Scientific Forecaster Discussion
fxus62 kjax 180810
Area forecast discussion
National Weather Service Jacksonville Florida
310 am EST Mon Nov 18 2019
..early morning showers for southeast Georgia...
..More sunshine and warmer today...
..high rip current risk continues for NE Florida coast...
Near term [through tonight]...
Light showers and drizzle will impact our northern Georgia zones
through mid-morning tracking west to east as a weak low level
trough axis (850 mb) pushes east as the parent mid and upper level
short wave trough axis digs east of the MS River Valley. By mid-
morning, bulk of the low level moisture and lift associated with
this trough will be offshore, ending precip chances and enabling
some drier low/mid level air to advect across the local are from
the west-northwest which will bring more sunshine today. Still not completely
cloud free as high cirrus will begin to increase once again from
the west this afternoon into the evening with some passing low
clouds as yet another but final long wave trough axis pivots
across the deep south into tonight. Low level moisture will be
meager as the surface passes north then east of the local area
tonight which will keep this frontal passage dry. Surface high
pressure across the western Gomex begin to nose an axis eastward
across the Suwannee River valley tonight, with light winds and
clearing skies. Enough low level moisture, subsidence and clearing
skies could bring some shallow ground fog across our southern Florida
zones toward daybreak Tue.
Temperatures will continue to trend below climo values. Lows this
morning will range from the mid 40s to near 50 toward to the
Atlantic coast under insulating cloud cover. High temperatures
today will trend a bit warmer due to more sunshine compared to
recent days with highs in the low/mid 60s across southeast Georgia to the
mid/upper 60s across NE Florida. Tonight, although there will be
passing cloud cover, the extent of the clouds and persistence is
not expected to be as much as this morning, so radiational cooling
conditions as well as a ridge building to our west will funnel a
cooler, drier west-northwest drainage flow over the local area with low
temperatures falling into the low/mid 40s inland to upper 40s
toward the coast.
Short term [tuesday through wednesday]...
Upper trough will push off the East Coast Tuesday morning with a
dry northwest flow prevailing across the area. Surface high pressure
will build into the area from the west and become situated overhead
on Wednesday. Temperatures will be near seasonal levels with
winds becoming light on Wednesday.
Long term [thursday through monday]...
Ridging at the surface and aloft over the region will bring warmer
temperatures and continued dry conditions through at least Friday.
Models continue to differ with timing of next cold front and upper
trough. The GFS is faster than the European model (ecmwf) solution by 12-24 hours
with frontal boundary. Will continue with consensus chance of
showers Saturday into Sunday. Temperatures will be at or above
[through 06z tuesday]
Low stratus deck ahead of weak surface cold front could bring
periodic MVFR restrictions to NE Florida terminals through 12-14z. Low
potential of light rain/drizzle near ssi through 14z. Mid-morning,
cloud cover will decrease west to east with partly cloudy to
mostly sunny skies into the afternoon with VFR conditions through
the evening. Prevailing west-northwest winds 10 kts or less will increase
after sunrise and weaken after sunset.
High pressure across the western Gulf of Mexico will build
eastward as a couple of weak cold fronts move across the local
waters through tonight. Small Craft Advisory conditions will
continue for outer waters and near shore Florida waters due to
elevated seas composed of large swells from the east-northeast of 2-5 ft.
Wave amplitudes dampen tonight and will drop the near shore and
outer Georgia water scas. Will continue Small Craft Advisory for our outer Florida waters
through Tue evening due to elevated seas.
High pressure will build across the local area from the west
Tuesday night into Wednesday with prevailing offshore flow. Winds
veer north-northeast into Thu with fairly weak magnitudes as surface high
pressure builds over the region from the west, then lifts
northward and builds east-northeast of the waters late Thu with a return of
onshore flow. Winds veer south Fri into Sat and increase ahead of
weekend storm system approaching from the west.
Rip currents: despite offshore flow today, 2-5 ft east-northeast swells with
periods of 13-15 seconds from departing surface low offshore of the
mid-Atlantic coast will continue a high rip current risk along the
NE Florida Atlantic coast and a moderate rip current risk for southeast Georgia coast
where east-northeast swell impact will translate less mass due to more
concave coastline. Anticipate moderate risk for all waters Tue
with dampening but lingering swells.
The coastal flood advisory will continue through tonight due to
minor tidal flooding within the St. Johns River basin and along
the NE Florida Atlantic coast around high tides. Offshore flow will
reduce peak tide amplitude compared to yesterday, but still expect
water level rise today up to 2 ft above mhhw (normally dry
Preliminary point temps/pops...
Amg 65 42 65 42 69 / 10 0 0 0 0
ssi 63 48 65 47 68 / 10 0 0 0 0
jax 67 45 68 45 70 / 0 0 0 0 0
sgj 67 49 68 49 69 / 0 0 0 0 0
gnv 69 45 67 44 71 / 0 0 0 0 0
ocf 69 47 69 45 71 / 0 0 0 0 0
Florida...high rip current risk through this evening for coastal Duval-
coastal Flagler-coastal Nassau-coastal St. Johns.
Coastal flood advisory until 7 am EST Tuesday for Clay-coastal
Duval-coastal Flagler-coastal Nassau-coastal St. Johns-
inland Duval-inland Flagler-inland Nassau-inland St. Johns-
Am...Small Craft Advisory until 11 PM EST Tuesday for waters from
Fernandina Beach to St. Augustine Florida from 20 to 60 nm-
waters from St. Augustine to Flagler Beach Florida from 20 to 60
Small Craft Advisory until 7 PM EST this evening for coastal
waters from Fernandina Beach to St. Augustine Florida out 20 nm-