« Back
NWS Peachtree City, Ga » Text Product » CHS Area Forecast Discussion

Printer-friendly Version
Current Version              Previous Versions:   1  2  3  4  5  6  7  8  9  

Area Forecast Discussion

FXUS62 KCHS 250205

Area Forecast Discussion
National Weather Service Charleston SC
1005 PM EDT Sat Sep 24 2016

High pressure will build into the area Sunday but will weaken by
late Monday ahead of an approaching cold front. The front will
cross the forecast area and push off the coast by mid week and,
high pressure build into the region by the end of the week.


High resolution guidance continues to support isolated to
scattered showers developing along the Georgia coast prior to
sunrise along what appears to be a sharpening 925-850 hPA
moisture channel. KCLX is already picking up on scattered showers
over the gulf stream, where models are showing said development.
The strongest speed convergence is pointed right into the Tybee
Island area, so plan to increase pops to 40% for coastal Chatham
County with 30% pops for the area roughly bounded by Hilton Head,
the Savannah Airport, Midway and Shellman Bluff. Expect mainly
dry conditions elsewhere.

Conditions look to favor patchy fog development inland. Lows from
the upper 60s well inland to the mid 70s at the beaches look
reasonable and were maintained.


Sunday and Sunday night: The pattern aloft will feature a high
amplitude ridge across the eastern third of the country with a weak
upper low undercutting the ridge and meandering to the west. At the
surface, high pressure will shift into the northeastern part of the
country and will build into the Carolinas through the day. This will
help set up a prevailing onshore flow through the day. Model time
heights and soundings show that moisture will increase in the lowest
5 kft within the onshore flow, but mid and upper levels will remain
relatively dry. Better moisture will be in place across southeast
Georgia and that is where the best PoP`s are in place, though they
are still in the 20-30 percent range. Have continued to carry a
slight chance of thunder, though profiles are very unimpressive.
Highs should range from the mid 80s at the coast to the upper 80s
further inland. Overnight, the inland ridge of high pressure will be
at its strongest and there are hints of a sharpening coastal trough.
Rain chances will primarily align along the coastal waters with the
chance for a few showers to brush the coast. Expect another mild
night with low 70s in most areas.

Monday through Tuesday: As the high to the north slips off the
coast, it will push a cold front into the Carolinas near the state
line. The region will stay within the onshore flow regime, and
moisture looks deeper through the column. Coverage of showers and a
few thunderstorms will be better, but the overall risk of severe
weather will remain low. By Tuesday, a cold front will push in from
the west and the low level convergence will improve with the front
in the vicinity of the forecast area. Again, most of the activity
will be showers, but there is enough instability to produce a few
thunderstorms. Temperatures remain above normal with mid 80s just
about everywhere.


Global models are coming into better agreement with the passage of a
cold front Wednesday night. Will keep chance POPs in the forecast
Wednesday and Wednesday night to account for possible showers and
thunderstorms ahead of and along the front. Cold air advection
ensues Thursday as mild continental high pressure builds in and the
cold front stalls to our south and west. Comfortable temps and dry
conditions are expected Thursday and Friday, though the close
proximity of the front adds some uncertainty to this forecast.


Synoptic conditions do not looks as favorable for widespread
stratus development compared to previous nights. However,
some low-stratus could still develop, but will not be as
concentrated. Will limit the KCHS terminal to SCT004 with the
potential for light fog prior to sunrise, but trends will need to
be monitored for possible inclusion of IFR or LIFR cigs later. At
KSAV, a 2000-5000 cloud deck should preclude fog/low-stratus
development, but if this deck does not materialize as expected,
the risk would increase. Again, will need to monitor trends before
committing to IFR conditions. VFR will prevail for the remainder
of the 25/00z TAF cycle.

Extended Aviation Outlook: Flight restrictions will be possible each
morning through mid week each morning for possible stratus/fog
development. Also, showers and isolated thunderstorms could cause
brief reductions in ceilings and visibility, mainly in the


Tonight: Lowered winds by about a category all legs based on the
latest model data. Look for east to northeast winds <10 kt with
seas 2-4 ft.

Sunday through Thursday: High pressure will set up inland Sunday and
Monday, with a sharpening coastal trough Sunday night. Northeast
winds could surge into the 15-20 knot range at times, but should
stay below Small Craft Advisory thresholds. A cold front will
approach on Tuesday and finally push off the coast by mid week. No
significant increase in winds is expected through the end of the
forecast period. Seas will generally range 2-4 feet through early in
the week thanks to some lingering swell from Karl in the open






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.