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Office: LIX

FXUS64 KLIX 180055
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
655 PM CST Sat Feb 17 2018

.SOUNDING DISCUSSION...
The sounding this evening is a warm one for February with a well
mixed boundary layer up to an elevated inversion at almost 700 mb.
A drier airmass is present above, though overall PW is at 1.1
inches. Winds are westerly through the profile. Patchy fog is
possible later tonight and tomorrow morning over land areas. The
most fog will likely be over nearshore water and in river basins.

Krautmann

&&


.PREV DISCUSSION... /issued 348 PM CST Sat Feb 17 2018/

DISCUSSION...
A front is slowly drifting southward today across the southeast. A
few showers ahead of the front developed today and we can expect a
few more showers to be possible tonight. The front really does not
make it through the forecast area thanks to a fairly decent ridge
over the Atlantic. After the cold front all but dissipates and
moves north, the foggy mornings should begin to improve for the
beginning of the work week. Temperatures still will remain warm
as the spring like conditions continue through next week. Expect
onshore flow to setup for next week. That will increase the
moisture available in the atmosphere and a few showers can be
expected each day especially over the eastern portions of the
forecast area. The next organized chance of rain looks to come by
the middle of next week through the end of the week. Guidance is
pointing to a prolonged period of unsettled weather for the back
half of next week. A cold front will slow quite a bit as it
approaches the area and stall at some point either very close to
the area or to the northwest before moving back north by Friday.
Heavy rain for some portion of the mid south will be an issue
depending on where this boundary sets up. We will have to watch
this in future forecasts. It does not look like a huge issue for
our forecast area but a good chance of showers and thunderstorms
will be in the forecast for the second half of next week. 13/MH

AVIATION...
VFR conditions will be persistent through the remainder
of the afternoon and much of the evening however expect at least
MVFR cigs and possibly vsbys as well. By 07/08 cigs will begin to
lower towards IFR and possibly even into LIFR status shortly after.
Vsbys will likely fall slower and mainly around coastal sites.
MSY/NEW have the best chance of falling into IFR and LIFR status due
to vsbys but can not rule out ASD or GPT as well. /CAB/

MARINE...
Front is very slowly sliding south and could eventually
reach the tidal lakes and MS coast. Along this front and just to the
south winds will be fairly light and moisture will pool. Combine
that with the relatively cooler shelf waters and there could be one
more night of fog concerns over the inner waters and tidal lakes. On
shore will take back over by midday tomorrow and could even become
moderate by late Sunday night and Monday. Onshore flow will continue
through the first half of the week. Persistent moderate onshore flow
and southeast winds across much of the Gulf will eventually lead to
a decent swell leading to higher seas. /CAB/

DECISION SUPPORT...
DSS code: Blue.
Deployed: None.
Activation: None.
Activities: Marine Dense Fog Adv.

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  57  74  62  79 /  30  10  10  20
BTR  61  75  62  81 /  30  10  10  10
ASD  63  77  63  80 /  20  10  10  20
MSY  64  78  64  81 /  20  10  10  20
GPT  63  72  63  75 /  20  10  10  20
PQL  62  75  62  76 /  20  10  10  20

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...Dense Fog Advisory until 9 AM CST Sunday for GMZ532-534-536-538-
     550-552-555-557.

MS...None.
GM...Dense Fog Advisory until 9 AM CST Sunday for GMZ534-536-538-550-
     552-555-557.

&&

$$



Office: LCH FXUS64 KLCH 172340 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA 540 PM CST Sat Feb 17 2018 .AVIATION... A front that has stalled over southeast Texas and southern La this afternoon is producing sctd showers. Showers are moving to the northeast. It appears that this boundary is again on the move to the east. Ceilings are beginning to drop over srn La attm w/ ceilings and vsby better over se Tx. But se Tx and srn La will see the same outcome w/ both ceilings and vsby becmg IFR/LIFR twrds midnight hr. This will cont thru sr before a slowly improving. && .PREV DISCUSSION... /issued 401 PM CST Sat Feb 17 2018/ DISCUSSION... A shallow cold front extends from near Natchitoches southwest to near Lufkin where temperatures are in the mid 50s compared with Alexandria which reported 74 degrees last hour. The front is producing enough lift to spark scattered showers across the area this afternoon. Expect these showers to sink further south through the evening before the front stalls somewhere over the area. Exactly where the front comes to rest may potentially wreak havoc on overnight lows which are presently based on relatively little CAA. Should the front advance to near the coast, this may need to be revised. The front will lift back to the north Sunday as a warm front which will be enough to sustain at least low end POPs early Sunday before precipitation comes to an end Sunday afternoon. Marine fog is once again expected to begin moving inland after sunset this evening although the northward extent should be limited to near the coast due to the boundary. Thus, opted to forgo any inland dense fog advisories at this time. That said, areas along the immediate coastline will likely see visibilities drop to a mile or less. Fog should abate from land areas by mid morning. Guidance remains very consistent in bringing drier mid and upper level air across the region Monday into early Tuesday which might be enough to give the area a break from the mostly cloudy skies that have been the hallmark of the last couple of weeks. Another slow moving frontal boundary is progged to approach the area late Tuesday. The GFS is the only reliable guidance actually that actually pushes the front through the area while the remaining guidance stalls the front over east Texas setting up a prolonged period of potentially heavy rain. Following the majority rule approach, I am inclined to lean the forecast towards the stalling solution which will result in widespread showers and thunderstorms beginning late Tuesday through Thursday. QPF values were based on WPC's forecast and show widespread totals of two to two and a half inches Tuesday through Thursday. Forecast soundings also show more instability than we've seen recently indicative of potentially stronger thunderstorms. However, given the considerable model uncertainty, that is subject to change. Jones MARINE... Widespread dense marine fog is expected to develop across the nearshore coastal waters and coastal lakes and bays beginning shortly after sunset this evening. Visibilities of less than a mile area expected. Patchy dense fog will also be possible across the outer coastal waters. The fog is expected to begin to dissipate late Sunday as drier air works its way into the region. && .PRELIMINARY POINT TEMPS/POPS... AEX 55 71 60 77 / 50 20 10 10 LCH 61 73 62 75 / 40 10 10 10 LFT 65 75 64 78 / 30 10 10 10 BPT 62 73 62 76 / 40 10 10 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...Dense Fog Advisory until noon CST Sunday for GMZ430-432-435-450- 452-455. && $$ AVIATION...19
Office: SHV FXUS64 KSHV 172335 AFDSHV Area Forecast Discussion National Weather Service Shreveport LA 535 PM CST Sat Feb 17 2018 .AVIATION... IFR conditions to prevail through much of the terminal forecast period with tempo MVFR possible. Mist/BR may keep visibilities around 4SM tonight through Sunday morning. Surface winds will be North 5-10 knots into the evening, becoming Northeast and east 18/06z. By 18/18Z, winds will become south and increase to 10 knots. /06/ && .PREV DISCUSSION... /issued 415 PM CST Sat Feb 17 2018/ DISCUSSION... Cloudy and dreary conditions today are a sign of things to come as the weather pattern looks very unsettled throughout next week with appreciable rain chances nearly every day. For the short term, frontal boundary remains hung up right at our southeasternmost CWA near Colfax over to near Jena but will slowly push on south overnight. Post-frontal light rain will with a few embedded moderate showers will continue to shift SE behind the front this evening and overnight. The front is expected to stall along the coast early Sunday before washing out and giving way to a return to much warmer air during the day on Sunday. Returning SW flow aloft will allow for slight to low chance POPs for Sunday but expect most areas to remain dry. This warming trend will carry through early in the new work week with well above average temperatures both Monday and Tuesday. Very warm and moist flow from the Gulf will produce more springlike air mass with high temperatures pushing the lower 80s for many areas, possibly warmer over our southern sections. Slight to low chance POPs will also carry into Monday for much of the area with our NW zones seeing better odds with embedded upper disturbances passing in the SW flow aloft. Rain chances will really ramp Tuesday and especially Tuesday night into Wednesday with a slow-moving cold front transitioning across the region. Widespread showers and thunderstorms will accompany the front with 2-3 inches of rainfall spread across much of the region through the end of next week and possibly higher amounts along and north of I-30 where 4+ inches may occur. For now, the severe potential looks quite low with the heavy rainfall spread out over several days so that flash flooding doesn't appear to be a major concern. Wet and unsettled weather will continue through next weekend with the cold front stalling to our south and lifting back northward as SW flow aloft returns as well. Therefore, POPs have been carried through the remainder of the extended period. Temperatures will return closer to normal by Wednesday behind the cold front, but then push back above normal by the end of the week as the front lifts back northward as a warm front on Friday. Models diverge on the timing of our next cold front but generally agree on a slow progression through our region late next weekend. /19/ && .PRELIMINARY POINT TEMPS/POPS... SHV 47 66 60 80 / 20 30 20 10 MLU 46 66 60 80 / 60 40 10 10 DEQ 38 58 52 73 / 10 30 40 50 TXK 44 59 56 78 / 10 30 30 30 ELD 43 60 55 79 / 10 30 20 10 TYR 47 67 61 76 / 10 30 20 30 GGG 47 67 60 79 / 10 30 20 20 LFK 52 74 62 80 / 30 30 10 20 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 05/19