Scientific Forecaster Discussion
fxus64 klix 121714
Area forecast discussion
National Weather Service New Orleans la
1114 am CST Tue Dec 12 2017
VFR ceiling and visibility unlimited conditions to prevail all terminals next 24-30 hours. Northwest
winds generally around 10 kt to become light and variable
overnight and Wed morning. 24/rr
Previous discussion... /issued 341 am CST Tue Dec 12 2017/
an amplifying shortwave trough will dive south across the
southeastern United States today. A strong cold front will accompany
this feature. It is currently moving southeast across northern
Louisiana and could reach northwestern zones of the County Warning Area by daybreak.
Continental airmass will knock temps back down about 10 degrees or
so for a couple days. Generally speaking, lows will be in the 30s
and highs in the 50s. One night of near freezing mins is expected
Wednesday morning. This is for locations along and north of a
Pascagoula to Slidell to Baton Rouge line. There won't be any rain
with this boundary as there will not be any chance for moisture to
return before it moves through.
Temperatures will rebound slightly Thursday before yet another cold
front moves through thurs night/Fri morning. A slightly better
chance of rain will be possible with this front as the sub-tropical
jet carries Pacific moisture across Mexico to the northern Gulf
Coast. However, it appears the timing of this moisture will be such
that showers don't develop along the front until it reaches the
coast. So, have kept pops to locations south of a Houma to LaFitte
line. This is a southward shift of rain chances, which is what
model solutions have been trending towards.
This last trough will finally be the one that shifts east to the
Atlantic, allowing a ridge to develop over the County Warning Area. Temperatures
will respond over the end of the week and weekend by rising into the
upper 60s to near 70. Moisture will begin to rise as surface high
pressure shifts east and southerly flow develops. The next
appreciable chance of rain will develop Sunday/Monday as a trough
moves into the midsection of the country then.
Cold front moving through this morning causing winds to become northwest at
10kt while those sites on the Lee side of lakes will be closer to
20kt. VFR conditions through taf cycle.
Winds will rise to 20 to 25kt today as a cold front moves through
this morning. Winds will again lower before responding once again to
another cold front that should move through Thursday night into
Friday morning. High pressure will quickly move east after the
Friday front causing winds to become onshore by Saturday and Sunday.
Another cold front will move through Sunday night into Monday. Each
of these fronts will bring with them at least short durations of
flag conditions whether that be caution or Small Craft Advisory conditions.
dss code: blue.
Activities: small craft advisories.
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 55 31 58 38 / 0 0 0 0
btr 59 32 60 39 / 0 0 0 0
asd 60 31 59 39 / 0 0 0 0
msy 59 38 61 45 / 0 0 0 0
gpt 58 34 58 42 / 0 0 0 0
pql 59 30 58 39 / 0 0 0 0
GM...Small Craft Advisory until noon CST today for gmz536-538-550-552-
GM...Small Craft Advisory until noon CST today for gmz538-550-552-555-