Weakening "Karen" Near the Louisiana Coast.......
FOR THE FIRST COAST: (our weather (forecast/effects) changes very little even as "Karen" dissipates due to a plume of tropical moisture spreading across the area. The moisture + an approaching cold front will combine for rain & storms into Mon.)
given the forecast thinking/reasoning (as discussed below), local impacts remain -- generally -- pretty minor....as I've tried to articulate for the last 5-6 days.
** Scattered showers & a few t'storms will occur through Sun. night with some heavy rain in some spots. Rain & storms will increase Monday.
** still a very isolated threat for tornadoes Monday given the combination of Karen's remnants, a cold front, a strong upper level trough + some surface heating.
** some heavy rain but speed of the system should limit the overall amounts -- perhaps an average of a half inch to 1.5", locally 2"+. There could be some short-lived street flooding & ponding of water.
** breezy through Mon. but not overly strong as winds average 15-20 mph. Stronger t'storms may produce winds nearing 50 or even 60 mph but only in isolated cases.
** somewhat rough seas & surf Sunday-Mon. but again pretty minor. An offshore component to the winds by later Tue. will make for happy surfers(!).
While the "fat lady" isn't singing yet when it comes to the complete demise of "Karen", she's starting to clear her throat & has is at the microphone.
Infrared satellite below shows strong but disorganized convection way to the east of the center of "Karen" while convection from Texas to the Tennessee Valley is associated with the approaching cold front & strong upper level trough.
The visible satellite below nicely shows the center of the circulation [just about due south of New Orleans Sun. morning] removed (to the west/northwest) from the intense convection that remains heavily weighted on the east side of the circulation.
While there has been -- & will be -- bursts of convection, the very hostile atmospheric conditions -- shear + dry air -- should eventually combine to destroy Karen's circulation which is already only a shadow of its former self.
Sea surface analysis below. The numbers show the wave heights with the highest numbers closer to what's left of "Karen", of course. Higher waves/rough seas & surf & a high rip current risk will affect the Fl. Panhandle coast through the weekend. Wave heights will not be significant for the First Coast.
Satellite imagery shows "Karen"
struggling thanks to the persistent moderate west/southwest shear. The center remains displaced to the west/northwest of the strong convection as mentioned above. The track has generally been a little west & north due to the shallow nature of the system but a pretty sharp right hand turn (to the northeast then east) will occur as a strong upper level trough & surface cold front approach.
As the upper trough approaches, an upper level ridge near Jacksonville will collapse paving the way for the east then northeast acceleration of "Karen" Sun. night-Mon. night. The remnant low will become attached to the cold front & become absorbed by the upper trough over the Eastern U.S. It's questionable as to whether or not even the remnant low will stay in tact, but the approaching upper level trough/disturbance should either maintain the remnant low ore develop a new weak nontropical low along the front over or near Fl. Monday.
Ultimately.....the evolution of "Karen" does not change the so-called sensible weather for the First Coast through Mon. night: on-&-off showers & storms with heavy rain at times + some risk of a severe storm, especially Mon. What I termed much of the past week as "fringe effects" from the storm for the First Coast will still be valid thanks to the tropical moisture & cold front moving into the area.
The image below shows the moderate -- 20(+) knots -- over a good portion of the Gulf of Mexico.
Water vapor satellite images below showing the vast area of very dry air in close proximity to "Karen":
Model plots + radar imagery (with projected track of "Karen") below courtesy S. Fl. Water Management District:
3-day total rainfall forecast:
The satellite imagery below shows the mature upper level storm system over the Central U.S. that's driving the cold front eastward (note t'storms north-south along the front) which will eventually turn "Karen" & its remnants -- east & northeast.
Tropical waves continue to decrease as they move off the coast of Africa. This late in the season, development -- or at least long track tropical cyclones across the Atlantic -- is not likely so deep in the tropics. Still...these waves would have at least some potential for long term development if they can get across the Atlantic near the Caribbean &/or SW Atlantic. There are some indications of long term development in or near the Caribbean & SW Atlantic in roughly 10 days to 2 weeks.