401 
FXUS62 KMLB 121530
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
1030 AM EST Sun Nov 12 2017

.DISCUSSION...

Latest RAP40 analysis shows a deep H100-H70 anticyclone centered 
over the Carolinas with its axis extending SW into the FL Big Bend 
area, a stalled frontal boundary draped over the south FL Peninsula 
extending from just south of Tampa Bay to Stuart, and high mean RH 
values thru the H100-H70 lyr over much of the central peninsula. 
Morning RAOBs revealed a saturated airmass thru H100-H70...PWat 
values btwn 1.25"-1.50", almost all of which is trapped blo a sharp 
subsidence inversion arnd the H70 lvl. Latest wind profiler data 
shows a solid 20-25KTS of E/NE flow thru 5KFT. 

With the brisk onshore flow tapping the deep low lvl moisture, 
intermittent light to moderate shras continus to push onshore arnd 
25KTS...bulk of the activity south of Orlando/Cape Canaveral. Rapid 
motion has limited the QPF potential with most areas generally AOB 
0.10"...lcl amounts arnd 0.25". Lcl JAX/MIA pgrad has slackened 
slightly to btwn 6-7MB, and will continue to do so thru the day as 
the ridge axis over the SE CONUS steadily weakens. 

Aside from the diminishing winds thru late aftn, the overall WX 
pattern is largely unchanged. Slightly lower mean RH values north of 
Orlando/Cape Canaveral will keep precip chances btwn 20-40pct, while 
deeper moisture and enhanced lift in the vcnty of the frontal 
boundary will keep precip chances btwn 50-60pct over the Treasure 
Coast/Lake-O region. With high moisture trapped blo the H70 
inversion, skies will be cldy/mostly cldy, keeping max temps largely 
in the 75-80F range. 

Poor beach conditions this aftn as the fresh onshore flow generates 
rough pounding surf with large breakers btwn 5-7FT. This will pile 
water behind the sand bar, leading to a frequent and dangerous rip 
currents. A High Surf Advisory in effect thru 6 PM, a few hours 
beyond the next high tide cycle.

&&

.AVIATION...Thru 13/12Z.
Sfc winds: Thru 12/23Z...coastal sites E/NE 15-19KTS with fqnt G22-
26KTS...interior sites E/NE 11-15KTS with ocnl G18-22KTS. Btwn 
12/23Z-13/02Z...coastal sites bcmg NE 8-12KTS with ocnl G18-22KTS... 
interior sites bcmg NE 6-10KTS. Btwn 13/02Z-13/05...bcmg NE 4-7KTS. 

Vsbys/WX/Cigs:  Prevailing CIGS btwn FL040-060 all sites. Thru 
13/00Z...S of KTIX-KISM ocnl MVFR vsbys/cigs in -RA/RA brief IFR 
vsbys/cigs in RA/BR...N of KTIX-KISM...chc MVFR shras/IFR +shras. 
Aft 13/00Z...S of KTIX-KISM sct MVFR shras/lcl IFR vsbys/cigs in 
RA/BR...N of KTIX-KISM slgt chc MVFR shras areas MVFR/lcl IFR vsbys 
cigs in BR.    

&&

.MARINE...
Hi pres ridge over the Mid Atlc/Deep South has become elongated over 
the past 24hrs, weakening in the process. Even so, lcl pres field 
remains quite tight with a 6-7MB gradient btwn KJAX-KMFL, capable of 
maintaining a solid 20-25KT E/NE flow. Lcl data buoys show little 
change in overall conditions over the past 12hrs with seas running 
10-12FT in the Gulf Stream, 7-9FT over the shelf waters. While a 
gradual diminishing wind/sea trend is expected late today-tonight, 
strong SCA conditions will remain in place thru sunset. No changes 
to the current SCA configuration. 

&&

.HYDROLOGY...(prev disc)
The Saint Johns River at ASTF1 has risen further to 2.90FT due to 
continued impedance/backup of the northward current by the strong 
winds. With flow having veered more easterly/onshore, there has been 
some delay in the gauge response, since the flow rate has increased 
from around 10kcfs to 11.5kcfs since late Friday, even as the river 
level there has continued to rise. Elsewhere within the MLB HSA, the 
river level has continued to slowly drop.

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...High Surf Advisory until 6 PM EST this evening for Coastal 
     Volusia County-Indian River-Martin-Northern Brevard County-
     Southern Brevard County-St. Lucie.

AM...Small Craft Advisory until 7 PM EST this evening for Flagler 
     Beach to Volusia-Brevard County Line 0-20 nm.

     Small Craft Advisory until 10 PM EST this evening for Flagler 
     Beach to Volusia-Brevard County Line 20-60 nm-Volusia-
     Brevard County Line to Sebastian Inlet 0-20 nm.

     Small Craft Advisory until 4 AM EST Monday for Sebastian Inlet 
     to Jupiter Inlet 20-60 nm.

     Small Craft Advisory until 1 AM EST Monday for Sebastian Inlet 
     to Jupiter Inlet 0-20 nm-Volusia-Brevard County Line to 
     Sebastian Inlet 20-60 nm.

&&

$$

Short Term/Aviation...Bragaw
Long Term/Impact WX...Pendergrast