Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

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579
FXUS64 KLIX 200421 AAC
AFDLIX

Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
1121 PM CDT Wed Jun 19 2024

...NEW AVIATION...

.UPDATE...
Issued at 949 PM CDT Wed Jun 19 2024

Most of the isolated to scattered showers and storms have
dissipated across the region this evening. Still may see
additional isolated convection offshore with the diurnal cycle
late tonight. The wind advisory was allowed to expire earlier as
pressure gradient is finally starting to relax just a bit across
the land based zones. Did keep the Gales for the 20-60nm Gulf
waters as winds are still reaching those thresholds well offshore.
Otherwise, no other changes to the headlines or forecast with this
midpoint update. (Frye)

&&

.SHORT TERM...
(This evening through Friday night)
Issued at 402 PM CDT Wed Jun 19 2024

Current radar shows scattered showers across the CWA. These showers
are moving relatively quickly at around 25kts towards the west due
to strong onshore flow north of Tropical Storm Alberto. Will
continue to see easterly moisture advection combined with daytime
heating to promote shallow convection through the rest of this
afternoon. Although showers will be brief, rainfall rates will be
fairly impressive with such a moisture rich column in place. In
addition, don`t be surprised to experience gusty winds 30-40 mph
and precip loading transfers stronger winds aloft down to the
surface. Loss of daytime heating will be the end of inland
convection with coastal showers expected overnight.

0A strengthening upper ridge, possibly reaching 600dm (that`s really
really high), centered over the Appalachian Mountains will spread
farther westward through the southeastern CONUS into tomorrow. This
will cause Alberto to track west into northern Mexico, therefore
removing some moisture content in our CWA. The other aspect of this
is subsidence from the ridge. So should see much less rainfall
activity in the northern half of the CWA Thursday into Friday. At
the same time, high temperatures will begin to increase closer to
normal with decreased rainfall and cloud coverage and then
surpassing climo with highs reaching mid/upper 90s late week to the
weekend.

MEFFER

&&

.LONG TERM...
(Saturday through Tuesday night)
Issued at 402 PM CDT Wed Jun 19 2024

Medium range models initially in decent agreement as we head through
the weekend and then begin to has some disagreements in the details.
That said the differences are subtle and overall suggest expect the
warmer muggy conditions to return with scattered afternoon
convection. NBM is on the warmer side compared to the MOS numbers
but is very close and given the possible setup not confident enough
drop temps from the NBM. One change was to increase the morning lows
at the typical warm spots this weekend around the lake.

As we kick the weekend off the ridge will continue to slowly
retrograde across the Lower MS and become centered over the 4
corners by early next work week. Over the weekend this should keep
rainfall potential on the low side with the best chance for any
afternoon storms south of the 10/12 corridor likely associated with
the seabreeze. Not anticipating the seabreeze making it that far
north Saturday given the LL winds will remain out of the east or
northeast but on Sunday there may be a slightly better chance of the
seabreeze getting north of I-12 east of I-55 with slightly stronger
southerly winds and up to h925. That said pops will still be in the
20 to 30% range for much of the area and with h925 temps hovering
around 25-26C highs will likely range from the lower 90s in
southwest MS to mid 90s most other locations. Sunday may be fairly
similar with the highs and with increasing LL moisture there is a
chance that the heat index values could jump up into the 100 to 108
range.

Early next week as the ridge continues to strengthen over the 4
corners with the ridge axis extending north into Canada the eastern
periphery will start to tighten up and could place the region back
under northwest to northerly flow. This would begin to favor
convection once again but likely occurring very late in the day.
This would also mean we would see the rather warm temps continue as
well. /CAB/

&&

.AVIATION...
(00Z TAFS)
Issued at 650 PM CDT Wed Jun 19 2024

Outside of any residual showers, VFR conditions are anticipated
through the cycle. Southeasterly or easterly winds will remain
elevated through again today, especially closer to the coast.
There will be a chance of isolated showers and maybe a
thunderstorm or two, but the lack of coverage and timing...will
not add TS PROB or VCs for now. (Frye)

&&

.MARINE...
Issued at 402 PM CDT Wed Jun 19 2024

Strong easterly winds in response to pressure gradient created by
Alberto continue to impact the local coastal waters. Latest
observations still show 20 to 30 knot winds with higher gusts over
all marine areas other than the outer coastal zones. In those outer
waters that are closer to the storm, winds are 5 to 10 knots
stronger, hence the Gale Warning in effect there. Small Craft
Advisory remains in effect for all other areas. These strong winds
will continue drive water into to tidal lakes as well as all other
eastern facing shores. No changes made to the current Coastal
Flood Advisory in place but did extend the Coastal Flood Warning
to include coastal Tangipahoa, Livingston, St Tammany and St John
Parishes. Recent observations in Pontchartrain and Maurepas show
that water is still steadily rising and now nearing 3 feet above
where they typically should be. With winds not expected to slack
off through the night, thinking those water levels will slowly
increase and justify the upgrade to the warning. Winds should be
at their peak and begin gradually relaxing with time later tonight
through Friday as Alberto moves into northern Mexico. Non-
impactful winds/seas expected through this weekend. This will help

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  88  71  90  70 /  30  20  10   0
BTR  91  77  93  75 /  30  20  30   0
ASD  89  76  91  74 /  40  30  30  10
MSY  89  80  89  79 /  50  20  40  10
GPT  89  76  90  75 /  40  30  20  20
PQL  91  74  93  73 /  40  20  10  20

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Small Craft Advisory until 4 PM CDT Thursday for LAZ068.

     Coastal Flood Warning until 4 PM CDT Thursday for LAZ058-070-076-
     078-080-082-084-086.

     Coastal Flood Advisory until 4 PM CDT Thursday for LAZ060-
     066>069-077-087.

GM...Small Craft Advisory until 4 PM CDT Thursday for GMZ530-532-534-
     536-538-550-552-555-557-577.

     Gale Warning until 1 AM CDT Thursday for GMZ570-572-575.

     Small Craft Advisory until 4 PM CDT Thursday for GMZ570-572-575.

MS...Coastal Flood Warning until 4 PM CDT Thursday for MSZ086.

     Coastal Flood Advisory until 4 PM CDT Thursday for MSZ087-088.

GM...Small Craft Advisory until 4 PM CDT Thursday for GMZ532-534-536-
     538-550-552-555-557-577.

     Gale Warning until 1 AM CDT Thursday for GMZ572-575.

     Small Craft Advisory until 4 PM CDT Thursday for GMZ572-575.

&&

$$

UPDATE...RDF
SHORT TERM...ME
LONG TERM....CAB
AVIATION...RDF
MARINE...ME