Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Melbourne Florida
325 am EST Sat Dec 7 2013
Frontal boundary that has been plaguing the deep south will stall
out well to the north of the area as it bumps into deep layer
Atlantic ridge. The GFS shows east/southeast low level winds
pushing a little higher moisture into southern sections...
especially tonight when a slight surge in the flow is forecast.
Probably the most significant forecast element is fog. The GFS
shows light boundary layer winds this morning and still expect
patchy fog to form with some dense patches possible especially
along/west of I-4. MOS hits the fog harder tonight but with some
onshore moving showers across the south...expect stratocumulus to
push inland. Will keep mention of areas of fog across the north
but limit to patchy in the south.
Radar has only been detecting a few Atlantic showers during the
pre dawn hours...but plan to include a less than 20 percent
chance of showers along the South Coast today. Will continue
current forecast for slight chance of showers along the south half
of the coast tonight since the GFS showed the slight wind surge
occurring 24 hours ago too.
Temperatures will continue well above normal with highs in the lower 80s
near the coast and middle 80s inland.
Sun...the area will remain on the western periphery of high pressure
over the Atlantic. Anticipating a small spike in probability of precipitation Sunday as a
slug of higher moisture approaches the area from the southeast. Both
the Euro and GFS are picking up on this subtle feature...though
neither show impressive moisture and quantitative precipitation forecast fields. Maintained the
slight chance of showers during the period. Precipitation amounts expected
to be limited. Ridging aloft and southeast flow will continue our
stretch of above normal temperatures...expecting low 80s most
locations though slightly cooler closer to the North Brevard and
Volusia County coast.
MOS guidance continues to suggest fog formation each late night and
early morning into early next week. This the result of thinning sky
cover at night...light winds and moisture trapped beneath a nightly
inversion above the surface.
Mon-Fri...ridging will remain in place early next week before giving
way to a deep longwave trough whose axis will gradually work it's
way towards the eastern Seaboard by Wednesday. Closer to the
surface...a front across the southeast will gradually approach the
forecast area with limited fanfare. GFS has aligned with the Euro
and now both models slow the progression of the front...moving it
through late Wednesday and into Thursday. Regardless of the timing
of the frontal passage...the dynamics aloft look lackluster as does
atmospheric moisture...so rain chances have been capped at 20 to 30
percent during the middle to late week period.
Due to the slower progression of the front...winds have been reduced
during the midweek period. High pressure building across the eastern
Continental U.S. Will allow winds to turn onshore and increase late next week
after the front finally passes through.
Aviation...light surface winds and areas of clear skies have led
to high relative humidity values and a few reports of light mist. Canaveral
profilers have been showing 15 knot low level flow though.
This along with a few areas of stratocumulus should delay
formation of patchy IFR-LIFR. The main chance for this should be
along/west of I-4 early this morning...and again late tonight.
today-tonight...overall pretty decent conditions for small craft
as pressure gradient is forecast to weaken slightly today. Expect
southerly winds 5-10 knots near the coast starting out the day
then becoming east/southeast in the afternoon. Pressure gradient
is forecast to increase a little tonight with east/southeast flow
picking up to 10-15 knots except staying 5-10 knots in the north
and probably closer to 15 knots in the south.
Sun-Wed...generally southeast flow with a slight uptick in winds
Sunday afternoon. Winds 10-15 kts...some higher gusts Sunday
afternoon into the first half of Monday. Long period swells
continue with seas building to 3-5 feet into Monday.
Influence of the high pressure will gradually wane through the
midweek period as a cold front inches towards the area from the
north. Winds expected to shift to more southerly...then westerly.
After the front moves through...expect northeast flow to resume.
Preliminary point temps/pops...
dab 81 63 79 65 / 10 10 20 10
mco 84 64 82 64 / 10 10 10 10
mlb 81 67 80 69 / 10 20 20 10
vrb 82 68 82 68 / 10 20 20 10
Lee 84 63 83 64 / 10 10 10 10
sfb 84 64 82 66 / 10 10 10 10
orl 84 65 82 64 / 10 10 10 10
fpr 81 68 81 68 / 10 20 20 10