Area Forecast Discussion
Issued by NWS Miami, FL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KMFL 210010
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
810 PM EDT Fri Apr 20 2018

.AVIATION...
Easterly winds below 10 knots prevail tonight. VFR conditions
continue through Saturday early in the afternoon, then periods of
VCSH and increasing low cloud cover may affect the Atlantic
terminals, along with increasing ESE winds. Only exception will be
KAPF where afternoon sea breezes will again bring westerly flow
along the Gulf coast.

&&

.PREV DISCUSSION... /issued 748 PM EDT Fri Apr 20 2018/

UPDATE...
Mostly clear skies are still prevalent across South Florida with
the sea breeze advancements diminishing. Expecting light easterly
flow to become dominant overnight as the surface high pressure
axis slides eastward into the western Atlantic. The SREF wasn`t
too excited about fog development tonight, so opted to keep
mention out of the latest grid package. Other than loading in the
latest wind and cloud cover guidance, all other variables
appeared on track.

PREV DISCUSSION... /issued 416 PM EDT Fri Apr 20 2018/

DISCUSSION...
Weak high pressure over the peninsula has allowed for another warm
and dry day across South Florida. In response to light southerly
flow across the region, a thermal surface low pressure center has
developed in the interior, allowing both sea breezes to push well
inland from their respective coasts. Latest WPC analysis depicts
a cold front stalled east to west across Central Florida, north of
Lake Okeechobee. As the front becomes nearly stationary tonight,
it should act to increase easterly flow, especially noticeable
over the Atlantic and adjacent east coast metro. Expecting
moisture to deepen in the lower levels with GFS forecast PWAT
increasing from around an inch to above 1.33". Weak lift generated
from the stationary front, combined with this bump up in moisture
should aid in the development of showers over the Atlantic
waters, then advect inland as Saturday progresses. Instability
parameters appear rather weak on Saturday, though a rumble of
thunder can not be ruled out in northern portions of our CWA.

Late this weekend through mid next week: Saturday night into
Sunday, mid range models continue to prog a potent low pressure
system to slide eastward along the southern CONUS. Moisture ahead
of the associated cold front will deepen further, as low level
winds veer more south southeasterly. As confluence overspreads
south Florida and various vorticity maxima pass over the area,
the atmosphere may begin to turn more unstable. Sunday afternoon,
showers remain likely, with a chance of thunderstorms, esepcailly
over the interior, with focus shifting to the northeastern
portion of the peninsula as evening approaches. On Monday, flow
continues to veer southerly or even south southwesterly. Expect
repeat of Sundays activity with showers likely and a chance of
thunderstorms. As forecast PWATs increase to near 1.75", periods
of moderate to occasionally heavy rain remain possible along
central and northern portions of the east coast metro region. Both
the ECMWF and GFS prog the aforementioned front to push through
South Florida sometime late Tuesday into Wednesday. In the wake of
the front, dry conditions are forecast prevail mid to late next
week.

MARINE...
A cold front will push southward down the Florida
Peninsula and stall over the Lake Okeechobee region tonight.
Marine conditions will begin to deteriorate starting tonight as
wind speeds pick up, particularly over the Atlantic waters,
where a Small Craft Advisory has been hoisted. Showers and
thunderstorms will bring locally higher winds and waves late this
weekend into early next week. Conditions will gradually improve
early to mid next week.

AVIATION...
The winds will be easterly around 5 to 10 knots this afternoon
before decreasing to around 5 knots tonight, except for KAPF taf
site where the winds will be westerly this afternoon around 5 to
10 knots. The weather will remain dry over all of the taf sites
along with VFR conditions for the ceiling and vis through tonight.
&&

.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach  71  83  71  81 /  20  30  50  50
Fort Lauderdale  73  83  73  81 /  10  30  40  50
Miami            72  84  72  82 /  10  20  40  40
Naples           68  86  69  85 /   0  20  20  40

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...Small Craft Advisory from 5 PM Saturday to 5 AM EDT Sunday for
     AMZ651-671.

     Small Craft Advisory from 11 AM Saturday to 5 AM EDT Sunday for
     AMZ650-670.

GM...None.
&&




AVIATION...17/AR







USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.