FXUS62 KJAX 140012
Area Forecast Discussion
National Weather Service Jacksonville FL
712 PM EST Wed Dec 13 2017
The forecast for tonight looks good. The only update was to tweak
hourly temps down a few degrees here this evening based on how
quickly temps have fallen off since sunset. In fact we are already
closing in on our forecast min temps. Temperatures, however, will
level off and are likely to even come up a degree or two after
midnight as warm air advection kicks in and high clouds increase
from the west. Southwesterly flow may also come up just a tad
during the early morning hours. Main forecast challenge is
determining extent of low clouds moving into portions of northeast
Florida from the Gulf of Mexico late tonight. Should see skies in
our southern zones become at least partly cloudy if not mostly
cloudy by sunrise.
VFR conditions will generally prevail. The only question mark is
the potential for some low clouds moving in across portions of
northeast Florida from the Gulf of Mexico late tonight. Latest
forecast soundings and high res data lend enough confidence to
show MVFR ceilings at GNV an SGJ late tonight into Thursday.
SCEC looks good overnight into Thursday. Southwest winds will
steadily increase during the night and will approach 20 knots
over the offshore waters after midnight. Southwest winds will only
gradually subside during the day on Thursday.
Rip Currents: Low Risk.
.PRELIMINARY POINT TEMPS/POPS...
AMG 36 65 42 61 / 0 0 0 20
SSI 44 65 49 63 / 0 0 0 10
JAX 40 70 47 68 / 0 0 0 20
SGJ 43 70 51 68 / 0 0 10 30
GNV 39 70 48 70 / 0 0 10 30
OCF 40 70 51 73 / 0 10 10 20
FXUS62 KMLB 140732
Area Forecast Discussion
National Weather Service Melbourne FL
230 AM EST Thu Dec 14 2017
Currently...Surface high pressure was located over the southern
Florida peninsula with early morning temperatures in the lower to
mid 40s across much of east central Florida with the coldest
readings across the southern interior to Ft Pierce in the upper 30s
at 2 am. Skies were mainly clear with some scattered cirrus across
north Florida. Patchy frost is expected early this morning across
srn interior sections.
Today...The surface ridge will extend eastward from south FL toward
the nrn Bahamas today with low level W-SW winds north of the ridge
axis. This will allow high temperatures to reach the lower 70s
across much of the area. Low level westerly flow at 15-20 knots in
the H9-H8 layer will advect some gulf marine stratocu onshore across
nrn sections in the afternoon bringing a period of considerable
cloudiness from Lake county eastward. Low levels will still remain
rather dry from Okeechobee county to the Treasure coast where
mostly sunny skies are expected into the afternoon.
Tonight...The surface ridge will remain from south Florida and
extend eastward into the Atlantic. This will allow for light
southwest flow and milder low temps in the 50s nrn sections to mid
to upper 40s across the south closer to the ridge. Short range
guidance indicates a period of enhanced cloudiness will linger
across the nrn half of the forecast area with a persistent stratocu
deck in the low level WSW flow.
Fri-Sun...Mid level trough axis moves into the Southeast U.S. late
week, shifting a weak cool front slowly through the region Friday
night into early Saturday. Models continue to generate a few
showers, mainly across northern portions of central Florida ahead of
this boundary on Friday. Will leave rain chances around 20 percent
for this area, as overall moisture is fairly low and limited to the
lower levels. Dry conditions are then expected into the weekend as
boundary moves south, stalls and weakens near Lake Okeechobee. Highs
will range from the low to mid 70s Friday, dropping slightly over
northern areas behind the weak front Saturday, and then warm into
the upper 70s over much of the region Sunday. Lows will generally
remain in the 50s Fri/Sat nights and then are expected to be milder
in the low/mid 60s Sun night.
Mon-Wed...Models are coming into better agreement into early next
week with timing of next frontal boundary to move through the
region. The ECMWF has trended more toward the GFS solution keeping a
stronger mid level ridge in place across South Florida and Caribbean
region. This will keep boundary and deeper moisture/rain chances
north of the region, with warm and generally dry conditions in place
across east central Florida through at least Tuesday. Ridge is then
shunted southward as S/W moves through the southern U.S., pushing
front through the area. ECMWF is drier with this frontal passage
than the GFS, but for now will keep a slight chance for showers
across much of east central Florida for Wednesday.
.AVIATION...VFR/SKC through around 12z. SCT-BKN035-040 expected to
KLEE vcnty around 15z then moving eastward along and north of KISM-
KTIX line from 15z-21z into the afternoon. Areas of VFR CIGS around
4 kft will linger along and north of a KISM-KMLB line into the
evening and overnight.
Today...Westerly wind will be slightly stronger to 10-15 knots
farther north of the ridge axis across the nrn waters to 5-10 knots
across the srn waters. Seas 2-3 ft near shore to 3-4 ft offshore.
Tonight...W/SW winds to 10-15 knots nrn and central waters will
continue to 5-10 knots from Sebastian to Jupiter Inlet. Seas 2 ft
near shore to 3 ft offshore for the overnight hours.
Tonight-Thursday...Winds/seas will continue to subside as a high
pressure ridge builds over south Florida and then expands eastward
across the Bahamas. Northwest winds will back to westerly and
decrease from 12-17KT to around 7-12KT...the highest speeds in this
range occurring north of Cape Canaveral. Seas subsiding to 2FT near
shore as 3-4FT offshore.
Friday-Monday...A weak cold front is then forecast to move through
the region Friday night into Saturday, switching winds briefly out
of the north and building seas to 4-5 feet offshore. High pressure
building offshore north of the area will then allow winds to quickly
veer onshore into Sunday, with speeds forecast to remain less than
15 knots and seas around 2-3 feet.
Today...Modest low level moistening with W/SW flow off the Gulf will
keep Min RHS from around 50 percent north to 40-45 percent across
the far south.
Thursday-Friday...Increasing southwest flow emanating from the Gulf
of Mexico will provide shallow low level air mass moistening. Expect
min RH values in the M40s Thursday and U40s-L50s on Friday.
.PRELIMINARY POINT TEMPS/POPS...
DAB 71 53 74 53 / 0 10 20 10
MCO 72 54 74 55 / 0 10 20 10
MLB 71 52 75 57 / 0 0 10 10
VRB 71 49 74 56 / 0 0 10 10
LEE 71 55 74 55 / 10 10 20 10
SFB 72 54 74 54 / 0 10 20 10
ORL 72 57 74 57 / 0 10 20 10
FPR 71 47 75 55 / 0 0 0 10
FXUS64 KMOB 140533 AAA
Area Forecast Discussion...UPDATED
National Weather Service Mobile AL
1133 PM CST Wed Dec 13 2017
.DISCUSSION...Updated for latest aviation discussion below.
06Z issuance...VFR conditions through 15.06z. Winds will be
southwest at 4 to 8 kts through 14.08z becoming west to northwest
through 14.22z then diminishing to the less than 5 kts through
.PREV DISCUSSION... /issued 549 PM CST Wed Dec 13 2017/
DISCUSSION...Updated for latest aviation discussion below.
00Z issuance...VFR conditions through 15.00z. Winds will be
southwest at 4 to 8 kts through 14.06z becoming west to northwest
through 15.00z. 32/ee
PREV DISCUSSION... /issued 354 PM CST Wed Dec 13 2017/
NEAR TERM /Now Through Thursday/...A surface ridge of high
pressure holds over the Gulf tonight while next frontal boundary
eases southward across the Lower Mississippi River Delta. The
front continues southward through the day Thursday, becoming
aligned over the heart of the forecast area by late in the day.
Deep layer moisture continues to be very low for any frontal
ascent approaching from the north to work with, so will leave
precipitation out of the forecast. /10
SHORT TERM /Thursday night Through Saturday night/...A cool and
generally dry weather pattern expected to persist through Saturday
night. A weak cold front should approach from the north Thursday
night and push offshore by Friday morning. Expect any measurable
precipitation to remain offshore but can't rule out a few
sprinkles perhaps Friday morning. An onshore flow redevelops
Saturday into Saturday night as a cold front approaches from the
northwest. Temperatures will trend a near to a little cooler than
LONG TERM /Sunday Through Wednesday/...Global spectral models
diverge with the strength and the timing of the major shortwave
trough and associated surface frontal system expected to bring a
bout of wet weather to the area by Sunday. ECMWF is far more
progressive with this system as a cut off low develops in the base
of the upper level trough and is left spinning over the
Pacific...west of Baja California...while the more northward
.mid-latitude open wave propagates relatively quickly eastward
bringing precipitation to the area Sunday through Sunday night
then shifting it eastward. The GFS never fully cuts off the upper
level low and continues to propagate the closed low more slowly
eastward keeping rain chances over the region through at least
Tuesday. Trended the forecast toward the highest potential of
precipitation Sunday into Sunday night with the possibility of
some embedded thunderstorms depending on the strength of the upper
level forcing...most of the rainfall amounts though will likely
come from strong isentropic ascent. Temperatures during this
period should trend generally warmer than normal for this time of
MARINE...Late in the weekend brings the next chance for increased
impacts as a wave of frontal low pressure lifts northeast over
the deep south. Onshore flow strengthens and seas build. Winds,
waves and seas locally higher in and near storms Sunday and
Sunday night. /10
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FXUS62 KTBW 140749
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
249 AM EST Thu Dec 14 2017
.SHORT TERM (Today - Friday)...
Surface high pressure over the southern peninsula early
this morning is supporting mainly clear skies and light to
calm winds across the forecast area. Good radiational
cooling has allowed temperatures to drop into the lower
and middle 40s across most of the area, with some upper
30s being observed across Highlands and portions of Polk
counties under the high, and with temp/dew point spreads now
3 degree or less along with calm winds some patchy frost
formation will be possible prior to sunrise especially
across southeast Highlands county where the coolest
temperatures will reside, so will include a mention of in
the zones in these locations.
After a cool start temperatures should rebound fairly quickly
as a southwest wind flow develops across the region in response
to the surface high slowly shifting east into the western
Atlantic during the day. The southwest flow will allow the
cool and very dry airmass to modify with an increase in
moisture off the Gulf supporting an increase in clouds
during the day. Temperatures today will be milder than
yesterday given the southwest flow with highs climbing into
the lower 70s during the afternoon.
Tonight dry and milder weather is expected as zonal flow
aloft remains in place and surface high pressure from the
western Atlantic extending west across the southern peninsula
remains in control. A continued slow increase in low level
moisture combined with light to calm winds will likely lead
to some patchy fog development over inland locations after
midnight and will introduce into the grids and zones.
Temperatures will be milder than this morning with lows
generally in the 50s which is close to normal for this time
of the year.
On Friday little overall change is expected. A weakening
short wave trough approaching the lower Mississippi valley
will push a weak cold front south toward the forecast area
during the day. This boundary combined with a continued
slow increase in low level moisture may help to generate a
few showers (Pops 20 percent) across central and northern
locations during the afternoon, otherwise dry weather with
seasonal level temperatures can be expected with temperatures
climbing into the lower to mid 70s during the afternoon.
.MID TERM/LONG TERM (Friday night through next Wednesday)...
For the weekend: Aloft - A low over northwest Mexico lifts
up to the central plains as it opens into a trough while a
short wave trough tracks across the Deep South and dampens
out off the southeast U.S. coast. An Atlantic ridge builds
across FL and into the Gulf of Mexico. A second short wave
trough moves into the central Gulf coast on Sun. Surface - A
weak cold front dissipates across the state early in the
period as high pressure moves northeastward...from the
southern plains to the Mid-Atlantic coastal waters. For the
most part the weekend stays dry. The front dissipates with
limited moisture and while the second short wave trough will
produce some precipitation most of this will be in north
FL...only a few showers could spread into the northern
Nature Coast Sun afternoon. Temperatures will run slightly
above normal...with readings Sun a degree or two higher than
Mon-Wed: Aloft - The central plains trough shifts to the
eastern states and deepens with the Gulf ridge getting
shunted south of FL. Surface - The high pressure off the
Mid-Atlantic coast slides out over the open
Atlantic...initially ridging back across FL to the Gulf but
dropping south as the upper troughing pushes a cold front
into the region. The lower to mid level flow becomes
southerly and southwesterly with increasing moisture for the
northern half of the state...resulting a slight chance to a
chance of showers generally around and north of Tampa
Bay...and enhanced somewhat by the approaching front. The
temperatures continue to run above normal although the
clouds and rainfall with the front will lower highs Wed down
a bit compared to earlier in the week.
VFR will prevail during the next 24 hours. Clear skies early
this morning will give way to scattered to broken cigs aoa
050 across the northern terminals after 12Z and then across
the southern ones after 17Z as low level moisture increases
across the area, with some additional mid/high clouds aoa
100 streaming in from the Gulf. Light and variable winds
this morning will become southwest and increase to 7 to 10
knots after 15Z then diminish to around 5 knots or less
after 02Z tonight.
High pressure over the southern peninsula this morning will
shift slowly east into the Atlantic today and will then
extend back to west across the southern peninsula through
Friday night with southwest to west winds around 10 knots
along with slight seas expected over the Gulf waters through
the period. During the upcoming weekend a weak cool front
will sink south into the north central waters where it will
wash out as surface high pressure to the north bridges
across it with a northeast to easterly wind flow developing
over the waters through Saturday night. On Sunday and
continuing into Monday winds will veer to the southeast with
a slight uptick in speeds expected as the gradient tightens
some between high pressure offshore the mid Atlantic coast
and developing low pressure over the lower Mississippi
valley. Wind and seas should remain below 15 knots and 5
feet through the period with no headlines expected.
Increasing low level moisture will keep humidity values
above critical levels through the end of the week and into
the upcoming weekend with no fire weather issues expected.
.Preliminary Point Temps/PoPs...
TPA 72 60 74 58 / 10 10 20 0
FMY 72 55 75 58 / 0 0 10 0
GIF 72 54 75 56 / 0 10 20 10
SRQ 72 59 74 58 / 10 10 20 0
BKV 72 55 74 51 / 10 10 20 10
SPG 71 62 73 59 / 10 10 20 0
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...57/McMichael
MID TERM/LONG TERM/DECISION SUPPORT...09/Rude
FXUS62 KTAE 140653
Area Forecast Discussion
National Weather Service Tallahassee FL
153 AM EST Thu Dec 14 2017
.NEAR TERM [Through Today]...
A quick moving area of low pressure will move off the Delmarva coast
this morning with troughing extending southwestward down the
Appalachians. This will help erode the surface ridge from the north.
At the same time, a shortwave trough moving southward across the
High Plains will support a frontal boundary which will move into the
southeast this afternoon. The tap of high level moisture from the
Pacific will continue across the south today and tonight with
plentiful high clouds around. Light rain may develop south of the
front across the Gulf waters today with land areas remaining dry.
Dewpoints will increase today in a warm air advection regime with
mainly southwest winds and high temperatures today some 10 degrees
warmer than Wednesday (low to mid 60s today versus low to mid 50s
.SHORT TERM [Tonight Through Saturday]...
Mostly cloudy skies are expected on Friday, as sub-tropical moisture
currently streaming into the area ahead of a broad shortwave trough
traversing the Mid-Mississippi and Ohio River Valley's. An
associated surface front is expected to slide into the region and
is expected to weaken and stall along the Gulf Coast, providing a
focal point for shower development before somewhat drier air
filters into the region late Friday night. At this time, POPs
generally range from 20 to 40% late tonight/Friday morning, with
the highest POPs remaining offshore. While immediate coastal
locations could see a shower or 2, it looks less likely given the
latest model guidance. Drier conditions will resume Saturday, as a
brief shortwave ridge traverses the region ahead of a series of
approaching shortwave troughs that will bring unsettled conditions
back to the region in the long term period. Temperatures will
remain near average through the period, with highs generally
running in the low to mid 60s and lows in the 40s tonight,
dropping into the mid to upper 30s Friday night behind the
.LONG TERM [Saturday Night Through Thursday]...
The cut off mid-level low that meandered over the Gulf of California
the past few days will finally get ejected eastward by a kicker
trough diving southeastward out of the Gulf of Alaska. This feature
will push the ridge of high pressure away from the west coast. This
pattern change will open the door for an active long term period, as
medium and longer range guidance continues shows a series of
shortwave troughs traversing the region through mid next week.
Abundant sub-tropical moisture will be in place across the region
through this period, allowing for appreciable shower chances Sunday
through at least the early part of the week. While the latest
guidance remains in good agreement regarding an overall pattern
change, some differences regarding how progressive and moist the
next weeks (Tuesday/Wednesday timeframe) shortwave trough will be,
which will affect POPs for the region early next week. Temperatures
will generally run above average for mid December, with highs in the
upper 60s to low 70s and lows generally in the 50s, as a ridge of
high pressure builds into the region from the southeast.
.AVIATION [Through 06Z Friday]...
VFR through the period. High clouds will continue to stream across
the aerodromes from the Pacific on the southside of a northeast
Mexico cutoff low. Winds will remain light from the southwest. A few
more prescribed burns will take place today with slight restrictions
to vsbys in/around these areas.
Westerly winds between 15 and 20 knots will prevail through sunrise
before decreasing. Resultant seas will range from 2 to 4 feet. The
next chance at elevated conditions coming Saturday night into
Sunday, as cautionary conditions will be possible offshore.
Hazardous fire weather conditions are not expected over the next
There will be a slight chance for rain on Friday. A wet pattern is
expected early next week. Forecast rain totals for the next 7 days
range from 0.75 inch in the easternmost counties to 3 inches in the
westernmost counties. This will be a slow steady rain of light to
moderate intensity over 2 or 3 days. Flooding is not expected.
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 68 45 65 38 62 / 0 0 10 10 0
Panama City 66 49 61 40 61 / 0 10 10 10 0
Dothan 65 41 57 34 59 / 0 0 10 0 0
Albany 64 40 60 34 59 / 0 0 10 0 0
Valdosta 67 43 65 37 60 / 0 0 10 10 0
Cross City 70 48 72 41 65 / 10 10 10 0 0
Apalachicola 67 52 66 42 61 / 10 10 20 10 0
FL...High Rip Current Risk until 4 AM EST /3 AM CST/ early this
morning for Coastal Bay-Coastal Gulf.
FXUS62 KMFL 140617
Area Forecast Discussion
National Weather Service Miami FL
117 AM EST Thu Dec 14 2017
VFR conditions under high pressure through the TAF period. The
wind may try to pick up tomorrow, being mainly dominated by a
weak sea breeze. Even so, will likely be only around 5 kts, then
go light and variable once again after sunset.
.PREV DISCUSSION... /issued 637 PM EST Wed Dec 13 2017/
UPDATE...With sunset, winds are quickly becoming calm with
temperatures dropping through the 50s. Some cirrus is already
moving into the area, which will serve to arrest the best
radiational cooling. However, still expect a relatively chilly
night across the region.
Temperatures expected to drop into the upper 30s/around 40 near
Lake Okeechobee with low 40s for the remainder of the interior.
The Gulf coast and western portions of the east coast metro will
dip into the mid 40s, though wouldn't be surprised for a few low
40s in the coldest spots in these areas. The remainder of the east
coast will stay in the upper 40s to around 50 east of I-95.
No significant changes to the ongoing forecast.
PREV DISCUSSION... /issued 318 PM EST Wed Dec 13 2017/
THIS AFTERNOON AND TONIGHT: Another cool day across South Florida
with temperatures currently maxing out in the low to mid 60s across
the region. Dewpoints are generally in the mid-upper 30s with a few
low 40s in spots, showing just how dry the airmass is across the
The surface high over the Gulf is expected to slide east this
evening, centered directly over South Florida overnight. This should
allow temperatures to decouple quickly after sunset, becoming calm
or nearly so. This, coupled with the dry air and mostly clear skies
will set the stage for excellent radiational cooling. The one curve
ball in temperatures free falling overnight is the cirrus that
visible satellite currently shows over the Central Gulf. Depending
on when and how much of this cirrus moves overhead, which models
differ slightly about, peak radiational cooling potential may not be
achieved. Tonight's forecast will lean on the cooler side of
guidance, with temperatures dipping into the upper 30s around Lake
Okeechobee and low 40s for the remainder of the interior. Gulf coast
and western portions of the east coast metro will dip into the mid
40s, though wouldn't be surprised for a few low 40s in the coldest
spots in these areas. The remainder of the east coast will stay in
the upper 40s to around 50 east of I-95.
THURSDAY AND FRIDAY: High pressure center will slide across the
region on Thursday and off to our east on Friday, keeping very light
low level southwesterly flow in place. Dry and cool conditions
continue, though with slowly rising 500 mb heights, a slight warming
trend will ensue. Maximum temperatures Thursday are forecast to rise
to the low 70s, then mid to upper 70s by Friday. Overnight lows will
be range from the upper 40s across the far interior to low 60s
Thursday night, with 50s and 60s for everyone Friday night.
SATURDAY THROUGH MONDAY: The threat for any appreciable
precipitation has all but evaporated with the last two model runs.
12Z models keep the upper level ridge in place just to our
southeast, limiting any significant southward progress of the
shortwaves moving through the southern US. It looks like another
dry frontal passage Friday night, but unlike the previous few
fronts, the airmass will be modified by the time it arrives along
with winds quickly veering east-northeast. As a result
temperatures will be near normal in the mid-upper 70s on Saturday
and low 80s on Sunday. South-southeasterly flow on Monday may
allow temps to climb to near record levels in the mid 80s.
MARINE...Northwesterly winds will continue to diminish this
afternoon as high pressure builds across the region through the end
of the week. Except light and variable winds tonight into Thursday,
with flow becoming south-southwest on Friday though at less than
10kts. Weak frontal passage on Saturday will bring a little stronger
northeasterly flow with winds around 15kts, veering east on Sunday.
Seas highest this afternoon and evening at 2-4ft in the Gulf and 3-
5ft in the Atlantic, then subsiding to 2ft or less late Thursday.
FIRE WEATHER...High pressure will build across the region from
the Gulf the next few days, leading to light winds and poor
dispersions. RH values will bottom out in the mid 30s this
afternoon for most locations. A little more low level moisture is
expected to keep RHs above critical values the next few days,
though a few locations may drop into the upper 30s on Thursday. No
appreciable rain chances are expected through the period.
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 71 56 77 57 / 0 0 0 0
Fort Lauderdale 71 58 76 61 / 0 0 0 0
Miami 72 56 76 62 / 0 0 0 0
Naples 73 55 76 59 / 0 0 0 0