Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 281852
Area Forecast Discussion
National Weather Service Columbia SC
252 PM EDT THU JUL 28 2016
High pressure over the region will keep above normal temperatures
in the forecast through the end of the week. Afternoon thunderstorms
will be isolated the next couple of days...possible better chance
over the weekend into next week as moisture increases.
.NEAR TERM /THROUGH TONIGHT/...
Upper level ridge continues over the Southeastern states and
offshore. With warm temperatures aloft limited instability
expected. The focus for convection will remain north and west of
the region...near stalled front again this afternoon/evening. An
isolated showers at best with limited vertical motion this
afternoon. Warm advection noted today with winds around 10 to 15
mph with gusts to 20 mph. Boundary layer temperatures along with
local scheme suggests it will be warmer today than yesterday by 1
to 2 degrees. Taking mos cool bias into account...will continue
with high at CAE around 102 although will not be surprised if the
max temperature is higher. Several areas in the region will reach
100 degrees today. With slightly drier air in place this afternoon
along with more mixing with westerly winds...expect heat index
values to range from 105 to 100 degrees this afternoon. Will
continue highlight increased threat in HWO and social media.
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
The ridge will weaken Friday as an upper trough moves eastward. A
surface trough in the area may trigger some convection as a few
shortwaves support development. Instability remains weak on
Friday...so afternoon showers/thunderstorms should remain
isolated or widely scattered at best. The good news is the chances
for afternoon/evening showers and thunderstorms will be increasing
over the weekend. Thanks to slightly colder air aloft...increased
low-level moisture and weak trough/frontal boundary in the
vicinity should be a much better focus for convection than the
area has seen in awhile. Chance pops mainly afternoon showers and
thunderstorms over the weekend. Weak cold advection noted Friday
although may be offset by downslope flow. Slight decrease in
maximum temperatures over the weekend although still above normal
for late July. Also overnight minimum temperatures continue to be
above normal through the period.
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Both ECMWF and GFS indicate the mid/upper level ridge will
continue to weaken from Sunday night through much of next week. As
main ridge will continue across the wrn/cntrl U.S. and trough
lingers along the ern portion of the country. This will support
a general increase in pops as shortwaves move over the region and
lee-side troughing promotes convergence. Scattered thunderstorms
expected each day as surface high pressure shifts eastward and a
backdoor front moves into the mid- Atlantic States. The best
chance for widespread convection appear to be Sunday
afternoon/evening through Monday/Monday night. The synoptic
pattern supports above normal temperatures with highs in the
low/mid 90s and overnight lows in the low/mid 70s.
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR conditions through the TAF period.
An upper level ridge over the area will shift slightly east
through Friday generally promoting hot and dry weather. Satellite
imagery this afternoon shows a fair weather cumulus field which
should diminish by the early evening hours. Instability is weak
and moisture is shallow, thus thunderstorm development is not
expected at the TAF sites this afternoon and evening. Mostly
clear skies will return for tonight. Southwesterly winds from 10
to 15 knots with gusts around 20 knots will continue through the
afternoon but diminishing around/just afternoon sunset. Some wind
is also expected overnight with low level jet around 30 knots. Fog
is not expected tonight as another low level jet will develop
tonight and combine with the warm temperatures. Instability
appears weak again on Friday although shortwave energy may help
support isolated convection. Chances remain too low at the TAF
sites to include in current TAF issuance.
EXTENDED AVIATION OUTLOOK...Low potential for restrictions in
afternoon and evening convection each day.