Area forecast discussion 
National Weather Service Jacksonville Florida 
645 am EDT Thursday may 23 2013 


Short term /through sun/... 


Today...surface wave will move east across southeast Georgia this 
morning. Models continue to depict the line of convection 
dissipating as it moves east. At this time will focus best 
precipitation potential during the pre dawn hours. Expect patchy fog 
to develop this morning. However...anticipate cloud cover with 
surface wave will help minimize coverage and intensity of the fog. 
Weak troughing is expected to develop along the coast this 
afternoon...as a sea breeze tries to push inland. As the flow 
becomes increasingly westerly today...expect sea breeze boundary 
will be pinned to near the coast. Therefore...focusing precipitation 
potential this afternoon near the coast. As the sea breeze is not 
expected to make it far inland...temperatures will have a chance to 
heat up...with most locations away from the immediate coast reaching 
highs around 90. 


Tonight...any afternoon convection is expected to dissipate shortly 
after sunset...with convection lingering over the waters. A 
secondary trough will approach the region from the north late in the 
period...and looks dry at this point. 


Friday...secondary trough will move south across the region during 
the day Friday. A noticeably drier airmass will advect south behind 
this boundary. Models are hinting that there could be enough 
moisture and convergence along this boundary late Friday for 
convection to initiate as it pushes toward the south. Will hold any 
precipitation mention until the afternoon as diurnal effects have a chance 
to aid in development. With this timing...will limit the precipitation to 
the far south. While expecting southeast Georgia to be cooler Friday 
following the trough...ample sunshine should still allow heating to 
around normal there. 


Friday night...much cooler and drier air filters in from the northwest 
trailing the frontal passage. Temperatures will fall into the low 50s 
inland to low/middle 60s toward the coast under clear skies. 


Weekend...a gorgeous weekend expected with dry conditions and cooler 
temperatures under northwest flow as high pressure builds north-northeast of the region. Maximum 
temperatures will be held in the upper 70s to near 80 along the coast under 
breezy onshore flow...with highs reaching the upper 80s toward the 
Interstate 75 corridor. Min temperatures will range in the 50s inland to 
low/middle 60s coast. Not much fog expected due to dry air in place. 


Long term...Monday through Thursday...an extended period of onshore flow is 
expected as surface high pressure over the Atlantic extends an axis 
over the Georgia/SC coastline. Mostly dry conditions are expected under 
mean layer ridging...but continued to advertise a low 20% chance of 
passing coastal showers Tue-Thu. Maximum temperatures will moderate through the 
period with values near to slightly above climatology by Thursday with highs 
near 90 inland to near 80 along the coast. Mins will range to 
slightly below climatology from the low 60s inland to near 70 along the 
coast. 


&& 


Aviation...anticipate MVFR to LIFR conditions at least temporarily 
at the terminals through sunrise. Will monitor progress and 
evolution of squall line over southeast Georgia to see if thunderstorm activity 
needs to be included at ssi later this morning...but short term 
model guidance insists on the line weakening and dissipating as it 
nears the Georgia coast. After sunrise expect prevailing VFR conditions 
today as west-southwest winds prevail in advance of approaching cold front. 
Continued with vcsh at the terminals during the early afternoon. 


&& 


Marine... 


A weak frontal boundary will move east across the region this 
morning. Another will cross Friday afternoon. Following this 
boundary on Friday...high pressure will build to the north. The 
pressure gradient will build across the waters Friday night into 
Saturday as the high builds in...with Small Craft Advisory 
conditions possible. This high will build northeast of the region 
Sunday into early next week...leading to a prolonged period of 
onshore flow...and an enhanced risk for rip currents. 


Rip currents...low risk through Friday. The rip current risk will be 
elevated over the weekend due to onshore flow. 


&& 


Fire weather...high dispersions will be headlined today as 
temperatures inland rise to near 90 inland under westerly flow. Much 
drier air will filter over the area from the northwest Friday when rhs will 
fall to near 30% inland under northwest flow. Over the weekend relative 
humidities crash into the 25-30% range inland each afternoon with 
north-northeast onshore flow developing. 


&& 


Preliminary point temps/pops... 
amg 90 63 87 53 / 10 10 10 0 
ssi 87 69 88 62 / 20 20 10 0 
jax 89 67 89 58 / 30 20 10 0 
sgj 87 70 87 66 / 20 20 10 0 
gnv 91 65 91 59 / 20 10 10 0 
ocf 90 66 92 61 / 20 10 10 10 


&& 


Jax watches/warnings/advisories... 
Florida...none. 
Georgia...none. 
Am...none. 
&& 


$$ 


Struble/enyedi