Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL

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FXUS62 KTBW 220747

Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
247 AM EST Fri Jan 22 2021

Models are pretty consistent since yesterday. A trough over the
Southwestern states will kick out and fill as it moves east. In
its place a deeper trough will build over the southwest building a
deep layer ridge over Florida. This ridge will translate into some
unseasonably warm temperatures next week with areas over the
southern interior seeing widespread mid 80s and maybe even a few
upper 80s. 80 degree temperatures are possible as far north as
inland Levy County by mid next week. Water temperatures are still
in the lower and mid 60s so do not expect 80s in you live
anywhere near the coast.

There is a boundary of sorts (although I really cannot find any
discernible difference in the air mass on either side of it,
Valdosta is 60 degrees with a 59 TD and Tampa is 60 degrees with a
56 TD) across North Florida that the models are insisting will
bring a shower or two to Levy County. The bigger impact is that
the col associated with the boundary will bring light onshore
winds Saturday morning blowing mid and upper 60s dewpoint air over
low and mid 60s water temperatures. I will introduce some sea fog
to the forecast for Saturday. Sunday the surface ridge builds to
the north and the winds turn offshore so sea fog should not be an
issue again until Tuesday when the wind switches to onshore ahead
of an approaching front.

That front which will impact us late in the forecast period is the
result of the longwave trough over the southwest kicking out to
the east through the Ohio Valley. That in turn will lower surface
pressures over South Georgia and then eastward into the Atlantic.
The surface low will tap Gulf Stream energy and deepen pulling
cold air southward in its wake. Yesterday it looked like the axis
of the maximum of cold advection would be a couple hundred miles
east of the state. Today it is starting to look like a cold air
damming/backdoor cold front event setting up for a week from
today. For those of us that do not like cold wx it does not look
like it will last too long as the system is very progressive. I
have also learned to take models seven days out with a grain of
salt, but it is something to watch.


The VISPROB insists on radiation fog at PGD, RSW and FMY. It is
starting to show up in Immokolee at the time of my writing. I have
lowered VSBYs a little on the 6z package but kept everything well
withing VFR range. I will amend if they drop to a level affecting
flight rules.



Very light winds and warm weather will make for great boating all
week. There may be some sea fog issues Saturday morning and again
starting Tuesday morning.


Humidities will be increasing and dispersion decreasing the next
few days. The next shot of dry air should be in about a week.


.Preliminary Point Temps/PoPs...
TPA  73  62  73  60 /   0  10  10   0
FMY  75  60  77  61 /   0   0   0   0
GIF  76  61  72  60 /   0  10  10   0
SRQ  73  62  74  60 /   0   0   0   0
BKV  74  58  71  55 /   0  10  10   0
SPG  71  62  71  61 /   0  10   0   0


Gulf waters...None.


UPPER AIR...19/Hurt
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