Weather

352 
fxus62 kmlb 060234 aaa 
afdmlb 


Area forecast discussion 
National Weather Service Melbourne Florida 
930 PM EST Monday Jan 5 2009 


Discussion... 


..near record highs possible Tuesday... 


As expected...fog product is showing low clouds and fog advecting 
back over land from the Gulf of Mexico north of Tampa. This should 
eventually affect much of our northern counties overnight... 
beginning with Lake County. Light winds and increased low level 
moisture should allow for at least patchy fog to form all areas 
initially. But 925 mb winds are forecast to increase to 15-20 knots by 
sunrise so think primary concern will shift from fog to low clouds 
especially north. Do not plan on issuing dense fog advisory at this time. 


Increased southerly flow Tuesday and more sun than clouds will send maximum 
temperatures into the low-middle 80s...10 degrees above normal. Most record 
highs appear out of reach but Orlando and Daytona could get within a 
degree or two. 


Record highs Tuesday Jan 6: 
Daytona Beach 85 (1936) 
Orlando 84 (1990) 
Melbourne 88 (1960) 
Vero Beach 85 (1997) 




Aviation... 
/00z tafs/ 
VFR through at least 06z. Conditions appear more favorable for low 
clouds than fog late tonight as 925 mb winds increase from the S/SW. 
Widespread fog and stratus lingers over the northeast Gulf...and is 
advecting back over land this evening. Low level winds are forecast 
to be mainly southerly but expect some of the low stratus to reach 
into our north interior late tonight (lee/sfb/mco/dab). Have 
highlighted low ceilings there (fl004-006) but they could be even lower. 
Did not hit fog very hard but included at least tempo MVFR fog all 
terminals. On Tuesday...south winds will increase 10ktg17kt. 


Kelly 






Previous discussion... 


Tuesday...phasing of northern/southern stream shortwaves over the plains 
will result in an amplified trough and an organizing surface low 
over the deep south on Tuesday. This will cause the light flow regime of 
the past few days to become southerly 10-15 miles per hour...producing a few 
more degrees of warming as well as dew points rising into the middle 
60s. An overall dry air mass in place due to deep layer ridging will 
result in another dry day but it will feel more humid than the past 
few days. 


Tuesday night...a gradual increase in high/middle level cloudiness expected 
from the north with the approach of the next weather system. A 
pre-frontal squall line will move through the Florida Panhandle 
overnight. Will keep mention of probability of precipitation out of the zones as it appears 
activity will remain north of our County Warning Area until after daybreak. Lows 
mild and in the 60s. S-SW surface winds to remain 5-10 miles per hour over the 
interior and 10-15 miles per hour near the coast. 


Wednesday...a cold frontal boundary will pass across central Florida 
through the day with a line of showers and isolated thunderstorms out 
ahead of it. Latest GFS guidance has increased precipitation chances to 
between 60 and 70 percent but will keep 50 percent probability of precipitation in areawide 
for the moment. Instability looks to remain marginal but will have 
impressive upper dynamics in the form of a 160 knots jet. The main 
threat from convection likely to be strong wind gusts. A lake Wind 
Advisory may be necessary on this day as breezy/windy conditions are 
forecast. Depending on frontal/squall line timing will go with lower 
to middle 70s north for highs and upper 70s to lower 80s south. 


Wednesday night-Fri...(previous discussion)...front will move offshore Wednesday 
night with surface high pressure building across the eastern Gulf by Thursday and 
over Florida on Friday. This will spell a period of dry weather with highs 
in the lower 70s and morning lows in the 40s-lower 50s. 


Sat-Mon...(previous discussion)...disagreement continues between the 
European model (ecmwf) and GFS in the extended range. Operational 00z GFS run 
continues more progressive solution with next trough and cold front 
forecasted to move through by Sat night. European model (ecmwf) slower bringing front in 
Sunday night and also slower to clear frontal moisture which lingers 
into Monday. Ydays HPC forecasts leaned toward a compromise solution 
(actually 70 percent ecm weighting) and will likely go this direction as 
well yielding some low probability of precipitation to end the upcoming weekend with the 
next system. Will trend temperatures a bit warmer Sun afternoon/Sun night 
(closer to climo) with possibility for less progressive trough/front 
late next weekend. 


&& 


Marine...surface ridge sliding south and lowering pressures over 
the southeast states will cause southerly winds to increase to about 
10-15 knots late tonight. Winds by late Tuesday may 15-20 knots in the 
offshore waters. 


Tuesday night-Sat...marine conditions to deteriorate Tuesday night into 
early Thursday as as S-SW flow increases ahead of a cold front...with 
winds veering west-northwest Wednesday evening into Thursday. Speeds will increase to 20 
to 25 kts with stronger gusts. Winds will fall to under 15 kts again 
Thursday afternoon. Seas are gradually expected to build to 6-7 feet well 
offshore during the day Wednesday into the night. A line of storms is 
expected to pass across the coastal waters during the day Wednesday into 
the evening with main threat being strong winds. High pressure will 
build into the region Thursday afternoon-Sat with improving marine conditions 
as both winds & seas relax. 


&& 


Fire weather...will see afternoon relative humidity values drop 
into the upper 30s to lower 40s for a few hours across the northwest 
interior on Thu/Fri. 


&& 


Preliminary point temps/pops... 
dab 60 82 65 75 / 10 0 10 50 
mco 58 81 64 73 / 10 0 10 50 
mlb 62 81 67 80 / 10 0 10 50 
vrb 62 81 67 81 / 10 0 10 50 


&& 


Mlb watches/warnings/advisories... 
Florida...none. 
Am...none. 
&& 


$$