334
FXUS64 KLZK 012111
AFDLZK

Area Forecast Discussion
National Weather Service Little Rock AR
411 PM CDT Sun Jun 1 2025

...New KEY MESSAGES, SHORT TERM, LONG TERM...

.KEY MESSAGES...
Issued at 133 PM CDT Sun Jun 1 2025

+ Pleasant but hot conditions are expected early this week with
highs in the upper 80s to lower 90s for most locations.

+ From mid week on, temperatures will remain warm and humid, but
cloud cover will be on the increase as a frontal boundary stalls
out near the northwestern part of the state.

+ Multiple rounds of thunderstorms will develop near and generally
move along this boundary that also extends into eastern Oklahoma.
Multiple rounds of storms may produce enough heavy rainfall to
result in a more widespread flooding threat by late this week or
next weekend.

&&

.SHORT TERM...
(This evening through Tuesday)
Issued at 133 PM CDT Sun Jun 1 2025

Early afternoon water vapor satellite imagery showed a weak
shortwave trough over Arkansas moving slowly to the southeast.
Regional radars showed some scattered light rain showers over the
southeast part of Arkansas associated with lift tied to the
trough. KLZK Radar also showed a thunderstorm near the
Perry/Pulaski border, not moving much at the time of this
discussion. Visible satellite imagery and regional surface
observations showed some scattered stratocumulus clouds away from
the small areas of precipitation around the state. Surface
observations showed temperatures in the lower to mid 80s with dew
point values in the lower 60s.

At those temperatures with a 25 degree F dew point spread and
with thunderstorms occurring, the primary threat is likely to be
collapsing thunderstorms producing microbursts. Don`t think storms
are likely to get tall enough to produce strong microbursts, but
40-50 mph winds will likely be associated with any storm that
develops through late this afternoon. Before sunset, we will
likely cool down enough to prevent additional storms from
developing, so this is primarily a concern here for just the next
few hours.

Behind the departing weak shortwave trough, shortwave ridging will
build over the state and remain in place through Tuesday morning.
Shortwave ridging will help support mostly clear/sunny skies while
winds generally remain light and southerly. The combination of
full early June sun and weak southerly winds will cause
temperatures to rise quickly on Monday with highs likely to flirt
with 90 degrees at several locations across the state. Shortwave
ridging will move east of the state Tuesday morning as the upper
low currently over southern California moves east towards
Arkansas. The upper low is expected to weaken quite a bit as it
moves east, and is expected to phase with a stronger northern
stream trough the central high plains Tuesday morning. This phased
upper troughing is expected to push east-northeast, causing most
of its associated dynamics to remain north of Arkansas, moving
over the western Great Lakes region. However this large area of
troughing is expected to be sufficient to push a large cold front
south out of the plains towards far northwest Arkansas by sunset
on Tuesday.

With all that in mind, closer to home here in Arkansas, the
aggregate of the discussion above will result in another mainly
hot and dry day across Arkansas, with little change from Monday
for most locations. There will likely be a slight uptick in
humidity owing to the second day in a row tapping into some Gulf
moisture. The frontal boundary is expected to slow down as it
approaches Arkansas, likely reaching the far northwest part of the
state near sunset. Along the entire frontal boundary will be a
line of showers and thunderstorms extending from Wisconsin to
north central Texas. As the front slows down, we may see some of
that thunderstorm activity across northwest or west central
Arkansas right around or just before sunset. Some strong to
marginally severe storms are possible, but wind shear is expected
to be fairly weak, so pulsing type of storms seem to pose the
primary threat for gusty winds and small hail.

Cavanaugh

&&

.LONG TERM...
(Tuesday Night through next Sunday)
Issued at 133 PM CDT Sun Jun 1 2025

As the combined troughs continue off to the east, they will mark a
large scale pattern shift that will remain with the Continental
United States (CONUS) through next weekend. The northern stream
jet/trough becomes zonally oriented along or just north of the
Canadian border. An elongated upper level ridge, also more or less
zonally oriented is expected to set up over Mexico-Texas-Florida
to the south, leaving most of the CONUS under the influence of
pure westerly flow aloft.

The upper ridge is interesting in that the center of anticyclonic
circulation below the level of non- divergence is basically
centered over Florida while aloft the center of anticyclonic
circulation is over northern Mexico. This offset configuration is
important because with the center of circulation at the low levels
set well off to the southeast this will direct Gulf moisture
directly at the state of Arkansas for an extended period of time.
When you couple that dynamic with a quasi-stationary boundary in
the region and westerly flow aloft promoting an oscillation of
shortwave troughing and ridging, kind of like extending a slinky
and wagging one end back and forth causing waves and troughs to
propagate along its length, it sets the stage for an active
weather pattern for the region for several days.

The eventual position of the stalled frontal boundary will be key
to pinning down weather impacts from Wednesday through early next
week. The large scale pattern supports multiple rounds of
thunderstorms during this period, with each round likely to push
the boundary south while the lack of storms along the boundary in
between rounds of storms will generally cause the boundary to move
back to the north. Each round of storms may come in the form of a
convective system that is difficult to predict more than 2-3 days
out because of factors on smaller scales of time and space that
can`t be currently observed because they don`t exist yet. These
convective systems, often called mesoscale convective systems or
MCSs, make it quite challenging to trust any deterministic
guidance regarding impacts moving forward. However ensemble
guidance can give us some clue as to which areas are more likely
to see multiple rounds of storms, thereby likely to experience
more negative impacts from the weather during the long term
forecast period.

Right now the long range ensemble forecasts generally indicate
that northern and western Arkansas have the best chances at seeing
multiple rounds of heavy thunderstorms Wednesday through next
Sunday. The average or mean guidance for rainfall totals is
probably not the best metric to use during this period as the
constant supply of Gulf moisture combined with westerly winds
aloft really favors storms that will be efficient rainfall
producers without undercutting on another due to strong cold pool
propagation. This pattern likely favors ensemble guidance rainfall
totals at or around the 90th percentile as a good first guess,
keeping in mind that rainfall totals will likely be higher if
storms move over the exact same areas on any 3 days during the 5
day long term forecast period. This would bring 5-day rainfall
totals up in the 4-6 inch range across the northern half of the
state and 2-4 inches across the southern half. Northwest Arkansas
currently seems to have the highest chance at seeing 6 inch plus
totals, but that may extend south across west central Arkansas as
well.

Initially individual storms will likely pose primarily a lower end
damaging wind and large hail threat, bearing in mind that short
term factors may enhance that potential... we just can`t see it
this far out. Tornadoes generally don`t seem favored, but they`ll
remain possible, just isolated and weaker in nature if they occur
at all. The largest obvious threat is the threat for heavy
rainfall and the associated flooding. Flash flooding could occur
with any individual round of storms on any given day. River and
more widespread flash flooding will become increasingly likely as
we get into next weekend. Some significant flooding is possible,
but this far out it`s difficult to say if that will occur in
Arkansas or in states/areas nearby. Either way, obviously
something we`ll be watching closely in future forecasts this week.

Storms aside, we will likely remain warm and very humid through
this period. Highs will climb into the 80s each day with overnight
lows only falling into the upper 60s or low 70s due to the high
humidity in place.

Cavanaugh

&&

.PRELIMINARY POINT TEMPS/POPS...
Batesville AR     64  88  68  89 /   0   0   0   0
Camden AR         62  89  67  90 /   0   0   0   0
Harrison AR       62  85  66  85 /   0   0   0  20
Hot Springs AR    63  89  67  89 /   0   0   0   0
Little Rock   AR  65  88  68  90 /   0   0   0   0
Monticello AR     65  90  69  91 /   0   0   0   0
Mount Ida AR      62  89  68  89 /   0   0   0  10
Mountain Home AR  62  87  67  86 /   0   0   0  20
Newport AR        65  88  68  89 /   0   0   0   0
Pine Bluff AR     64  88  67  90 /   0   0   0   0
Russellville AR   64  89  68  89 /   0   0   0  10
Searcy AR         63  88  66  89 /   0   0   0   0
Stuttgart AR      66  87  69  89 /   0   0   0   0

&&

.LZK WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...LONG TERM...AVIATION...Cavanaugh