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
FXUS62 KMFL 121735

Area Forecast Discussion
National Weather Service Miami FL
1235 PM EST Tue Dec 12 2017

VFR will prevail through the period. There may be a few clouds
today during the late afternoon and early evening around 4K
ft ahead of a dry cold front...otherwise expect mostly clear
skies. The front will pass thru South FL this evening from
northwest to southeast. Expect W-WNW winds to be strongest late
this afternoon, possibly as high as 12-15 knots gusting to 22
knots for several east coast terminals. Behind the front, winds
will gradually shift to NW over the course of a few hours tonight
in the 320-340 degree range. Winds around 7-9 kts from the NW-NNW
will prevail from late tonight well into Wednesday.


.PREV DISCUSSION... /issued 958 AM EST Tue Dec 12 2017/

12Z MFL sounding and TPW imagery show that dry air continues
over South Florida today. Temperature forecast for today appears
to be on track, with highs expected to rise into the low 70s for
most locations this afternoon. Cold front over northern Florida
expected to track through South Florida overnight. There should be
some low clouds during the first part of the night with the
frontal passage, but skies should clear out a few hours before
daybreak. I expect low temperatures tonight/Wednesday morning to
be a few degrees warmer than last night/this morning due to a more
moist lower troposphere and stronger low-level winds. However, if
the clouds clear out sooner than expected, and if the winds
become light enough, then it could get 1 or 2 degrees colder late
tonight than currently forecast. For this update, I nudged
tonight`s forecast low temperatures down 1 degree from the
previous forecast for eastern and interior portions of South
Florida. Still do not expect it to be quite as cold as this

PREV DISCUSSION... /issued 406 AM EST Tue Dec 12 2017/

Latest IR satellite imagery shows mostly clear skies
across Southern Florida, with the exception of a few quickly
moving cirrus clouds. A relatively dry atmosphere, combined with
mostly clear conditions, will lead good radiational cooling
through early this morning. Minimum temperatures are forecast to
drop into the upper 30s around the Lake Okeechobee region, with
40s to around 50 elsewhere. Isolated frost may be possible west of
the lake, but not widespread enough to warrant an advisory. For
the remainder of today, a broad trough draped over the southeast
CONUS will maintain westerly flow in the low levels. Mostly sunny
skies and dry weather should prevail with dewpoints struggling to
reach the mid 50s. A dry frontal passage late this afternoon into
tonight should reinforce west and northwest flow.

Wednesday through Friday: Through the mid range forecast, broad
troughing will remain in place over the peninsula. This pattern is
expected to continue the north or northwest flow, along with dry
and cool conditions. Wednesday, behind the aforementioned dry
front, maximum temperatures are only forecast in the mid to upper
60s, around 10 degrees below seasonal norms, before rebounding
slightly on Thursday. Minimum temperatures both Wednesday and
Thursday are may only reach the upper 40s to lower 50s, around 10
to 15 degrees below normal.

Friday night through Saturday: Long range models have slightly
different solutions for the extended. The GFS drops a cold front
down from the northwest Friday night into Saturday, generating
enough lift and instability ahead of the front for a chance of
showers over the whole CWA. Meanwhile, the ECMWF washes the front
out over central Florida and keeps our area dry. For now, have
compromised with low end PoPs during this time frame, to account
for the rather uncertain path and intensity of this front.

A dry frontal passage will bring a surge of west to
northwest winds this afternoon into tonight, with small craft
advisories hoisted for the outer Gulf waters and for the waters
off Palm Beach county. Moderate rip currents are also expected
along the Gulf Coast, due to the breezy west northwest winds.
High pressure quickly rebuilds across the state on Wednesday with
diminishing winds. No significant rain chances are forecast
through most of the upcoming week.

West Palm Beach  71  47  67  45 /   0   0   0   0
Fort Lauderdale  72  51  67  50 /   0   0   0   0
Miami            72  52  69  49 /   0   0   0   0
Naples           71  54  65  48 /  10   0   0   0


AM...Small Craft Advisory from 7 PM this evening to 4 AM EST
     Wednesday for AMZ650-670.

GM...Small Craft Advisory until 4 AM EST Wednesday for GMZ676.


AVIATION...98/ABH is the U.S. government's official web portal to all federal, state and local government web resources and services.