Area Forecast Discussion
Issued by NWS Melbourne, FL

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FXUS62 KMLB 221428

Area Forecast Discussion
National Weather Service Melbourne FL
1028 AM EDT Thu Mar 22 2018


No significant changes to current forecast over land. The forecast
area is sandwiched between deep low pressure off the NE U.S. coast
and elongated high pressure ridge over the MS river valley. This
is producing a deep N/NW flow of cool dry air over EC FL. Although
not as windy as yesterday, daytime mixing is bringing some
stronger winds down to the surface in gusts this morning, esp
along the coast. The gustiness should gradually ease during the
afternoon as the pressure gradient relaxes. Max temps will about
10 degrees below normal in the upper 60s/lower 70s despite full
late March sunshine.


.MARINE...Based on surface analysis, have extended the Small Craft
Advisory into early afternoon for nearshore Volusia and Brevard
county Atlc waters. The pressure gradient remains supportive of
winds near 20 knots late this morning but is still forecast to
ease this afternoon. So the SCA will continue for all the waters
into early afternoon and for the offshore waters/Gulf stream
through this evening. Seas up to 9 feet in the Gulf Stream into
this afternoon.

.FIRE WEATHER...Despite below normal temperatures, very dry air
will promote long duration of critical RH values with lowest RH
between 20 and 25 percent. Red Flag Warning continues where ERC
values are highest. Martin county ERC values are suspect (too
high compared to surrounding counties). It is possible a few
additional areas may briefly see Red Flag conditions where 20 ft
winds are 15 mph or greater and RH dips below 35 percent.




Large H100-H70 anticyclone centered south of the ArkLaTex will push
acrs the Deep South/GOMex in the wake of the nor`easter lifting up
the Atlc seaboard. Progress will be slow as the center of the
anticyclone is positioned south of an H30-H20 jet core extending
from the nrn Rockies to the Carolina Coast, allowing the anticyclone
to be the dominant WX feature for central FL thru the upcoming

N/NW flow thru H100-H70 will prevail on Fri, veering to W/SW on Sat
as the anticyclone axis pushes acrs the FL Peninsula and into the FL
Straits. Dry/suppressed air mass will keep PWat values btwn 0.50"-
0.75" on Fri, increasing to 0.75"-1.00" by daybreak Sat as sfc/low
lvl winds shift to onshore, then to the south. H85-H70 profile shows
strong subsidence inversion and dewpoint depressions btwn 10-15C,
suggesting little in the way of meaningful precip chances, but will
go with slgt chc of predawn coastal -shras north of Sebastian Inlet
Sun night into Mon as a backdoor front works its way into the lcl

Gradual warming trend thru the weekend winds shift from a nrly
component to a srly component. Fri max temps in the U60s/L70s and
min temps in the U40s/L50s will be 5-10C blo avg. Temps recovering
to near avg on Sat with max temps in the M70s along the coast, U70s
interior...min temps in the M/U50s except L60s along the immediate
Treasure Coast. W/SW flow on Sun and minimal cloud cover will push
temps back abv avg with max temps in the L/M80s...mins in the

Models continue to bring a backdoor front into the lcl Atlc early
next week, with brisk H100-H70 winds shifting to N/NE by daybreak
Mon, bcmg E/NE by daybreak Tue. Mean RH lvls thru H100-H85
increasing to 80-90pct with onshore flow increasing to arnd 20kts
thru H100-H70. Close proximity of the post frontal high pres ridge
will maintain a strong subsidence inversion in the H90-H70 lyr,
keeping the lcl airmass suppressed and limiting atmospheric
instability. While N/NE flow regimes typically do not result in high
precip coverage for central FL, strength of the onshore component
suggests chc/slgt chc of low-topped shras over the coastal/interior
counties, respectively. Onshore flow will temper any large scale
temp swings, max/mins generally with 5F of climo avg.

Fri-Fri Night...Sfc/bndry lyr winds bcmg a light to gentle N/NW
breeze by midday as high pres approaches the FL peninsula. Seas 3-
4FT over the shelf waters and 4-5FT in the Gulf Stream early mrng,
subsiding to 2-3FT shelf waters and 3-4FT Gulf Stream by early

Sat-Sat Night...Hi pres building over the FL Peninsula in into the W
Atlc will force winds to shift from a light to gentle N/NE breeze at
daybreak to due east by midday, S/SE thru late aftn, then gentle to
moderate S/SW overnight. Seas 2-3FT shelf waters and 3-4FT Gulf

Sun-Sun Night...Shifting winds, esp overnight, as a backdoor frontal
boundary pushes into the lcl Atlc. Gentle to moderate S/SW breeze
thru the day, bcmg W/NW by sunset, bcmg N/NE in the predawn hrs.
Seas generally 2-3FT...up to 4FT in the Gulf Stream. Chc of -shras
dvlpg, with the approaching front, mainly aft midnight.

Mon-Mon Night...Deteriorating boating conds as a NE wind surge
pushes the frontal boundary down the ern seaboard. Gentle to
moderate N/NE breeze at daybreak bcmg moderate to fresh E/NE by
early aftn, contg overnight. Seas building from NE to SW, bcmg
hazardous from Sebastian Inlet northward thru late aftn, then
areawide overnight. Seas north of the Inlet up to 4-6FT nearshore
and 6-8FT offshore in the aftn, then 6-8FT nearshore and 7-9FT
offshore overnight. South of Sebastian Inlet, seas generally 2-3FT
thru the day, up to 4ft in the Gulf Stream, but bcmg hazardous
overnight, building to 6-8FT nearshore and 7-9FT offshore.


DAB  66  42  68  52 /   0   0   0   0
MCO  70  44  72  50 /   0   0   0   0
MLB  68  41  69  52 /   0   0   0   0
VRB  70  43  70  53 /   0   0   0   0
LEE  70  41  73  49 /   0   0   0   0
SFB  68  43  71  49 /   0   0   0   0
ORL  69  45  72  50 /   0   0   0   0
FPR  70  40  70  53 /   0   0   0   0


FL...Red Flag Warning until 8 PM EDT this evening for Indian River-
     Northern Brevard County-Orange-Osceola-Seminole-Southern
     Brevard County.

     Fire Weather Watch from Friday afternoon through Friday evening
     for Okeechobee-Orange-Osceola-Seminole.

AM...Small Craft Advisory until 2 PM EDT this afternoon for Flagler
     Beach to Volusia-Brevard County Line 0-20 nm-Volusia-
     Brevard County Line to Sebastian Inlet 0-20 nm.

     Small Craft Advisory until 10 PM EDT this evening for Flagler
     Beach to Volusia-Brevard County Line 20-60 nm-Sebastian
     Inlet to Jupiter Inlet 0-20 nm-Sebastian Inlet to Jupiter
     Inlet 20-60 nm-Volusia-Brevard County Line to Sebastian
     Inlet 20-60 nm.


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