Rob Perillo Chief Meteorologist KATC 15 hrs · Sunday Afternoon Tropical Update June 2:
The tropical disturbance in the Bay of Campeche remained disorganized enough for Hurricane Hunters not to fly a recon today, however, they may get out there tomorrow if necessary.
The global models continue to disagree on organization and certainly moisture fields, with the GFS stringing the system out and northward into Texas and points east, while the much more reliable Euro maintains a weak organized low pressure system that could become a tropical storm or hybrid type of a system that will likely bring a "weather event" to Louisiana and Acadiana Thursday.
The system identified as 91L has a 60% chance for development per the NHC as of 2pm.
While I await the latest run of the tropical models, I'll comment on the big picture...
It looks like there will be a low pressure system skirting the Western Gulf Coast from Eastern Mexico to South Texas over the next several days...following the lead of the Euro Model, this system may get picked up by an initially, progressive upper low emanating from the west, and rolling through Texas Wednesday which will energize the system as it approaches the Gulf Coast From Southeast Texas eastward, or even after it moves inland.
Whether this remains a disturbance, becomes a depression, tropical storm or sub-tropical storm, it looks to bring several threats to Louisiana by Thursday.
The threats include a possible rainfall of 4-8" (and may ultimately be more as you can never underestimate deep tropical moisture interacting with an approaching upper level low) and a storm tide to the Louisiana Coast, that we can ill afford due to already high water levels, particularly in St Mary and Lower Saint Martin Parishes.
These weather threats should be in and (mostly) out Thursday into Friday morning for Acadiana, ending for Eastern Louisiana around midday Friday (based on latest Euro), but there are hints that the system may become a "meanderer" later in the week and into the following weekend, producing torrential rains from Eastern Texas, to Louisiana, then Arkansas, into the Mid-Mississippi, Tennessee and Ohio River Valleys...so we may be talking about this system for quite a while (all by the way, the runoff will feed back into the Mississippi down the road).
In the short term, we need to be ready here in Louisiana for a moderate risk of at the very least, a low end tropical storm arriving Thursday...and even if we don't see that, I do see tides increasing 2-3ft above normal minimally along the coast, and there will likely by a swath of area wide rains of 2-6", but there could be a stripe of 6-12", in my opinion, somewhere within the deep tropical moisture heading for the state...these are scenarios that the Euro provides today and are fairly consistent with previous runs.
So we have something likely to come to Acadiana and Louisiana, and the details will likely change, but I see us having to deal with something unpleasant Thursday anyway you slice it.
Be ready for the possibility of a "Potential Tropical Cyclone" statement coming from the NHC at some point early this week too.
I'll stay away from the impacts on the Morganza Spillway opening Thursday, as I'm sure USACE is dealing or will deal with this scenario.
Stay with us on every weathercast this week...and get direct updates through the KATC WX app.
WOW...he's really booming those rain chances! GFS may be undermining them big time.
As of 12z:
At 1200 UTC, 03 June 2019, LOW INVEST 91 (AL91) was located in the North Atlantic basin at 20.0°N and 94.9°W. The current intensity was 25 kt and the center was moving at 2 kt at a bearing of 310 degrees. The minimum central pressure was 1007 mb.
CWOP ID: DW2721, CoCoRaHs Station: LA-TG-11 NWS's Ponchatoula/Hammond Area's COOP Member, Station ID 16-7425-08, PONL1
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This morning's GFS never gets it going but does allow it to increase our rain chances later in the week.
Last night's Canadian gets it near a tropical depression, riding it along the Texas and Louisiana coasts with 2 - 4" from southeast Louisiana through eastern Mississippi.
00z EURO is close to TD as well, but doesn't look to fully close off a low level circulation, but as far as a "path", similar to the Canadian.
Regardless...this does look like it'll cool us off a bit and increase our rain chances.
If it were to follow this scenario, what effects would Southwestern LA have and when? I'm planning to drive to Houston on Friday and don't want to have to drive in a storm. Thanks in advance.
Not a professional forecast by any means and should not be viewed as such - just my opinion. Audrey'57, Carla'61 Hilda'64, Betsy'65, Edith'71, Carmen'74, Danny'85, Juan'85, Andrew'92, Iniki'92 (while on vacation in Kauai), Lili'02, Rita'05, Gustav'08, Ike'08, No-Name'16, Harvey'17.
Post by grisairgasm on Jun 3, 2019 14:48:28 GMT -6
Upper level outflow looks decent. Water vapor suggests a moist atmosphere. So far the classic lack of sustained convection and no distinct LLC. Interesting how these early BOC disturbances take so long to separate from Central America monsoons. Local pocket it sits in currently looks rather conducive. SE Louisiana really needs some passing rains and hopefully the SE US will see the brunt sparing the Midwest. All I see at this time is finally some rain and a break in these temps. Maybe the shear in the N Gulfcoast will vent some storms and contribute to rhe rain. We’ll see.......but it IS hurricane season in the GOM and never take you eyes off it LOL!
Post by grisairgasm on Jun 3, 2019 17:34:01 GMT -6
Lot of discussion on some other sites about this finally coming together. There is no sustained convection and clouds are mid and upper level. Upper outflow in itself does not mean genesis. When you begin to see those boiling hot towers popping up and continuing then you may have something. I find it rather strange that there are so few bouys in that region of the Gulf based on today’s technology. Perhaps proximity to Hurricane Hunter bases negates the need for them but the N Gulf has tons.Still looks to me that needed rain will come and move on. Doesn’t look like a generalized threat to current river levels regarding rain. However, if the A basin and Miss River were to wind up on the East side of a weak TS there could be some issues. A pressure gradient created by the W side of the high could also exacerbate the situation. On my “Hurricane Terror Alcohol Consumption Scale” this rates at a 1. 1 being a half glass of wine and 10 being Margaritas for breakfast , lunch, and dinner!