Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Jacksonville Florida
241 PM EST sun Feb 1 2015
Near term /through Monday/...
surface high pressure is exiting the region to the east...with a
cold front entering the Mississippi Valley. In between these
features...southerly winds are providing for a breezy and warm
afternoon...with temperatures mainly in the Lower/Middle 70s.
Initial pre-frontal showers currently entering western Georgia will
enter interior southeast Georgia by late this evening/overnight...spreading
east to the I-75 corridor in NE Florida by late overnight. As the
front crosses the area Monday...the precipitation shield will enter
NE Florida Monday morning...pushing southeast to north-central Florida by
afternoon...exiting late afternoon. NAM remains somewhat slower with
the frontal crossing than is the GFS/ECMWF. Will use categorical
probability of precipitation as the front crosses late tngt/Monday. With some surface
based instability along/just ahead of the frontal boundary...will
include isolated thunderstorms in the highest precipitation coverage areas. Lows
tonight will be warm due to cloud cover and breezy southerly winds
ahead of the front...with readings in the upper 50s to lower
60sfor most areas. Temperatures will not move much Monday with the
frontal passage...with highs of 60-65 for southeast Georgia and 65-70 for NE
Florida. Breezy to locally windy conditions will prevail Monday...but
speeds will remain under advisory criteria.
Short term /Monday night through Wednesday/...
high pressure building in Monday night will bring temperatures
down below normal. A light freeze will be possible over interior
southeast Georgia and the Suwannee Valley where winds will drop off by
morning. Highs Tuesday will be cool with winds becoming onshore.
Highs will range from the middle 50s north to the lower 60s south.
Clouds will increase Tuesday night and Wednesday as an inverted
surface trough forms offshore and a Gulf low develops over the
western Gulf. Rain will likely develop late Wednesday as
Long term /Thursday through Sunday/...
southern stream shortwave with associated surface low over the
eastern Gulf will bring a good chance of rain Thursday. 12z models
differ with surface low track and moisture as this system moves
across the area and into the Atlantic Thursday night. A cold rain
may linger into early Friday as models show a northern stream
shortwave dropping southeast into Georgia which will amplify the upper trough
along the East Coast. The weekend should be dry and colder as
strong surface high pressure builds into the southeast.
Temperatures will fall below normal Friday and Saturday before
rebounding back to average on Sunday.
VFR will prevail through the overnight...with mainly high clouds
this evening lowering to low end VFR by morning as the cold front
approaches. Will use prevailing MVFR showers with the immediate
frontal approach and crossing. With thunderstorms isolated in coverage
will not mention for now. South winds 9-13 knots this evening will
increase to SW 12-18 knots with gusts to 20-25 knots late tonight...shifting
to the west/northwest with the passage of the cold front.
southerly winds will increase to Small Craft Advisory offshore late this
afternoon...increasing further tonight to middle/high end Small Craft Advisory with occasional
gusts to gale force overnight/Monday. Conditions will worsen to
scec nearshore by this evening...with a brief period of Small Craft Advisory
possible Monday. With the short duration of this possibility...will
leave caution for the nearshore legs. Advisory conditions will
continue offshore through Monday night...with scec nearshore.
Conditions will improve Tuesday afternoon into Thursday...with
another significant event for the end of the week as a Gulf low
crosses the region.
Rip currents: moderate risk today with onshore/sideshore flow and
long period easterly swell. Low risk Monday as flow becomes offshore.
Fire weather...strong winds will produce high dispersions on
Monday. Relative humidity values and fuel moisture will be too high for a red flag
Preliminary point temps/pops...
amg 56 60 31 54 / 90 90 0 0
ssi 57 62 37 52 / 50 90 0 0
jax 59 66 36 56 / 40 90 0 0
sgj 61 68 43 56 / 10 70 0 0
gnv 58 65 36 60 / 40 90 0 0
ocf 59 67 37 62 / 20 80 0 0
Am...Small Craft Advisory until 5 am EST Tuesday for waters from
Altamaha Sound Georgia to Fernandina Beach Florida from 20 to 60 nm-
waters from Fernandina Beach to St. Augustine Florida from 20 to
60 nm-waters from St. Augustine to Flagler Beach Florida from 20
to 60 nm.