Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Melbourne Florida
359 am EST Sat Jan 31 2015
Today/tonight...high pressure over the Ohio Valley will build
southeast today...veering elevated low level winds from the
northeast to east by late afternoon. This onshore flow will begin to
modify the dry airmass in place and limit any Post frontal cooling.
Highs will be a few degrees below normal ranging from the middle 60s
along the Volusia County coast to upper 60s to around 70 degrees
farther south and across the interior. A mix of high clouds and
onshore moving marine stratocu will vary sky cover today from mostly
sunny to partly cloudy. Low level moisture fields look too shallow
for isolated Atlantic showers to develop in the east/NE flow and MOS
probability of precipitation remain quite low along the coast (around 5% or less) so will
keep rain chances out of the forecast.
Low level easterly winds veer to the southeast late tonight with
models showing 925mb flow remaining around 15-20 kts. This should
keep onshore surface winds around 5-10 miles per hour overnight from the cape
southward with milder overnight lows from the middle 50s to low 60s
forecast. Farther north and inland min temperatures expected to range from
the upper 40s to low 50s.
Sun-Sun night...surface high will continue to build east/southeast
away from the area...in advance of frontal boundary that will
push into the southeast states. This will produce a southeast wind
flow during the day and southerly at night...which will cause
temperatures to be a little above normal Sunday and around 10 degrees
above normal Sun night.
Forecast soundings show a subsidence inversion on Sunday with
shallow moistening coming in off the Atlantic. Expect a few cloud
lines over the water...but veering low level wind profiles should
keep substantive showers offshore. Will not include probability of precipitation during
the day. Pre frontal moisture will increase Sun night and expect a
small chance for showers across the north.
Mon-Tue...mid/upper level trough will swing through eastern U.S.
And offshore Monday. This will push a cold front through the region
Monday afternoon/evening. The main energy associated with the trough
will remain well north...so MOS probability of precipitation from 30 to 40 percent over
north/central areas and around 20 percent in the south look good.
Maximum temperatures should range from the lower 70s northwest to lower 80s
in the far south.
Drier/cooler air behind the front will again be short lived as
winds quickly veer to onshore Tuesday. This will keep temperatures in the
south close to normal...lower/mid 50s Tuesday morning and lower 70s
Tuesday afternoon. It will be cooler in the north though with below
normal lows in the Lower/Middle 40s and highs in the Lower/Middle 60s.
Wednesday-next Sat...there continue to be differences in the models with
respect to their handling of cut off low over northern Mexico
that will eject eastward on Wed-Thu. This system will dampen out
as it enters a more confluent downstream flow regime...but expect
enough troughing to generate some sort of Gulf low that will move
towards the state. The latest models show more of a chance for
this on Thursday. So after a 20-30 percent chance of showers Wednesday in
increasing onshore flow...will go with slightly higher chances...
around 40 percent Wednesday night and Thursday.
The 00z GFS is stronger and slower with the low pressure center
as it moves east of the region Friday...but even the European model (ecmwf) indicates
lingering moisture into Friday. Will maintain slight coastal shower
After mild temperatures at or above normal Wed-Thu...readings will drop
off to normal or a little below Fri-Sat.
Aviation...VFR conds expected. North/NE winds this morning will become
east/NE into the late morning and afternoon increasing up to 10-15 kts
and gusty at times along the coast. Onshore moving marine stratocu
will produce scattered-broken sky cover around 4kft.
today/tonight...poor to hazardous boating conditions will persist
today with NE winds 15-20 knots continuing to produce seas up to 7
feet in the Gulf Stream through this morning. As winds veer more
easterly into the afternoon speeds decrease to 10-15 knots with seas
up to 6 feet offshore into tonight.
Sun...surface high pushing seaward will cause winds to veer to the
southeast and south. Speeds look to be at least 15 knots and may
increase in the northern waters to 20 knots late in the day and
overnight as a frontal boundary advances into the southeast
states. Conditions for small craft look poor.
Mon-Wed...a front will move through the waters Monday with gusty
southwest flow turning to the west/northwest in the afternoon.
Small Craft Advisory conditions look likely Monday and Monday night.
High pressure ridge will build across the southeast states Tuesday and
swing winds around to northeast...then east/southeast Wednesday...generally
at 10-15 knots.
Fire weather...onshore winds into this weekend will mitigate any
low relative humidity concerns. Increasing moisture late Sunday into Monday will
lead to eventual rain chances with next approaching front Monday.
Preliminary point temps/pops...
dab 65 49 75 62 / 0 0 10 20
mco 69 50 76 62 / 0 0 10 20
mlb 69 55 73 62 / 10 10 10 10
vrb 69 58 74 62 / 10 10 10 10
Lee 68 50 76 63 / 0 0 0 20
sfb 68 50 74 61 / 0 0 10 20
orl 68 51 75 63 / 0 0 10 20
fpr 69 57 75 62 / 10 10 10 10
Am...Small Craft Advisory until 10 am EST this morning for coastal
waters from Sebastian Inlet to Jupiter Inlet out 20 nm-
waters from Flagler Beach to Volusia Brevard County line 20
to 60 nm offshore-waters from Sebastian Inlet to Jupiter
Inlet 20 to 60 nm offshore-waters from Volusia Brevard
County line to Sebastian Inlet 20 to 60 nm offshore.