Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Melbourne Florida
340 PM EDT Tuesday Sep 2 2014
tonight...h100-h70 anticyclone centered S of the Alabama/MS bootheels
will combine with an Erly wave over the central Bahamas/southern Cuba to
generate a deep and steady Erly flow across the Florida Peninsula. Lurking
upstream...h100-h85 mean relative humidity values between 85-90pct along with a thin
850 mb-h50 vorticity band north of the Bahamas will drift into the local Atlantic
waters. Aloft...a 40-50kt h25 jet streak extending from western Cuba to
the north Bahamas will provide upper level evacuation.
Deep Erly flow pushing diurnal convection steadily across central Florida
this afternoon. As in recent days...most if not all of it should be clear
of the County Warning Area well before sunset. Will keep interior probability of precipitation at or below 10pct.
However...given the moisture and instability over the Atlantic...the
possibility of scattered rain showers/thunderstorms and rain showers developing over the Gulf Stream and
pushing onshore cannot be ruled out. Will keep slight chance rain showers in
for the coastal zones S of the cape...north of the cape the cooler shelf
waters should prevent any convection from forming outside the Gulf
Light onshore flow and surface dewpoints in the l/m70s will keep min
temperatures a few degrees above average.
incrsg dynamic instability as the middle level Erly wave pushes into S
Florida...allowing noteworthy pockets of 850 mb-h50 vorticity to push into
central Florida. Thermodynamic profile becoming more favorable as well with
h70 temperatures cooling to around 8c...h50 temperatures to around -8c...resulting in
lapses between 6.0-6.5c/km through the layer. Moisture advection will occur
from S-N...will go with 50pct probability of precipitation around the Lake Okeechobee
region...decreasing to 30-40pct elsewhere due to lingering dry middle
level air. Maximum temperatures in the l90s will be within a degree or two of climatology
average...onshore flow overnight will keep min temperatures a few degrees above average.
Thu-Fri...(modified previous disc)
peninsula will be on the favored side of the middle/upper level trough
as it crosses into the eastern Gulf early Thursday and weakens into Friday.
S-southeast flow will advect fairly deep moisture into east central Florida. Middle
level vorticity associated with the trough will push probability of precipitation to 40-60pct
both days. Low level east-southeast flow will continue to favor the
interior/western side of the peninsula...but the presence of the
trough should allow activity to continue to move onshore through the
day...especially on Thursday.
inverted trough dampens out by the weekend as ridge builds back in
from the west. While surface frontal boundary sliding through the
south will reach into S Georgia or North Florida...Atlantic ridge axis remains
firmly in place just to the north or across the region preventing
further southward progress. However moisture associated with the
boundary will combine with the remnant moisture from the trough to
keep probability of precipitation just above normal in the 40-50 percent range. Winds will
be light enough for both sea breezes to form...though East Coast
dominant...with activity favoring the interior in the afternoons and
evenings. Still expecting nocturnal Atlantic showers through the
through 03/00z...S of ktix-kism scattered MVFR rain showers/isolated IFR thunderstorms and rain showers...north of
ktix-kism isolated MVFR rain showers/IFR thunderstorms and rain showers. After 03/00z...VFR all sites.
tonight...weak ridge axis extending from the northern Gulf Coast to
Bermuda will maintain a light to gentle east/southeast breeze across the local
Atlantic waters. Seas at or below 2ft in an Erly background swell...dominant periods
8-9sec. Isolated rain showers/thunderstorms and rain showers S of Sebastian Inlet due to convergence
cloud bands forming in the wake of the northern Bahamas.
Wed-sun...generally favorable boating conditions through the weekend.
Moderate to fresh southeast breeze Wednesday night and Thursday as an Erly wave over
the central Bahamas/southern Cuba works its way across the Florida Peninsula...
generating 2-3ft seas. Otherwise...the Atlantic ridge axis will be the
dominant weather feature as it remains north of central Florida...producing a
gentle but steady east/southeast breeze...sea 1s-2ft. Primary boating concern
will be scattered rain showers and thunderstorms as the aforementioned wave crosses the
peninsula into Gulf...highest coverage Thu-Fri.
Preliminary point temps/pops...
dab 90 74 90 75 / 20 10 20 20
mco 93 74 93 74 / 30 10 20 10
mlb 90 76 90 77 / 20 10 20 30
vrb 89 75 90 76 / 20 10 20 40
Lee 93 74 94 75 / 40 10 30 10
sfb 93 75 93 75 / 20 10 20 10
orl 93 75 93 75 / 30 10 20 10
fpr 88 73 90 75 / 20 20 30 40