Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 230810
Area Forecast Discussion
National Weather Service Columbia SC
410 AM EDT SAT JUL 23 2016
High pressure will be in control of the region through early next
week. A weak frontal boundary will approach from the north around
the middle of next week. Mostly dry weather and hot temperatures
this weekend will give way to scattered showers and thunderstorms
next week. Temperatures should remain above normal.
.NEAR TERM /THROUGH TONIGHT/...
Early this morning...an upper level disturbance will move
southward into the FA. The HRRR suggests a few showers may develop
around 5 am. However with no convection currently in the area
there may not be a source of low level forcing to initiate
convection. Keeping in mind that the HRRR was overdone yesterday
morning as a shortwave moved through, kept the FA precip free in
the near term.
Today...the mid/upper level ridge centered over the Southern
Plains will build eastward across the Carolinas. At the
surface...a weak surface trough will linger along the mountains
with Atlantic high pressure ridging into the southeastern states.
Cannot rule out weak short wave energy crossing the area in
northerly flow aloft. PW values are forecast to range between 1.5
and 2.0 inches with weak to moderate instability this afternoon.
Our forecast continues with only a slight chance for afternoon
and evening thunderstorms.
Models remain consistent with temperatures. Should see afternoon
highs in the mid and upper 90s with heat indices around 105
degrees. Went with persistence for overnight lows lows in the
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
The mid/upper level ridge axis will continue to extend eastward
into the Carolinas through Sunday with temperatures climbing
another couple of degrees by Sunday afternoon. Expect temperatures
to approach the century mark at many locations. Heat index values
will range from 105-109 degrees. This will be close to heat
advisory criteria but will likely fall slightly short. Isolated
diurnal convection possible with moderate instability Sunday
afternoon and evening...although subsidence from the upper ridge
may limit convection.
.LONG TERM /MONDAY THROUGH FRIDAY/...
Both GFS/ECMWF indicate the the eastward extent of the mid/upper
level ridge will begin to weaken and retrograde westward back over
the central plains/four corners region by mid/late week. A surface
front will also approach the region stalling out north of the
forecast area Mon/Tue. Another stronger s/w will try to push a
front slightly farther southward toward the cwa by late week.
Looks as though any front through the week will remain north of
the area and gradually weaken. Our forecast area will remain south
of the frontal boundary in the hotter air and PW values ranging
from 1.5 to 20.0 inches...so cannot rule out isolated/widely
scattered thunderstorms each afternoon/evening across the CWA.
Temperatures through the period will remain above normal through
the end of next week with highs in the mid 90s to around 100
degrees and lows in the 70s.
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions expected, outside of convection, through the TAF
Early this morning, a 25 kt LLJ will promote some mixing and SW
surface winds through 09z at CAE, OGB and DNL. Afterwhich, surface
winds may become light and variable at all TAF sites as the
inversion strengthens. Convective debris clouds and some mixing
will limit fog potential through the period.
Today, there will be a slight chance of diurnal convection. Hi-res
models tend to favor convective initiation in the central Midlands
northward. However cannot rule out scattered to isolated
thunderstorms throughout the forecast area this afternoon.
This evening, models indicate the potential for another 20 to 25
kt LLJ. Kept winds between 5 to 10 kts at CAE, OGB and DNL
EXTENDED AVIATION OUTLOOK...Low confidence in restrictions
in afternoon and evening convection each day. Low potential for
early morning fog/stratus each morning...mainly at AGS/OGB.