Scientific Forecaster Discussion
fxus64 klix 170926
Area forecast discussion
National Weather Service New Orleans la
426 am CDT Tue Sep 17 2019
again we find our area in between two different air masses. This
time the moisture gradient is located roughly along the miss
river. Wpc has set a portion of this area west of the gradient in
a marginal risk for today. But most of this area could use and
may be capable of handling some of the heavy rainfall, but there
will still be the possibility of an isolated location having
rainfall rates high enough to cause some nuissance flooding.
The heat will be back today, sounds like a broken record, as heat
index values will top around 107f for some areas mainly east of
the miss river. Cloud cover should help keep other areas cooler.
We should see a back door front move into the area by Thursday.
As the tropical disturbance over the northwest Gulf begins to unwind
after coming ashore, there may be enough moisture provided to the
front to give some much needed rain to the whole area by Thursday
and Friday. Sfc high pressure then looks to settle over the Gulf
south by the middle of next week. Eventhough models want to paint
some quantitative precipitation forecast in some grid sections, this may be a little drier than
indicated next week. One or two tropical waves look to traverse
the southern Gulf next week as well, but as the stacked high
settles in over the area, any wave capable of producing a
disturbance would likely continue moving west keeping the area dry
and hot. Within this fcast pack, it is hard to find any relief
from the heat. But we will keep looking.
Expect VFR conditions for all area terminals early this morning
through late morning/early afternoon. Only feature to watch will be
for western area terminals, generally including khum and kbtr later
this afternoon as guidance suggests a band of tropical
showers/storms to develop and drift north across south-central la.
Main threats associated with these showers/storms will be temporary
reductions in visibility leading to periodic lowering of flight
categories, and gusty erratic surface winds of around 20 to 30
knots. Elsewhere, typical late morning cu field will develop, but
should remain largely dry through the afternoon and evening. All
areas dry out tonight with VFR conditions prevailing. Klg
a weak pressure field has caused winds to colapse this morning.
This should continue to be the case until Thursday when a back
door front will move into the coastal waters causing easterly
winds to rise to around 15-20kt through the weekend. By the early
part of next week, high pressure settles back into the area and
winds again go light.
Dss code: blue.
Activities: marginal risk for excessive rainfall western areas.
Decision support services (dss) code legend
green = no weather impacts that require action.
Blue = long-fused watch, warning, or advisory in effect or high
visibility event; marginal risk severe or excessive rain.
Yellow = heightened impacts with short-fused watch, warning or
advisory issuances; radar support for slight risk severe
or excessive rain.
Orange = high impacts; enhanced risk severe; nearby tropical events;
hazmat or other large episodes.
Red = full engagement for moderate to high risk of severe and/or
excessive rainfall, or direct tropical threats; events of
Preliminary point temps/pops...
mcb 94 71 94 72 / 10 0 10 0
btr 92 73 92 74 / 40 10 30 0
asd 94 72 94 73 / 10 0 10 0
msy 92 77 93 78 / 30 0 30 0
gpt 92 74 93 75 / 10 0 10 0
pql 96 73 97 73 / 10 0 10 0