Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Tampa Bay Ruskin Florida
921 am EDT Monday Aug 31 2015

..Flood Watch remains in effect through this evening...
..Some locally heavy rain and flooding possible today...

a trough of low pressure (remnants of erika) over the eastern Gulf
waters this morning will continue to lift slowly to the west and
northwest around the subtropical ridge located over the Atlantic
the remainder of today. Deep tropical moisture (pw 2.12 inches)
associated with this trough combined with some upper level energy
moving around the western periphery of the upper ridge...daytime
heating...lingering divergence aloft and sea breeze interactions
will allow numerous showers and storms to develop over the region
by later this morning and into the afternoon with some locally
heavy rain possible...especially in areas where any training of
storms occur. With the deepest moisture axis (pw's in the 2.2. To
2.4 inch range) slowly lifting north today in tandem with the
trough axis expect the best and highest rain chances to set up
along and to the north of the I-4 corridor during the afternoon
hours...although fairly good storm coverage is also expected
inland and to the south as well as sea breeze and outflow
boundary interactions take place with a southerly steering flow
pushing all of the convection to the north through early evening.

With the ground around the region extremely saturated any
additional heavy rainfall will cause rapid runoff and additional
flooding problems. Given this will maintain the Flood Watch from
Hernando County south to Lee County through this evening...and
will evaluate whether this watch will need to be expanded further
north or extended out in time by later this afternoon once new
model guidance has been reviewed.

Current forecast is in good shape so a morning update will not be
required at this time.


developing rain showers/thunderstorms and rain will bring brief MVFR/IFR conditions to the
terminal sites after 16z. Outside of the convection VFR is
expected. Prevailing VFR should return to all sites after 02z
tonight. Southeast winds around 5 knots early this morning will
become southeast to south around 10 knots after 16z...with gusts
up to 35 knots possible in the vicinity of thunderstorms and rain.


a trough of low pressure (remnants of erika) lifting slowly west
northwest over the eastern Gulf will support southeast to
southerly winds in the 10 to 15 knot range near shore...and
around 15 knots offshore with seas of 2 to 4 feet the remainder of
today with higher gusts in the vicinity of thunderstorms. The
current forecast is on track with no changes expected in the next
forecast issuance later this morning.


heavy rainfall over the region dating back to late July has
brought numerous rivers across the area into minor or moderate
flood. Additional rainfall is forecast for the first half of the
week as the remnants of Erika skirts the Florida Peninsula...which
will exacerbate existing river flooding. As of early this morning
a total of 14 river forecast points across the forecast area are
already in flood or forecast to reach flood stage this week. Visit
weather.Gov/Tampa and click 'rivers/lakes' along the right hand
side for up to date forecasts on each river forecast point.

Residents living along rivers or faster flowing streams should
monitor water levels and be ready to move to higher ground should
flooding be observed.


with this the last day of August and the potential for more heavy
rainfall...Tampa could end up as the wettest August or July
August combined...and could reach into the top 3 wettest Summers
(june/July/august) since record began in 1890.

Tampa area Tampa area Tampa area
wettest August wettest Jul/Aug wettest Summer

1 18.59 in 1949 1 28.31 in 1960 1 43.03 in 1945
2 17.83 in 1898 2 28.28 in 2015* 2 36.13 in 2012
3 16.44 in 2015* 3 26.33 in 1925 3 34.79 in 1909
4 15.17 in 1932 4 26.12 in 1898 4 34.67 in 1960
5 14.90 in 2003 5 24.53 in 1906 5 34.51 in 2015*

* 2015 rainfall total as of early this morning.


Tbw watches/warnings/advisories...
Florida...Flood Watch until 8 PM EDT this evening for coastal
Charlotte-coastal Hernando-coastal Hillsborough-
coastal Lee-coastal Manatee-coastal Pasco-coastal
Sarasota-DeSoto-Hardee-Highlands-inland Charlotte-
inland Hernando-inland Hillsborough-inland Lee-inland
Manatee-inland Pasco-inland Sarasota-Pinellas-Polk.

Gulf waters...none.


upper air/rivers...007/Dougherty
decision support...20/Barron

National Weather Service Glossary of Abbreviations