Area Forecast Discussion
Issued by NWS Melbourne, FL
FXUS62 KMLB 242000
Area Forecast Discussion
National Weather Service Melbourne FL
400 PM EDT Mon Apr 24 2017
By mid aftn, the cold front extended from New Smyrna Beach to Venice
y mid aftn with isold low-topped shras pushing south of the I-4
Corridor. Double barreled sfc low consolidating off the Carolina
Coast is part of a deep cutoff low centered over south GA that will
crank the front into south FL by around sunset.
Latest profiler data shows brisk W/SW flow acrs central FL with mean
H100-H70 winds btwn 25-30kts. These winds will tap a dry and very
stable airmass over the GOMex...RAP40 analysis showing H100-H70 mean
RH values AOB 60pct and H85-H70 lapse rates blo 1.0C/KM encroaching
on the west FL coast. Model soundings show a massive subsidence
inversion dvlpg in the H85-H70 lyr over central FL by sunset that
only gets stronger by daybreak...theta-e values thru the layer arnd
20C at 00Z, increasing to arnd 25C by 12Z.
Westerly flow will push what little shra activity remains offshore
well before sunset...fcst will have zero PoPs. Dewpoints dropping
into the L/M50s behind the front will make for comfortably dry
conditions. Pgrad will slacken overnight as the low pulls up the east
coast, but should remain tight enough to prevent decoupling. Min
temps in the M/U50s...near 60 along the coast. Westerly flow and
near full sun on Tue will push aftn temps in the L/M80s, near avg
for late Apr.
Winds will take on a more southerly component by mid to late week as
the axis of a high pressure ridge settles closer to the central
Florida Peninsula. Gradient appears weak enough to allow for an
afternoon seabreeze to form, enhancing onshore flow closer to the
coast each afternoon. No prospects for showers during this time
frame as moisture appears too low. Southerly flow combined with
ample daytime heating will allow temperatures to climb warmer each
afternoon, up to 90 across the interior by Thursday.
High pressure building across the western Atlantic toward the
southeast will maintain onshore/SE flow into the weekend. GFS
indicates some moistening of the low levels during the beginning of
the period as a weakening front moves toward the state; however, not
enough to include mentionable rain chances at this point. Maritime
flow would suggest isolated showers pushing onshore off the
Atlantic, and perhaps if moisture levels are high enough some pop-up
showers over the interior. Coverage appears low enough to maintain a
dry forecast at this venture.
Temperatures late this week through the weekend will be running
warmer than average for late April, which should be in the low/mid
80s. Highs will climb to near 90/lower 90s inland each day and
mid/upper 80s at the coast before the sea breeze puts a lid on the
temperature climb. Overnight mins will be running noticeably warmer
than the lower 60s that are normal for late April, with lows ranging
from the mid/upper 60s inland to lower 70s at the coast.
Sfc Winds: Thru 25/00Z...W/SW 10-14KTS with fqnt G21-25KTS. Btwn
25/00Z-24/03Z...bcmg W/SW 5-9KTS. Btwn 25/12Z-25/15Z...bcmg W/NW 8-
Vsbys/WX/Cigs: Thru 25/00Z...Prevailing cigs btwn FL040-060...E of
KISM-KDAB isold MVFR shras/brief IFR vsbys in +RA.
Tonight...Cold front just south of the I-4 Corridor will push south
of Jupiter Inlet/Lake-O by sunset under the influence of a brisk
westerly flow aloft. Newly deployed Canaveral buoys still showing
W/SW winds arnd 10kts as of mid aftn, but these are expected to
increase rapidly behind the fropa. Moderate to fresh westerly breeze
overnight as the front pushes south of Jupiter Inlet. Limited fetch
due to the offshore winds will keep seas AOB 6FT, but will generate
choppy to rough, short pd chop. Conditions will require the
continuation of a cautionary statement over the open waters...seas 2-
4FT within 20NM and up to 6FT offshore.
Tuesday...Pgrad will slacken as the low pressure system lifts up the
eastern seaboard. Moderate to fresh westerly breeze at daybreak bcmg
light to gentle by midday...then veering to S/SW in the aftn. Seas
subsiding to 2-4FT nearshore and 4-5FT offshore by early aftn.
Wed-Sat...Persistent Atlantic ridge axis in the vicinity of the
central Peninsula will keep local waters in south/southeast flow at
or below 15 knots through the period. Expect some local enhancement
closer to the coast each afternoon with the development of the
Atlantic sea breeze. Seas mainly 2-3 ft nearshore and up to 4 ft
Dry forecast through the weekend with steadily increasing
temperatures. RH values are forecast to drop into the mid 30s
Tuesday afternoon across inland areas with continued westerly flow,
though lighter than today. Minimum RH values will remain in the
mid/upper 30s through late week well inland from the coast as winds
transition to the south and then southeast. Winds appear light to
enough to allow for the development of a sea breeze each afternoon.
.PRELIMINARY POINT TEMPS/POPS...
DAB 59 83 60 84 / 0 0 10 0
MCO 59 85 60 87 / 0 0 10 0
MLB 61 83 61 82 / 0 0 10 0
VRB 61 84 60 82 / 10 0 10 0
LEE 59 85 60 86 / 0 0 10 0
SFB 60 86 61 87 / 0 0 10 0
ORL 62 85 61 87 / 0 0 10 0
FPR 59 84 60 82 / 10 0 10 10
Long Term/Impact WX...Ulrich