Scientific Forecaster Discussion
fxus62 ktbw 202342
Area forecast discussion
National Weather Service Tampa Bay Ruskin Florida
642 PM EST Mon Feb 20 2017
mainly VFR conditions are expected through the forecast period with
the exception of some patchy fog at klal and kpgd. Otherwise, some
lower clouds could affect terminals for a few hours tonight
underneath the currently-forecast bkn cirrus deck, but confidence is
not high enough to include any restrictions with this forecast
Prev discussion... /issued 254 PM EST Mon Feb 20 2017/
Short term (tonight - Tuesday...
a highly amplified upper level pattern has set up over the eastern
U.S. With sharp ridging extending from Florida northward through the
Great Lakes region. Farther to the west, deep troughing extends
across the Great Plains region southward through Texas. This trough
deepens and closes into an upper low over eastern Texas by early
Tuesday morning. This will cause the ridge over Florida to slightly
weaken and slide east of the state. By late Tuesday, the ridge is
now over the Bahamas as the upper low sits over the la/MS border. On
the surface, high pressure remains the dominant feature over the
eastern U.S. Through the short term period. Mostly sunny skies and
warm temperatures will prevail through the period. Winds will remain
light out of the east until Tuesday afternoon as the surface high
shifts east of the area and a developing area of low pressure and
frontal boundary over the northern Gulf Coast approaches the region.
This will cause a shift in the winds to the south-southeast.
Temperatures will be quite warm on Tuesday once again with highs
8-10 degrees above normal for late February.
complex weather weather pattern at the start of the mid-term
forecast period. Models have been consistently inconsistent from run-
to-run with an area of low pressure that they've been showing for
days now and trying to narrow down specifics has been difficult.
That being said, over the last few runs they seem to be in much
better agreement with pushing the low into the eastern Gulf after it
moves out of the Mississippi Delta Region. Because of this, forecast
rain chances have been increased significantly for Wednesday and
Thursday compared to this morning's forecast. Likely showers have
been added to the forecast area wide Wednesday with pops now in the
60-80 range area-wide. A few slight discrepancies remain wrt to
specific location of the surface low which will have an impact on
wind direction/speeds for areas. Ample lift on Thursday should
continue to support sct shower chances for much of Thursday as well.
The area of low pressure will track east of Florida late in the week
with skies gradually clearing across the forecast area...although no
significant airmass change will occur as temperatures will continue
to run several degrees above normal through the mid/long term
period. A cold front will approach west central Florida over the
weekend, however the front will likely weaken and stall over North
Florida as it becomes parallel to quasi-zonal u/l flow across the
Gulf of Mexico and Florida. The front will also have little in the
way of deep layer moisture to work with and no u/l support so no
shower activity expected attm.
VFR conditions will prevail through the period, with some patchy br
possible in the 08z to 14z timeframe. This looks to mainly
affect the more fog-prone terminals of klal and kpgd.
Easterly winds will shift to onshore near the coast from srq
north later in the afternoon.
high pressure has set up over the eastern half of the U.S. Producing
favorable boating conditions over the coastal waters. Winds will
remain 15 knots or less with seas 3 feet or less through
the week. Conditions will remain rain free until Wednesday
when a frontal boundary moves through the area. In the wake
of this front, conditions will still remain below any
advisory or cautionary level for winds and seas through the
end of the week.
despite having high pressure ridging over the area, the lowest
relative humidity values will remain between 40-50 percent for the
next couple of days. A frontal boundary approaches the area on
Wednesday into early Thursday and will bring rainshowers
and isolated storms to the area and will also keep relative humidity values
above any critical level for fire weather concerns.
Preliminary point temps/pops...
tpa 64 80 65 75 / 0 0 20 80
fmy 62 82 64 76 / 0 0 10 80
gif 61 82 63 76 / 0 0 10 80
srq 61 78 63 74 / 0 0 20 80
bkv 57 82 60 76 / 0 0 10 70
spg 65 79 66 74 / 0 0 20 80