Area Forecast Discussion
Issued by NWS Melbourne, FL
FXUS62 KMLB 222123
Area Forecast Discussion
National Weather Service Melbourne FL
425 PM EST Sun Jan 22 2017
...Potentially Rare & Significant Severe Weather Event This
Short Term...All eyes remain focused on the potential for a rare
and significant severe weather event taking shape across the
central and northern Florida Peninsula. A significant upper level
system will move over the Mississippi Valley and aid in the rapid
deepening of low pressure over the southeast tonight. Increasingly
favorable wind and shear profiles are expected to align and lead
to a very active late afternoon and evening period across the
forecast area. Low/mid layer flow will continue to increase to
65-70 knots through late afternoon, with 850mb winds as high as
50-60 knots across northern sections by 21-00Z. The strengthening
environmental wind profiles and shear will support very fast
moving storms with the potential for damaging winds and also
isolated strong to violent (EF2+) tornadoes. Some of these have
the potential to be long tracked and significant. Tornado Watches
will likely go into effect shortly.
Expect threats to evolve from two different modes of convection,
including the potential for isolated supercell development out
ahead of a organized and powerful squall line that will begin to
move through after sunset. Pre-squall line convection will
continue to develop in an increasingly favorable environment along
and north of the I-4 corridor through sunset. The squall line is
expected to approach our westernmost areas between 23Z-00Z and
quickly pushing to the south and east from there, pressing off the
Treasure Coast around or slightly after midnight.
Short-lived intense rainfall can also be expected but given the
fast forward motion, amounts should not be excessive with
widespread one half inch accumulations and locally up to 2 inches.
Will maintain a small chance for showers and thunderstorms past
midnight as upper level energy in association with the parent low
passes over the state. In fact, more recent runs of some mesoscale
models indicate additional low-topped convection developing over
the Gulf and moving across the Peninsula toward sunrise. It should
be noted that while some strong wind gusts may accompany these
showers, any severe weather threat will have passed.
Monday...Windy conditions will exist across the area Monday as a
strong westerly flow ushers in drier/cooler air behind the front.
Another Wind Advisory may be needed across the area as winds are
forecast to reach near 25 mph with gusts to 30-35 mph. Lingering
low clouds and areas of light rain/isolated showers may continue
into the morning hours as axis of low aloft pushes across the
state. Rain chances should then end into the afternoon, with skies
gradually clearing into the evening. Highs will reach the low to
mid 70s with temperatures falling into the upper 40s to low 50s
over much of the region Monday night.
Tuesday-Wednesday...High pressure will approach the area from the
west Tuesday, then will continue eastward across the state and
offshore into mid week. This will lead to decreasing winds through
the period, shifting from the W/NW Tuesday to S/SW on Wednesday.
Drier airmass across the area will keep rain chances out of the
forecast, and temperatures will gradually increase from near normal
on Tuesday/Tuesday Night to slightly above normal into Wednesday.
Thursday-Saturday...Warmer than normal conditions will continue
across the area Thursday before a cold front moves southward through
the region late in the day through Thursday night. Rain chances
remain rather low with this frontal passage, and any rainfall looks
to be rather light. Cooler/drier conditions then expected across
the area behind the front late week into Saturday.
Strong south to southwest flow, with sustained surface winds 20-25
kts gust 30-35 knts will continue ahead of a developing squall
line over the eastern Gulf of Mexico. Rapidly deterioratingconditions
are anticipated late this afternoon and especially sunset as the
squall line approaches from the west. Expect squall line to
approach KLEE between 23Z-00Z and move rapidly to the south and
east, exiting the Treasure Coast after 05Z-06Z.
Today/Tonight...Gale Warning will go into effect at 4PM/21Z as winds
increase to 30-35 knots offshore this evening and overnight.
Frequent gusts to Gale Force (34 knots) expected over the
nearshore waters. Seas building to 7 feet this afternoon
offshore, then 10-11 feet tonight. The offshore flow will suppress
seas nearshore to 4-5 feet.
Monday...Very hazardous boating conditions will continue across
the waters, as strong W/NW winds up to 25-30 knots persist,
maintaining seas of 9-11 feet offshore. A Gale Warning will remain
in effect over the waters through the late evening.
Tuesday-Thursday...High pressure will shift eastward across the Gulf
Tuesday and then cross the state and push offshore into mid week.
This will allow W/NW winds and seas to gradually decrease into
Tuesday, but poor to hazardous boating conditions will likely
persist. As winds decrease even further and switch to the S/SW into
mid week, boating conditions will become more favorable.
.PRELIMINARY POINT TEMPS/POPS...
DAB 60 71 49 70 / 90 20 0 0
MCO 62 72 51 72 / 90 20 0 0
MLB 63 75 49 72 / 90 20 0 0
VRB 65 74 52 74 / 90 20 10 0
LEE 60 70 50 70 / 90 20 0 0
SFB 62 72 50 73 / 90 20 0 0
ORL 62 72 51 72 / 90 20 0 0
FPR 64 75 48 74 / 90 20 10 0
FL...Wind Advisory until midnight EST tonight for Coastal Volusia
County-Indian River-Inland Volusia County-Martin-Northern
Brevard County-Northern Lake County-Okeechobee-Orange-
Osceola-Seminole-Southern Brevard County-Southern Lake
AM...Small Craft Advisory until 4 PM EST this afternoon for Flagler
Beach to Volusia-Brevard County Line 0-20 nm-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 0-20
nm-Volusia-Brevard County Line to Sebastian Inlet 20-60 nm.
Small Craft Advisory from 11 PM Monday to 9 AM EST Tuesday for
Flagler Beach to Volusia-Brevard County Line 0-20 nm-
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 0-20 nm-Volusia-Brevard County Line to
Sebastian Inlet 20-60 nm.
Gale Warning until 11 PM EST Monday for Flagler Beach to Volusia-
Brevard County Line 0-20 nm-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 0-20 nm-
Volusia-Brevard County Line to Sebastian Inlet 20-60 nm.