Area forecast discussion
National Weather Service Jacksonville Florida
234 PM EDT Tuesday may 21 2013
Short term /tonight through Friday/...
scattered to numerous showers and storms are developing along the
Atlantic seabreeze in conjunction with weak troughing/cool pooling
aloft across the region. Coverage will continue to increase this
afternoon...pushing inland. Will use numerous probability of precipitation through early this
evening for NE Florida inland areas from 20-75 miles from the
Atlantic where the greatest small scale boundary interaction will
take place...with scattered probability of precipitation for other areas. Activity will
diminish middle/late evening as heating is lost. With ample low level
moisture and some subsidence overnight...patchy/areas of fog will
develop. Lows tonight in the middle/upper 60s will prevail.
For Wednesday...upper level troughing will approach from the
northwest...with a weak impulse prognosticated to cross the local area.
This...along with seabreeze and small scale boundary interactions
will result in another round of scattered showers/thunderstorms Wednesday
afternoon. Will use the highest probability of precipitation inland as Gulf/Atlantic seabreeze
boundary collide...with lesser coverage coast. Highs will range
from the lower 80s coast...to the middle/upper 80s inland.
Wednesday night through Friday...surface wave and upper shortwave trough
will be over the area Wednesday night before lifting NE on Thursday. Will
keep probability of precipitation along the East Coast and over the waters through the
night. Weak offshore flow on Thursday with the sea breeze getting a
late start. Drier air will begin to advect into southeast Georgia and diurnal
convection is expected to concentrate across NE Florida between Highway 301
and the East Coast. Upper trough will pivot off the eastern
Seaboard and Thursday night/Friday pulling a frontal boundary through the
region. Drier airmass will filter in behind the front...thus will
go with slight chance probability of precipitation (20%) for only NE Florida. Expect near normal
temperatures for this period.
Long term /Friday night through Tuesday/...
surface high pressure will build to the north Friday night into
Sat...then shift to the northeast sun/Mon. Drier air will push
south with the building high...therefore keeping this period dry.
With a north/northeasterly flow this period...expect temperature
readings to be a little below normal.
Aviation...
sea breeze began early storms have passed Duval terminals. Will
keep thunderstorms in the vicinity for possible redevelopment. Have tempo at gnv for thunderstorms and rain
from 19z-21z. Fog is possible tonight at terminals where heavy
rains occurred. Have not included in tafs at this time.
&&
Marine...
southeast winds expected through Wednesday night with combined seas 2-4
feet. Winds shift to offshore Thursday/Thursday night ahead of an approaching
frontal system...although weak flow will allow sea breeze to form
near shore Thursday afternoon. High pressure building north of the area
Friday will produce a stronger NE flow through the weekend and Small Craft Advisory
headlines are expected for offshore legs with speeds around 20 knots
and seas building to 5-7 feet. Expect scec conditions near shore.
Rip currents: moderate risk through Wednesday with onshore flow and
long period easterly swell.
&&
Preliminary point temps/pops...
amg 64 89 66 91 / 30 40 40 30
ssi 69 81 70 85 / 20 30 20 30
jax 66 85 67 89 / 20 30 30 30
sgj 67 83 68 85 / 20 30 30 30
gnv 64 87 67 89 / 50 50 40 20
ocf 66 88 67 89 / 60 50 40 30
&&
Jax watches/warnings/advisories...
Florida...none.
Georgia...none.
Am...none.
&&
$$
Allen/trabert
