Scientific Forecaster Discussion
fxus62 kmlb 210659
Area forecast discussion
National Weather Service Melbourne Florida
259 am EDT Fri Jul 21 2017
..another round of storms again this afternoon...
Today and tonight...little change in the regional pattern today will
lead to a persistent forecast as a favorable wet season SW flow
pattern combines with daytime instability to produce sct to
numerous afternoon storms. A mid level circulation/low moving wwd
toward the NE Gulf wl provide unsettled conditions with slightly
cooler temps aloft. This will lead to the chance of a few stronger
storms with hail and downburst winds through mid-afternoon. Storm
level steering winds out of the SW wl move activity to the Florida East
Coast and Atlc waters during the late afternoon and into evening
with storms over land coming to an end by around midnight. Expect
highs in the l90s and lows tonight in the m70s.
Sat-sun...remnants of weak mid-level low will continue to retrograde
along the Gulf Coast states, west of Florida, to across southeast
Texas during the period. Other mid-level energy along the east Florida
coast will drift northward slowly to off of the northeast FL/SC
coasts. The flow aloft remains light zonal. Latest model runs do not
shift the low-level Atlantic ridge axis quite as far north, but do
shift it towards the central Florida Peninsula. Precipitable water values still soar to
around or just in excess of two inches. Storm steering flow remains
mainly out of the southwest at up to 10 mph. With periodic impulses
aloft and 500 mb temperatures forecast -7c to -8c, see no reason
while we would not see scattered-numerous (50-60pct) afternoon/early evening
thunderstorms daily. Sea breezes/daily heating should both promote
convective development by late morning/early afternoon across ecfl.
Highs will be low 90s with lows in the lower to mid 70s.
Mon-Thu...the low-level ridge axis is forecast to lie between
central/south-central Florida thru this time. Deep layer moisture values
sufficient enough to continue at least scattered mention for daily
afternoon/early evening showers/storms. The storm motion is forecast
to be of a light westerly component, though late day boundary
collisions may make storm motion chaotic at times. Continue to see
daily threats from storms to include torrential downpours leading to
nuisance minor flooding over areas that have recently seen heavy
rainfall, gusty winds, frequent cloud to ground lightning in a few
storms, as well as small hail. Cannot rule out a couple of locally
strong storms each day. 500 mb temperatures still forecast around -
6c/-7c each day. Seasonal temps in the m70s for lows and highs in
the l90s expected.
early development of showers/storms is expected along the coastal sea
breeze, with activity forming further inland through afternoon.
Cig/vsby reductions to tempo MVFR conds and brief IFR wl be
possible mainly from early through mid-aftn at all sites.
today and tonight...the surface wrn Atlc high will remain
centered just to the south of the local waters for one more day,
keeping winds light out of the south. An onshore sea breeze wl
develop during the afternoon. Seas 1-2 feet, occasionally 3 feet
Another round of lightning storms forecast to develop close to
the intracoastal waters, especially along the space and Treasure
coasts. Mariners are reminded that sudden wind shifts and choppy
seas can occur in and near lightning storms.
Sat-Tue...the low-level Atlantic ridge axis generally around central
Florida through this time. Winds will vary from S/southeast during the day to
S/south-southwest in the evening/overnight with speeds at or below 15 kts. Seas
generally 2 ft very near shore and up to 3 ft offshore (occasionally
4 ft well offshore). Biggest threat to mariners will be from
night/morning Gulf Stream convection and late morning/afternoon-
early evening convection along the East Coast intracoastal/near
shore Atlantic waters.
Preliminary point temps/pops...
dab 91 74 91 74 / 50 30 50 30
mco 93 75 93 74 / 60 30 50 30
mlb 90 73 90 74 / 50 30 60 30
vrb 90 73 90 74 / 60 30 60 30
Lee 94 76 92 76 / 50 20 50 20
sfb 94 75 93 75 / 50 30 50 30
orl 94 76 92 75 / 60 30 50 30
fpr 90 73 90 73 / 60 40 60 30