Area Forecast Discussion
Issued by NWS Jacksonville, FL
FXUS62 KJAX 251834
Area Forecast Discussion
National Weather Service Jacksonville FL
134 PM EST Sat Feb 25 2017
.NEAR TERM /Through Sunday/...
At 18Z, a cold front was pushing into southeast Georgia, with
isolated light showers along the boundary. Scattered to broken
ceilings in the 2-6kft range were ahead of and right along the
boundary. Very dry air was immediately behind the boundary, and
dewpoints were dropping around 15 degrees in 1 hour after frontal
passage. The front was moving eastward at about 25 knots, so the
front should push towards coastal southeast Georgia around 21-22Z
and then towards Jacksonville around 23-00Z. The front should then
clear the area the southeastern portion of the region by 04Z.
Surface high pressure will settle northwest of the region over
eastern Tennessee tonight, and north to northwesterly winds will
remain around 5 mph overnight (10 mph along the east coast). Much
drier and cooler conditions are expected tonight behind the
frontal passage, with lows in the upper 30s to lower 40s across
inland southeast Georgia, the low 40s across interior portions of
northeast Florida, and the mid to upper 40s for the east coast and
A shortwave will move into the Four Corners region and southern
plains on Sunday, and surface high pressure will shift quickly
eastward to the coast of the Carolinas by Sunday evening. A light
northeasterly flow will prevail. Very dry conditions are forecast
away from the immediate coastline, with relative humidities in the
15-20% range. Sunny skies will prevail. Highs on Sunday will be
cooler, with temperatures in the low to mid 60s for the coastal
areas and the upper 60s to lower 70s inland.
.SHORT TERM /Sunday Night through Tuesday Night/...
Sunday night...Surface high pressure builds offshore of the NC/VA
coast as upper level flow backs SW. This regime will bring warmer
flow across the local area with minimum temperatures increasing
into the mid 40s across inland to mid 50s coast. Cloud cover
gradually begin to increase from the south ahead of an approaching
warm front lifting northward over the south-central FL peninsula.
May have some patchy fog form around sunrise Monday morning but
probably more of low stratus given elevated southerly boundary
layer winds of 20-25 kts per the GFS/NAM at 925 mb across N FL.
Mon & Mon night...Warm and breezy at times Monday with a chance
of showers as a warm front lifts northward over the area and
interacts with the sea breezes as temperatures warm into the upper
70s to near 80 inland despite mostly cloudy skies due to warm air
advection pattern ahead of a frontal system. Included isolated
thunderstorms in the forecast given diurnal instability and
cooling temperatures aloft at 500 mb falling into the -12 to
potentially -16 deg C range per the NAM. A few strong storms will
be possible given cold pool moving in aloft which could favor hail
formation...but CAPE within hail growth region appears limited at
this time. Rainfall will tapper off into the evening hours with
loss of daytime heating and as frontal forcing lifts NNE of the
area and the surface front becomes diffuse north of the region
with a continuation of above normal warmth expected.
Tue & Tue night...High pressure over the western Atlantic will
extend a ridge axis across north-central Florida which will bring
dry conditions and above normal warmth. Aloft mid/upper level
ridge will amplify over the eastern Gulf of Mexico briefing Tue
then break down Tue night. Highs will warm into the mid 80s inland
Tue which could challenge daily records for the date with mild
overnight lows in the 60s Tue night. Expect partly cloudy to
mostly clear skies.
.LONG TERM /Wed through Sat/...
Wed-Thu...The ridge breaks down over the region ahead of the next
long wave frontal system. Wed above normal warmth will continue
under breezy and warm SSW flow with a low chance of a shower
focused across SE GA and along the Atlantic coast due to sea
breeze convergence. Pre-frontal showers including isolated tstorms
will enter the western tier of the forecast area after midnight
Wed night and press eastward across the area through midday Thu.
Thunderstorms are expected with the greatest potential for a few
strong storms capable of gusty winds across SE GA early Thu
morning with decreasing intensity expected as the rainfall shifts
southward across NE Florida through midday Thu.
Fri-Sat...A return to cooler and dry weather as a strong 1035 mb
surface ridge builds across the central CONUS Fri with a dry NNW
flow over the local area and highs only in the 60s with lows in
the 40s to potentially some upper 30s Fri night in normally cooler
locales across SE GA due to dry and cool air drainage.
Brief MVFR cigs are possible ahead of the front. Otherwise, VFR
conditions will prevail through the period. Immediately behind the
front skies should become mostly clear. Clear skies are forecast
overnight and through the end of the TAF period. Westerly winds
around 10 knots with gusts up to 20 knots will continue this
afternoon. Winds will shift to the northwest 5-10 knots behind the
front. High pressure will push east on Sunday and winds will
become northeasterly 5-10 knots.
Cold front was moving into southeast Georgia at 18Z this
afternoon, and the front will move through the waters this
evening. Winds will shift to the northwest and increase to around
20 knots nearshore and 20-25 knots offshore. Seas will build to
5-7 feet nearshore and 6-8 feet offshore tonight. Winds will
diminish by Sunday morning as high pressure builds into the region
and then east of the region. Winds will become northeasterly
10-15 knots on Sunday.
Rip Currents: Moderate risk through the weekend.
Very low humidity near 15-20% is expected tomorrow inland under
dry and cooler northerly flow with winds 10 mph or less. At this
time fire danger indices and fuel moisture do not support critical
or near critical fire weather conditions.
.PRELIMINARY POINT TEMPS/POPS...
AMG 39 67 44 77 / 0 0 0 40
SSI 46 63 54 71 / 0 0 0 30
JAX 44 68 52 77 / 0 0 0 30
SGJ 49 66 56 76 / 10 0 0 20
GNV 44 72 50 80 / 10 0 0 30
OCF 46 74 52 81 / 0 0 0 30
AM...Small Craft Advisory from 7 PM this evening to 10 AM EST Sunday
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-Waters from Altamaha Sound GA to
Fernandina Beach FL from 20 to 60 NM-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.