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924
FXUS62 KCAE 211746
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
146 PM EDT Tue May 21 2024

.SYNOPSIS...
High pressure will dominate the region through early Thursday
keeping fair and dry conditions in place along with warming
temperatures. A frontal boundary will approach the region
Thursday night and Friday and is expected to stall just north
of the area resulting in chances of showers and thunderstorms
Friday through next weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
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Dry high pressure remains over the region with partly to mostly
sunny skies. Temperatures should top out in the mid 80s.

Tonight, the combination of high pressure in place and clearing
skies with light and variable to calm winds, strong radiational
cooling is expected. Leaned toward the cooler guidance and in
line with local radiation scheme with lows again in the upper
50s to lower 60s. Low level flow does shift around to the
southeast off the Atlantic, although generally weak, and may
support some stratus and fog across the Coastal Plain which may
reach the eastern Midlands. If this does occur, temperatures may
plateau or rise slightly thereafter.
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.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
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High confidence in a fairly quiet period through Friday as
guidance is in good agreement on the expected pattern. Upper
level ridging is forecast to be centered across the southeastern
US by Wednesday morning, with deep troughing settling into the
OH Valley. Ensembles & operational models push the axis of this
ridge offshore by Thursday evening, with more zonal flow
emerging on its heels. The ridging will keep us warm, dry, and
sunny on Wednesday. Highs are likely to be in the low 90s during
the afternoon, with only a few clouds. A strong mid-level
inversion looks to settle in with subsidence beneath the
ridging, so chances of rain are near zero. Clear skies and lows
in the low 60s are expected Wednesday night. The zonal flow is
forecast to take over on Thursday at the same time as we begin
to see an increase in low-level moisture across the forecast
area. Surface theta-e is forecast to climb to 340-345k across
the area on the western side of the surface high across the
Atlantic, increase potential instability. However, it still
looks like a strong cap will remain in place and keep storms at
bay for most of the area. The GFS/NAM/LREF suite of members do
show a weak shortwave trough approaching by Thursday evening.
Thinking that this could break the cap in the northern FA and
spark an isolated to scattered storm across that area. Bumped
PoPs up to slight chance as a result of this. LREF probabilities
of >0.01" of rain in the period are 20-30%, which support the
idea that, while not widespread, some precip is definitely
possible with this shortwave. Highs will likely be in the lower
90s on Thursday, with overnight lows in the upper 60s.
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.LONG TERM /FRIDAY THROUGH MONDAY/...
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Fairly high confidence in the general pattern in the long term.
LREF member means and operational models are in fairly good
agreement showing zonal flow continuing through early next
week, with multiple robust shortwaves progressing through the
flow in the long term period. At the surface, rich BL moisture
characterized by high theta-e, PWs 125-130% of normal, and
dewpoints in the upper 60s to around 70 will be in place. This
is forecast to all sit southward of a slow moving surface front
that should approach on Friday and become diffuse or weak around
the area into the weekend. Combine all of this with seasonally
warm temps in the low 90s and the stage is set for a fitting
start to the summer season and Memorial Day Weekend. So look for
highs to be 90-95F each day through early next week, with
chances for storms each afternoon as well. Given the strength of
some of these shortwaves combined with the rich low-level
moisture that is expected and there is a chance that strong
storms become a possibility each afternoon. The mesoscale
details will be important, so stay abreast of the forecast
especially if you have outdoor plans this weekend. For what its
worth, the CSU ML Probabilities are showing elevated severe
probabilities at this range on Sat/Sun/Mon, so it will be worth
watching this weekend. A more developed system and front look
likely to push in and through the region by the middle of next
week, which could cool us down if the front actually
materializes.
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&&

.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
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High confidence in VFR conditions all terminals through 06z then
possible predawn vsby restrictions in patchy fog primarily at
fog prone OGB/AGS.

High pressure remains in place across the region with a
relatively dry air mass in place. However, low level winds
overnight shift more southeasterly and may allow for some weak
onshore flow possibly leading to early morning fog/stratus over
the Coastal Plain. Some guidance suggesting OGB may be impacted
by fog with MVFR/IFR vsby restrictions during the 08z-12z time
frame. Also feel AGS could be at risk as well so included
restrictions at both OGB/AGS but keep VFR conditions elsewhere
where confidence is lower. Winds this afternoon from the east
around 5 to 7 knots should diminish to near calm overnight
before picking up from the southwest at 5 knots or less by 15z.

EXTENDED AVIATION OUTLOOK...No significant flight restrictions
are currently anticipated through Thursday outside of brief
morning fog. Low probability of restrictions during the late
week period into the weekend from afternoon and evening
convection.
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&&

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

&&

$$