Scientific Forecaster Discussion
fxus62 ktbw 261921
Area forecast discussion
National Weather Service Tampa Bay Ruskin Florida
321 PM EDT Wed Apr 26 2017
Short term (tonight-thursday)...
mid/upper level shortwave trough will swing through the Mississippi
and Ohio valleys moving by to the north of the region with its
associated cold front weakening and dissipating before it reaches
the forecast area. The mid/upper level dynamics will remain well to
the north of the area and with limited moisture not expecting any
precipitation. What we will see however is an increase temperatures
and humidity as the southeast to south flow continues around surface
high pressure ridging west from well out in the Atlantic Ocean with
a shift to southwest near the coast as the sea breeze develops
Thursday afternoon. The increase in low level moisture along with
the mostly clear skies could lead to some patchy fog over inland
areas late tonight. Otherwise temperatures will be above normal with
lows in the mid 60s to around 70 tonight and climbing into the mid
80s coast to the lower 90s inland Thursday.
Middle term/long term (thursday night - wednesday)...
an upper level low sits over northern Minnesota with broad
troughing extending over the western half of the U.S. Upper level
ridging continues to hold over the Florida Peninsula into the long
term period. The troughing over the western U.S. Will further
deepen by Saturday as a closed upper low moves southeast and will
be located over The Four Corners region. As the trough out west
deepens, the ridge over the southeast U.S. Will strengthen and
build northeastward toward Bermuda. The pattern shifts east by the
beginning of next week with the closed upper low now located over
the Great Lakes region and the upper ridge moving east into the
western Atlantic. The upper low moves northeast by midweek and a
quasi-zonal flow sets up over Florida.
On the surface, an area of low pressure over Ontario extends a cold
front southward along the East Coast. This front dissipates over
northern Florida as high pressure continues to ridge across the
peninsula through the end of the week and into the weekend. This
will keep a southeast through southwest wind flow over the area
which will result in above average temperatures with the inland
counties seeing daytime highs in the 90's. Rain free conditions will
also continue through Sunday. An area of low pressure develops over
Missouri on Sunday and extends a cold front south through Louisiana
and eastern Texas. This system tracks east and will bring increasing
rain chances (30-50 pops) to Florida on Monday and Tuesday.
VFR conditions will prevail for the next 24 hours with some
scattered to occasional broken ceilings between 5000 and 7000 feet
this afternoon and early evening. South to southwest at around 10
knots will diminish this evening and back to southeast overnight
and then increase out of the south again Thursday morning.
southeast to south flow will persist into early next week with a
shift to southwest near the coast each afternoon. Winds will
generally remain around 15 knots or less with seas 3 feet or less.
Winds could reach exercise caution criteria late tonight and
early Thursday morning across the northern waters for a short
period and then across the offshore waters Saturday night and
relative humidity values are expected to dip into the middle and
upper 30s each afternoon through the weekend, but critical
durations are not expected and sustained winds should remain less
than 15 mph. Therefore, no red flag conditions are anticipated.
Preliminary point temps/pops...
tpa 73 88 73 90 / 0 0 0 10
fmy 69 91 72 92 / 0 0 0 10
gif 67 93 71 95 / 0 0 0 20
srq 70 86 71 86 / 0 0 0 10
bkv 63 91 66 93 / 0 0 0 20
spg 73 85 75 89 / 0 0 0 10