Gale Warning 7, NWS New Orleans, LA

Area Forecast Discussion
National Weather Service New Orleans LA
1234 PM CDT Tue Mar 29 2022

.AVIATION (18Z TAF package)...

Most terminals currently VFR although one or two may occasionally
report BKN025. For the next 15 hours or so, VFR should be the
predominant condition. Could be some MVFR ceilings as we get
closer to sunrise, with greater potential in late morning/early
afternoon tomorrow. Currently appears that TSRA will not be a
factor prior to 18z tomorrow. Next package this evening will need
to address it at all terminals.

Winds likely to be a factor at most terminals, especially those
with east-west runway configurations, as gusts in excess of 25
knots likely late this afternoon and portions of the overnight
hours. Those wind gusts could exceed 35 knots on Wednesday, even
outside of TSRA. LLWS will also be mentioned, especially prior to
sunrise. Winds at FL020 are likely to exceed 50 knots for a good
portion of the day tomorrow. 35

&&

.PREV DISCUSSION... /issued 436 AM CDT Tue Mar 29 2022/

SHORT TERM (Today through Wednesday night)...Expect the current
gradient light wind to continue for most locations this morning. The
12z sounding profile fits only a radiation fog event and with any
mixing, most sites should remain under a strat deck. But if any of
these locations can decouple and winds go to zero, there could be
some fog at that location but still only expect it to be near or
1sm. Full decoupling usually does occur around sunrise and it is
possible that if there is going to be any strong reduction in vis,
it would be around that time frame.

Expectation is for a squall line to be produced west of the area and
move at a good pace through the area starting around noon Wed. No
real changes in perception has occurred. So, we will discuss the
questions for Wed. The gradient ahead of this front is amazing
robust with a full mb drop over an 8 mile distance. This will simply
translate into a VERY windy situation. Some gusts are expected to be
50+mph(not associated with the line of storms). The line of storms
will have the potential to produce this and then some especially
with bowing segments. A wind advisory will be posted with this
package but this could be upgraded to a high wind warning if these
numbers hold or increase. The next thing will be a coastal flood
advisory. We don't have the numbers that support it but the numbers
we do have are bumping the threshold. The neap tide  it is on the we
are in is also helping to tamper these levels, but with strong winds
and frequent gusts above gale force, thinking is that we see these
numbers move up and there will be that possibility of a coastal
flood advisory being issued, although more of an annoyance.
Kinematics, especially with the low level varaibles are extremely
impressive. Upper level lift provided by dynamic forcing is also
quite robust. All the ingredients are there for a svr wx event.
Stability could be a bit better but we do go sfc based just ahead of
the squall line. The biggest problem will be damaging winds at
70+mph with bowing segments. QLCS tornadoes are a definite
possibility. At the moment, the thinking is this line should stay
together. If there were breaks and a few cells could manage
individuality, there would be a quick issue with spin ups. The
front(dew pt gradient) will begin to lag the main line of convection
as the sfc boundary stalls near the Atchafalaya Basin and slowly
creeps through the area by during the night. But the line moves east
bringing dry wx for a few day at least.

Long Term (Thursday through Tuesday)...
The apex of the main axis of the upper level trough that brings
severe potential to the local area midweek will be passing across
the the Mississippi River Valley on Thursday. Post frontal airmass
will certainly knock down temps for a day or so, but starting out so
warm in the days leading up to this means behind the cold front will
feel like normal for this time of year. Guidance is fairly tight for
temps, so stuck with deterministic NBM. The progressive nature of
this week's pattern means a ridge is already overhead by Friday. It
appears to be quite shallow, so really just aides in starting the
moderation of temps process.

Models are hinting at a mid latitude shortwave racing east across
the country this weekend. Due to its expected weak structure, models
not resolving it consistently. Therefore, have just went with NBM
POPs and is a lower confidence forecast. In general though, looks
like moisture is drawn north along a weak warm front. Not much
dynamics with this system, so just expected showers with a few
thunderstorms. Weak upper ridge follows the the shortwave to subside
convection and moderate temps before the next more significant
trough moves in early next week.

MEFFER

AVIATION...
Not expected to get many sites with vis restrictions but cigs will
be the issue. OVC008+ should be found at most sites this morning
with VFR conditions by mid to late morning. Cigs will be back at
these levels again tonight with no vis restrictions expected.

MARINE...Onshore flow will continue to rise today and be higher than
20+kt by tonight. Sustained wind speeds will be 25-30kt Wednesday
with frequent gusts above gale force. Small craft advisory flags
will get hoisted either later today or tonight for Tuesday night but
there is a possibility of a gale warning due to the frequent gusts
>=34kt. A cold front will move through Wed night into Thu with
strong thunderstorms and West to NW winds will reach the area post
front but speeds will remain weak. This front is expected to stall
over the outer waters befor moving back north as a warm front by the
end of the week.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  83  66  82  52 /   0   0  90  40
BTR  84  67  82  53 /   0   0 100  30
ASD  83  66  84  56 /   0   0  70  80
MSY  81  69  83  60 /   0   0  70  70
GPT  79  67  79  60 /   0   0  50 100
PQL  79  66  80  61 /   0   0  50 100

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Wind Advisory from 8 AM to 9 PM CDT Wednesday for LAZ034>037-039-
     046>050-056>061-063>072-075>078.

GM...Gale Watch from 7 PM CDT this evening through late Wednesday
     night for GMZ530-532-534-536-538-550-552-555-557-570-572-
     575-577.

     Small Craft Advisory until 7 PM CDT this evening for GMZ530-532-
     534-536-538-550-552-555-557-570-572-575-577.

MS...Wind Advisory from 8 AM to 9 PM CDT Wednesday for MSZ068>071-077-
     080>082.

GM...Gale Watch from 7 PM CDT this evening through late Wednesday
     night for GMZ532-534-536-538-550-552-555-557-570-572-575-
     577.

     Small Craft Advisory until 7 PM CDT this evening for GMZ532-534-
     536-538-550-552-555-557-570-572-575-577.

&&