Red Flag Warning 5, NWS New Orleans, LA

Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Livingston Parish, LA, Pointe Coupee Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Pike County, MS, Walthall County, MS, Wilkinson County, MS

Area Forecast Discussion
National Weather Service New Orleans LA
1255 PM CDT Sat Aug 26 2023

...New AVIATION...

.SHORT TERM...
(Today through Sunday Night)
Issued at 348 AM CDT Sat Aug 26 2023

This morning a weak H5 impulse is moving south and westward over
the western Florida panhandle, which has caused some shower and
thunderstorm activity south of Panama City, FL. This feature will
continue to move around the southern periphery of the upper level
ridge still situated over the high plains. Ridging continues to
extend eastward across Oklahoma stretching as far east as the
Coastal sections of the Carolinas. The upper ridge and dry
antecedent conditions will continue to favor well above average to
near record temperatures again today. Like a broken record (no
pun intended) Excessive Heat Warnings area wide continue along
with a continuation of a Red Flag Warning due to again very dry
antecedent conditions. That said, with the upper impulse along
with sea/lake breeze, some isolated to scattered showers and
thunderstorms will be possible later this evening. Although this
may help reduce the heat for some, we will likely hit headline
criteria prior to convective initiation.

Later tonight the upcoming pattern change comes within sight as
an upper level weakness begins to develop in the ridge, first
across the cornbelt region and then amplifying/digging southward
into the Ohio and Tennessee River Valleys by Sunday. A surface
cold front will also begin to move through these areas as the
parent weakness continues to amplify. Unfortunately, this feature
doesn't make it to our region by Sunday. Still a few diurnally
driven updrafts along the sea/lake breeze will be possible,
however, overall rain chances look to be around or slightly below
climo POPs for now with much of the limited QPF signal across our
northern tier Sunday evening. Additional heat headlines will
likely be needed on Sunday once again as temperatures surge into
the lower to mid 100s across the CWFA. Similar to the last couple
of days, any stronger updraft would likely contain strong gusty
winds given favorable DCAPE numbers, especially as updrafts
collapse under the dry upper levels. (Frye)

&&

.LONG TERM...
(Monday through Friday)
Issued at 348 AM CDT Sat Aug 26 2023

The long term begins hot again with perhaps one more day of heat
headlines on Monday. However, as the upper level weakness settles
across the eastern U.S. and the surface front stalls pretty close
to the coast, an uptick in POPs will take place with a solid QPF
signal during the afternoon hours on all Globals. Still think heat
index values will hit headline criteria just prior to the
development of convection in the late afternoon, especially with
low level moisture pooling ahead of the front. This front,
however, should break the seemingly never ending need for heat
headlines and recent broken records beyond Monday. The frontal
boundary should remain in rather close proximity through Tuesday
before it begins to decay leaving a surface trough. At the same
time, an upper level low will begin to slide west across the
western Gulf of Mexico. Depending on the speed of this feature could
have some clue in terms of where 93L goes upon developing early
to midweek.

Speaking of, globals and respective ensembles continue to develop
Invest 93L over the southeastern Gulf or western Caribbean by
early next week. NHC continues to advertise a "high" chance of
development over the next seven days (90 percent chance). Model
spread has slightly meandered a bit over the last 24 hours with
the GFS finally waking up fashionably late. Without getting too
involved in terms of where the feature will go, we'll hold off on
mentioning exact specifics for now. Globals will continue to
struggle for a bit in terms of track and intensity at least until
we can get a better sample (provided by our hometown Hurricane
Hunter friends over in Biloxi on Sunday afternoon) and/or
development of a low level center. As previously mentioned, the
overall pressure field appears broad and multiple MCVs could
develop under stronger convective bursts in all quads of the broad
low...which adds a bit of uncertainty to the guidance. As of now,
continued to limit any local impacts from a northward moving TC
to the eastern marine zones.

Regardless of where 93L goes, the pattern is FINALLY changing
across the region. With more clouds and an upper low developing
across the Sabine, daily high temperatures cool to the lower and
middle 90s across the region. Also with this pattern shift we will
begin to see some rainy periods through much of the long term
period. This again is considered a net positive in respect to the
ongoing heat and drought. (Frye)

&&

.AVIATION...
(18Z TAFS)
Issued at 1246 PM CDT Sat Aug 26 2023

VFR conditions continue with winds light (<10kt) and generally
northerly. Have added VCTS to BTR, HDC, ASD, MCB, and GPT given
increased confidence in pop up afternoon storm development around
2100 UTC. Some brief periods of gusty winds and heavy downpours
cannot be ruled out with stronger downdrafts. Should see these
showers and storms gust out and abate by around 01Z. Otherwise,
another quiet night with VFR prevailing at all terminals.

&&

.MARINE...
Issued at 348 AM CDT Sat Aug 26 2023

Mostly favorable marine conditions through the weekend. There
could be a slight uptick in rainfall chances especially during the
overnight and early morning hours. The strongest activity might
contain locally higher winds and seas. Going into the early to
midweek next week, eyes will focus across the western Caribbean or
southeast Gulf of Mexico where a tropical low is forecast to
develop. This feature should deepen as it moves generally
northward across the eastern Gulf of Mexico. This will likely
increase winds and seas to near SCA thresholds during that
timeframe. Rain chances will also develop as a stalled front will
continue to reside across the region. (Frye)

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  76 102  74  96 /  20  50  40  70
BTR  79 105  79 100 /  10  40  30  70
ASD  78 103  78  97 /  20  40  30  70
MSY  82 102  82  97 /  30  40  30  70
GPT  79 100  79  94 /  20  40  40  70
PQL  77 102  77  96 /  10  30  30  60

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Excessive Heat Warning until 8 PM CDT this evening for
     LAZ034>037-039-046>048-056>060-064>071-076>090.

     Red Flag Warning until 8 PM CDT this evening for LAZ034>037-039-
     046>048-056>058-071-076-079>086.

     Excessive Heat Watch from Sunday morning through Sunday evening
     for LAZ034>037-039-046>048-056>060-064>071-076>090.

GM...None.
MS...Excessive Heat Warning until 8 PM CDT this evening for
     MSZ068>071-077-083>088.

     Red Flag Warning until 8 PM CDT this evening for MSZ068>071-077-
     080>082.

     Excessive Heat Watch from Sunday morning through Sunday evening
     for MSZ068>071-077-083>088.

GM...None.
&&

SHORT TERM...RDF
LONG TERM....RDF
AVIATION...TJS
MARINE...RDF