Area Forecast Discussion
Issued by NWS Melbourne, FL
FXUS62 KMLB 201855
Area Forecast Discussion
National Weather Service Melbourne FL
255 PM EDT Thu Oct 20 2016
...Cooler temperatures on the way this weekend with lows in the 50s
away from the coast...
Tonight/Friday...No change to the premise of the short range (first
24hr) forecast. Tightening low pressure area centered northeast of
the Bahamas will lift steadily northward tonight/Friday, with local
winds backing to north and northwest ahead of an approaching cold
front. Resultant continental trajectory of relatively drier air
coupled with minimized low level convergence ahead of the cold front
should negate any threat for precip. With clearing skies tonight and
mostly sunny to partly cloudy tomorrow.
Cooler temps on tap overnight with lower to middle 60s inland and
only upper 60s along the coast. Maxes in the middle to upper 80s.
Modified Previous Discussion...
Sat-Sun...High pressure centered over the lower Mississippi Valley
will extend eastward across the southeast U.S. into the weekend
behind the cold front. This will allow winds to veer from the north
Saturday to northeast into Sunday. The more northerly flow early in
the weekend will continue to transport drier air/cooler temps into
the region. Coolest temperatures expected into Saturday night/early
Sunday with lows in the 50s over much of the area, except low/mid
60s across coastal sections south of the Cape where low level
onshore flow will keep temps a tad warmer. These temperatures will
be some of the lowest seen in the region since early May of this
year. Highs each day will be around 5 degrees below normal ranging
from the mid 70s to around 80 degrees.
Mon-Wed...High pressure north of the area will weaken as a back door
front approaches and moves through the area toward mid week. Airmass
remains dry enough to keep PoPs out of the forecast Monday and
Tuesday, but increasing moisture and onshore flow with the weak
boundary will introduce lower end rain chances by Tuesday night and
Wednesday. Onshore flow will allow temperatures to moderate back to
more normal values for this time of year with highs reaching back
into the low 80s and lows in the 60s, except low 70s along the coast
south of the Cape.
Tonight/Friday...winds will maintain their speeds (13-18KT) as they
back to north tonight and northwest on Friday. Both the WNWAVE and
NWPS model guidance keep seas right at 7FT offshore/over the Gulf
Stream, so will need to extend the "SCA for seas" one more cycle
past tonight (through 18Z/2PM).
Sat-Mon...Northerly wind surge up to 20 knots behind the cold front
will continue into the first half of Saturday, keeping boating
conditions poor especially offshore and in the Gulf Stream. Winds
will gradually veer and develop a slight onshore component by Sunday
while decreasing to around 15 knots. Given the northerly component,
seas will remain choppy, especially in the vicinity of the Gulf
Northerly winds then gradually decrease into early next week as they
continue to the veer to the northeast Monday. Wave heights will also
slowly decrease to 4 feet or less.
The St. Johns River at Astor (2.88ft) remains in Minor Flood Stage
this afternoon while continuing a very gradual fall. The river is
forecast to fall below flood stage (2.8 ft) by Friday, remaining
above Action Stage (2.5ft) through this weekend, possibly falling
below action stage from the early to middle part of next week.
At Geneva/above Lake Harney, the St. Johns River will remain near
7.0ft through this weekend, keeping it in Action Stage.
.PRELIMINARY POINT TEMPS/POPS...
DAB 65 86 61 77 / 10 10 10 0
MCO 65 86 60 78 / 0 10 10 0
MLB 68 85 65 79 / 10 10 10 0
VRB 66 85 65 80 / 10 10 10 0
LEE 64 86 58 78 / 0 10 10 0
SFB 65 87 60 78 / 10 10 10 0
ORL 65 86 60 79 / 0 10 10 0
FPR 67 85 64 80 / 10 10 10 0
AM...Small Craft Advisory for hazardous seas until 2 PM Friday
from Flagler Beach to Jupiter Inlet 20-60 nm offshore.
LONG TERM./IMPACT WX...Ulrich