Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Miami Florida
340 PM EDT Tuesday Sep 30 2014

Short term...(tonight-Thursday night)

The latest short-range model guidance remains in decent agreement
through the middle-week period and indicates the upper trough and
surface low currently impacting the region lifting northeast over
the western Atlantic. A trailing frontal boundary will stall
across the state and continue to weaken. Westerly low-level flow
will prevail across South Florida and is forecast to slightly
weaken tonight through Wednesday. This weakening flow combined
with rising upper heights and slightly drier middle-level air should
translate to more of a typical pattern with mainly afternoon sea
breeze activity expected each day beginning Wednesday. Westerly
low-level flow up to 10 kft combined with the East Coast sea
breeze will focus the bulk of this afternoon activity across the
central and eastern portions of the area...which is well
reflected in the latest numerical guidance. Although the severe
thunderstorm threat will remain low through this time...localized
heavy rainfall could result in flooding through the afternoon and
early evening periods across the East Coast areas. Overnight and
through the morning periods...showers and a few storms developing
over the adjacent Gulf waters will remain possible and may impact
the Gulf coastal areas briefly.

/85

Long term (friday-sunday)...

A significant shortwave is shown by both the GFS and European model (ecmwf) digging
into the upper Midwest Friday and amplifying with a longwave trough
encompassing the eastern Seaboard by Sunday. A strong cold front
will plow southeastward with this highly amplified trough with the
possibility (low confidence right now) of an early season cold front
moving all the way across South Florida on Sunday! European model (ecmwf) is more
aggressive compared to the past couple GFS runs, showing dewpoints
into the 60s sun-Monday (and temperatures a few degrees lower) which would be
a very noticeable airmass change since Spring here. GFS though hangs
this front near the Lake Okeechobee region with dewpoints hanging at
or above 70f across South Florida. Scattered thunderstorms are expected
this weekend, but possibly ending for a couple days should the front
clear our area, the extended forecast shows a trend of lowering probability of precipitation
to account for this possibility. /Gregoria

&&

Marine...

Low pressure over the Atlantic will move east with a dissipating
frontal boundary draped across central Florida. Weak high pressure
will then prevail across the local waters through late this week. A
strong cold front will move into North Florida on Saturday. This
cold front could move into or across the local waters on Sunday
while losing its punch.

/Gregoria

&&

Preliminary point temps/pops...
West Palm Beach 74 88 75 87 / 20 60 30 60
Fort Lauderdale 77 89 77 89 / 20 60 30 60
Miami 77 89 77 89 / 20 60 20 70
Naples 77 87 77 88 / 20 40 10 40

&&

Mfl watches/warnings/advisories...
Florida...none.
Am...none.
GM...none.
&&

$$

Ag/dg

National Weather Service Glossary of Abbreviations