780
FXUS64 KLZK 161727
AFDLZK

Area Forecast Discussion
National Weather Service Little Rock AR
1227 PM CDT Fri Aug 16 2024

...New AVIATION...

.SHORT TERM...
(This afternoon through Sunday)
Issued at 640 AM CDT Fri Aug 16 2024

Regional WSR-88D radars depicted a complex of showers and
thunderstorms ongoing across far Nrn AR into much of Srn MO. This
activity was located and moving along and adjacent to a quasi-
stationary boundary draped roughly W to E through Srn MO.
Secondly, a small area of precipitation was lingering over Ern OK
associated with a remnant MCV. Locally, conditions were fairly
quiet but hot and humid conditions persisted overnight. Predawn
temperatures were holding steady in the upper 70s to mid 80s.
Synoptically, the upper ridge will begin to retrograde today and
be replaced with subtle NWrly flow heading into Saturday.

Today, the complex of showers and thunderstorm over Nrn AR will move
E of the area by mid-day with mostly sunny skies returning by this
afternoon. Temperatures are expected to be very hot, ranging from
the mid 90s over N AR, to 100-105 degrees over Cntrl/S AR. When
factoring in the forecast dew points with these expected hot
temperatures, excessive heat warnings are in effect across much of
the state except for the Boston Mtns and portions of NW AR where
heat advisories are in place. Across the heat advisory area, heat
indices are expected to range from 105 to 110 degrees. Across the
excessive heat warning area, heat indices are expected to range from
110 to 120 degrees.

Hi-Res CAM has been persistent run-to-run with firing up isolated
thunderstorms over portions of Cntrl and portions of S-Cntrl AR late
this afternoon. The aforementioned MCV over Ern OK could be the
triggering mechanism being picked up with this guidance. Given
the expected timing of this convective initiation, high
temperatures should still be realized before clouds and
thunderstorm cold-pools are generated. Confidence is low in
coverage of this activity, therefore went with slight PoPs for
the afternoon. If these storms do occur, DCAPE will be impressive
by late afternoon, therefore damaging winds would be the primary
hazard followed by large hail thanks to high CAPE values and steep
lapse rates.

Tonight into Saturday, another round of showers and thunderstorms
are possible over N AR beginning as early as tonight. This activity
is currently forecast to drop SE into Cntrl sections of the state
on Saturday morning as the frontal boundary dips into Nrn AR. By
late morning this activity should dissipate with ample sunshine
returning during the afternoon. Overnight lows will be hot and
humid once again in locations that stay rain-free and away from
thunderstorm generated cold-pools. This will set the stage for
more triple digit heat across W/ portions of Cntrl/S/and SW AR.
Lower 90s are expected over N/NE/far E AR. Heat headlines will
likely be needed for Saturday over a good portion of AR which will
likely be address with the next forecast update. Relief is on the
way however as we head into the long term period.

&&

.LONG TERM...
(Sunday Night through next Friday)
Issued at 640 AM CDT Fri Aug 16 2024

Long term PD cont to advertise a cooler PD, w/ much of the FA
expected to see near-normal to below-normal temps by early next
week.

Sun, perturbed and amplified H500 flow wl be prevalent over the
CONUS, w/ ridging over the Cont Divide and deep troughing acrs the
Great Lakes region yielding a strong meridional component of Nrly to
N/Wrly flow aloft. This fetch of stronger upper flow is currently
progged to extend from the Midwest/Nrn Plains, S/Ewrd towards the
Mid-MS River Valley. A sfc cdfrnt wl lkly be moving Swrd thru the
Cntrl Plains on Sun, and be approaching Nrn AR by later Sun night.
Ahead of this frnt, a sultry airmass is fcst, w/ sfc buoyancy progs
of 3000 to 4000 J/kg acrs much of Cntrl to Srn AR Sun aftn. For now,
medium range model guidance has not been very consistent, and often
origins of convective clusters and larger complexes are not well
resolved until we reach CAM range. Of note, some recent runs of
global guidance have suggested the initiation of cold pools along
the aforementioned frnt, and possibly accelerating into the FA
thru the aftn, capitalizing on a mid-August overlap of buoyancy,
and prominent vertical shear, possibly in excess of 40 to 50
knots.

Should model consistency bcm more apparent, stronger wording for
severe weather potential, including damaging winds from convective
complexes and MCS`s, may bcm necessary for Sun aftn/evng. For now,
the ingredients wl be in place, and wl cont to monitor for severe
weather potential.

Thru the remainder of the PD, sfc high pressure over the Midwest and
N/Erly sfc winds look to drive the local pattern, w/ rain chances
bcmg negligible, and a PD of near-normal to slightly cooler than
normal temps prevailing over much of the FA, before upper ridging
begins to shift Ewrd again by late next week.

&&

.AVIATION...
(18Z TAFS)
Issued at 1225 PM CDT Fri Aug 16 2024

Latest CAM output has supported forecaster confidence regarding
overnight convection potential. Forecasts reflect this confidence,
with highest probabilities across the northern third of the
forecast area, between 6-12z.

&&

.PRELIMINARY POINT TEMPS/POPS...
Batesville AR     99  75  94  72 /  20  40  50  20
Camden AR        101  77 101  75 /  10  10  10   0
Harrison AR       95  71  93  68 /  10  50  40  10
Hot Springs AR   104  77 103  77 /  10  10  10  10
Little Rock   AR 103  79 100  77 /  10  10  20  10
Monticello AR    101  79 101  78 /  10  10  10  10
Mount Ida AR     103  74 102  74 /  20  10  10  10
Mountain Home AR  95  72  92  69 /  10  50  40  20
Newport AR        99  75  95  72 /  20  30  40  20
Pine Bluff AR    101  78 100  75 /  10  10  10  10
Russellville AR  101  75  99  75 /  10  20  20  10
Searcy AR        101  75  96  73 /  20  20  40  10
Stuttgart AR     100  78  98  75 /  10  10  20  10

&&

.LZK WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM CDT this evening for ARZ004>006-103-112-
113-203-212-213-221>223-313.

Excessive Heat Warning until 9 PM CDT this evening for ARZ007-
008-014>017-024-025-031>034-039-042>047-052>057-062>069-121>123-
130-137-138-140-141-230-237-238-240-241-340-341.

&&

$$

SHORT TERM...55
LONG TERM....72
AVIATION...55