Area Forecast Discussion
Issued by NWS Jacksonville, FL
FXUS62 KJAX 290729
Area Forecast Discussion
National Weather Service Jacksonville FL
329 AM EDT Sat Apr 29 2017
.NEAR TERM /Through Tonight/...
Thanks to moist southeast flow off the Atlantic, the area
continues to be mild and muggy with temps/dewpoints still in the
low to mid 70s early this morning. Stratocu clouds will continue
to spread westward overnight, resulting in partly to mostly cloudy
skies. These clouds should mix out relatively quickly after
sunrise with skies becoming mostly sunny for most areas Today.
Strong ridge aloft will result in hot and humid conditions inland
with near record temps expected across the interior towards our
western zones. We favored the higher side of guidance for max
temps west of Highway 301 today. Climate records in most jeopardy
of being tied or broken include GNV and AMG. Here are the
previous max temp records for this date: GNV...95 in 1914 and
AMG...93 in 2012.
The onshore flow will push the seabreeze well inland with breezy
conditions expected this afternoon into early this evening,
especially along the coast. This will also bring significant
relief from the heat along the coast, resulting in rather pleasant
conditions at the beaches. No chance for any rain today thanks to
strong capping inversion aloft and strong subsidence/dry air in
the mid levels.
Special weather statement continues for the smoke from the west
Mims wildfire. The smoke will move north to northwest today,
affecting Waycross, and then move more west northwest, possibly
into Homerville, behind the seabreeze late this afternoon into
Tonight will be nearly a carbon copy of what we just saw last
night. Mild and muggy conditions will persist with a stiff breeze
off the Atlantic at the coast. Another round of low clouds will
likely spread in as well during the overnight hours.
.SHORT TERM.../Sunday through Tuesday night/...
Sunday...Upper level ridging will continue along the east coast with
the surface ridge extending west across the southeast states. With
the mean ridge axis north of the region we will see a synoptic
southeast to southerly flow. This flow pattern should advect smoke
toward the central Georgia area. Temperatures will be above
climatology in the mid to upper 80s across the interior areas with
more moderated temperatures along the beaches due to the onshore
flow and cooler sea surface temperatures. A few afternoon and
evening showers and thunderstorms will be possible across the
interior as the Atlantic sea breeze moves westward with little
chance of rain for the coastal counties.
Sunday night...The ridge begins to flatten on the west and pulls
offshore as the next upper level short wave begins to dig southward
into the lower Mississippi River Valley. We should maintain enough
synoptic southerly flow to inhibit fog development with smoke
generally advected toward the Waycross and Alma areas.
Monday...The upper level trough, a cold front and a weakening pre-
frontal squall line approach the area. The best chance of rainfall
will be over interior southeast Georgia west of U.S. Highway 1 and
north of State Road 84. Overall looking at a 30 to 50 percent chance
of rain from south to north but general rainfall amounts look to be
in the .1 to .25 inch range. While locally higher amounts are always
possible with convection this is not going to be a drought buster
and certainly nothing that should help with the West Mims Fire
Monday night...The front will approach the coast with a continuing
chance of showers and a few thunderstorms. Again rainfall rates look
to be fairly light at less than .25 inch.
Tuesday...The frontal system moves to an east-west position over
Central Florida with a 20-30 percent pops over the southern areas
south of State Road 16 in Florida. Otherwise weak high pressure
builds into southeast Georgia and extreme north Florida.
Tuesday night...The high is reinforced by a ridge over the
Carolina`s with a weak synoptic southeast flow. This should
generally advect smoke in the direction of Fargo and Homerville.
High temperatures through the period look to be near to above climo
with interior high temperatures near 90 on Wednesday.
.LONG TERM.../Wednesday through Saturday/...A shortwave ridge will
build over the east coast on Wednesday with the southeasterly flow
continuing. On Thursday a very vigorous short wave trough will dig
into the Southern Plains and lower Mississippi River Valley with
Gulf moisture beginning to advect onto the southeast. The greatest
benefactor of this looks to be areas northwest of a line from
Homerville to Jesup. Looks like some sea breeze front convergence
over the interior Florida Peninsula, but overall rainfall rates
continue to look light in Thursday.
On Friday a band of thunderstorms will move across the area and we
will have to look for the possibility of severe weather. While
people are looking to this system to drop a significant amount of
rain, am not seeing it right now. Right now looking at 5. to 1 inch
over Florida and 1 to 2 inches across interior southeast Georgia but
nothing that is going to extinguish fires or bust the drought looks
to be in the cards right now. Going to use the old forecaster adage
of "when in drought forecast more drought" at least until something
big comes along to kick it over and this is just not that system.
Would not be surprised to see future model runs backing off on this
system`s storm total rainfall.
Saturday...High pressure builds in behind the front with a moderate
northwest flow and drying conditions.
Increased flow off the Atlantic has brought an increase in low
level moisture which has translated to a stratocumulus deck for
our coastal communities. The ceiling heights are checking in right
around 1000 feet, very close to the IFR threshold. As a result,
ceiling heights could fluctuate back and forth between IFR and
MVFR through sunrise this morning. Between the wind and the
clouds, there`s little chance for any fog to develop. Ceilings
will mix out after sunrise with VFR conditions and gusty onshore
winds expected. We will likely have a repeat of low clouds off the
Atlantic again this evening.
High pressure to the east will maintain se winds through
the weekend with SCEC headlines likely on Sunday. Small craft
advisory conditions look likely Monday and Monday night as a cold
front approaches. Winds and seas should decrease for Tuesday and
Wednesday as front slows down and weakens.
Rip Currents: Moderate Risk through Saturday due to an onshore
flow and a long period swell.
.FIRE WEATHER...With the synoptic southeasterly flow set up today
the general direction of the smoke plume will be into southeast
Georgia with the highest concentrations between Waycross and
Homerville. Minimum afternoon relative humidity values on Saturday
should be in the lower to mid 40s with dispersions moderately high
in the 60 to 75 range with the highest dispersion values over the
Suwannee River Valley. Maximum temperatures across the interior will
be in the 92 to 94 degree range with heat index values in the upper
90s to near 100. Crews will have to take extra precautions to remain
hydrated today. Expect the southeast flow to be reinforced during
the later afternoon and evening hours as the Atlantic sea breeze
front moves west.
.PRELIMINARY POINT TEMPS/POPS...
AMG 92 69 89 69 / 0 0 10 10
SSI 82 74 81 73 / 0 10 10 10
JAX 90 71 87 70 / 0 10 10 10
SGJ 85 73 84 71 / 0 10 10 10
GNV 95 69 89 68 / 0 0 20 10
OCF 94 70 90 68 / 0 0 20 10