Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
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992 FXUS64 KLIX 020950 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 450 AM CDT Tue Jul 2 2024 ...New SHORT TERM, LONG TERM, AVIATION, MARINE... .SHORT TERM... (Today through Independence Day) Issued at 322 AM CDT Tue Jul 2 2024 The beat on the street is the heat and unless you have been sitting inside an air conditioned room (pretty smart more by the way) you have probably noticed. This is not going to get better today but should be slightly better the next few days. Better will be relative as it will still be hot but rain chances go up for Wednesday and the 4th of July and that should help keep the afternoon highs down some. But until we get to tomorrow we will have to get through today which may be every bit as rough as yesterday. As for today, the biggest change will be the moisture and that is more so the mid and upper levels. The ridge has continued to slide to the east and will be centered directly north of the area this afternoon while drier air will slowly continue to work in from the north and northeast. The 00Z sndg last night had a PW just below 2" and GOES16 TPW showed drier air just off to the north and northeast drifting to the area. This along with very warm mid lvl temps and an increase in subsidence should drastically hinder convective development over the northern half of the area. PWs will still be at or just abv 2" along the coast and this may allow for greater potential for storms to develop this afternoon along the seabreeze and or lake breeze. The biggest issue for the seabreeze is the northerly winds in the LL which will keep it from moving to the north much thus why the best rain chances will likely be across the southern and southwestern portions of the CWA. The lake breeze heading south and southwest out of Lakes Pontchartrain and Maurepas may actually provide the best chance for rain in portions of the river parishes as it pushes southwest of I-10. So what does this mean for the heat today. The biggest problem is the lack of rain and cloud cover meaning that most of the area will have little difficulty warming up today. LL moisture is still very high with maybe the one exception being across portions of southwest MS where slightly drier air may mix in enough to get the dewpoints to fall to near 70. Elsewhere it doesn`t look like there will be any relief in humidity values. High yesterday got even hotter than expected in many locations with MSY and ASD topping out around 98. The only real change from yesterday with respect to temps is that the LL may be a degree or two warmer. With that highs should be every bit as high as they were yesterday if not a degree or two hotter. The one exception could be coastal MS where the we should not have the light to moderate northerly flow which typically leads to some local compressional heating. Winds from the sfc to h925 will begin very light and slowly veer around to the east by midday and possibly ESE this afternoon. This would help keep coastal Ms from torching out but it could be a double edged sword as if the seabreeze can develop and try to penetrate inland some the humidity will increase or as the seabreeze approaches microscale compressional heating in front of that boundary and moisture pooling could make things even more miserable. With highs once again expected to be in the mid 90s to near 100 across the entire area and the very humid airmass in place heat index values should have no problem getting into the 110s again for a large chunk of the area and could once again approach 120 in isolated areas. An Excessive Heat Warning and Heat Advisory has already been issued and no changes were made to it. As for tomorrow and Independence Day it looks like we could see some relief in the form of much higher rain chances along with early initiation. The ridge remains over the southeastern CONUS but does begin to flatten out more while the drier air that could move in today looks to be replaced by a very moist airmass. Almost a weak easterly wave as it moves under the ridge. But possibly the biggest change and positive aspect for convection will be LL winds as the h85 winds come already back around and should be out of the southeast by late morning/midday Wednesday. This should allow for the seabreeze to develop much earlier say around late morning/midday. That along with increasing cloud cover will help contain the afternoon highs some but make no mistake highs will still be in the lower to mid 90s. Of course the humidity will be high and could be even greater now and that will likely lead to the oppressive conditions continuing but should be nothing like what should be seen today and what has already occurred the last few days. Thursday could be a carbon copy of tomorrow but the concern is that we may actually be between weak waves rotating around the ridge and thus depending on timing Thursday could be a good bit drier rain wise and likely a degree or two warm. At this time we have held off on any heat headlines for Wednesday and Thursday due to the uncertainty of rain coverage, timing, and impacts on the temps. That said it is highly likely that some locations will be under a heat advisory both days. /CAB/ && .LONG TERM... (Friday through Monday) Issued at 322 AM CDT Tue Jul 2 2024 Heat is the first concern with the forecast for Friday and into the weekend but obviously many are interested in the forecast for Beryl. Medium range models are in decent agreement and the more trust worthy ones show a similar setup as Beryl moves across the Yucatan and into the southwestern GOM. Given the high uncertainty with rain potential and where Beryl eventually ends up we have stuck pretty close to the NBM guidance. The ridge that has brought us our heat wave and will dominate the region through the week will start to slowly slide east on Friday and the decreasing subsidence and lower hghts may allow for a decent shot of rain again but LL temps remain quite high and this should still lead to widespread lower to mid 90s Friday and into the weekend with a few upper 90s not out of the question Friday. With that we could easily see heat headlines continue. As for Beryl, it continues to hold its own as it begins to move into the central Caribbean today. At 8Z Beryl was still a category 5 hurricane and even though it is moving into a more hostile environment, has not weakened yet but this is expected to begin today. The latest forecast brings Beryl over the Yucatan early Friday and into the southwestern GOM overnight Friday night. Key things to watch over the next few days. Track as it approaches Jamaica. If it moves south or over Jamaica there is a good chance that Beryl will continue moving more west especially if it weakens significantly. Second, how strong is Beryl as it approaches the Yucatan. A stronger system will feel the steering currents more and that could play a big role into where Beryl eventually goes. Third will be our ridge. As long as it remains over the southeastern CONUS and Gulf coast it should help to continue to steer Beryl to the west-northwest and northwest. That said the western periphery of the ridge will begin to erode this weekend as a disturbance drops southeast out of the northern Plains and Upper MS Valley. The steering currents could break down rather quickly over the western Gulf and that is why you may be seeing that larger spread in the media/social media. At this time it still looks unlikely we will see any direct impacts from Beryl. If Beryl weakens significantly over the next 24-36 hours as it moves into a hostile environment and/or hits Jamaica which would significantly disrupt it, Beryl would likely take more a almost due west and could very well just continue west. If Beryl remains organized it should continue to follow a WNW to NW motion into the southwest Gulf and then slow down some. It could then take a NW to NNW turn or if far enough south slowly to the W and WNW. So the main take away is for our area relax and just continue to follow the latest forecast. Latest forecast from NHC has Beryl as tropical storm just off the Mexican coast Sunday morning. If you have family along the coast in Mexico and southern to central TX coast remind them to closely pay attention. /CAB/ && .AVIATION... (12Z TAFS) Issued at 322 AM CDT Tue Jul 2 2024 VFR conditions will likely persist through the forecast for most if not all but HUM today. HUM has the best chance of seeing convection but there could be a few storms near MSY, NEW and GPT late this afternoon. Obviously any passing TSRA will lead to reduced vsbys and lowered CIGs. Gusty winds are also possible but outside of that VFR condtions will be the rule. /CAB/ && .MARINE... Issued at 322 AM CDT Tue Jul 2 2024 Weather across the coastal waters will remain generally benign outside of convection and convection may be a tad harder to get today but still possible each morning. While higher winds and seas will accompany any storms, winds otherwise should generally be no higher than 10-15 knots with seas/waves mostly 2 ft or less. /CAB/ && .PRELIMINARY POINT TEMPS/POPS... MCB 98 76 92 74 / 10 10 70 10 BTR 101 80 95 79 / 20 10 80 0 ASD 98 79 92 78 / 20 20 80 10 MSY 98 81 92 80 / 20 20 80 10 GPT 96 79 90 78 / 30 40 70 10 PQL 97 78 94 77 / 30 40 70 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...Excessive Heat Warning from 10 AM this morning to 7 PM CDT this evening for LAZ034>037-039-046>048-056>060-064-065-071- 076>090. Heat Advisory from 10 AM this morning to 7 PM CDT this evening for LAZ066>070. GM...None. MS...Excessive Heat Warning from 10 AM this morning to 7 PM CDT this evening for MSZ068-077-083>088. Heat Advisory from 10 AM this morning to 7 PM CDT this evening for MSZ069>071. GM...None. && $$ SHORT TERM...CAB LONG TERM....CAB AVIATION...CAB MARINE...CAB