Flash Flood Warning 3, NWS New Orleans, LA

566 
WGUS74 KLIX 090201
FFSLIX

Flash Flood Statement
National Weather Service New Orleans LA
801 PM CST Mon Jan 8 2024

MSC045-047-109-090211-
/O.CAN.KLIX.FF.W.0003.000000T0000Z-240109T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hancock MS-Harrison MS-Pearl River MS-
801 PM CST Mon Jan 8 2024

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHERN HANCOCK, 
NORTHWESTERN HARRISON AND SOUTHEASTERN PEARL RIVER COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures. Additional 
rainfall will be possible overnight as a front moves through. Use 
caution if driving overnight.

A Flood Watch remains in effect until 900 AM CST Tuesday for 
portions of southeast Louisiana and southern Mississippi.

LAT...LON 3052 8963 3069 8934 3065 8934 3065 8924
      3068 8923 3068 8894 3032 8947

$$

JL

Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
533 PM CST Mon Jan 8 2024

...NEW AVIATION...

.SHORT TERM...
(This evening through Tuesday night)
Issued at 415 PM CST Mon Jan 8 2024

A vigorous storm system is moving across the TX/OK panhandles and
will continue east through the Central Plains tonight. A surface low
associated with the upper low is located just east of it with an
appendant cold front draped across East Texas. Surface obs show
the front to be right along the I-35 corridor and racing eastward.
At the same time, a warm front extends eastward from this cold
front. It appears this boundary is right along the extreme
southern LA coast along a line from LCH to BVE. Shower and
thunderstorm coverage has rapidly expanded SW to NE across the
forecast area over the last few hours. Surface obs, model
soundings and SPC meso page all show the vast majority of the area
at 21Z is still north of the warm front which means inversion is
keeping storms from being surface based. The only except is right
on the LA coastal parishes where the actual warm front is.
Regardless, there's still ample instability aloft with those
levels cooling while the surface still warms. The main threats for
storms north of the boundary are are large hail and heavy
rainfall. The warm sector to move farther north with time
providing lift and ample low level instability as it removes the
inversion. Tight pressure gradient from 994mb surface low will
keep inflow strong. This combined with strong flow from the
approaching upper low/trough have resulted in quite high wind
shear and helicity. Thus, the potential for multiple tornadoes,
possibly strong, will be possible through this evening for storms
in the warm sector to just north of the warm front.

The aforementioned cold front racing eastward across Texas is
expected reach the western side of the CWA before midnight and exit
the eastern side before sunrise Tuesday. Yet more strong/severe
storms will be possible along this boundary with QLCS tornadoes
possible.

No changes made to current hazards out for the area. Current winds
may be a bit less than forecast but suspect that'll change as the
warm front lifts north and better mixing takes place. For the Flood
Watch, forecast still looks on track for areal 3-5 inches with
pockets of 50% more and isolated locations with double that
possible. Coastal flooding could be quite impactful on coastlines
perpendicular to the winds as high tides fall right at the same time
as peak winds this evening and overnight.

&&

.LONG TERM...
(Tuesday through Sunday night)
Issued at 415 PM CST Mon Jan 8 2024

The deepening upper level low should be crossing the mid Mississippi
River Valley around 18Z Tuesday before reaching the southern
periphery of the Great Lakes by Wednesday morning. This will bring
the apex of the trough into the western edge of the CWA 18z Tuesday
as well and the likely timing when all showers/storms are completely
east of the entire forecast area. The back edge of the rain shield
may still be over coastal MS and extreme southeastern LA 12-15Z, but
after that the rain should be over. Although rain ends, some weather
impacts continue. It's quite evident looking at model surface
pressure plot with time on Tuesday that the pressure gradient will
remain very tight throughout the day. This would support relatively
strong winds even over land areas. Even though conditions may be
borderline, have above normal confidence that Wind Advisory
conditions will persist throughout the day across the entire CWA and
will be extending Wind Advisory with current forecast package to
reflect that.

Much more benign weather expected Wednesday as trough/low ejects
east and zonal flow to slight ridging slides across the region.
Fairly rapid moderation of temps on Thursday as post front ridge
moves east of the local area and southerly flow increases. Should
see temps jump from low/mid 50s to closing in on 70 degrees for
highs on Thursday. This will be the lead-up to the next approaching
system late in the week. Models continue to lower confidence in the
forecast with a lack of run-to-run consistency in terms of timing
and position of the through. Regardless, will need to watch for
severe potential yet again.

&&

.AVIATION...
(00Z TAFS)
Issued at 527 PM CST Mon Jan 8 2024

Convection is ongoing across the region with many terminals at
MVFR or below. Widespread showers and a clap of thunder or two
will be possible over the next couple of hours. There will
probably be a break between the early convection and stronger
convection starting around midnight and pushing east from there.
All terminals should have impacts from this second round of
convection with winds shifting to a westerly direction and
remaining gusty. By 12-15z on Tuesday, conditions will improve to
VFR once again...although westerly winds will remain gusty AOA
30kts in many locations. (Frye)

&&

.MARINE...
Issued at 415 PM CST Mon Jan 8 2024

A 994mb surface low over the eastern Texas Panhandle will be quickly
moving eastward across Oklahoma this evening and overnight, crossing
the Mississippi River mid morning Tuesday. A strong surface high is
embedded within a broad upper level ridge east of the region. This
setup is creating a very tight pressure gradient over the local
coastal waters. That gradient will tighten even more as the low
moves east and deepens. In response to this, very strong (Gale to
Storm Force) winds are/will shortly be developing over all of the
local coastal waters. Open Gulf water obs are already showing
sustained 30-40 knot winds with higher gusts. Stronger winds are
possible before the front reaches the area. Once it does, an abrupt
wind direction change is expected from SE to WNW. Strong to severe
storms will also accompany this cold front while the front races
east tonight. A very peaked confused sea condition is expected with
FROPA. Little change in wind speeds behind the front as the pressure
gradient remains tight for quite awhile. Thus, have added a Gale
Warning and Small Craft Advisory to the tale end of this event as
wind speeds gradually fall Tuesday night. All marine headlines may
be lowered by mid week before the next front impacts the area
starting the end of the week.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  41  51  29  55 / 100  10   0   0
BTR  45  54  32  59 / 100   0   0   0
ASD  46  56  33  57 / 100  10   0   0
MSY  49  56  37  58 / 100  10   0   0
GPT  48  57  34  54 / 100  30   0   0
PQL  49  61  32  56 / 100  40   0   0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Flood Watch through Tuesday morning for LAZ034>037-039-046>048-
     056>060-064>071-076>090.

     Wind Advisory until 6 PM CST Tuesday for LAZ034>037-039-046>048-
     056-057-059-064-065-071-079-081-083-085-086-088>090.

     Coastal Flood Advisory until noon CST Tuesday for LAZ058-066>070-
     076-078-080-082-084.

     High Wind Warning until 3 AM CST Tuesday for LAZ058-060-066>070-
     076>078-080-082-084-087.

     Wind Advisory from 3 AM to 6 PM CST Tuesday for LAZ058-060-
     066>070-076>078-080-082-084-087.

GM...Gale Warning until 9 PM CST Tuesday for GMZ530-534.

     Small Craft Advisory from 9 PM Tuesday to 6 AM CST Wednesday for
     GMZ530-532-534-536-538-550-552-555-557-570-572-575-577.

     Storm Warning until 9 AM CST Tuesday for GMZ532-536-538-550-552-
     555-557-570-572-575-577.

     Gale Warning from 9 AM to 9 PM CST Tuesday for GMZ532-536-538-
     550-552-555-557-570-572-575-577.

MS...Flood Watch through Tuesday morning for MSZ068>071-077-083>088.

     Wind Advisory until 6 PM CST Tuesday for MSZ068>071-077-083>085.

     Coastal Flood Advisory until noon CST Tuesday for MSZ087-088.

     High Wind Warning until 3 AM CST Tuesday for MSZ086>088.

     Wind Advisory from 3 AM to 6 PM CST Tuesday for MSZ086>088.

     Coastal Flood Warning until noon CST Tuesday for MSZ086.

GM...Gale Warning until 9 PM CST Tuesday for GMZ534.

     Small Craft Advisory from 9 PM Tuesday to 6 AM CST Wednesday for
     GMZ532-534-536-538-550-552-555-557-570-572-575-577.

     Storm Warning until 9 AM CST Tuesday for GMZ536-538-550-552-555-
     557-570-572-575-577.

     Gale Warning from 9 AM to 9 PM CST Tuesday for GMZ536-538-550-
     552-555-557-570-572-575-577.

&&

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

Preliminary Local Storm Report
National Weather Service New Orleans LA
533 PM CST Mon Jan 8 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0519 PM     Hail             2 ESE Mandeville        30.36N 90.05W
01/08/2024  E1.00 inch       St. Tammany        LA   NWS Employee

&&

LNN

Preliminary Local Storm Report
National Weather Service New Orleans LA
553 PM CST Mon Jan 8 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0540 PM     Flash Flood      1 SE Laplace            30.06N 90.46W
01/08/2024                   St. John The BaptisLA   Broadcast Media

            Flooding reported along Windsor Blvd in the
            River Forest Subdivision. Water covering
            streets and some water in garages.

&&

JFL

Preliminary Local Storm Report
National Weather Service New Orleans LA
603 PM CST Mon Jan 8 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0540 PM     Flash Flood      5 NNW Lacombe           30.38N 89.97W
01/08/2024                   St. Tammany        LA   NWS Employee

            Several inches of water across I-12 between
            Covington and Slidell.

&&

JFL

Preliminary Local Storm Report
National Weather Service New Orleans LA
610 PM CST Mon Jan 8 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0600 PM     Flash Flood      1 NNE Mandeville        30.39N 90.08W
01/08/2024                   St. Tammany        LA   Public

            Several reports on social media of flooding
            over roadways and ~3-6 inches of water over
            roadways.

&&

MSW

Preliminary Local Storm Report
National Weather Service New Orleans LA
611 PM CST Mon Jan 8 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0552 PM     Flash Flood      Pearl River             30.38N 89.74W
01/08/2024                   St. Tammany        LA   Public

            Public reports quarter-sized hail in Pearl
            River in St Tammany Parish.

&&

MSW

Preliminary Local Storm Report
National Weather Service New Orleans LA
612 PM CST Mon Jan 8 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0600 PM     Flash Flood      4 WNW Lacombe           30.34N 89.99W
01/08/2024                   St. Tammany        LA   Public

            Several reports of street flooding and 3-6
            inches of water over Hwy 190 in
            Mandeville/Covington.

&&

MSW