Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
FXUS64 KLIX 170541
Area Forecast Discussion
National Weather Service New Orleans LA
1141 PM CST Mon Jan 16 2017
Forecast confidence is low with regards to where persistent low
stratus and fog will occur. Variable conditions with some airports
seeing VFR to LIFR over short distances and time periods are
possible, but trending more towards IFR as the overnight
progresses. 06z TAFS go with a trend down to IFR/LIFR & alternate
airport required levels during the 06z-12z period for all the TAF
airports, then improving in the 14-17z period Tuesday morning. A
few SHRA and possible isolated TSRA could briefly impact a few
airports Tuesday afternoon, mainly KBTR and KMCB, so have added
.PREV DISCUSSION... /issued 708 PM CST Mon Jan 16 2017/
Moisture has continued to return the past 24 hours with PW now
above average at 1.3 inches. Strong warm air advection has been
ongoing in the onshore flow with winds at 25 kts by 1600 ft. Winds
become more westerly by 700 mb where an elevated inversion is
present. The low level profile up to about 800 mb is warmer and
closer to saturation than yesterday evening, so more widespread
and dense fog could return tonight compared to last night and we
will monitor for that trend.
PREV DISCUSSION... /issued 413 PM CST Mon Jan 16 2017/
Another warm day across the forecast area on the western side of
high pressure today. A few clouds and even a stay sprinkle or two
out there as an upper level system over the Plains will move
northeast over the next few days. Major rain chances do not pick
up until later on this week. Expect southerly winds and warm
temperatures to continue through Wednesday. Only slight chances of
showers and a storm 20 to 30 percent each day through Wednesday.
Temperatures remain extremely warm for mid-January through midweek
and beyond. Not a lot of variance in guidance temperatures,
trended toward the warm side. Again the bigger chance of storms
comes Thursday and into the weekend. 13/MH
An active period in the forecast begins to take shape Thursday and
lasting through the weekend. Guidance points to a upper level
system moving through the Southern Plains Wednesday night into
Thursday and taking on a negative tilt as it moves across the
forecast area Thursday into Friday. Have adjusted POPs for the
Thursday into Friday have bumped them up a good bit from last
package. Looking at some of the guidance the limiting factor for
Thursday as far as a big severe threat is the CAPE does not look
as robust as it should...but of course this could be one of those
high shear low CAPE events and we will definitely have to watch
this as it develops over the next few forecast cycles. The Storm
Prediction Center does not have the area highlighted in any threat
thus far, but again we will have to watch for the possibility of
a few strong to severe storms Thursday afternoon through Friday
morning. We a catch a small break Friday as we are in between
Right now, all guidance points to a greater severe threat for
portions of the southeast United States on Saturday. This one will
be the one to really watch as robust dynamics and instability for
this time of year looks like it could be in place. Just browsing
the forecast soundings for this weekend the loaded gun sounding
makes an appearance at all forecast sites with a strong jet and
diffluence over the lower Mississippi Valley Saturday afternoon
into Sunday morning. This will have to be watched this week as all
of the signals are starting to point to a decent severe weather
event this weekend. The Storm Prediction Center already highlights
portions of the area for severe weather in the Day 4-8 outlook.
Much above normal temps continue through Saturday night, will
keep with previous trends. Sunday into Monday will see temps
return to levels more common in mid to late January. 13/MH
Not anticipating as much fog tonight. Low clouds will probably be
the bigger issue with MVFR cigs impacting just about all terminals
by 6z. After that look for cigs to continue to lower with many if
not all terminals down to IFR at some point. A few sites may
actually see cigs fall to LIFR around 300 ft. Reduced vsbys are
still likely but expect mainly around 2-5sm for much of the early
morning hours. A few showers may also impact the region but
confidence is not high enough to warrant mention of shra or vcsh.
Light to moderate onshore flow will prevail across the coastal
waters through the week. Seas will mainly range from 2 to 5
feet during the period. Some areas of fog will be possible across the
relatively cooler waters of the near shore and tidal lakes. Rain
chances will gradually increase as the work week progresses, with
the best chance across the coastal waters Thursday and Thursday
DSS code: Green.
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 63 75 61 73 / 20 30 20 30
BTR 64 77 62 75 / 10 30 20 30
ASD 62 75 62 74 / 40 20 10 30
MSY 64 76 62 74 / 10 20 10 30
GPT 62 73 61 70 / 10 20 10 20
PQL 62 75 60 74 / 10 20 10 20
GM...Dense Fog Advisory until 9 AM CST Tuesday for GMZ530-532-534-536-
GM...Dense Fog Advisory until 9 AM CST Tuesday for GMZ532-534-536-538.