Area Forecast Discussion
Issued by NWS Melbourne, FL
FXUS62 KMLB 301915
Area Forecast Discussion
National Weather Service Melbourne FL
315 PM EDT Sun Apr 30 2017
...A chance of rain most days this week...
Current-Tonight...Updated grids/zones around noon-time to account
for the isolated shower activity across the area. Will do a pre-
first period package for the afternoon zones to account for this
potential thru sunset. Models/water vapor imagery hint at some
additional deep layer moisture infiltrating the area this
afternoon, along with weak energy and slightly cooler temperatures
aloft. All of this apparently enough to promote the light
precipitation across ECFL with coverage likely remaining below 20
pct overall. The late day/evening sea breeze boundary collision
likely west of Lake Cty. Will keep a small PoP in place along the
Treasure Coast for tonight. Overnight mins remain mild, L70s
inland and L-M70s along the coast as LLVL SE-SSE winds remain
Mon...Generally S/SE surface flow again though winds above the
surface will begin to veer more with the approach of a weak front
into the FL panhandle by late day. This will allow the west coast
sea breeze to penetrate further into the interior than recent days
with the late day/early evening boundary collision near the
Lake/Orange Cty border. PWAT values start off unimpressive early in
the period but are forecast to increase to 1.50-1.70 inches by late
in the day. The western Altc ridge will also weaken a bit. SE/SSE
winds still a bit breezy with 10-15 mph inland/Volusia coast and 15-
20 mph Space/Treasure coasts. There will be higher gusts in the late
morning/afternoon, once again. Still keeping higher PoPs
concentrated further southward on this day, 30 to 40 pct south of
KMLB with 20 to 24 pct northward. There will be an isolated threat
for a lightning storm or two in the afternoon areawide. Mid-upper
level support still not terribly impressive overall for confidence
in going with higher PoPs. Afternoon highs in the M80s along the
coast and U80s/L90s interior.
Tue-Tue Night...(From previous disc) Developed sfc low over the
Grt Lks lifting north into Canada will abandon the srn extension
of its frontal trof leaving it washing out roughly over central
Mid lvl vorticity/upr lvl divergence not particularly strong, but
suitable moisture combined with diurnal heating suggests the best
precip chances for central FL in over almost a month. Still, this
would require temps reaching their convective triggers, which
could be hampered by substantial cloud cover and a brief pd of
northerly winds in the immediate wake of the trof. Will go with
mid range sct PoPs areawide along with a slgt chc for thunder.
Max temps in the M/U80s, mins in the U60s/L70s.
Wed-Sat...Unsettled WX pattern will continue for much of the week
the troffing pattern left in its wake of the initial storm system
prevails acrs eastern CONUS. Additional jet energy will work its way
east from the central/eastern Pacific...latest analysis shows a
zonal 180KT jet just south of the Aleutians that will be the driver
for a second low pressure system to dvlp over the Lwr MS Valley by
Global models suggest the srn extent of the attendant mid lvl trof
extending almost into the Bay of Campeche by 12Z Fri, suggesting the
second system will take a track further SE than the first system.
This will prevent the wrn flank of the Atlc ridge from rebuilding
acrs the Deep South/FL peninsula. As the sfc low tracks up the Mid
Atlc/New England region thru late week, it will have the opportunity
to crank a new frontal boundary into central FL by late week.
GFS continues to track the system further south than the ECMWF, but
is not as aggressive than ECMWF wrt its sfc low. Either way, both
indicate a new frontal boundary and its associated moisture band
working its way thru into central FL by late Fri. Extended numerical
guidance agrees that moisture will be sufficient to support
isold/sct PoPs thru the latter half of next week.
Continue VFR outside of ISOLD -shra/shra activity into
early evening. Keep a small threat for a shower along the Treasure
Coast tonight. SE winds diminish a bit again tonight, but remain
elevated along the Space/Treasure coasts. MOS again hinting at areas
of MVFR CIGS late overnight into early Mon morning. An increase in
moisture is forecast with perhaps a slightly higher threat of shower
activity on Mon and a few TSRA`s possible in the afternoon. S/SE
winds on Mon still a bit breezy at times.
.MARINE...Afternoon-Tonight...Tough call, but will continue marginal
SCA and include north offshore marine leg at 20Z/4PM. Will carry out
the SCA thru 08Z/4AM Mon morning and allow overnight shift to either
extend or opt for Cautionary Statements. Will continue cautionary
statements elsewhere, even for near shore Volusia as Wavewatch
suggests 4 to 6 ft seas late tonight. SE/SSE winds still hovering
near 20 kts with seas around 6 ft across Advisory areas.
Mon...A weak frontal boundary will move into the FL panhandle by the
end of the day. A gradual increase in deep moisture is forecast.
Isolated shower activity will continue across the coastal waters.
Rather poor conditions still continue for small craft with SE/SSE
winds 15-20 kts and seas 5-6 ft over the open Atlc. It will be a
judgement call to go with either an SCEC or SCA for much of the
Tue-Tue Night...Weakening frontal boundary will push into central
FL and stall. Variable winds thru the day as the trof works its
way over the waters...gentle to moderate S/SE breeze ahead of the
boundary, shifting to a light to gentle N/NE breeze in its wake.
Winds shifting back to a light to gentle E/SE breeze arnd sunset,
contg overnight. Seas 2-3FT nearshore and 3-4FT offshore,
subsiding to 2-3FT areawide by sunset. Chc shras, slgt chc tsras.
Wed-Wed Night...Weak post frontal ridge will push east along the
FL/GA boarder thru the day, pushing off the Carolina Coast overnight
to merge with the Atlc ridge. Light to gentle E/SE breeze thru late
aftn, increasing to a gentle to moderate S/SE breeze by midnight.
Seas 2-3FT areawide thru the day, building to 3-4FT overnight. Slgt
Thu-Thu Night...Center of the Atlc ridge axis will push east of
Bermuda as a new storm system dvlps over the OH/TN river valleys.
The system will pull a frontal boundary into the FL Panhandle by
late aftn/early evng and could reach as far as the Big Bend area
overnight. Sfc winds bcmg a moderate to fresh S/SE breeze by midday,
gradually veering to S/SW overnight as the front approaches the FL
Peninsula. Seas 3-4FT thru the day, building to 4-5FT aft
sunset...up to 6FT in the Gulf Stream. Chc shras, slgt chc tsras.
.FIRE WEATHER...Monday...Min RH values expected to remain above
40 percent as low level moisture continues to creep upward. Gusty
SE surface and transport winds will produce high dispersion and
promote rapid spread of any new fires and possible flareups of
existing/smoldering burns or hot spots.
.CLIMATE...Record warm min temperatures in jeopardy (DAB/MLB/VRB)
RECORDS FOR DATE
DAB...72 in 1991 (Currently 75)
MCO...73 in 1991
MLB...73 in 2012 (Currently 77)
VRB...75 in 1991 (Currently 75)
.PRELIMINARY POINT TEMPS/POPS...
DAB 71 87 70 83 / 10 20 40 40
MCO 70 91 72 88 / 10 20 40 40
MLB 75 86 71 85 / 10 20 30 40
VRB 73 86 72 85 / 20 30 30 40
LEE 73 90 74 88 / 10 20 40 40
SFB 70 90 72 86 / 10 20 40 40
ORL 72 90 73 86 / 10 20 40 40
FPR 72 87 70 86 / 20 30 30 40
AM...Small Craft Advisory until 5 AM EDT Monday for Sebastian Inlet
to Jupiter Inlet 0-20 nm-Sebastian Inlet to Jupiter Inlet
20-60 nm-Volusia-Brevard County Line to Sebastian Inlet 20-
Small Craft Advisory until 5 AM EDT Monday for Flagler Beach to
Volusia-Brevard County Line 20-60 nm.