ATL: INVEST 93L - Discussion

[cycloneye]

2 PM:

Southwestern Gulf of Mexico (AL93):
Showers and thunderstorms have not become any better organized this
afternoon in association with an area of low pressure over the
southwestern Gulf of Mexico. Environmental conditions appear only
marginally favorable and this system has a short window to develop
further over the next day or so. By Wednesday morning, the system is
forecast to merge with a developing frontal boundary over the
western Gulf of Mexico. An Air Force Reserve Reconnaissance aircraft
is in route to investigate the system this afternoon and will
provide more information about the system's structure.

Regardless of tropical cyclone development, the system is forecast
to produce gale-force winds over portions of the northern Gulf of
Mexico by tomorrow, and potentially heavy rainfall along the Gulf
Coast by the latter portion of this week. For more information, see
products from your local National Weather Service office, and high
seas forecasts issued by the National Weather Service.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 7 days...low...30 percent.

[cycloneye]

Plane found a weak low.

[Sciencerocks]

[wxman57]

Its best chance of tropical development was yesterday. Moving onto the upper-level wind superhighway now.

[cycloneye]

Southwestern Gulf of Mexico (AL93):
Updated: Showers and thunderstorms remain disorganized this
afternoon in association with a broad area of low pressure located
over the southwestern Gulf of Mexico. Data from an Air Force
Reserve Reconnaissance aircraft investigating the system has so far
found the circulation remains elongated and not well-defined, with
maximum sustained winds of only 20-25 mph. Based on the current
structure, additional development is becoming unlikely before the
system merges with a developing frontal boundary over the western
Gulf of Mexico on Wednesday.

Regardless of tropical cyclone development, the system is forecast
to produce gale-force winds over portions of the northern Gulf of
Mexico by tomorrow, and potentially heavy rainfall along the Gulf
Coast by the latter portion of this week. For more information, see
products from your local National Weather Service office, and high
seas forecasts issued by the National Weather Service.
* Formation chance through 48 hours...low...10 percent.

[Steve]

Latest guidance soaks northern and central peninsular Florida along with southern Georgia.

https://www.wpc.ncep.noaa.gov/qpf/p120i.gif?1696981817

[cycloneye]

Southwestern Gulf of Mexico (AL93):
An area of low pressure located over the southwestern Gulf of Mexico
is producing limited and disorganized shower and thunderstorm
activity. This system is forecast to merge with a developing
frontal boundary over the western Gulf of Mexico early Wednesday,
and tropical cyclone formation is not expected. Regardless of
tropical cyclone development, the system is forecast to produce
gale-force winds over portions of the northern Gulf of Mexico by
tomorrow, and potentially heavy rainfall along the Gulf Coast by the
latter portion of this week. For more information, see products from
your local National Weather Service office, and high seas forecasts
issued by the National Weather Service.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...near 0 percent.

[wxman57]

Yep, its best shot at developing was in the BoC. It's moving into the jet stream now. Just a typical west Gulf low tomorrow. Nothing remotely tropical.

[USTropics]

Here to show some love for our soon to be departed 93L. There's actually a surface low trying to form down off the coast of LA, but since this is along the warm frontal boundary, it's purely extratropical in nature:


Most of the instability is actually located much further east in the EGOM, while most of the turbulent flow is located over the southeast US (in part to the strong subtropical jet that has lifted north). This is a really cool new product from PivotalWeather, where we basically have an overlay of hodographs with surface CAPE plotted beneath this (hodographs are essentially a vertical profile of the winds). In this instance, we can see large portions of Florida are experiencing strong vertical flow, with highest values concentrated over the panhandle area. Plotted under this is surface cape (i.e., instability), and the boundary layer between this CAPE and turbulent flow will begin to initialize severe weather over Florida (we've already had a few tornado warnings over western Florida/Tampa area). The biggest threat will be from instability lifting north this evening, and likely high surface winds in certain areas.

[Steve]

Drizzly day here with a few heavy but light rain downpours. Front came down, energy came up. Clockwork.