la discuss
Office: LIX
FXUS64 KLIX 210434 AAB
AFDLIX
Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
1134 PM CDT Mon Aug 20 2018
.AVIATION...
Currently monitoring pre-frontal convection moving southward
through Mississippi. Convective allowing models show an overall
weakening trend upon approach into KMCB, KBTR and KHDC. Feel not
as optimistic as some cells may pulse in intensity on influences
from warm lake waters when the activity gets closer. Will be
including some mention of TSRA in TAFs in the predawn hours where
complex is expected to have greater impact then show convection at
other locations just after sunrise but terminating rather early.
VFR conditions should then prevail generally 18Z onward at all
terminals as drier air starts infiltrating the region. 24/RR
&&
.PREV DISCUSSION... /issued 657 PM CDT Mon Aug 20 2018/
UPDATE...
Removing the headlines for Flash Flood Watch, which is expiring at
the top of the hour. All products should be updated at 7 pm. 24/RR
DECISION SUPPORT...
DSS code: Green.
Deployed: None.
Activation: None.
Activities: None.
PREV DISCUSSION... /issued 410 PM CDT Mon Aug 20 2018/
DISCUSSION...
Ongoing convection is oriented just like yesterday with a swath
of numerous storms from Baton Rouge to New Orleans and
northeastward. Outside of that zone, storms are much more
scattered and weaker in nature. The likely reason for northern
limitation of coverage is just how far north the high PW's extend.
Recent local RAOB and satellite imagery both confirm column
moisture levels are quite high at around 2.2-2.3". With such a
saturated sounding, you wouldn't think gusty winds would be an
issue, but observations prove otherwise. Thinking that precip
loading is accelerating downdrafts, because dry air aloft isn't
the culprit. The areas with these gusty winds tend to be mostly
offshore. Gusts have been just above 40 mph in marine environments
and mid 30s inland. Coastal locations will see this potential
impact through the afternoon hours as storms persist through a
little past 00Z. Although the threat for flash flooding is
diminishing, will just allow the watch to expire on its own.
Changes will be coming to the forecast going into Tuesday. Closed
low and trough in the upper atmosphere that is currently situated
along the Mississippi River Basin from the Great Lakes to
Louisiana will be shifting east. A cold front associated with this
feature is currently located in central Texas. Showers and
thunderstorms will begin early in the morning across northwestern
zones Tuesday as the boundary approaches. Convection will then
shift south and east during the afternoon hours. Model soundings
show mid/upper level dry air quickly infiltrating the area with PW
already down to 1.5" in Baton Rouge by noon. The front will be
slow to push offshore due to the base of the upper trough quickly
shifting northeast. However, broadening of the western shoulder of
the main trough will completely push in the post frontal air mass
Wednesday. This will bring with it much drier air and knock down
temperatures by a few degrees. The more noticeable change will be
dewpoints and even morning lows could be dropping into the upper
60s for some locations (mainly I-12 and northward). The pleasant
weather will be short- lived however, with moisture and lower rain
chances returning going into this weekend.
MEFFER
MARINE...Previous forecast looks good. Still looks like a weak
front will drift into the area tomorrow and then meander across the
coastal waters. Eventual placement of the front will determine the.SHORT TERM...
DECISION SUPPORT...
DSS code: Blue.
Deployed: None.
Activation: None.
Activities: Locally heavy rainfall and coastal storm wind gusts
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 73 91 69 90 / 30 40 10 0
BTR 76 91 71 92 / 30 50 10 0
ASD 76 90 72 91 / 20 60 10 10
MSY 80 90 76 91 / 20 60 20 10
GPT 77 90 74 90 / 20 60 20 10
PQL 76 89 72 91 / 20 50 20 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
Office: LCH
FXUS64 KLCH 210411
AFDLCH
Area Forecast Discussion
National Weather Service Lake Charles LA
1111 PM CDT Mon Aug 20 2018
.DISCUSSION...Surface analysis showing incoming boundary
stretching from near Monroe to Lufkin then continuing southwest.
Earlier strong convection this evening along pre-frontal trof
over north Louisiana into Mississippi has weakened while advancing
east and currently seeing much less and weaker activity ongoing.
Current forecast does maintain low end pops across the forecast
area tonight and seems reasonable. Forecast on track and no update
needed.
&&
.PREV DISCUSSION... /issued 658 PM CDT Mon Aug 20 2018/
DISCUSSION...
For 00z TAF issuance.
AVIATION...
Local 88Ds show some convection hanging around, most notably
moving into interior sern TX ahead of approaching weak
front...have maintained VCTS for the wrn terminals for an hour or
so to account. Re-introduced VCSH at KAEX later this evening as
high-res guidance indicates a return of scattered convection with
FROPA...not sure the front will advance this far swd tonight but
elected to insert the slim chance mention just in case. The srn
sites all see a return of VCSH after daybreak tomorrow as
additional convection could re-develop along the front.
25
PREV DISCUSSION... /issued 308 PM CDT Mon Aug 20 2018/
DISCUSSION...
Wx map shows large sfc low over the Plains, with the cool front over
N TX. Cooler and drier air behind the front in OK, where mid to
upper 70s prevail there. Down here, lower to mid 90s prevail, heat
index values in the 100-105 range. Radar showing scattered SHRA/TSRA
over the I-10 corridor of SE TX/S LA this afternoon. Expect
additional activity further inland in the next couple of hours.
For this evening, the cool front will gradually move southeast,
with additional showers and thunderstorms possible along and ahead
of the boundary. Thus, keeping 30-50% late this evening for this
across inland SE TX/C LA. A brief lull expected after midnight,
with showers and thunderstorms firing up toward the I-10 corridor
southward into the Gulf by Tuesday morning.
Behind the front, slightly lower dewpoints should keep morning
lows near 70/lower 70s Wednesday through Friday. Afternoon highs
will still be in the lower to mid 90 during this period, but the
lower dewpoints in the mid 60s/near 70 will keep the heat index
lower for these days.
By Friday afternoon into early next week, the mid to upper level
high expected to build over the southern U.S. with the typical
late summer surface high off the east coast. While the upper high
over the region usually spells oppressive heat, we should see
enough of a southeast flow off the Gulf to bring moisture off the
Gulf and the return of scattered afternoon showers and
thunderstorms during this period.
DML
MARINE...
Light to occasionally moderate onshore flow will continue as
high pressure continues to ridge across the northern Gulf. A
frontal boundary will slowly move south over the region Tuesday
into Wednesday, accompanied by an increasing chance for showers
and thunderstorms. The front is expected to stall over or just
south of the coastal waters, bringing a brief period of offshore
flow mid-week. The front will gradually dissipate by the end of
the week with return flow expected to resume.
DML
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 75 95 68 95 / 50 20 10 10
LCH 79 94 74 96 / 20 40 10 10
LFT 77 93 74 95 / 20 40 10 10
BPT 79 94 75 96 / 20 40 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&
$$
PUBLIC...23
FXUS64 KLCH 210454
AFDLCH
Area Forecast Discussion
National Weather Service Lake Charles LA
1154 PM CDT Mon Aug 20 2018
.DISCUSSION...
For 06z TAF issuance.
&&
.AVIATION...
Local 88D data and high res forecast guidance indicate the bulk of
the convection currently pushing esewd across e-cntl/nern LA will
skirt KAEX, but could have enough of an impact over the next few
hours to warrant a TEMPO shower mention for now. Otherwise no
significant changes to previous TAF thinking with this
package...although rain chances for the Acadiana terminals will
need to be looked at a little closer with the 12z package as
convective potential looks a little better than just a VC mention,
but not enough to warrant a full-blown TEMPO for now.
25
&&
.PREV DISCUSSION... /issued 1111 PM CDT Mon Aug 20 2018/
DISCUSSION...Surface analysis showing incoming boundary
stretching from near Monroe to Lufkin then continuing southwest.
Earlier strong convection this evening along pre-frontal trof
over north Louisiana into Mississippi has weakened while advancing
east and currently seeing much less and weaker activity ongoing.
Current forecast does maintain low end pops across the forecast
area tonight and seems reasonable. Forecast on track and no update
needed.
PREV DISCUSSION... /issued 658 PM CDT Mon Aug 20 2018/
DISCUSSION...
For 00z TAF issuance.
AVIATION...
Local 88Ds show some convection hanging around, most notably
moving into interior sern TX ahead of approaching weak
front...have maintained VCTS for the wrn terminals for an hour or
so to account. Re-introduced VCSH at KAEX later this evening as
high-res guidance indicates a return of scattered convection with
FROPA...not sure the front will advance this far swd tonight but
elected to insert the slim chance mention just in case. The srn
sites all see a return of VCSH after daybreak tomorrow as
additional convection could re-develop along the front.
25
PREV DISCUSSION... /issued 308 PM CDT Mon Aug 20 2018/
DISCUSSION...
Wx map shows large sfc low over the Plains, with the cool front over
N TX. Cooler and drier air behind the front in OK, where mid to
upper 70s prevail there. Down here, lower to mid 90s prevail, heat
index values in the 100-105 range. Radar showing scattered SHRA/TSRA
over the I-10 corridor of SE TX/S LA this afternoon. Expect
additional activity further inland in the next couple of hours.
For this evening, the cool front will gradually move southeast,
with additional showers and thunderstorms possible along and ahead
of the boundary. Thus, keeping 30-50% late this evening for this
across inland SE TX/C LA. A brief lull expected after midnight,
with showers and thunderstorms firing up toward the I-10 corridor
southward into the Gulf by Tuesday morning.
Behind the front, slightly lower dewpoints should keep morning
lows near 70/lower 70s Wednesday through Friday. Afternoon highs
will still be in the lower to mid 90 during this period, but the
lower dewpoints in the mid 60s/near 70 will keep the heat index
lower for these days.
By Friday afternoon into early next week, the mid to upper level
high expected to build over the southern U.S. with the typical
late summer surface high off the east coast. While the upper high
over the region usually spells oppressive heat, we should see
enough of a southeast flow off the Gulf to bring moisture off the
Gulf and the return of scattered afternoon showers and
thunderstorms during this period.
DML
MARINE...
Light to occasionally moderate onshore flow will continue as
high pressure continues to ridge across the northern Gulf. A
frontal boundary will slowly move south over the region Tuesday
into Wednesday, accompanied by an increasing chance for showers
and thunderstorms. The front is expected to stall over or just
south of the coastal waters, bringing a brief period of offshore
flow mid-week. The front will gradually dissipate by the end of
the week with return flow expected to resume.
DML
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 75 95 68 95 / 50 20 10 10
LCH 79 94 74 96 / 20 40 10 10
LFT 77 93 74 95 / 20 40 10 10
BPT 79 94 75 96 / 20 40 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&
$$
Office: SHV
FXUS64 KSHV 210459
AFDSHV
Area Forecast Discussion
National Weather Service Shreveport LA
1159 PM CDT Mon Aug 20 2018
AVIATION...
For the ArkLaTex, skies clearing with a fropa past KELD and near
KLFK with showers in the vicinity across Toledo Bend country to
KAEX with TS movg E. SFC winds N/NW around 5KT, climb winds are
N10-20KT and back to W/NW 20-40KT for flight level. Expect FEW CU
and W/NW winds TUE around 10KT with some midday gusts less than
20KT. Outlook is for midweek is hot and dry with NE winds on the
surface and for climb out with NW light flow abv. /24/
&&
.PREV DISCUSSION... /issued 950 PM CDT Mon Aug 20 2018/
SHORT TERM...
Active night still in progress for North central LA with the tail
end Charlie cluster south of I-20 and well east of I-49 moving SE
at 25mph. We have had numerous trees down with wind as strong as
Hurricane force in Monroe at the airport at 7:38 p.m. There are
3hr grid changes to this moving weather through the overnight, but
most of this will fizzle out and east by around midnight aside
from a Parish or two. It is 73 now in Idabel, but it is really
still warm out where no rain fell ranging all through the 80s. The
cold front is swinging low to mid 60 dew points from deep east TX
into NW LA and S AR. Not a bad front for August, just not very
wet for everyone. /24/
PREV DISCUSSION... /issued 322 PM CDT Mon Aug 20 2018/
SHORT TERM.../Tonight through Wednesday Morning/
Cold front currently along a line from Jacksonville Texas to
Shreveport and northeast to Magnolia Arkansas. Convection expected
to gradually increase in coverage along the front through the
late afternoon into the early evening hours during the time of
peak diurnal heating. With upper-trough swinging east across the
region in conjunction with the cold front, strong storms producing
gusty winds, small hail and locally heavy rainfall may be
possible.
Conditions to improve overnight with convection forecast to shift
south and dissipate. Overnight low temperatures forecast to fall
into the mid 60s across the southern Ozarks to the low to mid 70s
elsewhere.
Otherwise, upper-level ridge to rebuild across the region bringing
dry conditions through the remainder of the short term period
ending Wednesday morning. High temperatures on Tuesday to range
from the upper 80s across the I-30 corridor to the mid 90s across
deep east Texas with lows in the upper 60s on Wednesday morning.
/05/
LONG TERM.../Wednesday through Monday/
Most of the long-term forecast period will be dominated by a strong
upper ridge that will gradually move directly over the ArkLaTex
region. By Wednesday, a broad surface high pressure originated from
Southwest Canada will move in the Mid Mississippi River Valley.
Northerly surface flow will result in dry air advection across the
region and will keep Gulf moisture cut off from the area. Combined
with deep layer subsidence from the upper ridge and surface high,
dry weather is expected for Wednesday. Daytime high temperatures
will generally range from mid to upper 80s in Southeast Oklahoma to
mid 90s along and south of Interstate 20. However, the dry air
advection should keep heat index values below 100 degrees F.
On Thursday, the surface high will move into the Upper Ohio River
Valley, and a shortwave trough will move across the Northern Plains.
There still remains a slight chance that convection that develops
over Oklahoma may affect portions of Southeast Oklahoma and extreme
Southwest Arkansas during the daytime hours Thursday. However, every
subsequent run of the GFS has been trending closer and closer to the
precip-free solution of the ECMWF. Slight-chance PoPs will be
maintained with this forecast, but I would not be surprised to see
them removed entirely in later issuances.
By Friday and into the weekend, the center of the upper ridge move
overhead and towards Northeast Mississippi by Monday. Depending on
the ridge's exact position, on-shore flow will resume, which should
bring back chances for daily diurnal thunderstorm chances associated
with the sea breeze. Otherwise, with rain chances overall being slim
to none, the heat will be on. Daytime high temperatures will likely
climb into the upper 90s and possibly near or just over 100 degrees
by Saturday.
CN
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 74 94 70 95 / 10 10 0 0
MLU 73 93 68 92 / 70 10 0 0
DEQ 66 88 67 90 / 0 10 0 10
TXK 70 90 68 91 / 10 10 0 0
ELD 70 92 67 91 / 10 10 0 0
TYR 72 95 68 94 / 10 10 0 0
GGG 73 95 69 94 / 10 10 0 0
LFK 76 96 70 96 / 30 10 0 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
24/05/09
