393
FXUS64 KLIX 150842
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
342 AM CDT Mon Jul 15 2024

...NEW SHORT TERM, LONG TERM, MARINE...

.SHORT TERM...
(Today through Tuesday)
Issued at 342 AM CDT Mon Jul 15 2024

Another somewhat typical summer day across the Central Gulf Coast.
Similar to the last few days, conditions will remain hot with a
roughly 594dam H5 ridge centered across the Gulf of Mexico and
southwest Atlantic Ocean. At the surface, light southerly flow
will continue to provide a source for low level moisture. Combined
with the high low level moisture and hot temperatures, heat index
values will once again climb into the dangerous range...generally
up to around 110F and in the more extreme cases some locations
probably closing in on 112F or so (again, these are "feels like"
temperatures). Showers and storms will again develop this
afternoon across the region, with the best potential residing
along the I10/12 corridor during the late afternoon hours or early
evening. Although the POPs are a bit on the higher side, expect
the initiation to be delayed just a bit to allow temperatures to
rise and meet heat advisory criteria. Again, as stated the POPs
are a bit higher with the diurnal cycle, lake/sea breeze, and some
upper level support with a weakness in place across the Lower MS
River Valley.

Going into this evening, convection will gradually shift from
landbased zones to marine zones naturally via the diurnal
processes. POPs will largely shift offshore through the late
evening and into the overnight period. Tuesday doesn`t look very
different when compared to Monday. The upper level weakness will
remain. Convection will remain possible. The only change I have
made from the consensus output was the reduction in POPs for
interior south MS. Consensus blends are a bit overdone in this
area, especially compared to both statistical guidance and
global/mesoscale guidances. Still carrying low-end POPs, but
coverage seems to struggle just a bit. Outside of the rain
chances, again it will be another hot day. Although at this
juncture didn`t issue another heat advisory for Tuesday yet as it
(Max ApTs) appears to be very borderline with the highest probs
for reaching advisory criteria residing closer to Lake
Pontchartrain...both on the north and south shore. (Frye)

&&

.LONG TERM...
(Tuesday night through Sunday)
Issued at 342 AM CDT Mon Jul 15 2024

Going into the long term period, the overall synoptic pattern
doesn`t really change very much with the weakness between a ridge
across the SW Atlantic Basin and the Desert Southwest still in
place (generally across the Mid/Lower MS River Valley). This will
continue to keep some upper level support for a bit higher
coverage of showers and thunderstorms during the afternoon hours.
Light onshore flow will continue, and this should help continue
to inject plenty of low level moisture into the region and
maintain a juicy boundary layer. The only question would be the
need for additional heat headlines. For now, depending on timing,
cannot rule out the need for additional headlines through midweek
(Wednesday most likely).

By Thursday a surface boundary will move southward from the I40
corridor toward our region. As this feature moves into the region
during peak heating, coverage of showers and thunderstorms will
be enhanced. An early look at the numbers show PWAT values just
over 2.0" along and south of I10/12...perhaps just below 2.0"
across interior south MS. Regardless, convection will be
efficient rainfall producers. With the more numerous showers and
storms around, hydro concerns may develop, especially in those
urbanized and poor drainage areas prone to flooding. Steering will
also slow with only cold pool propagation helping push things
along. Additionally, a strong wind gust or two will also be
possible. DCAPE values are marginal, but still enough to get the
job done in terms of gusty winds.

This pattern looks to continue into the upcoming weekend with the
residual surface boundary stalled over our region. Rain chances
will be the highest or enhanced during max heating over landbased
zones and again weak steering could lead to additional localized
flooding concerns respectively. As one could probably guess,
temperatures will be held down throughout much of the medium range
due to higher POPs and move cloudiness during the afternoon hours.
(Frye)



&&

.AVIATION...
(06Z TAFS)
Issued at 1149 PM CDT Sun Jul 14 2024

VFR conditions will prevail through the period with the main
impact being scattered diurnal convection. As was the case today,
expect convective initiation during the late afternoon with
isolated to scattered showers and storms persisting through much
of the evening in some areas, especially north of Lake
Pontchartrain. Have included PROB30 or VCTS at all terminals,
though as confidence in timing and location of thunderstorms
increases, tempo groups may be introduced with later updates. If
any storms move over the terminals, the main concerns would be
reduced vis due to heavy rain as well as gusty winds up to 25 or
30 knots. (DM)

&&

.MARINE...
Issued at 342 AM CDT Mon Jul 15 2024

Mostly benign marine conditions through this cycle. Generally a
southerly or onshore flow is anticipated through the workweek with
winds generally around or less than 10kts. That said, diurnally
driven convection will be possible during the late night hours
through the morning. Locally higher winds and seas will be
possible in the strongest convection. With the generally light low
level flow and likelihood of outflow boundaries from previous
convection the evening before, waterspouts will also remain a
threat. (Frye)

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  93  74  94  74 /  50  10  40   0
BTR  97  78  96  78 /  50   0  50  10
ASD  95  78  94  77 /  60  10  60  10
MSY  94  80  93  79 /  60  10  60  10
GPT  92  79  92  78 /  50  10  50  10
PQL  95  78  95  77 /  50  20  40  10

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory from 11 AM this morning to 7 PM CDT this evening
     for LAZ034>037-039-046>048-056>060-064-065-071-076>090.

GM...None.
MS...Heat Advisory from 11 AM this morning to 7 PM CDT this evening
     for MSZ068>071-077-083>088.

GM...None.
&&

$$

SHORT TERM...RDF
LONG TERM....RDF
AVIATION...DM
MARINE...RDF