Area Forecast Discussion
Issued by NWS Melbourne, FL
FXUS62 KMLB 261910
Area Forecast Discussion
National Weather Service Melbourne FL
310 PM EDT THU MAY 26 2016
...Increasing Rip Current threat this weekend...
Hi pres ridge extending down the Carolina coast into the NE GOMex
will maintain a steady E/NE flow thru the H100-H70 lyr overnight.
Latest RAP40 displays this well with very dry air mid lvl air (avg
H85-H50 RH values remain aob 20pct), as well as a strong low/mid lvl
thermal cap (H85-H70 lapse rates aob 3.0C/KM). However, low lvl
moisture has become concentrated enough to drive H100-H85 dewpoint
depressions blo 3C acrs the lcl Atlc. This has allowed isold shras
to dvlp over the Gulf Stream and press toward the E FL coast.
Little change anticipated in current prevailing WX features tonight.
Mid/upr lvl dynamic flow is quite weak with negligible vorticity
thru the H85-H30 lyr and a convergent H30-H20 lyr. Nevertheless,the
increased low lvl moisture and depth of the onshore flow may allow a
few shras to dvlp in the coastal convergence zone. Measurable
precip will be far more the exception than the rule, however, as the
lack of support combined with the thermal cap will effectively limit
vertical growth BLO 10kft. Furthermore, E/NE flow regimes do not
favor deep convection...nothing more than brief pds of light to
moderate rain in low-topped showers. Steady onshore flow will keep
temps in the M/U60s interior...U60s/L70s along the coast.
Late week attention remains focused on the development and track the
incoming area of disturbed WX encroaching on the central/srn
Bahamas. NHC guidance continues to indicate an increasing chance for
this system to dvlp into a tropical/subtropical system on Fri as it
passes NE of the nrn Bahamas and makes a beeline for the Carolina
coast through Sat.
This track would put central FL in its peripheral subsidence region
that would tend to suppress precip. Indeed...winds thru the H100-H70
lyr will back to the N/NE as the system makes its closest approach
to the FL peninsula. However...this track also will erode the wrn
flank of the Atlc ridge while allowing PWAT values to increase to
1.25"-1.50" by 00Z Sat...and to arnd 1.50" by 00Z Sun.
Users should note that while direct impacts from this system are not
expected...its anticipated track would generate a NE long pd swell
over the lcl Atlc that will raise rip current threats along area
beaches as the Memorial Day weekend approaches.
Will go with 20/30 PoPs Fri...increasing to 30 PoPs Sat. Will limit
the use tsras to slgt chc given the increasing NE flow regime into
the weekend. Tempted to go higher on Sat...but it appears peninsula
will get caught in a col on the system`s srn flank that will
collapse the mid lvl steering flow. While this would favor the
formation of the east coast sea breeze...any shra/tsras that do form
most likely would dvlp and die in place.
Max temps near avg (U80s/L90s) except M80s along the immediate coast
due to the onshore flow. Those same winds will keep min temps AOA
Departing low pressure to the north of the area will leave a loosely
organized pressure pattern regionally with a setup favoring
development of breeze boundaries each afternoon. Presence of near
seasonal precipitable water values will lead to diurnal storms
similar to what one would expect with the wet season fully underway.
Sfc Winds: Thru 27/00Z...E/NE 12-15KTS with ocnl G18-22KTS. Btwn
27/00Z-27/03Z...bcmg NE 3-5KTS. Btwn 27/13Z-27/16Z...bcmg E/NE
Vsbys/WX/Cigs: Thru 27/12Z...S of KVRB slgt chc MVFR shras. Aft
27/12Z...S of KMLB-KISM chc MVFR shras...N of KMLB-KISM slgt chc
Tonight...Hi pres ridge axis extending from the NC Outer Banks to
the NW GOMex will maintain a gentle to moderate E/NE breeze
overnight. Seas generally 3-4FT. Isold/sct shras in the Gulf
Stream mvg onshore.
Fri-Fri Night...Gentle to moderate E/NE breeze contg as an Erly wave
approaching the Srn Bahamas slowly dvlps into a closed low and lifts
NW toward the Carolina Coast. Seas 3-4FT nearshore and 4-5FT
offshore. Isold/sct shras.
Sat-Sat Night...Storm system will pass well N of the lcl Atlc
waters...but secondary effects may be felt in the form of a NE swell
that will enhance the lcl seas. Light to gentle E/NE breeze thru the
day...bcmg light W/SW overnight as the system approaches the
Carolina Coast. Seas 3-4FT areawide...up to 5FT in the Gulf Stream.
Chc shras/slgt chc tsras.
Sun-Sun Night...Lcl Atlc will be caught in a col on the storm
system`s Srn flank...resulting in a weak pgrad that will generate
shifting winds. Sfc/bndry lyr winds bcmg a light to gentle N/NE
breeze thru midday...light to gentle E/SE thru sunset...then light
to gentle S/SW overnight. Seas 3-4FT N of Sebastian Inlet...2-3FT S
of the Inlet. Chc shras/slgt chc tsras.
Mon-Tue...Storm system will gradually break down over the
Carolinas...allowing sfc hi pres ridge to reestablish itself over
the central/south FL peninsula. Prevailing light to gentle Srly
breeze...meandering btwn SE-SW with the formation of the diurnal
seabreeze/nocturnal land breeze. Seas subsiding to 2-3FT by Mon
aftn...contg thru Tue. Chc shras/slgt chc tsras.
.PRELIMINARY POINT TEMPS/POPS...
DAB 72 82 68 86 / 10 20 20 30
MCO 67 88 70 90 / 10 20 10 40
MLB 73 84 72 85 / 10 20 30 30
VRB 73 84 70 87 / 10 30 30 30
LEE 66 90 69 92 / 10 20 10 30
SFB 66 87 68 90 / 10 20 10 30
ORL 67 86 70 90 / 10 20 10 30
FPR 73 84 70 86 / 10 30 30 30