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238
FXUS62 KCAE 202329
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
729 PM EDT Thu Jun 20 2024

.SYNOPSIS...
Dry weather and near normal temperatures will continue through
tonight as synoptic situation remains relatively unchanged.
Unsettled conditions are possible tomorrow and into the weekend
as moisture moves in from the Atlantic. Well above normal
temperatures are expected by Sunday into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
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Little change in the overall pattern and the surface high
remaining in control of the region. Easterly winds will
diminish this evening becoming light and variable overnight.
With good radiational cooling tonight overnight lows will be in
the mid to upper 60s.
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&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
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Westerly moving wave/low pressure center is forecast to move
ashore northern Florida during the day on Friday, pushing
westward by the evening hours. Initially, our forecast area will
have quite a bit of subsidence north of this feature as we`ll
still be stuck underneath the mid and upper level ridge. As a
result, the day is initially expected to be dry and warm. By the
afternoon hours, however, a surge of PWs is forecast by all
guidance, with HREF members generally showing the highest PWs
>1.5" approaching the I20 corridor and points southward. This is
the area most likely to see rain between 2p and 8p, though it
should remain generally scattered in nature. Thunderstorms are
possible but generally expecting things to remain sub-severe. I
do want to note that the well-performing HRRR has been
consistently showing no precip developing but it also is mixing
the boundary layer substantially more than its fellow CAMs (even
those that have had that bias in the past) so tend to think
that is the outlier. Highs will likely end up in the lower 90s,
maybe a touch cooler in the coastal plain where clouds are
likely to develop earlier in the day. Showers/storms will likely
hang around for a bit after sunset, diminishing as the night
goes along. Look for lows in the upper 60s.

Saturday looks fairly similar, as the plume of higher PWs is
expected to fully overspread the forecast area by this point. Given
hot temperatures and rich boundary layer moisture, we should see
scattered showers/thunderstorms develop across the forecast area
again on Saturday. Again, generally expecting these to remain
sub-severe but can`t rule out a strong storm here or there. Highs are
likely to be in the low to mid 90s, with overnight lows again in the
upper 60s or lower 70s.
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&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Guidance continues to show fairly conflicting signals in terms of
heat in the long term. The ridge that has been parked across the OH
Valley and Mid Atlantic regions is expected to shift westward and
yield troughing as the next work week approaches. The first signs of
this are expected by Sunday as heights will begin falling across the
Carolinas. Heights should continue to remain at or below 588dm by
Monday and Tuesday as the western CONUS ridge builds and persistent
troughing looks like it may set up. LREF Members support the
operational models in showing, leading to higher confidence than
normal in the pattern evolution through early next week.

However, the sensible weather that results from this in the forecast
is conflicting to say the least. The trough is forecast and expected
to yield a surface low into the northeast CONUS by Monday, pushing a
weakening cold front towards the FA by Monday afternoon and the
overnight hours. PWs will still be near to slightly above normal
both Sunday and Monday, with scattered to potentially numerous
thunderstorms expected both days given the favorable setup. This
conflicts with models also showing high chances at temps in the
upper 90s to around 100F for highs by Monday. This is also shown on
Tuesday despite the cold front likely stalling near the area. Part
of this looks like it could be westerly or northwesterly flow that
develops in the base of this trough advecting warm (20-22C) 850 hPa
temps across the area Sun-Wed of next week. Given the expectation
that daily showers/thunderstorms will be a risk, and lowering 500
hPa heights, it is hard to believe NBM guidance that temps will make
it to near 100F any day next week, let alone multiple days. Have
capped forecast highs around 98F as that makes conceptual sense
given the forecast as it stands right now. Lows will likely be in
the 70s given surface moisture in place. Overall, it does look hot
but nothing too crazy for June in the southeast. By the middle of
next week, things still look to be active with a building western
CONUS ridge, so expect daily chances at rain to continue into
Wednesday and Thursday.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
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VFR conditions expected through the TAF period.

With high pressure generally in control tonight into Friday,
conditions are expected to remain vfr through the period. Late
afternoon cumulus will be dissipating towards sunset once again.
Winds should diminish to less than 5 knots, but should still be
enough mixing near the surface to keep them from going
completely calm for long periods. In addition, the mixing will
also help to inhibit any fog formation late tonight. Friday will
see an increase in low-level moisture as an area of low pressure
off the coast begins tracking closer to the region. This may
only produce more scattered to occasionally broken vfr clouds
through the afternoon. As for rainfall potential Friday, most
guidance keeps the activity much closer to the coast through
much of the day, but can not completely rule out an isolated
shower approaching ogb late in the afternoon as the sea-breeze
moves inland more.

EXTENDED AVIATION OUTLOOK...Brief restrictions possible in
isolated to scattered afternoon and evening thunderstorms Saturday
with increasing chances Sunday through Tuesday.
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&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.

&&

$$