Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Melbourne Florida
815 PM EST Friday Feb 12 2016
Discussion... the 500mb trough over the southeast U.S. Should have
enough of a push to move the front currently stretched west to east
over Alabama/Georgia into Florida early in the night and clear central Florida
Saturday afternoon. Low moisture levels in the 1000-500mb layer
support a none pop as the front drops down the peninsula.
Forecast in good shape. Updating/freshening the wording for the
Marine...buoy 009 recording southwest wind 15 to 20 knots and 2
foot seas. Cmans at Sebastian Inlet and Trident pier recording
southwest to west wind 10 to 15 knots. The two scripps buoys were
recording 1 foot seas.
The southwesterly wind should pick up during the evening as the
front over the southeast U.S. Pushes southeast and tightens the
gradient between itself and the departing high pressure ridge over
South Florida and the Keys.
Previous afd issued 255 PM EST Friday Feb 12 2016
Current-tonight...a pleasant and seasonal day across east
central Florida this afternoon. The atmosphere continues to be very
dry as visible satellite imagery only picking up on a small cumulus
field along/north of I-4. Surface high pressure across the southern
Florida Peninsula will continue to weaken overnight. A cold front
draped across the deep south will slide south into/through central
Florida late tonight. Very little middle-level support with this
feature and coupled with very dry conditions will keep precipitation
absent from the forecast. Gusty southwesterly/wrly winds will decrease this
evening veering west-northwest/northwest overnight as the boundary passes through.
Overnight lows near climatology and in the u40s/l50s.
Sat...NW/NNW winds behind most recent front will increase to around
15 miles per hour with higher gusts expected. Dry conditions continue to
dominate with mostly sunny skies forecast. Highs in the 60s with a
few l70 degree readings possible southward. Coolest highs along the
Volusia coast around 60 to 62 degrees.
Sat night-Sunday...north-northeast low level flow Sat evening will veer to the east-northeast
near the immediate coast with light northerly flow inland as coastal
trough sets up overnight. Models indicate some isolated showers
developing across the Atlantic waters north of Sebastian but do not look
to reach the coast before sunrise. High pressure near the middle Atlantic
Sunday will allow low level flow to veer to onshore and bring some
marine stratocu inland and a slight chance for an onshore moving
light shower near the coast. Lows Monday night in the 40 interior to
around 50 southern coastal. Highs Sunday in the lower 60s Volusia coast to
middle to upper 60s for the remainder of east central Florida.
Modified previous discussion...
the pattern over the Continental U.S. Will become more progressive as the deep
eastern trough lifts out and shortwave troughs moving over
weakening West Coast ridge gradually develop a deeper trough in
the east by midweek.
The main item of interest is a shortwave trough that is forecast to
move across the southern states Monday and offshore the Carolinas
Tuesday. The associated surface low will be strengthening as it moves
across the Gulf Coast states...so low level southerly winds will
increase. The quick movement of this system will limit moisture
return however. Precipitable water values are forecast in the 1.3 to
1.4 inch range Monday night with surface dew points in the middle 50s to
around 60. The GFS and European model (ecmwf) place the highest probability of precipitation on Monday night so
will continue to Show Low probability of precipitation Monday afternoon and early Tuesday with probability of precipitation
around 50-60 percent for Monday night. Thunder chances look marginal
due to limited instability...but have added a slight thunder
mention for Monday night and early Tuesday based on the 12z guidance.
Surface high pressure ridge will build from the Midwest at midweek
to the Atlantic Seaboard Friday. No rain chances anticipated after
the frontal passage on Tuesday. Temperatures look to be a little above normal
Monday then settling back close to normal Tue-Fri.
Aviation...mainly VFR. High pressure weakens over the southern
peninsula with cool front moving into a moisture-starved atmosphere
over the Florida Peninsula overnight/early Sat. No precipitation with this
boundary but will watch for short interval of cumulus/SC in associated. Gusty
southwesterly winds will decrease this evening and veer to west-northwest/northwest behind the
cold front late in the night. West-northwest/northwest winds behind front gusty on Sat
with dry conditions continuing.
Afternoon-tonight...southwesterly winds continue to increase this
afternoon as the pgrad tightens ahead of a cold front. Favoring
cautionary conditions for winds offshore north of Sebastian Inlet
for next coastal waters forecast issuance (21z/4pm)...with an Small Craft Advisory taking effect at
03z/10pm for these same marine legs. Will initiate Small Craft Advisory for offshore
marine leg Sebastian Inlet-Jupiter Inlet at 09z/4am. Cautionary
statements will be necessary at least for near shore Sebastian Inlet
northward later in the evening/overnight. Winds gradually veer to
wrly then west-northwest/northwest late this evening/overnight as the front
approaches/passes. Speeds also gradually increase to 20-25 kts and
gusty over the offshore legs. Near shore winds (scec) will also be
gusty later tonight. Seas 2-3 feet areawide...except 4 feet well
offshore/north of cape will build 4-6 feet by Sat daybreak well
offshore cape northward.
Sat...Small Craft Advisory continues offshore legs with cautionary statements near
shore. Will allow future shifts to monitor and decide if Small Craft Advisory needs
to be brought near shore (for winds). Seas by the end of the day
will build to 6 feet offshore and 4-6 feet near shore...but away from
the coast. Northwest/north-northwest winds continue areawide at sustained 20 kts
offshore and 15-20 kts near shore with frequent higher gusts all
Modified previous discussion...Sat night into Sunday...breezy north-
NE winds to 20 knots on Sat night will turn to the east by Sunday
afternoon. A Small Craft Advisory will continue offshore Sat night
with higher seas in the Gulf Stream. Exercise caution conditions are
expected for much of the remaining waters through early Sunday.
Mon-Tue...breezy east southeast flow early Monday will quickly veer
to the south Monday evening and southwest by sunrise Tuesday. Exercise
caution conditions are expected much of the period but an increase
of westerly winds behind a cold front on Tuesday to 20 knots
should result in advisory conditions.
afternoon...dewpoints have recovered a bit more quickly than forecast
north of Melbourne...with lowest afternoon relative humidity values across the southern
half of our coverage warning area. Gusty SW/wrly winds as advertised
will decrease this evening...but veer to west/northwest through late
evening/overnight as a front approaches/passes across the area.
Sat...continued dry behind latest cold front. Min relative humidity values in the
low/middle 30s west of I-95. 20ft winds northwest/north-northwest at 10-15 miles per hour and
frequent higher gusts.
Preliminary point temps/pops...
dab 49 61 42 63 / 0 0 0 20
mco 51 67 44 67 / 0 0 0 10
mlb 52 67 46 66 / 0 0 10 20
vrb 49 69 49 68 / 0 0 10 20
Lee 51 66 43 66 / 0 0 0 10
sfb 50 66 44 66 / 0 0 0 10
orl 52 67 46 66 / 0 0 0 10
fpr 48 70 48 68 / 0 0 10 20
Am...Small Craft Advisory from 4 am Saturday to 4 am EST Sunday for
Sebastian Inlet to Jupiter Inlet 20-60 nm.
Small Craft Advisory from 10 PM this evening to 4 am EST Sunday
for Flagler Beach to Volusia-Brevard County line 20-60 nm-
Volusia-Brevard County line to Sebastian Inlet 20-60 nm.