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000
FXUS62 KCAE 182347
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
747 PM EDT Tue Jun 18 2019

.SYNOPSIS...
Surface high pressure will extend from the Atlantic westward
into the Gulf of Mexico through the rest of the week. North of
this ridge, weak troughing will be in the forecast area. A
series of upper-level troughs will affect the area through
Thursday brining scattered to numerous diurnal thunderstorms.
Upper ridging will bring somewhat drier and hotter conditions
late this week and weekend.

&&

.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
A southern stream shortwave trough crossing GA is now approaching
the forecast area. Scattered showers and thunderstorms will
become more widespread and a broken line of convection is moving
into the CSRA. SPC has the northern and western portion of the
forecast area outlooked in a marginal risk for severe weather.
Instability is moderate, but 0-6 km shear is relatively weak, so
the overall severe threat appears low. Isolated damaging winds
are possible, but DCAPE values are marginal at 700 J/kg.
Locally heavy rainfall is also possible with Precipitable Water
around 2 inches. Convection will diminish as the shortwave
shifts east tonight, but isolated showers will remain possible.

Lows tonight will be in the lower 70s.

&&

.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
Wednesday, expect scattered afternoon thunderstorms with high
temperatures around 90 degrees. Though the deeper moisture will move
east of the forecast area Wednesday, SW low level flow will still
allow for diurnally driven convection. Recent model runs are now
showing a weak shortwave moving into the forecast area late in the
day. Given the better upper level support we have slightly increased
PoPs. Particularly across the northern FA where lee-side troughing
will be most prominent. Convection may linger into the evening as
the shortwave passes through. A strong low level jet from 30 to
40 knots will keep winds up overnight and prevent fog. Overnight
lows will be in the low to mid 70s.

Thursday, an upper level trough will move into the eastern CONUS.
Models are indicating the potential for moderate to strong
instability as the vorticity maxima moves into the FA. 0-6 km bulk
shear will also be strong for this time of year, around 30 knots.
This indicates that organized convection is likely during the
afternoon and evening. Steep mid-level lapse rates and strong shear
suggest the main hazard will be damaging wind gusts.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Drier air will be over the FA on Friday in the wake of an upper
level trough. Downslope flow will also contribute to dry, warm
weather. We expect highs to be a little warmer than guidance on
Friday due to the downslope flow, ranging from the low to mid 90s.
Any showers or thunderstorms that develop during the afternoon would
be isolated at best.

An upper level ridge will remain over the Southeast through much of
the remainder of the long term with PWAT values above 1.5 inches.
This pattern supports warmer than normal temperatures and mainly
diurnal convection, aided by the timing of a few shortwaves moving
over the ridge. Temperatures will warm late this week and into early
next week with temperatures above normal.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions generally expected through midnight outside of
any convection then possible stratus developing during the
morning hours on Wednesday.

Shortwave energy moving across GA has sustained convection
across eastern GA which will move into our area during the
00z-05z time frame, impacting AGS/DNL 00z-03z and CAE/CUB/OGB
01z-04z. Possible thunderstorms will accompany brief heavy
rainfall and possible wind gusts up to 25-30 knots. Otherwise
light south to southeasterly winds expected through the
overnight with a 20-25 knot low level jet helping to prevent fog
formation. Inconsistent guidance suggesting stratus
redevelopment late tonight but decided to go with persistence
and include MVFR cigs in forecast at all terminals during the
09z-15z time frame. Winds will pick up from the southwest on
Wednesday with speeds pushing into the 10 to 12 knot range after
18z. Scattered afternoon convection again possible with strong
heating and abundant atmospheric moisture but timing and
location uncertain so not including in this forecast issuance.

EXTENDED AVIATION OUTLOOK...Southerly flow will continue
pushing moisture into the area resulting late night/early
morning fog/stratus through Thursday. Widespread convection
possible Thursday into Thursday night as a cold front crosses
the area. Isolated diurnal showers and thunderstorms possible
Saturday and Sunday.

&&

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

&&

$$