Area Forecast Discussion
Issued by NWS Shreveport, LA

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055
FXUS64 KSHV 222303
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
603 PM CDT Tue May 22 2018


.AVIATION...
Scattered convection has developed areawide and potentially affect
any of the terminal locations during the early eve, but
especially kmlu and ktxk. Some late night fog possible wherever
rainfall occurs. Low clouds will remain isold again tonight and
not mentioned in this fcst package. Winds remaining mostly lgt and
vrbl thru period. Moist and unstable across eastern portions of
area, will mention vcnty tstms for AR/LA portions of region Wed
aftn, but will leave out mention across east TX terminals./07/


&&

.PREV DISCUSSION... /issued 356 PM CDT Tue May 22 2018/

SHORT TERM.../Tonight through Wednesday Night/
Sct convection has developed across much of the region this
afternoon, as even areas of Nrn LA have destabilized enough
despite the wedge of drier air noted earlier on the Ch 9 and 10 of
the water vapor imagery. The inverter trough aloft over far Ern
OK/Wrn and Cntrl AR has resulted in a cluster of more organized
convection which has built SSW along a SSW propagating outflow
bndry into Nrn McCurtain County OK and the Nrn sections of SW AR,
with the high res progs suggesting that this convection may linger
a while longer into mid-evening before diminishing with the loss
of heating. Thus, have retained low chance pops this evening for
SE OK/SW AR, with slight chance pops elsewhere as the convection
away from the adjoining shear axis over Ecntrl TX should weaken
quickly with the loss of heating/lesser forcing. Should still see
some convective debris linger across the region overnight, with
the potential for patchy FG as well over areas that see wetting
rain, but confidence remains too low to mention in the forecast
attm.

The weak upper low off the SE TX coast this afternoon is progged
to only drift slowly E along the far SE TX/near the SW LA coasts
Wednesday, with the accompanying weak shear axis lingering N from
this low across E TX into far Wrn AR. Prefer the NAM handling of
this low and better RH fields, with the GFS the outlier and much
drier with the afternoon convection, with a near carbon copy (if
not more in the way of sct convection) expected especially over N
LA into SW AR. Guidance remains too bullish with pops with high
end likelies/categoricals over a good portion of the region, thus
have toned them down to mid and high chance Wednesday night
areawide, more in line with MOS. However, the lack of the inverted
trough feature over Ern OK/Wrn AR should keep convection more
scattered and less organized in the afternoon, highly dependent on
outflow interactions and the moderate instability that develops
with strong insolation near and E of the shear axis. Have trended
max temps Wednesday similar to what was observed this afternoon,
generally in the upper 80s to near 90 as the sct convection should
wait to develop until early afternoon, allowing most locales to
quickly near max temps. Did maintain slight chance pops Wednesday
evening as the sct convection should again diminish with the loss
of heating, with the weak NW Gulf coastal low expected to continue
drifting E near/just off the LA coast Thursday.

15

LONG TERM.../Thursday through Tuesday/
General area of low pressure aloft across the Gulf and much of
the sern CONUS will keep our weather pattern unsettled through
much of the extended. Diurnal convection looks to be on the menu
daily, keeping PoPs in for the entirety of the long-term pd. This
convection looks to largely keep us from heating up too much,
although some of the blends have us reaching into the mid and even
flirting with upper 90s by early next work week. However, some
uncertainty exists with the potential development of a tropical
system in the srn Gulf late Friday, which would then move nwd
towards the nrn Gulf Coast through the weekend. Depending on the
strength and movement of this system, we could be looking at
enhanced rain chances for early next week. Or we could be looking
at a mostly dry forecast, with temps spiking. For this package,
have kept the wetter/cooler trend going. /12/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  71  89  71  91 /  20  40  20  30
MLU  70  90  71  89 /  20  50  20  40
DEQ  68  87  67  88 /  30  50  20  30
TXK  69  87  69  87 /  30  40  20  30
ELD  68  88  69  89 /  30  50  20  30
TYR  69  88  70  89 /  20  40  20  30
GGG  70  88  69  90 /  20  40  20  30
LFK  70  90  69  90 /  20  40  20  40

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&

$$



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