Area Forecast Discussion
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FXUS62 KILM 291054
Area Forecast Discussion
National Weather Service Wilmington NC
654 AM EDT SUN MAY 29 2016
Rain will stay in the area through Tuesday until the tropical
system makes its slow departure. Moisture will hang around for
most of the week so while sunshine should return in part there
will still be a scattering of storms each day. A cold front will
approach next weekend.
.NEAR TERM /THROUGH TONIGHT/...
As of 600 AM Sunday...A Tropical Storm Warning is in effect for
the South Carolina coast. Weak Tropical Storm Bonnie was located
about 190 miles south of Myrtle Beach and as of the last report
was moving slowly to the north. As was the case last night...all
of the convection was located NW and N of the actual center. There
is virtually no cold cloud tops/significant convection in the
vicinity of the center. This is indicative of a sheared
environment. Also, dry air to the south of the center, across
coastal GA and extreme southern SC was getting advected northward
and into the system. These conditions should continue to hinder
Bonnie is expected to be very near the coast, near CHS, late this
morning and early this afternoon. Steering flow remains weak, but
Bonnie is expected to be guided northward through tonight as
an upstream upper level trough moves toward the coast and western
Atlantic ridge builds near Bermuda. This may result in Bonnie
hugging the upper South Carolina coast.
Regardless of the exact track and lack of organization, the expected
weather conditions will be the same. High precipitable water values,
around 2 inches in deep east to southeast flow will necessitate high
pops. The potential remains for bouts of heavy rain in waves of
showers and a few thunderstorms streaming in from off the
Atlantic. This may cause localized ponding. ENE to E winds will
generally become ESE or SE today. Sustained wind speeds will be
10 to 15 mph...but up to 25 to 35 mph across the South Santee
River area and as far north as the southern Grand Strand. Wind
gusts may be higher in showers. Winds will be strongest later
this afternoon and into the eve hours.
A weak tornado can not be ruled out, mainly early today when the low-
level flow will exhibit the greatest veering with height.
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 AM Sunday...Bonnie may be a tropical depression before the
start of the period. The system or its remnants will be in the area
through the period as it moves slowly up along the Carolina coast.
The current forecast track has it lifting north of the Cape Fear
area Tue night. This will keep the weather unsettled, but drier air
and subsidence will eventually reach the area. Thus, would expect a
greater coverage of showers and thunderstorms throughout Mon with
coverage perhaps shrinking inland on Tue, but still high along the
coast. We are still forecasting total rainfall amounts in the 2 to 3
inch range although higher amounts will be possible.
Thick cloud cover Mon will be shrinking from W to E Tue and Tue
night and this will result in slightly warmer temps inland on Tue.
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 300 AM Sunday...The moisture directly associated with
Bonnie should be out of the picture by Wednesday. Sufficient
moisture will remain for scattered showers and storms however
especially if some upper troughiness remains behind. Rain chances
should arguably wind up just a bit higher over northern zones. No
more mid level trough on Thursday but a poorly defined surface
pressure pattern will remain. The sea breeze and outflow
boundaries should still manage to produce appreciable coverage of
mainly diurnal storms. The former should make good progress
inland. Rain chances then rise a bit Friday and maybe moreso
Saturday as the next upper trough and surface cold front approach
from the north and west.
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
As of 12Z...Difficult to nail down the TAFs today as
ceilings/visibilities will be all over the place, predominately
MVFR. Low pressure will continue to linger to our south, giving us a
nice plume of tropical moisture throughout the day. Water vapor
indicates the potential for us getting dry slotted, however any
solar insolation will only help to fuel convection. Look for
predominately easterly flow, with somewhat of a southeasterly
component this afternoon.
Extended Outlook...Unsettled weather through Thursday with possible
SHRA/isolated TSRA and TEMPO MVFR/IFR conditions.
NEAR TERM /THROUGH TONIGHT/...
As of 600 AM Sunday...A tropical Storm Warning is in effect for
the southern waters and a Small Craft Advisory is in effect for
the northern waters. The strongest winds are expected this
afternoon and this eve as Bonnie slowly lifts northward along the
coast. Wind speeds across the southern waters should peak in the
25 to 35 kt range...perhaps up to around 40 kt as stronger winds
to our south creep north. Sustained wind speeds across the
northern waters will be 15 to around 20 kt. Wind speeds may be
higher in the vicinity of showers. The wind direction will be ESE
to SE. The wind direction will veer to the SSE and S tonight. Seas
will be mainly 5 to 7 ft. A brief waterspout or two can not be
ruled out today.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 AM Sunday...Bonnie may be a tropical depression by the
start of the period. The depression or its remnants will slowly
lift north along the upper South Carolina coast and the southeast
North Carolina coast...perhaps lifting north of the Cape Fear
waters Tue night. This will keep showers and thunderstorms across
the waters for much of the period. South winds will hold across
the waters Mon and Mon night. As what is left of Bonnie lifts
slowly away from the area Tue and Tue night...winds should come
around to a more NW or N direction. Seas will be 4 to 5 ft Mon,
subsiding to 3 to 4 ft by Tue and then 2 to 3 ft Tue night.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
As of 300 AM Sunday...Decreasing wind and seas through the period
as tropical system moves off to the north and east. Wednesday`s
wind direction forecast may need some refining as there is still
guidance that stalls the system very near the area until then. Not
so by Thursday at which time the system`s exit will bring a west
wind that will then back to southerly as west Atlantic high
pressure takes hold.
SC...Tropical Storm Warning for SCZ053>056.
High Rip Current Risk through this evening for SCZ054-056.
NC...High Rip Current Risk through this evening for NCZ106-108-110.
MARINE...Tropical Storm Warning for AMZ254-256.
Small Craft Advisory until 10 PM EDT Monday for AMZ250-252.