Area Forecast Discussion
Issued by NWS Melbourne, FL

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FXUS62 KMLB 230832

Area Forecast Discussion
National Weather Service Melbourne FL
430 AM EDT Tue Jul 23 2019


...Tropical Depression 3, Offshore East Central Florida, Will Lift
Northeast Away From the Peninsula Later Today...

Current...Surface analysis and radar/satellite imagery place the
center of T.D. #3 offshore the Treasure Coast and lifting northward.
Several bands of showers and squalls are accompanying the system,
however the activity had been moving NNW, remaining just offshore.
Motion of both the cellular and banded convection is now due north,
and is starting to pivot toward N-NNE. With winds being forecast to
continue veering throughout the morning and afternoon, the threat
for showers/TS and associated squally winds will stay just offshore
through the remainder of this morning.

Today-tonight...A deep layer trough will continue to amplify over
the entirety of the eastern CONUS, all the way down into Florida.
This will quickly turn TD #3 north and northeast away from Florida
and also drive a surface cool front anomalously far south, reaching
the Gulf Coast and north Florida by tonight. Ahead of the front, a
deep layer SW flow will develop across the Florida peninsula. High
PWAT air (2.0" - 2.1") coupled with diurnal heating will generate
a WCSB-dominant convective regime, as advertised by local mesomodel
guidance. Numerous fast-moving showers and storms will develop and
reach the interior by early afternoon, then push across central and
eastern side of the peninsula through about sunset. There a could be
a lingering shower or storm a little past 00Z< however expect most
of the activity to be offshore by sunset.

Falling mid level heights accompanied by modest H25 divergence and
increasing steering winds (SW at ~15KT) will support isolated strong
storms with gusty winds/small hail potential (T of only -7C at H50).
max temps in the L90s areawide with mins in the 70s.

Wednesday-Thursday...Tuesday`s TD excitement quickly becomes
yesterday`s news as remnants are more fully absorbed into the
frontal trough that will be trailing down along the Atlantic
Seaboard, draped across north Florida, and onward across the rim of
the northeastern Gulf of Mexico. This frontal trough becomes the new
story as it encroaches upon the area before stalling out. The axis
of the Atlantic high pressure ridge gets shunted south and east
allowing central Florida to be situated in low-level offshore wind
flow ahead of the front. Ample moisture and a sluggish, if not
inhibited, east coast sea breeze should set the stage for convection
favoring the east half of the central peninsula. Storm chances will
be highest for the coastal counties, but likely as well for inland
sections north of Orlando/Kissimmee in closer proximity to the front
itself. Max temperatures in the U80s/L90s, and min temperatures
generally in the L/M70s.

Friday-Monday...The frontal trough remains wedged between the
Atlantic high pressure ridge and sprawling surface high pressure
across the eastern CONUS. The models wish to form a frontal wave or
two along the boundary Friday/Saturday, though upper support seems
dampening in trend. The boundary will become more diffuse despite
moisture remaining well pooled. Synoptically, the flow pattern will
adjust to assume onshore flow once again by the weekend. Higher
pressure builds aloft with somewhat perturbed ridging near the
surface. Daily convection will therefore favor an inland to west
coast skew, aided by an embedded sea breeze. Maritime E/SE flow more
entrenched to start next week, with the door open to potential
westward moving tropical waves (inverted troughs) off the Bahamas.
Max temperatures in the L90s, with min temperatures in the L/M70s
except U70s along the coast from Melbourne southward once the flow
pattern flips back to onshore.


.AVIATION...Expect all aerodromes to have a decent shot of showers
and storms along and ahead of the west coast sea breeze. High PWAT
air mass supporting POPs of 60-70 pct merits inclusion of TEMPO
groups for all aerodromes, with temporal extent (2hr) limited by
quick storm motion toward the NE. Onset/timing for the 06Z package
was based on the 00Z WRF-ARW, which indicated start times that were
2-3hr earlier for the interior aerodromes than the DAB-SUA corridor.


.MARINE...Today-tonight...SCEC expanded northward to include the
Brevard County waters beyond 20NM. South winds 15-20KT and seas to
around 4FT will be higher in squalls and storms, mainly during the
morning, as the center of TD #3 lifts N to NNE through the waters.

There is expected to be a "Round 2" of sorts with diurnal storms
over the peninsula moving offshore late in the afternoon and early
evening, some of which could be strong.

Wednesday-Saturday...SW offshore flow will occur ahead of a frontal
band positioning over north Florida mid-late week. A chance for
strong storms to push offshore during the late afternoon with
concern for gusts to 34 knots or more. The afternoon sea breeze will
be inhibited Wednesday and sluggish on Thursday. Friday and Saturday
will find the boundary stalled over north Florida and becoming
diffuse. This will allow for a return to onshore flow for the local
waters during the weekend.

S-SW winds 10 knots or less through Friday, except with a developed
easterly sea breeze on Friday. Seas 2 feet or less nearshore and 3
feet or less offshore. Winds flip onshore Saturday generally out of
the east. Wind speeds and sea heights maintain aforementioned
values.  Even so, winds and seas will be higher near scattered to
numerous showers and storms.


DAB  91  74  88  73 /  70  30  70  50
MCO  92  75  89  74 /  60  10  70  40
MLB  91  76  89  75 /  60  30  70  30
VRB  92  73  91  73 /  60  30  70  40
LEE  92  75  88  74 /  60  10  70  50
SFB  92  74  89  73 /  60  10  70  40
ORL  92  75  89  75 /  60  10  70  40
FPR  92  73  91  73 /  60  30  70  40




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