Area Forecast Discussion
Issued by NWS Jacksonville, FL
FXUS62 KJAX 290856
Area Forecast Discussion
National Weather Service Jacksonville FL
456 AM EDT SUN MAY 29 2016
...Unseasonably Dry and Seasonably Hot Weather through Memorial
Early morning surface analysis depicts the highly sheared center
of weak Tropical Storm Bonnie (1009 millibars) located about 60
miles to the southeast of Charleston at 5 AM EDT, with a slow
northward motion around 8 mph. Aloft...troughing extends from the
Florida peninsula southeastward through the Bahamas, with ridging
over the rest of the western Atlantic that extends over the Mid-
Atlantic states and New England. Our region remains in a dry and
subsident atmosphere, with fair skies and light winds allowing
inland temperatures and dewpoints generally in the mid 60s,
ranging to near 70 at the coast.
.Short Term /Today through Memorial Day/...
Tropical Storm Bonnie will continue to only gradually approach the
South Carolina coast today, keeping an offshore wind regime in
place locally. A dry and subsident air mass will prevail, which
will limit convective development over our area this afternoon. A
few showers or low-topped thunderstorms may wrap around Bonnie`s
southwestern circulation over coastal southeast Georgia. Somewhat
deeper moisture over central Florida may activate the Gulf coast
sea breeze during the late afternoon, with isolated to widely
scattered convection perhaps clipping Marion and Flagler counties
through early this evening. Plenty of sunshine and a dry air mass
will boost inland highs into the lower 90s, except upper 80s for
locations north of Alma that will experience interludes of wrap-
around cloudiness. Our local pressure gradient should loosen
enough to allow for a late afternoon sea breeze in coastal
northeast Florida. With the late development of the sea breeze,
highs will reach the upper 80s at the northeast Florida beaches.
Isolated early evening convection will quickly dissipate over
north central Florida and coastal southeast Georgia. Radiational
cooling will prevail for one more night as the meandering remnants
of Bonnie keep a dry NW flow pattern in place locally, allowing
lows to again fall to the mid 60s inland and near 70 at the coast.
A rather stagnant weather pattern will prevail on Memorial Day as
the meandering remnants of Bonnie keep a deep and unseasonably dry
NW flow pattern in place locally. Our local pressure gradient will
continue to gradually loosen, allowing for sea breeze development
during the afternoon hours. Moisture levels may increase enough
for isolated convection to develop along the sea breeze boundaries
during the late afternoon hours, with widely scattered coverage
possible over inland north central Florida and the southern
Suwannee Valley where an early evening collision of the Atlantic
and Gulf coast sea breezes is expected. The overall dry nature of
our air mass will boost highs into the low/mid 90s inland, with
upper 80s to near 90 expected at the coast.
.Medium Term.../Monday night through Wednesday/...
We will begin the period with a weak upper level and surface
pattern dominated by a diffuse frontal system near the Florida-
Georgia State Line. Convection will largely be driven by diurnal
sea breeze front initiation and convergence. Low temperatures will
be near climatology at the mid 60s and highs slightly above
climatology in the lower to mid 90s inland.
.Long Term.../Wednesday night through Sunday/...
An upper level short wave trough will dig southward from the Great
Lakes with a closed low developing over the lower Mississippi River
Valley on Friday. This low and trough will dig further into the
central and western Gulf over the weekend opening up an upper and
mid level fetch out of the Gulf. This will result in moisture
advection over the region enhancing the rain chances over the north
Florida and southeast Georgia area late in the week. Temperatures
will be close to climatology through the period.
VFR conditions will prevail at the regional terminals, with brief
periods of MVFR ceilings between 1500-2500 feet possible at SSI
this morning. Northwesterly surface winds will increase to near 15
knots at SS, SGJ and the Duval County terminals after 14Z. A sea
breeze will push across the SGJ terminal towards 20Z, with surface
winds becoming northeast and then easterly around 10 knots.
Tropical Storm Bonnie is moving slowly northward towards coastal
South Carolina, with winds over the Georgia offshore waters
becoming westerly and subsiding back to caution speeds of 15-20
knots. Seas have subsided at the Grays Reef Buoy (41008) overnight,
with the 08Z reading now down to 4.5 feet. Due to the slow
movement of Tropical Storm Bonnie, we extended the Small Craft
Advisory for the offshore Georgia waters has been extended through
late morning, where seas should remain the 6-9 ft range before
subsiding back to caution levels of 4-6 ft this afternoon and then
below caution levels tonight. Caution levels seas are expected to
prevail in the offshore Florida waters today, with gradually
subsiding seas tonight and Monday.
Our local pressure gradient will remain tight enough today to
prevent sea breeze development in the Georgia near shore waters,
with a late afternoon sea breeze expected over the Florida near
shore waters. Tropical Storm Bonnie will meander over the coastal
Carolina region through midweek, with a loosening pressure
gradient locally that will promote sea breeze development in the
near shore waters around noon each day. Headlines are not
anticipated after today throughout the upcoming week.
Rip Currents: Ocean swells generated by Tropical Storm Bonnie will
create a moderate risk of rip currents at area beaches today and
on Memorial Day, especially during the outgoing tide during the
late afternoon each day.
.PRELIMINARY POINT TEMPS/POPS...
AMG 89 64 91 69 / 10 10 20 10
SSI 86 70 88 71 / 20 10 20 20
JAX 90 66 91 71 / 10 10 20 20
SGJ 88 69 90 73 / 10 10 20 20
GNV 92 65 91 69 / 10 10 30 20
OCF 92 68 91 69 / 20 10 40 20
AM...Small Craft Advisory until 11 AM EDT this morning for Waters
from Altamaha Sound GA to Fernandina Beach FL from 20 to 60