National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

241
FXUS62 KMLB 251909
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
308 PM EDT Mon Sep 25 2017

.DISCUSSION...

...Rip Current Risk Expected to Remain High into Mid Week...

Current-Tonight...Dry mid level air is taking a toll on vertical
convective development with some towering cumulus along the east
coast sea breeze and lake breeze boundaries inland but have not seen
much in the way of showers today. Will lean away from the wetter GFS
and NAM into the evening and trend closer to the HRRR which has some
isolated showers at best into this evening which should dissipate
into the late evening hours. Light NW-NNW flow at the H9 layer and
dry mid levels in the wake of Maria moving well away from the area
should allow skies to become mostly clear to partly cloudy. Lows are
expected in the lower to mid 70s.

Tuesday...Moisture levels on Tuesday look similar to today when we
did see much convection at all with PWATs ~1.7 inches. Low level
wind are forecast to be NW with fairly dry air lingering in the mid
levels. Overall should be fairly dry but will continue a slight
shower chance across the south where GFS does show some higher
moisture values and perhaps a mid level impulse in the SW/WSW flow
at 500 mbs. High temps will remain warm around 90 coastal to lower
90s interior.

12Z guidance did not necessitate any substantive changes to
weather/pops through the mid and extended time ranges. Previous
discussion follows...

Wednesday-Thursday...Anomalously dry air filtering down the backside
of Maria will keep prospects for precipitation quite low for late
September. Should any showers manage to form, they would likely
occur over southern areas where slightly better atmospheric moisture
will exist in the presence of sea/lake breeze interactions. Thunder
was kept out of the forecast through Wednesday, with a slight chance
advertised Thursday as deeper moisture encroaches into the Treasure
Coast and Okeechobee county. High temperatures will be several
degrees above their late September averages, even along the coast
where light westerly flow will warm temps to 90-91 before the sea
breeze provides some mid/late afternoon relief.

Friday-Sunday...Guidance indicates a gradual uptick in moisture from
south to north late this week. At the same time, shortwave energy
aloft will try to cut off into a weak low over the peninsula,
providing both lift and instability. Will show a steady increase in
PoPs, initially 30-40% on Friday with higher chances across the
south, building to 50% areawide this weekend. Increased cloud cover
and developing onshore flow will drop temperatures from their mid-
week highs, still near 90 over inland areas on Friday, otherwise mid-
upper 80s expected.

&&

.AVIATION...
Appears any isold SHRA will be meager at best across east central FL
into the early evening hours. VFR conds expected through 18z Tuesday.

&&

.MARINE...
Tonight...Small Craft Advisory headlines will transition to a Small
Craft for Hazardous Seas as winds continue to decrease through the
overnight hours though large ENE/NE swells will continue to affect
the near shore and offshore waters. Seas up to 7-9 ft nearshore and
10-12 ft well offshore.

Tue-Fri...Swells from Hurricane Maria will gradually subside from
mid to late week, though advisory headlines for seas greater than 7
feet will be required through at least Wednesday afternoon
(especially offshore). Winds remain at or below 10 knots, starting
from the west each morning before turning onshore near the coast as
the Atlantic sea breeze develops. Abnormally dry air will keep
precipitation chances quite low through at least Thursday.

&&

.HYDROLOGY...
Single Creek at Campbell has fallen below action stage and a slow
fall of the creek level is expected into mid week.

A River Flood Warning remains in effect for the St Johns River near
Cocoa, above Lake Harney near Geneva, near Sanford, near Deland and
at Astor.

River levels remain high over the middle St Johns River Basin with
all forecast points above flood stage. The river stage at all
forecast points along the river will remain steady over the next
couple of days, with a very gradual decline beginning in the middle
part of this week.

Major flooding also continues above Lake Harney near Geneva.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  72  89  72  92 /   0  10  10  10
MCO  73  93  73  94 /  10  10  10  10
MLB  74  91  73  91 /  10  10  10  10
VRB  72  90  72  91 /  20  20  20  10
LEE  73  91  73  94 /  10  10  10  10
SFB  74  93  73  95 /  10  10  10  10
ORL  75  93  75  95 /  10  10  10  10
FPR  71  91  71  91 /  20  20  20  10

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...High Surf Advisory until 10 PM EDT this evening for Coastal
     Volusia County-Indian River-Martin-Northern Brevard County-
     Southern Brevard County-St. Lucie.

AM...Small Craft Advisory until 10 PM EDT this evening 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 for hazardous seas from 10 PM this evening
     to midnight EDT Tuesday night for Flagler Beach to Volusia-
     Brevard County Line 0-20 nm-Sebastian Inlet to Jupiter
     Inlet 0-20 nm-Volusia-Brevard County Line to Sebastian
     Inlet 0-20 nm.

     Small Craft Advisory for hazardous seas from 10 PM this evening
     to 4 PM EDT Wednesday for Flagler Beach to Volusia-Brevard
     County Line 20-60 nm-Sebastian Inlet to Jupiter Inlet 20-60
     nm-Volusia-Brevard County Line to Sebastian Inlet 20-60 nm.

&&

$$

SHORT/MID/LONG TERM...Volkmer
AVIATION/IMPACT WEATHER...Glitto