns will be mostly limited given the more short duration/transient nature of the complex. Bottom line here is damaging wind seems to be the biggest threat with the strong west to east flow aloft. The front moves through Friday and winds shift to a more northerly direction. Although by definition CAA initiates, we will still see some locations especially the southern most spot warm into the middle and upper 80s or perhaps touching 90 degrees along the Mississippi Gulf Coast during the afternoon, especially if clouds depart rather quickly. (Frye) && .LONG TERM... (Friday night through Wednesday) Issued at 305 AM CDT Thu May 9 2024 In the wake of the FROPA, cooler nights as well as drier days will materialize. The region will be under a slightly drier WNW flow aloft Friday Night through early Sunday. From this point forward eyes again shift up to the Texas Hill Country where another upper level shortwave will be amplifying. As it does, the general flow becomes zonal across our region. Ahead of the amplifying trough, our cold front that eventually stalls over the central Gulf will begin to lift forward as a warm front Sunday, Sunday night and into early Monday. Ahead of the front some isentropic upglide will help generate showers and perhaps some elevated convection across the CWFA. As the upper level disturbance moves eastward across east TX within the zonal flow, rain chances will gradually increase. A series of upper level short waves will develop within the newly established SW flow around the slowly approaching broader upper level trough. This is likely going to produce a source for additional waves of showers and thunderstorms through the start of the new workweek prior to the broader trough ejecting northeast eventually toward the Mid Atlantic sending yet another front through the region and shutting off the rain chances by Wednesday. Temperatures in the long term look to hang around seasonal averages or perhaps slightly cooler with the lower heights and increased cloud cover reducing insolation. (Frye) && .AVIATION... (06Z TAFS) Issued at 1140 PM CDT Wed May 8 2024 Primary condition at forecast issuance time will be MVFR ceilings, but at times, that deck scatters out to VFR conditions. While most of the night will see MVFR ceilings, there may be periods where ceilings fall to about FL008, especially at KMCB and perhaps KHDC. Those MVFR ceilings will remain common until midday, when the cumulus field may scatter out as bases lift to FL030 or a little above. Cloud bases will again lower to MVFR after sunset Thursday with the loss of heating. Still some uncertainty whether TSRA progresses far enough southward, or quick enough, to impact this forecast package. If it reaches KMCB or KBTR during the forecast package, it would be only in the last hour or two (04z or beyond), and there are some solutions indicating that`s too quick. Will hold off mention for this package, but 12z package will reassess. (RW) && .MARINE... Issued at 305 AM CDT Thu May 9 2024 A cold front will continue to move southward toward the central Gulf Coast today and should move through later tonight or early Friday. Ahead of the front southerly winds will remain moderate to strong through the early morning hours. A SCA has been issued for all waters outside of the Lake. As the front nears, the pressure gradient will relax a bit. Mostly moderate winds will be expected so cautionary headlines may be needed at some point Thursday and then again behind the front on Friday. Winds and seas will calm over the weekend as high pressure moves eastward to our north. However, another upper level disturbance will engage the front that pushes south into the Gulf later this weekend and through the start of the new workweek...leading to higher convective chances and perhaps locally higher winds and seas. (Frye) && .PRELIMINARY POINT TEMPS/POPS... MCB 90 66 83 58 / 20 40 20 0 BTR 94 72 89 64 / 10 20 10 0 ASD 92 71 88 62 / 10 30 30 0 MSY 92 75 89 69 / 10 20 20 0 GPT 89 71 89 63 / 10 50 40 0 PQL 90 71 90 60 / 20 50 40 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...Small Craft Advisory until 7 AM CDT this morning for GMZ532-534- 536-538-550-552-555-557-570-572-575-577. MS...None. GM...Small Craft Advisory until 7 AM CDT this morning for GMZ534-536- 538-550-552-555-557-570-572-575-577. && $$ SHORT TERM...RDF LONG TERM....RDF AVIATION...RW MARINE...RDF