Area forecast discussion
National Weather Service Melbourne Florida
1030 am EDT Friday may 24 2013
Discussion...
Latest analysis shows central Florida about to undergo a late Spring
airmass change: a weak frontal boundary pushing across the Florida Panhandle
embedded within a moderate north/northwest breeze through the h100-h70 layer.
Morning soundings show precipitable water values decreasing from 1.4" at kmfl...to
1.2" at ktbw...to 1.0" at kjax. H100-850 mb mean relative humidity values around 70pct
in the immediate vicinity of the boundary...but limited prefrontal
loading with central Florida values dropping below 60pct. Middle/upper level
analysis shows limited potential middle level vorticity advection as well
as a 70kt h30-h20 jet streak over the deep south positioned to place
the Central Peninsula under its descending right front quadrant.
What little precipitation may occur today will be limited to the Treasure
Coast and the Lake Okeechobee region where low level moisture is
highest and will take the longest to scour out. Indeed...latest
numerical guidance keeps surface dewpoints in the M/u60s S of ktix-kism
through late afternoon. Even so...the lack of middle/upper level dynamic support
means any precipitation will be dependent on mesoscale boundary
interaction...specifically the East Coast sea breeze. Given the wrly
synoptic wind component...this will not occur until middle afternoon.
Convective initiation will have a late start...current forecast around 20z
looks reasonable.
Despite the nearly wind component...with the Summer solstice less than
a month away...near full sun will allow maximum temperatures to warm into the
u80s along the coast...l/m90s inland.
&&
Aviation...
VFR all sites unless otherwise noted. Between 24/20z-25/01z...isolated
MVFR rain showers/IFR thunderstorms and rain showers S of kmlb-kbow. Between 25/09z-25/13z...local IFR
visibilities/ceilings in shallow mifg north of ktix-kism.
&&
Marine...
this afternoon...frontal trough pushing off the eastern Seaboard will generate
a gentle to moderate west/northwest breeze through late morning...becoming north/northwest through
the afternoon as the front pushes into the central Florida Peninsula. Latest
buoy observation show seas below 2ft nearshore and 2-3ft offshore...seas up to
4ft possible in the Gulf Stream as the winds shift to the more nearly
component. No sig changes necessary with the morning update.
Tonight...(prev disc)
local gradient will tighten late tonight as a ridge builds into the
region...with northeast winds coming up to 15-20kts after midnight
tonight. Seas 2-3ft nearshore and 3-4ft offshore through late
tonight...building to 3-5ft north of Sebastian Inlet and 2-4ft S of the
inlet by daybreak Sat.
&&
Mlb watches/warnings/advisories...
Florida...none.
Am...none.
&&
$$
Short term/aviation...bragaw
long term/impact weather...pendergrast
