Area Forecast Discussion
Issued by NWS Charleston, SC
FXUS62 KCHS 300451
Area Forecast Discussion
National Weather Service Charleston SC
1251 AM EDT MON MAY 30 2016
Tropical Depression Bonnie will meander over or near the coast of
South Carolina through Monday before gradually lifting northeast
away from the area. A cold front will then approach the region
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Low pressure was along the Northeast Charleston County coast as
of late Sunday evening, continuing with it`s counter-clockwise
movement from earlier. It is still stuck in a nebulous pattern
aloft under a weak and negatively tilted trough, but will lift a
bit further overnight to the north/northeast as there becomes a
little better flow between the trough and the Sub-Tropical
Bands of showers with a chance of localized heavy downpours will
continue to develop in deep moisture convergence on the back-side
of the low overnight. Instability remains weak and potential for
deep convection looks to be fairly low; however low-topped showers
will have good rainfall efficiency with pwats around 1.9 inches.
Current model projections indicate only modest additional rainfall
amounts and potential for significant flooding looks lower with
ponding and standing water a possibility in some areas of South
Temps won`t change too much through the night given extensive
cloudiness and already starting down in the upper 60s and lower
70s. But combined with the saturated conditions it will certainly
be a muggy night.
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
The remnants of TS Bonnie are expected to linger across eastern SC
through Monday before moving northeast into eastern NC through mid
week. The deeper moisture will shift northeast of the area with time
which will translate to generally lowering rain chances and warming
temperatures with time. However, heavy rainfall will be possible at
times, especially Monday across southeast SC. This could lead to
localized flash flooding given precipitable water values around 2
inches and generally weak steering flow.
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Weak surface pressure pattern will be in place Thursday into Friday
before a cold front approaches from the west over the weekend, and
potentially stalls near or over the area. Rain chances peak each day
in the afternoon with a relative minimum at night, with the better
chances occurring Saturday & Sunday. Upper ridge over the area will
boost temperatures a couple degrees above normal.
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
MVFR or possible IFR conditions to impact the terminals tonight
into Monday, due to the proximity of the meandering region of
surface low pressure, which will be in the vicinity of KCHS
tonight, finally starting to pull away later today and tonight.
This should allow for at least some improvement back to VFR at
KSAV later Monday.
EXTENDED AVIATION OUTLOOK...MVFR ceilings or worse are likely at
KCHS Mon night along with some showers/storms as the remnants of TS
Bonnie slowly lift northeast away from the area through mid week.
Thereafter...low risk for flight restrictions from mainly afternoon
showers/thunderstorms and early morning fog/stratus.
Overnight: For the late Sunday evening update we have dropped
mention of all Small Craft Advisories. Low pressure was found
along the upper Charleston County coast as of midnight, and will
gradually lift more north-northeast through the overnight at a
very slow pace. A scattered coverage of showers expected and
perhaps a few t-storms overnight.
Monday through Friday...Marine conditions expected to improve Monday
as the remnants of Tropical Storm Bonnie slowly move northeast near
the Carolina coast through mid week. Thereafter, no significant
winds/seas expected as a weak pressure pattern prevails before a
cold front approaches from the west late week and winds increase a
bit. Otherwise winds will mainly be 10 knots or less with seas 2-3
Rip Currents: An enhanced risk of rip currents is expected at all
beaches through at least Monday.