Area Forecast Discussion
Issued by NWS Jacksonville, FL
FXUS62 KJAX 301929
Area Forecast Discussion
National Weather Service Jacksonville FL
329 PM EDT Sun Apr 30 2017
.NEAR TERM (Tonight and Tomorrow)... Heights are falling slightly
today as a strong upper level low across the Plains pushes the
upper level ridge axis in place over the Atlantic eastward. At the
surface, the associated surface high pressure will also start
moving further east. Plenty of SBCAPE available this afternoon
with dewpoints in the upper 60s to low 70s, though a fairly strong
capping inversion and mid-level dry air will keep all but a few
isolated showers at bay. The east coast seabreeze will continue
pushing inland, and could also kick off a few showers west of I-75
in Florida as it meets the Gulf seabreeze, though confidence is
low. Another muggy night, though there will continue to be a
breeze in most locations.
Tomorrow the cold front currently across Mississippi will move eastward.
Surface winds will shift southwesterly, and could be quite gusty
during the morning hours if cloud cover isn`t present. Inland high
temperatures could be slightly cooler than today, though the
beaches will be warmer than today with southwesterly flow. QPF
continues to look pretty anemic as the system moves through
tomorrow afternoon and evening, so confidence is low that most
locations will see much in the way of measurable precip. The best
chances lie across southeastern Georgia, but other than a few
isolated higher totals near localized convection, a mere 0.10-0.25
inch is expected. SBCAPE will continue to be readily available,
and a brief period of 0-6km shear around 30-35kts could support a
few strong/marginally severe thunderstorms in southeast Georgia.
Monday night through Wednesday night...Slow moving cold front will
push across the area Monday night reaching southern zones of the
area on Tuesday. Convection with front should weaken overnight
as lift and instability decrease. Drier air will move in behind
the front on Tuesday over se Ga and the Suwannee Valley with a
continuing chance of showers/thunderstorms south of I-10 where
moisture and instability will linger longer. Drier air will
overspread ne Fl Tuesday night through Wednesday as the front
shifts into south Florida. Return flow will increase moisture
starting Wednesday night. Temperatures will be near or above
.LONG TERM...Thursday through Sunday...12z models in better
agreement with vigorous and progressive upper trough. Associated
cold front will move across the area Thursday night into early
Friday. Rain chances will start to increase on Thursday as return
flow increases along with moisture and instability. Best rain
chances will be Thursday night as the cold front sweeps across the
area. Strong to severe storms will be possible with this system.
Drier and cooler expected Friday through the weekend as surface
high builds in and upper trough moves across the se U.S. Above
normal temperatures Thursday are expected to drop below normal
Friday through Sunday with lower humidity.
.AVIATION...Still a few MVFR bases lingering, but cloud bases
should continue rising to SCT/BKN030-050 through the afternoon.
Southeast winds will continue around 10-15 knots sustained, with
gusts 25-30kts. Isolated showers are possible this afternoon, but
most location will remain dry. Gusts will subside after sunset,
but southeasterly sustained winds will likely remain above 10kts
most of the night. Medium to high confidence at least a SCT MVFR
deck will return late tonight. Winds will gradually shift more
southwesterly just after sunrise Monday. Thunderstorm chances
increase tomorrow afternoon just outside this TAF cycle,
especially across southeastern Georgia.
.MARINE...Solid SCEC conditions continue this afternoon and tonight
as southeasterly winds are expected to stay just shy of 20 knots.
Small craft advisory conditions will kick in Monday and continue
Monday night. Isolated showers and thunderstorms are possible as a
weak cold front will move through the area late Monday night into
Tuesday morning. Winds will quickly shift out of the north and
decrease behind the front as high pressure moves in. Winds/Seas
will begin to increase again on Thursday as a stronger frontal
system approaches the area.
Rip Currents: Moderate risk for Rip Currents continues today and
.FIRE WEATHER...High dispersions will continue on Monday...and
across southeast Georgia on Tuesday behind a cold front. Southeast
winds continuing through tonight will blow smoke to the nw. Winds
will be from the southwest on Monday with smoke plume moving
towards the ne. Showers and thunderstorms are expected Monday
afternoon and Monday night as a cold front moves into the area.
RH values will drop to near critical values Tuesday afternoon over
southeast Georgia and the Suwannee Valley as drier air advects in
behind cold front.
.PRELIMINARY POINT TEMPS/POPS...
AMG 71 85 59 85 / 30 60 40 10
SSI 75 80 67 80 / 10 30 40 20
JAX 72 88 67 84 / 10 30 50 20
SGJ 72 85 69 80 / 10 20 50 40
GNV 70 87 67 85 / 10 20 50 30
OCF 70 87 69 85 / 10 20 50 50