New Orleans/Baton Rouge, Louisiana

New SHORT TERM, LONG TERM, AVIATION, MARINE

• Wind speeds will slack off some over the Gulf but expect them to remain out of the east through Monday and pick back up to 15 to 20 knot mainly over open gulf waters. This will continue to create minor coastal flooding along sections of the Mississippi and Louisiana gulf coasts during high tide times each day through the weekend. A coastal flood advisory is in effect for locations expected to get minor coastal flooding.
• Rain has already returned to a few locations today but the remainder of the afternoon and thius evening there could be a little more storms the previously thoguht and over the western/northwestern portions of the outlook area. This would likely occur during prime Trick-or-Treating time and there could even be a few very isolated pockets of rainfall amounts greater than 3".
• Stronger system impacts the region Tuesday and Wednesday. Rain will begin during the day Tuesday impacting election day while strong to severe storms look possible Tuesday night through early Wednesday.

Remnants of once Hurricane Vance had spread out and moved across the region earlier but is now starting to speed away to the north and east. This appears to have finally eroded/nudged the ridge away enough to get some rain over the CWA. The large area of rain to our west/southwest overnight and early this morning looked like it hit a brick wall as it moved into south-central LA. Our ridge was stubborn and just wouldn`t allow that rain to move in but it looks like it has weakened enough finally. This still doesn`t make the forecast any easier for the remainder of the afternoon and tonight.

Moisture was quickly recovering with this mornings sounding showing PW`s already around 1.6" and GOES TPW showing anywhere from 1.7 to 1.9 trying to push into the area. This is already around the top 10% so moisture is not in question. The question is forcing, lift, and instability. One big issue is the lack of any real focus or forcing mechanism in the LL. Instability may be a little higher than previously expected thanks to enough breaks in the clouds to allow a good chunk of the area to get into the lower 80s and some possibly in the mid 80s before we are done. A few other things that appear to be favorable for showers and even thunderstorms to develop later this afternoon and evening, one is the nose of the mid level jet moving into central TX right now. It should approach the western portions of the area around 23/00z. This doesn`t look like it is being handled well by any of the models as they all look to be faster with it and farther north but tracking back for a few hours with GOES WV shows it is moving more easterly and not lifting as much and it could provide a little more lift than what models were thinking earlier. Second feature which has been mentioned before is the upper jet dropping SSE into the Gulf this afternoon and this evening. This is going to provide very favorable upper level diffluent pattern over the area between 22Z and 06Z which will likely lead to very efficient storms should any develop. This all suggests that there is still a window for more numerous showers and embedded thunderstorms some of which could actually develop heavy rain.

That said confidence is not extremely high. Again we lack any significant focus or forcing feature and if that mid lvl jet does start to nudge more north or get blocked by weak ridging behind last night and this mornings disturbance then rain will struggle however, last few hours are starting to make me think we may have a little more activity than previously thought. Just mentioned the disturbance (partial remnants of Vance) are departing and models had been showing not necessarily s/w ridging but definitely some increase in hghts and suppression behind it but latest analysis shows those mid lvl hghts are not rising and and even slightly falling. This is likely what has finally led to some rain develop over the area but with that I feel a little better about that lift getting into the region later. With that I am anticipating a little more activity over the northwestern/western portions of the CWA especially around the BTR metro and the problem is that this could occur right at prime Trick-or-Treating time. Right now it looks like between 22z and 04z would be the time where we would see the greatest amount of activity. Again not expecting widespread heavy rain but there definitely could be pockets of some heavier rain possibly greater than 3" and it now looks like that could be over portions of SELA along and north of I-10 and into portions of swMS. That is in stark contrast to where the earlier thoughts of the heavier rain potential being across coastal MS but if we get this tonight over the western 2/3rds of the CWA it would likely die off before getting into coastal MS and then that redevelopment overnight we previously thought was possible would likely occur tomorrow but be farther east and southeast possibly completely out of the area and into AL and the Gulf. Still anticipate a few showers and thunderstorms tomorrow early but we should begin to dry out tomorrow afternoon with ridging quickly building in.

Our next weather maker is already starting to slowly take shape but it is a complete mess right now. By Monday it should be a rather deep L/W trough having just crossed the Continental Divide while mid lvl ridging dominates the region. As we heading into Election day things start to pick back up but the forecast is definitely not clear cut and confidence honestly has taken a bit of a hit with the latest medium range model guidance. /CAB/

Focus on the extended portion of the forecast is our system Tuesday and into Wednesday. Models had come into much better agreement the last few days well there is definitely some disagreements with respect o how they handle the mid lvl pattern and the multitude of features. This has lowered confidence quite considerably in the forecast for Tuesday and Tuesday night. We will still see a pretty decent system along with a front which will bring showers and thunderstorms to the area the question though is timing and intensity. Because of that there were NO adjustments from the latest NBM.

Models are struggling with how to handle everything with respect to the large L/W trough off the west coast and the mid lvl jet coming out of the east Pac and merging into it tomorrow night over the 4 corners region. Typically with that much wind and most of the mid lvl jet downstream of the trough axis it should want to pull the trough north/lift it out and along with that most of the dynamics. There are some issues though. There will still be some strong mid lvl winds upstream of the trough axis and then there may be another strong s/w diving south out of Canada Monday night and into Tuesday.

A few different options then occur. First if that strong s/w develops and dives south out of Canada it would cause the L/W trough to rapidly close off and much farther north, over the north-central CONUS. This would then leave a much weaker trough axis at the base moving into the Lower MS Valley maybe even be held back to the southwest leading to a slower time frame. This also has any sfc reflection well north of the area and not much of a front moving into the region. We would still see rain and some thunderstorms but the risk for strong to severe storms would greatly be reduced. This also may keep a good chunk of Election day on the drier side thanks to a slower time frame.

Another option would be if that s/w doesn`t develop or is much weaker as it drops south. It still looks like the trough would close off given all of the energy that merges with it over the 4 corners but it would be a much broader closed low and it would close off farther to the southwest. This would lead to a much more defined and sharper trough axis and possibly even take on a negative tilt as it tries to move through Tuesday night. The main associated sfc low would still be well north but there would likely be a weak wave along the front farther south closer to the region. This scenario would continue to lead to the threat of strong to severe storms along with locally heavy rain. It also has more potential for showers and maybe some embedded thunderstorms during the day which would impact voting sites.

Right now this system is still in the Pacific and with this much energy the models are struggling. We should hopefully begin to tighten things up tomorrow as it finally begins to move into the upper air network we start to get some better data and sampling. With that like was said earlier stuck with the NBM which has high PoPs Tuesday afternoon through Tuesday night and then tapering off during the day Wednesday. Rainfall amounts being advertised right now is not overlie impressive but those will get adjusted as well depending on how thins evolve. After this move through we move into more zonal flow and and dry out the rest of the work week. /CAB/

We are strating to see some MVFR cigs develop as low clouds and even some rain have developed. OVer the next 6 hours it may be a little intersting as aactivity could pick up over the western half of the CWA impacting mostly BTR between 22 and 4z. Storms would impact other temrinals across SELA along with MCB between 23 and 5z. These storms would bring at least MVFR cigs and vsbys but if the rain gets heard enough vsbys could fall into IFR status for short time. Right now we aren`t explicitly showing IFR conditions but the most likely candidates would be BTR and MCB. Conditions would improve somehwat overnight but still expect MVFR cigs over most of the terminals tonight. /CAB/

into early next week as a broad surface high pressure system sits to the north of the area. Winds will generally remain in the 10 to 15 knot range in the lakes, sounds, and bays through the weekend and into early next. However, the open Gulf waters may see slightly higher winds of 15 to 20 knots over this period, resulting in choppier seas of 3 to 6 feet. Winds look like they slack off tonight enough to keep headlines out for now but there is a good chance the outer waters will need SCS headlines again Sunday and possibly through Monday. This persistent east wind will also lead to some minor coastal flooding less than one foot above ground level for east facing shores through the remainder of the weekend. We are already seeing some showers and a few thunderstorms which will continue tonight and Sunday as a weak disturbance passes through.

/CAB/

LA

Coastal Flood Advisory from 1 AM to 9 AM CDT Sunday for LAZ070-076-078.

GM

None.

MS

Coastal Flood Advisory from 1 AM to 9 AM CDT Sunday for MSZ086.

GM

None.