Area Forecast Discussion Issued by NWS New Orleans/Baton Rouge, LA
000
FXUS64 KLIX 150858
AFDLIX
Area Forecast Discussion
National Weather Service New Orleans LA
358 AM CDT Fri Mar 15 2024
...New SHORT TERM, LONG TERM, MARINE...
.SHORT TERM...
(Today through Saturday)
Issued at 348 AM CDT Fri Mar 15 2024
Upper ridging over most of the Gulf of Mexico and the southeast
corner of the country this morning, with an upper low near Yuma,
Arizona. That has southwesterly mid and upper flow across the
western Gulf of Mexico. One shortwave trough was near Memphis this
morning with another from New Mexico into Texas. Northern stream
shortwave energy was along Interstate 80 and near the Canadian
border. At the surface, high pressure extended from Bermuda to the
Florida-Georgia line. A frontal boundary extended from New England
to Arkansas to the Big Bend area of Texas. Locally, onshore flow
has been somewhat stronger and more moist than anticipated 24
hours ago. Southeast winds of 10 to 20 mph has pumped abundant
moisture into the area, and at 3 AM CDT, temperatures across the
area were in the lower and middle 70s for the most part. That`s
near or above normal highs for the day. Dew points were in the
lower 70s, about 3-5 degrees higher than anticipated. That
increased the potential for advective fog, and we`ve seen that
near the coast. Hasn`t been quite as widespread as anticipated,
but it is still out there. Radar at 3 AM showed a fairly solid
line of showers and thunderstorms from Middle Tennessee to
southern Arkansas to north Texas, working it`s way southeastward.
The northern stream troughing will continue to push the frontal
boundary southward, reaching the northern portions of our area
late this afternoon or early this evening before becoming
stationary. Moisture is already in place, with precipitable water
values around 1.6 inches, although the evening soundings showed a
bit of dry air in the mid levels. Forecast soundings erode much of
that dry air by midday with precipitable water values in the
1.6-1.8 range. Instability is certainly sufficient for strong
thunderstorms, but shear is fairly lacking with the potential
exception of southwest Mississippi. Most of the convection
allowing models have the line of storms reaching the northwest
portion of the area during the late morning hours and continuing
to sink southward. Locally heavy rain can`t be ruled out, and if
there`s a favored area, it would probably be the northeast quarter
of the area east of Interstate 55 and north of the Interstate
10/12 corridor, where 1-2 inch totals are possible. With the
shortwave energy departing and the loss of surface heating, areal
coverage of precipitation should diminish (if not end) pretty
quickly by early evening.
We`ll again be in a favorable scenario for fog overnight tonight
and there will be a mention of fog in the forecast. For this
morning`s fog, unlikely to make changes to the advisories with the
forecast issuance as we`ll still be several hours away from
sunrise.
Not much change in the upper pattern for Saturday with weak lift
and a front in the area, scattered showers will be possible. Won`t
be a total washout, but outdoor activities could certainly see
interruptions. Should note, however, that there are one or two
CAMs that do depict a stronger area of thunderstorms moving along
the boundary late Saturday afternoon, but they are the outliers at
this point.
Temperatures will be well above normal through Saturday south of
the frontal boundary, even without much sun. Considering where
temperatures are at now, much of the area shouldn`t have much
difficulty getting close to, if not exceeding 80 today, and close
to 80 tomorrow. Some concern that forecast lows may be too cool
tonight, but that`ll depend on convective trends later today.
&&
.LONG TERM...
(Saturday night through Thursday)
Issued at 348 AM CDT Fri Mar 15 2024
Sunday looks to be the wettest day of the bunch. The northern
stream troughing will be forcing the frontal boundary southward
and will combine with southern stream shortwave energy to produce
another round of showers and storms, a few potentially strong. The
favored area for this would be near and south of the Interstate 10
corridor, with another potential for widespread 1-2 inch rainfall
totals, and a few spot higher amounts. Precipitation could arrive
near or before sunrise Sunday, with a rainfall threat encompassing
much or all of the daytime hours Sunday.
Precipitation should diminish or end completely late Sunday
afternoon or early Sunday evening as the frontal boundary works
offshore. Cooler and drier air arrives for the beginning of the
workweek with temperatures 5-10 degrees below normal possible for
highs Monday and Tuesday before moderating Wednesday. Overnight
lows will be chilly Tuesday and Wednesday morning. A good portion
of the area will see overnight lows in the mid and upper 30s
Tuesday morning and near 40 Wednesday morning. While freezing
temperatures are not expected, patchy frost will be a possibility
in protected, normally cooler areas Tuesday morning.
The western upper low eventually begins to move eastward at
midweek next week, but disagreement between the global models
whether that would impact the area Thursday, or beyond that point.
For now, will keep with the NBM PoPs for Thursday.
After the frontal passage Sunday, temperatures generally will
remain below normal until perhaps Thursday or Friday of next week.
&&
.AVIATION...
(06Z TAFS)
Issued at 1130 PM CDT Thu Mar 14 2024
Conditions will continue to decline through the morning with
LIFR/IFR anticipated. Shower and thunderstorm development is
anticipated later today, which at times could be widespread
leading to a continuation of low VIS/CIGs. There could be some
gradual improvement late in the period, but it would likely come
around 16/00z before more VIS/CIG reductions take place with more
low stratus and fog development late tonight. (Frye)
&&
.MARINE...
Issued at 348 AM CDT Fri Mar 15 2024
No changes to this morning`s Fog Advisory, with the potential for
another overnight tonight. Thunderstorms will become more of a
concern to mariners later today, and then again on Sunday. While
there may be a few periods where sustained winds get a bit above
15 knots outside of thunderstorms, it doesn`t appear there will be
a need for Small Craft Advisories until perhaps later Sunday night
behind the front. Those conditions could continue into early
Tuesday before abating somewhat.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 77 60 75 60 / 90 30 30 60
BTR 82 65 80 65 / 90 30 40 50
ASD 81 64 79 63 / 80 30 30 40
MSY 81 66 78 65 / 80 30 30 40
GPT 77 64 78 62 / 60 30 30 30
PQL 80 63 79 61 / 50 30 20 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Dense Fog Advisory until 10 AM CDT this morning for LAZ064-069-
070-076-078>080-089-090.
GM...Dense Fog Advisory until 11 AM CDT this morning for GMZ530-532-
534-536-538-550-552-555-557.
MS...Dense Fog Advisory until 10 AM CDT this morning for MSZ077-
083>088.
GM...Dense Fog Advisory until 11 AM CDT this morning for GMZ532-534-
536-538-550-552-555-557.
&&
$$
SHORT TERM...RW
LONG TERM....RW
AVIATION...RDF
MARINE...RW