Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Jacksonville Florida
337 am EST Friday Dec 6 2013
..near record high temperatures possible today...
..Above normal temperatures will continue through Monday...
deep layer ridge stretches from the SW Atlantic across the Florida
Peninsula to the SW Gulf of Mexico. Cirrus clouds have thinned
over the area as the upper ridge pushes the clouds farther north.
A long wave trough covers the inter-mountain west from Manitoba
to Arizona. In between is a cold front extending from the northwestern
Gulf across southern la to a low centered near the tri-state border of
TN/NC/VA. Southerly boundary layer winds have increased to near 20
knots and inhibiting fog development. Some advection fog is drifting
over the Suwannee Valley into southeast Georgia. Radar shows a few showers
over the Gulf Stream are drifting into our outer coastal waters
before turning NE around the ridge. Temperatures are mainly in the
60s except for upper 50s near the Altamaha river.
Short term...today through Saturday night...
strong high pressure ridge will block the approaching cold front.
Near record warmth will continue today with highs in the lower 80s
and lows tonight mainly in the 60s. Boundary layer winds ahead of
the cold front will inhibit fog over southeast Georgia...but lighter winds
will allow fog formation over inland NE Florida. By Saturday...a
sheared out front will near the Altamaha river basin before
bumping into the low level Atlantic ridge. This will introduce low
rain chances to southeast Georgia. Will go with 40% near the Altamaha to 20%
near the Georgia/Florida state line to I-10 corridor Saturday aftn/evening.
Rain chances drop slightly Sat night. Will scale back temperatures on Sat
due to clouds/showers. Although still above normal...highs will range
from middle 70s near the Altamaha to lower 80s near Ocala. Lows are
expected to range from middle 50s to lower 60s.
Long term (sunday-thursday)...
the front begins to wash out just north of the area Sunday. Have
kept previous low probability of precipitation across the far northern zones near the
decaying front and also kept low probability of precipitation along the coast where a weak
coastal trough may produce a few showers there. A cold front will
bring a good chance of showers and possibly a few storms to the area
on Tuesday. Models continue to indicate the front will stall out
across cntl Florida Wednesday-Thursday with the European model (ecmwf) developing a coastal trough
offshore. Will keep low end chance probability of precipitation going across the southeast zones
and slight chance probability of precipitation elsewhere. Temperatures start out much above normal
(10+ degrees) then cool to near normal by middle week.
Aviation...fog getting a slow start due to boundary layer winds
promoting mixing. Still expecting some decrease in winds and for
fog to develop the next couple of hours. Have gone with prevailing
MVFR visibility and occasional IFR ceilings/visibility between 09z-14z. Conditions improve
to VFR thereafter.
south to southeast winds 10-15 knots and combined seas 2-4 feet will prevail
through Monday. Small craft exercise caution conds are expected
Monday night/Tuesday as S-SW winds increase in response to an
approaching cold front. Long term guidance indicates the front
will cross the waters late Tuesday.
Rip currents: low risk expected through the weekend.
Preliminary point temps/pops...
amg 83 61 76 55 / 10 20 40 40
ssi 75 62 75 60 / 10 10 30 30
jax 82 61 80 60 / 10 10 20 20
sgj 80 63 77 62 / 10 10 10 20
gnv 83 59 81 58 / 10 10 10 10
ocf 83 61 82 60 / 10 10 10 10