Scientific Forecaster Discussion
fxus64 klix 182148
Area forecast discussion
National Weather Service New Orleans la
348 PM CST Thu Jan 18 2018
biggest challenge in the short term will be low temperatures
tonight. Went close to guidance consensus, which results in mid
20s for northern areas and upper 20s and 30s for southern areas.
A little tricky, though, with some clouds forecast to move in
toward daybreak. These clouds are evident on satellite beginning
to stream into far East Texas and far southwest Louisiana. Another
limiting factor will be some warm advection aloft which can also
inhibit our radiative cooling efficiency. If either of these two
factors begins earlier than currently expected, the forecast will
Regardless, with hard freeze and freeze warnings already up, felt
it prudent to leave them in place. While some of the more urban
areas in the hard freeze warning area will likely remain above or
only touch 26 degrees, the more rural areas could still drop below
the 26 degree mark. Similar feelings for the freeze warning
area...some of the more urban places may only touch the freezing
mark, but the typically colder spots will likely spend a few hours
Expect nearly all locations to be above freezing by 8 or 9 am
tomorrow morning, with temperatures warming into the 50s by
tomorrow afternoon. Warming trend continues into the weekend with
highs near 70 on Sunday.
Next front comes through Sunday night into Monday. With decent
moisture return ahead of the front, expect scattered to numerous
showers with isolated along and ahead of the front. About an inch
of rainfall in the forecast as it stands right now, but as usual,
local amounts could be higher or lower depending on where any
thunderstorms move and whether any areas see more than one round.
Regarding possibility of severe weather...set up doesn't look
great. Instability is fairly limited with generally less than 500
j/kg of cape and a brief period of Li values or right around -1c.
However, with winds veering from south or even southeast at the
surface to west aloft, there will be a bit of shear to work with.
Sfc to 1km storm relative helicity is forecast in the 150 to 200
m2/s2 range. All that being said, we cannot rule out the
possibility of one or two strong storms, and will need to monitor
trends as the situation becomes clearer.
Air mass behind the front looks more Pacific in origin, so no
Arctic freezes this time around. Looks like for the most part the
front should drop temperatures to near normal through the middle
of the work week.
no issues. VFR conditions are expected to continue although
clouds will begin to return overnight tonight and tomorrow.
Luckily clouds will be more mid and upper level.
high pressure will push off to the east over the next few days.
As this occurs winds will veer around to onshore and should remain
in the 8-12 kt range through Sat night. By late sun a surface low
will develop around the Central Plains and overnight sun winds
will begin to become more moderate. A cold front is then expected
to swing through the region Mon with light to moderate offshore
winds developing behind it.
dss code: blue.
Activities: freeze and hard freeze warnings
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.
Yellow = heightened impacts with short-fused watch, warning or
advisory issuances; radar support.
Orange = high impacts; slight to moderate risk severe; nearby tropical
events; hazmat or other large episodes.
Red = full engagement for moderate risk of severe and/or
direct tropical threats; events of National significance.
Preliminary point temps/pops...
mcb 24 50 37 61 / 0 0 0 10
btr 27 51 40 64 / 0 0 10 10
asd 25 53 40 63 / 0 0 0 10
msy 31 53 44 64 / 0 0 10 10
gpt 25 52 42 61 / 0 0 0 10
pql 22 53 39 63 / 0 0 0 10
la...freeze warning until 10 am CST Friday for laz056>065.
Hard freeze warning until 10 am CST Friday for laz034>037-039-
MS...hard freeze warning until 10 am CST Friday for msz068>071-077-