Area Forecast Discussion
Issued by NWS Little Rock, AR

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FXUS64 KLZK 181507

Area Forecast Discussion
National Weather Service Little Rock AR
1007 AM CDT Sun Mar 18 2018


Updated forecast to reflect observed radar trends over the past
several hours, as well as the newest hi-res guidance. No
significant changes in thinking for now with showers ongoing
across central AR and additional convection likely later this
evening and tonight.

Continuing to assess severe potential and will include a full
discussion by early afternoon. For now, the probability of
appreciable severe risk this afternoon or evening appears low.
Later this evening into the overnight hours, the narrow warm
sector to our west...coincident with modest instability and
increasing dynamic forcing...may promote stronger to potentially
severe storms as a sharp surface boundary approaches and begins
crossing the area from the west. More details to come in future



.PREV DISCUSSION...(ISSUED 624 AM CDT Sun Mar 18 2018)

Updated to include the 12Z aviation discussion below...


Some isolated to scattered rain is ongoing across the SRN
sections of the state...with VFR conditions ongoing. Some chances
for SHRA and TSRA will be seen throughout the day...with only some
isolated to widely scattered activity expected. More widespread
coverage of this activity will be seen late this afternoon into
the overnight period. Expect some decreased flight rules with the
more widespread activity.


SHORT TERM...Today Through Monday Night

An area of convection is lifting slowly north into far SRN sections
of the CWA early this Sun morning as an upper level disturbance
rotates around the upper ridge over the state. At the same
time...the SFC frontal boundary has begun to shift further south as
well...enhancing some of this convective activity. With the SFC
front moving south of the CWA...most if not all of the convection
will become elevated in nature. While current trends are showing
just generally SHRA/TSRA...there may be some potential for some of
this activity to strengthen slightly and produce some small sub-SVR
hail. Otherwise...expect mainly some moderate to heavy rain...and a
few rumbles of thunder in SRN sections of the CWA.

Further north...much lighter precip is scattered as far north as
portion of central AR. Not expect much in the way of accumulation
with this...with just slight chance to low end chance POPs for a few
hundredths of an inch expected.

Precip chances by late this morning into the early afternoon hrs
will increase further north...but not expecting much widespread
precip. By late this afternoon into the early evening hrs...the
front pushing south of the CWA early this morning will have moved a
bit further south into NRN LA before stalling. SFC low pressure will
develop over NRN TX...with the SFC frontal boundary stretching ESE
from this SFC low. At the same time...a new upper disturbance will
lift NE over NWRN sections of AR...with scattered to widespread
elevated convection expected over the NWRN portion of AR. Some
marginally hail may be seen with this activity...but not expecting
widespread SVR hail in this area of the state.

Further area of convection looks to develop in vicinity
of the SFC low over NRN TX this afternoon...and move east near the
Red River near the aforementioned SFC boundary into SWRN AR by late
this evening. As this convection moves into looks to move
north of the SFC boundary...which looks to remain just south of AR
through just after midnight. Since this convection will remain north
of the SFC boundary as it moves into the LZK CWA...the primary
threat expected will be large hail...and some locally heavy
rainfall. Cannot completely rule out some damaging winds...but may
be difficult to get downburst winds through the lower level
inversion. The best potential for seeing any SVR hail will be across
the SRN third of AR through the early morning hrs Mon.

For Mon...the main upper level shortwave trough will shift east over
NRN sections of the state...with a cold frontal trough shifting east
through the state by early Mon afternoon. While some convective
activity will remain possible with this boundary...expect the
potential for precip to quickly end from west to east by late Mon
afternoon. Some increased winds and much drier air will create an
elevated wild fire threat as a result...especially over the SRN two-
thirds of AR. By late Mon night...a new upper shortwave will shift
SE over the state by late Mon night...with some additional SHRA

LONG TERM...Tuesday Through Saturday

Behind the surface front, an upper trough will dig down into the Mid
South region early in the period. This will allow for showers to
continue initially. However, the system will move eastward late
Tuesday, with surface high pressure moving down in northwest flow
aloft. This will keep temperatures cooler than average for a few
days. The frontal boundary will stall out or wash out south of the

By Thursday, the surface high will shift eastward, with south winds
returning. As a result, temperatures will warm back above seasonal
averages. Remnant surface boundary will advance back to the north,
with low pressure forming along it to the west of Arkansas. This,
along with several mid-level waves moving through in the mean flow
will allow for scattered showers and thunderstorms late in the week
and into next weekend for much of the area. The low will drag a new
cold front into the state around Friday or Saturday, but the
boundary is likely to stall as it hits zonal upper flow, which would
prolong rain chances.


.LZK Watches/Warnings/Advisories...NONE.


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