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fxus62 kjax 200805 
afdjax 


Area forecast discussion 
National Weather Service Jacksonville Florida 
300 am EST Thursday Nov 20 2008 


..freezing temperatures expected this morning... 
..Another cold blast expected for Saturday... 


Short term...latest msas analysis shows surface high pressure has 
settled into the East Gulf of Mexico...centered just offshore the 
Nature Coast of Florida. With no extensive ridge axis emanating 
from this feature...a gradient is realized at very little distance 
from the high's center. Resultant flow over the area is light 
westerly...but enough to alleviate rapid temperature drop seen 
earlier with more ideal radiational cooling conditions. Although 
most areas have leveled out in the middle 30s...expect a slower drop 
to commence through sunrise and a light freeze for the coastal 
counties and around 30 for inland areas remains on track. 


High pressure will get shunted south through this 
afternoon...maintaining the dry westerly flow across the area. 
Moderating temperatures will result in afternoon high temperatures in the middle to 
upper 60s across the area under clear skies. 


Another area of very strong high pressure is expected to drop into 
the Central Plains states Thursday night with a frontal boundary 
expected to race into the area between 06z and 12z. Although 
passage will occur over the Georgia portion prior to sunrise...cold air 
advection will be limited initially and should keep all areas above 
freezing...if only by a few degrees. 


Strong cold air advection pattern in place for Friday afternoon 
will allow for struggling temperatures and highs only in the upper 50s. 
Although 1040mb high is impressive for this time of year...middle 
level trough for this outbreak is not quite as deep and therefore 
will see high translate more east than south this time around. 
With high settling over the Carolinas Friday night into Sat 
morning...an advective type freeze will be in store with hints of 
an onshore flow for coastal Florida areas perhaps curbing the 
expected temperature drop. Still...cold air is formidable and 
expect freeze warnings for a good portion of inland areas. 


Long term...with strong high remaining over the middle Atlantic...a 
moderate easterly flow regime will be in store for early next 
week. Surface moisture does not increase appreciably until Sat 
morning and should only result in low clouds over the Mainland 
and isolated showers over the marine environment. Next best rain 
chances will be on Tuesday with another cold front to push through. 
Prep time ahead of this feature with moist easterly flow should be 
sufficient to allow for scattered probability of precipitation with the frontal passage. 


&& 


Aviation...other than some patchy ground fog near sunrise and some 
lingering smoke near kjax...no significant weather expected with VFR 
conditions continuing. 


&& 


Marine...Small Craft Advisory criteria expected in the offshore 
waters after midnight tonight and will add advisory to this package. 
Think winds may stay just below advisory criteria in the near shore 
waters...but later shifts can pin this down. Seas in the near shore 
area will stay below 7 feet until late Friday night or early Sat when 
flow becomes more onshore. Seas 7 feet or greater will likely continue 
in the offshore waters through Sat night. 


&& 


Fire weather...with light west flow and continued dry air in place... 
most of NE Florida should see red flag conditions today. Think the 
combination of dry air behind next front and sustained daytime winds 
near 15 miles per hour will necessitate a Fire Weather Watch for most of NE Florida for 
Friday. 


&& 


Preliminary point temps/pops... 
amg 66 33 58 26 / 0 0 0 0 
ssi 64 41 59 36 / 0 0 0 0 
jax 67 39 58 32 / 0 0 0 0 
sgj 66 44 61 40 / 0 0 0 0 
gnv 67 38 60 30 / 0 0 0 0 
ocf 67 40 63 34 / 0 0 0 0 


&& 


Jax watches/warnings/advisories... 
Florida...red flag warning from 11 am this morning to 5 PM this 
afternoon for Alachua-Baker-Bradford-Clay-Columbia-Duval- 
Flagler-Gilchrist-Hamilton-Marion-Nassau-Putnam-St Johns- 
Suwannee-Union. 


Freeze warning until 8 am this morning for Alachua-Baker- 
Bradford-Clay-Columbia-Duval-Gilchrist-Hamilton-Marion- 
Nassau-Putnam-Suwannee-Union. 


Frost advisory from 4 am to 8 am this morning for Flagler-St 
Johns. 


Fire Weather Watch from late Friday morning through Friday afternoon for Alachua- 
Baker-Bradford-Clay-Columbia-Duval-Gilchrist-Hamilton-Marion- 
Nassau-Putnam-Suwannee-Union. 


Fire Weather Watch for Friday afternoon for Duval-Flagler-Nassau-St Johns. 


Georgia...none. 


Am...Small Craft Advisory from 4 am Friday to 10 PM Sat for Altamaha 
Sound Georgia to Flagler Beach Florida 20 nm to 60 nm offshore. 


&& 


$$ 


Deese/Carroll