Heavy Rain in Florida, November 14 to 15, 2019

Area Forecast Discussion
National Weather Service Jacksonville FL
241 AM EST Thu Nov 14 2019

.NEAR TERM [Today through Tonight]...Surface high pressure ridge
to the north will shift east today. A coastal trough has sharpened
over the Atlantic waters and will linger today producing a few coastal
showers and gusty winds along the coast. To the west a southern
stream upper trough now located over northern Mexico will move
east and phase in with northern stream trough over the lower Ms
River Valley tonight. This will form a surface low over the
eastern Gulf of Mexico which will move across north Florida
tonight reaching the Fl east coast by late tonight. Widespread
rain will develop across the area this evening as isentropic lift
combines with the approach of surface low and upper trough. Weak
elevated instability may result in isolated embedded thunder over
ne Fl late tonight. PWAT values will surge to near 1.8" tonight
which will likely result in rainfall amounts reaching 1-2 inches
by early Friday morning.

.SHORT TERM...FRI THROUGH SUN...

Synopsis...Cloudy & wet Fri-early Sat, then dry Sat night into Sun.
Below normal temperatures, no frost/freeze. Cloudy and wet as a
surface low lifts NE from near the local FL Atlantic coast Fri
morning to offshore of the Carolina Coast through midday while the
parent upper level trough continues to dig across the eastern
Gulf Coast states. Plenty of moisture and dynamical lift to
support widespread rainfall, with a sliver of instability along a
surface trough axis across our coastal waters extending south
across Flagler & Putnam counties to produced isolated t'storms Fri
morning. As surface low tracks farther NE away from the local
area Fri afternoon, expect persistent rainfall to tapper off from
west to east.

As parent upper level low approaches from the west Fri afternoon into
Fri evening, another surface low is expected to form offshore of
the SE Atlantic coast Fri night with a return of more persistent,
widespread rainfall along a surface trough axis pivoting southward
across the local area around this secondary surface low into
Saturday. High moisture and strong dynamical lift will override a
cool, stable low level airmass with t'storms not expected. Locally
heavy rainfall will be possible, with a blustery NNE developing
Sat afternoon into Sat evening with gusts 25-35 mph at times along
the local coast as the second surface low deepens offshore of the
local coast as it phases with the upper level system. The bulk of
rainfall with this system is expected to fall over SE GA where
storm total rainfall amounts from 00Z Fri (Thu night) through 00
Sun (Sat night) range from 2-4 inches amongst 00Z operational
GFS/ECMWF/NAM12 with generally 0.5-1.5 inches across much of NE
FL.

This low will lift NE away from the local waters Sat evening, with
local rain chances ending from west to east Sat afternoon. Brief
mid level ridge builds over the local area Sat night into Sun
night with mostly dry conditions and a cool northerly flow over
the local area, with breezy conditions continuing near the
Atlantic coast.

Temperatures will trend below normal this period with highs in the
 mid/upper 50s across SE GA to the low/mid 60s across NE FL,
possible some low 70s only on Fri across our SE FL zones in the
morning...then cooling into the afternoon into the 60s trailing
wake trough frontal passage. Low temperatures will also trend
below normal with 40s/50s Fri night, then temperatures cooling
into the mid/upper 30s across SE GA Sat night to the low/mid 40s
across NE FL. Too much wind and lingering low clouds for frost
formation Sat night.

.LONG TERM...MON THROUGH THU...

Cool and dry Mon as weak surface ridge builds over the local area,
then a brief shot of showers Mon night into Tue as the last long
wave trough and surface front cross the the SE region. Pattern
transitions Wed-Fri with drier conditions and moderating
temperatures as stacked high pressure builds over the SE region. A
chance of coastal showers returns Thu as onshore flow develops. A
cooler airmass will remain in place this period with temperatures
remaining below normal values with highs generally in the 60s to
near 70 and lows in the 40s inland to 50s coast.

&&

.AVIATION...
[Through 06Z Friday]
MVFR ceilings will prevail today with VCSH near the east coast.
Conditions will lower to IFR tonight with rain becoming widespread
between 00z-06z. NNE winds will continue to gusty near 20 knots
near the coast.

&&

.MARINE...Strong northeast winds will continue Small Craft
Advisory today as coastal trough has sharpened which will maintain
strong NNE winds near the coast this morning. Seas will stay
elevated and Advisory will continue offshore through this evening.
The pressure gradient will begin to tighten again late Friday
through the weekend as a low pressure system moves off the southeast
coast and intensifies. Gusts to gale force possible Friday night
through Saturday. Winds and seas will decrease below headline
criteria by Monday.

Rip Currents: A high risk of rip currents today due to strong
onshore winds and rough surf. Moderate risk on Friday as winds
become offshore.

Coastal Flooding: Minor coastal flooding still possible near
times of high tides today as strong NNE winds persist. Tides
expected to peak around 1.5 feet above MHHW.

&&

.PRELIMINARY POINT TEMPS/POPS...

AMG  53  47  55  46  56 /  50 100  80  70  30
SSI  63  53  60  49  59 /  30 100  90  70  40
JAX  67  55  63  49  59 /  30 100  80  60  30
SGJ  71  60  66  52  62 /  30  90  80  50  40
GNV  70  55  63  49  61 /  30  90  60  30  20
OCF  73  60  67  52  63 /  30  80  70  20  20

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 5 PM EST this afternoon for Clay-
     Coastal Duval-Coastal Flagler-Coastal Nassau-Coastal St.
     Johns-Inland Duval-Inland Flagler-Inland Nassau-Inland St.
     Johns-Putnam.

     High Rip Current Risk through this evening for Coastal Duval-
     Coastal Flagler-Coastal Nassau-Coastal St. Johns.

GA...Coastal Flood Advisory until 5 PM EST this afternoon for Coastal
     Camden-Coastal Glynn-Inland Camden-Inland Glynn.

AM...Small Craft Advisory until 10 PM EST this evening for Waters
     from Fernandina Beach to St. Augustine FL from 20 to 60 NM-
     Waters from St. Augustine to Flagler Beach FL from 20 to 60
     NM.

     Small Craft Advisory until 2 PM EST this afternoon for Waters
     from Altamaha Sound GA to Fernandina Beach FL from 20 to 60
     NM.

     Small Craft Advisory until 10 AM EST this morning for Coastal
     waters from Altamaha Sound to Fernandina Beach FL out 20 NM-
     Coastal waters from Fernandina Beach to St. Augustine FL
     out 20 NM-Coastal waters from St. Augustine to Flagler
     Beach FL out 20 NM.

&&