Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 261022
Area Forecast Discussion
National Weather Service Columbia SC
622 AM EDT THU MAY 26 2016
High pressure will remain over the forecast area through Friday.
Moisture may increase over the weekend associated with low
pressure nearing the southeast coast.
.NEAR TERM /THROUGH TONIGHT/...
This morning`s analysis showed a pressure ridge extending along
the Southeast coast into the northeast Gulf of Mexico. The water
vapor imagery indicated a weakness in the mid-level ridge over the
forecast area. Strong heating combined with less mid-level
capping may help support thunderstorms but expect little coverage
because of shallow moisture. The greater thunderstorm chance may
be this afternoon and evening near the sea breeze front in the
southeast part of the forecast area and in the west section
closer to somewhat deeper moisture. The ARW supported isolated
coverage. The NAM and GFS MOS pops were very low. We forecasted
slight chance pops. Followed the guidance consensus for the
temperature forecast. Wind should be light with the ridge axis
just southeast of the area. The NAM and GFS MOS indicated mainly
southwest winds 5 to 10 mph.
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
The models depict the mid-level shortwave trough weakening or the
ridge building westward slightly from the Atlantic while an upper
low remains over the vicinity of the Bahamas for Friday and Friday
night. The models display continued surface ridging along the
southeast coast limiting moisture here. Model forecast soundings
indicate a mid-level subsidence inversion or cap becoming more
established Friday which should help diminish the thunderstorm
chance. All the GFS and NAM MOS have pops less than 20 percent. We
maintained the dry forecast. Used the guidance consensus for the
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The medium-range models continue to indicate a low pressure
system in the Atlantic moving toward the Southeast coast over the
weekend. The system may be stalled over the region early next
week. It is possible the low could gain sub-tropical characteristics.
There has been poor run-to-run model consistency with the timing
and placement of deepest moisture and confidence remains low. The
GFS, ECMWF, and EKD MOS pops have not been consistent. We
continued the forecast of chance pops. Depending on the track of
the storm, locally heavy rainfall and flooding could become an
issue in the forecast area.
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
Brief MVFR/IFR fog possible this morning at AGS and OGB until
13z, otherwise VFR conditions across the area today into tonight.
High pressure centered off the Atlantic coast will provide a
general light southerly flow over the area today. Expect some
cumulus to develop by late morning or early afternoon. Isolated
convection possible by late afternoon, but coverage is expected to
be minimal so will not mention in any of the TAF sites.
EXTENDED AVIATION OUTLOOK...Some fog possible at the fog prone sites
ags and ogb early each morning. Moisture return and associated
restrictions possible Saturday through Monday as a subtropical
low approaches the area.