909
FXUS64 KLIX 102049
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
349 PM CDT Sat Aug 10 2024

...New SHORT TERM, LONG TERM, AVIATION, MARINE...

.SHORT TERM...
(This evening through Monday night)
Issued at 312 PM CDT Sat Aug 10 2024

A deep layer ridge axis extending eastward from Texas will
continue to the dominant feature over the area on Sunday and
Monday. The ridge will weaken slightly on Monday as a longwave
northern stream trough digs into the eastern third of the CONUS,
but the overall upper level flow regime will remain out of the
northwest. Tomorrow, the strong subsidence in place beneath this
ridge will keep the mid-levels very dry and warm resulting in
lower than average precipitable water values of around 1.5 to 1.7
inches. A strong mid-level capping inversion will prohibit
rainfall development over most of the CWA, but enough low level
convergence along a weak seabreeze boundary in coastal Southeast
Louisiana could support a few low topped showers and
thunderstorms in the afternoon hours. Temperatures will once
again start out a bit cooler than average with lows in the low to
mid 70s across the northern half of the CWA. Highs will climb back
into the mid 90s due to the dry airmass in place. Fortunately, the
dry air will keep heat index values in check at between 100 and
105.

As the upper level ridge weakens over the area on Monday,
subsidence will decrease and mid-level moisture will begin to
return. Precipitable water values will increase back to more
normal levels of around 1.8 to 1.9 inches, and this help to push
heat index values back to near advisory levels. However, there
should still be just enough boundary layer mixing in the afternoon
hours to keep afternoon heat indices below 108 for most of the
CWA, and we may go one more day without a heat advisory. Even with
some slightly drier air lingering, temperatures will warm back
into the mid 90s after starting out in the 70s. Much like on
Sunday, there should be enough low level convergence along the
seabreeze boundary in coastal Southeast Louisiana to support some
isolated shower and thunderstorm activity in the afternoon hours
as MLCAPE approaches 1000 J/KG.

&&

.LONG TERM...
(Tuesday through Friday night)
Issued at 312 PM CDT Sat Aug 10 2024

From Tuesday through the end of the week, the deep layer ridge
axis will become centered directly over the forecast area. This
ridge is not unusual to see in the Summer months, and a return to
a more typical Summer pattern of diurnally driven afternoon
convection along developing seabreeze and lakebreeze boundaries
can be expected. This pattern will be supported by a seasonably moist
atmosphere as noted by precipitable water values of around 2
inches. Convective development will tend to occur in the mid to
late afternoon hours, and the convection could turn locally strong
at times with gusty winds being the primary threat. This is
supported by downdraft CAPE of around 1000 J/KG each afternoon and
fairly steep lapse rates in the lowest 3km of the atmosphere.
Unfortunately, the delayed convective development each day will
allow temperatures to push into the mid to upper 90s before any
cooling relief can occur, and the increase in humidity will cause
afternoon heat indices to climb to around 110 degrees each
afternoon. Heat headlines can be expected as we move into the mid
and latter part of the upcoming week.

&&

.AVIATION...
(18Z TAFS)
Issued at 312 PM CDT Sat Aug 10 2024

VFR conditions will continue at all of the terminals as high
pressure keeps dry and stable conditions in place.

&&

.MARINE...
Issued at 312 PM CDT Sat Aug 10 2024

Light winds below 10 knots and seas below 2 feet are expected
through the end of next week as a broad ridge of high pressure
remains in firm control of the area. The only concern will be the
threat of thunderstorms developing in the morning hours along a
land- breeze. These storms could produce some locally higher winds
and waves for brief periods of time.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  70  94  72  97 /   0  10   0  10
BTR  74  97  76  98 /   0  10   0  20
ASD  74  97  75  97 /   0  10   0  20
MSY  81  96  81  96 /   0  20   0  30
GPT  76  95  77  95 /   0  10  10  20
PQL  75  96  75  96 /   0  10  10  10

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&

$$

SHORT TERM...PG
LONG TERM....PG
AVIATION...PG
MARINE...PG