Area Forecast Discussion
Issued by NWS Charleston, SC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KCHS 310821
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
421 AM EDT TUE MAY 31 2016

.SYNOPSIS...
Remnant low pressure of Bonnie will continue to meander off the
upper South Carolina coast today, before gradually lifting
northeast Wednesday into Thursday. A weak cold front could then
approach the region late in the week and become stationary this
weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Pre-dawn: The remnants of Bonnie lingering off the upper South
Carolina coast at 4 AM. The only land-based rains persisting
overnight were occasional light showers and sprinkles along the
northeast Charleston County coast closer to the proximity of the
surface low. Along an instability gradient along the Savannah
River, cannot rule out an isolated shower through sunrise but most
areas will remain dry with mostly clear to partly cloudy skies in
se Georgia. Over the Charleston Tri-County area...widespread low
clouds were prevalent. We have a mention of patchy fog along our
nw tier; given the potential for some clearing and/or stratus
build-down. Temps will remain in the upper 60s to near 70 many
areas.

Today the remnant surface low south of the Grand Strand is
expected to ease further offshore and just a tad to the ne away
from the forecast area; a similar motion is also anticipated with
the mid level vort max. Deepest moisture will only slowly strip
out and linger across the Central South Carolina coastal zones
where we forecast 30-50 pops today, highest over ne Charleston
County and Berkeley County. On the fringe of the deeper moisture,
diurnal instability will be modest and strong insolation will result
in decent thermodynamics along the Savannah River and the I-95
corridor. Pockets of diurnal convection along mesoscale boundaries
should result in isolated showers and tstms this afternoon across
the remainder of the forecast area. Forecast downdraft capes are
generally weak but cannot rule out a couple of storms producing
some gusty winds and spotty downpours. Hot weather across se Georgia
where highs should reach the lower 90s in some areas.

Tonight...There is still a potential for isolated showers along the
central South Carolina coast but chances are becoming slimmer as
the low eases away. Otherwise is should be partly cloudy with lows
in the upper 60s to around 70.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Remnants of Bonnie will meander near the North Carolina coast
Wednesday into Thursday, leaving a rather ill-defined pressure
pattern over the local area. The remnant low will finally lift
northeast on Friday while a weak, slow-moving front approaches the
region from the west. More typical summertime rain chances expected
through the period, with coverage peaking in the afternoon and
evening when instability is greatest. Severe parameters aren`t too
impressive with lack of shear and no significant forcing mechanisms,
but sufficient CAPE and moisture could support a couple stronger
storms with gusty winds the main hazard. Rising heights aloft will
support temperatures near or slightly above normal. Highs in the
upper 80s/low 90s away from the coast; lows around 70.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
Models in pretty good agreement through the long term period. Weak
front stalled over the region will likely dissipate over the weekend,
before another cold front approaches and crosses the area early
next week. Typical diurnal convection expected, with perhaps
greater coverage Sunday and Monday with the front in the vicinity.
Tuesday looks to be the driest day of the period as the bulk of
precipitation associated with the front shifts offshore and high
pressure begins to build in from the northwest. Temperatures
mainly near normal.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
KCHS: IFR cigs overnight into mid morning as enough of an
inversion in the boundary layer will likely exist to keep moisture
trapped across the immediate area. Radar trends suggest dry
weather is likely overnight but showers and isolated tstms may
redevelop late morning and this afternoon. Outside of convective
rains pockets...conditions should become VFR this afternoon and
evening.

KSAV: We are currently forecasting VFR conditions through 06z
Wednesday, although there is a low end risk for some fog/stratus
around 10-14z this morning and isolated SHRA/TSRA late this
afternoon.

EXTENDED AVIATION OUTLOOK...Mainly VFR. Low risk for flight
restrictions from mainly afternoon showers/thunderstorms and
early morning fog/stratus.

&&

.MARINE...
Winds have become more sw and w overnight but are forecast to veer
w and nw by dawn before becoming variable with near shore sea
breeze influences this afternoon. Directions could remain rather
variable at times tonight. Speeds through sunrise on Wednesday
will be below 15 kt with seas 2 to 3 ft...highest well off the
Charleston County where a few 4 footers cannot be ruled out this
morning.

Wednesday through Sunday: Weak pressure pattern will be in place for
the second half of the work week as remnant low pressure of Bonnie
lingers to the north. Winds on average will be 10 knots or less
through Friday with seas 1 to 3 feet. Pressure gradient will begin
to tighten over the weekend as the coastal waters become sandwiched
between high pressure to the east and an approaching front to the
west. South/southwest winds will increase as a result, but
conditions are still expected to stay well below small craft
advisory criteria.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...ECT
AVIATION...ECT
MARINE...ECT


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