Flash Flood Warning 11, NWS Tallahassee, FL

Area Forecast Discussion
National Weather Service Tallahassee FL
548 AM EDT MON JUN 6 2016

...Tropical Storm Colin to Bring Impacts to the Area Today and
This Evening...

.DISCUSSION...

[UPDATED ON 5 AM ADVISORY CYCLE] Tropical Storm Colin formed
yesterday over the southern Gulf of Mexico, and per NHC became
the earliest 3rd tropical storm of the season in the Atlantic
basin records. We have updated the discussion below based on the
latest information, and it will be focused on the main impacts and
key messages associated with Colin in our local area. For more
detailed information, please see the HLSTAE or TCVTAE products.

***** KEY MESSAGES *****

  1. The primary impacts in our area are expected to be related
     to flooding, both due to localized heavy rainfall and storm
     surge along the Apalachee Bay coastline. Any tropical storm
     force winds should be largely confined to the Gulf of Mexico
     and immediate coastal land locations.

  2. Isolated very high rainfall totals - over 6 inches in a
     relatively short period of time - may lead to localized
     flash flooding, particularly in urban areas. It is difficult
     to pinpoint the exact areas this would occur, but the best
     chances will be in our Florida and Georgia zones.

  3. Several feet of storm surge inundation is expected along
     parts of the Apalachee Bay coastline on Monday afternoon
     during the high tide cycle. Interests along Apalachee Bay,
     especially on Wakulla, Jefferson, Taylor, and Dixie County
     coasts, should prepare for inundation on the higher end of
     current forecasts (3-4 feet).

***** FORECAST ANALYSIS *****

Colin remains a sheared and highly asymmetric system, with the
vast majority of the wind and rainfall situated in the eastern
semicircle. These situations can lead to greater forecast track
uncertainty (even if the model guidance is tightly clustered), as
low-level centers can reform underneath larger convective bursts.
The 5 AM NHC discussion noted that two different low-level centers
had recently been sampled by Hurricane Hunters aircraft.

The main change with this advisory cycle was to expand the Flood
Watch to the north and west of the existing area. Latest radar
loops show a band of enhanced rainfall rates already developing
from Panama City, to Bainbridge, to Tifton. Some model guidance
shows a band of heavy rain in this same corridor today, and out of
deference to those solutions (and the current radar trends), the
Flood Watch was expanded. High resolution models continue to
depict hourly rainfall rates peaking at 2-4"/hr in areas of slow-
moving or training convection later today. Several observation
sites this morning have already picked up around 0.4" rain in only
10-15 minutes with some of the first rain bands. The 06Z
Tallahassee sounding had a PWAT of 2.25" and a very high freezing
level of 16kft, suggesting very efficient warm rain processes will
be common today (and have already been observed). Given all of
this, locally very heavy rainfall and flash flooding continues to
be our primary concern related to TS Colin.

The storm surge flooding and tornado threats could be augmented by
the eventual track of the center of Colin. A track further to the
north and west of the NHC official forecast could yield a greater
tornado threat over the Florida Big Bend, as well as storm surge
inundation closer to the higher end of forecasts (around 4 feet).
Given the uncertainty in just how the low-level wind fields will
evolve, interests along the Apalachee Bay coastline should
prepare for the possibility of 3-4 feet of inundation due to storm
surge around the afternoon high tide cycle.

&&

.MARINE...

[NO CHANGES] Hazardous marine conditions should quickly develop
within a few hours of sunrise, and gradually worsen until the
center of Colin approaches later in the afternoon. The strongest
sustained winds in our marine areas are in the 40-45 knot range
with higher gusts, and seas peak around 10-15 feet.

&&

.AVIATION [Through 06Z Tuesday]...

[NO CHANGES] Bands of scattered heavy showers will fill in
through the AM hours with more widespread heavy rain expected
through the day. In heavier showers, IFR to LIFR visibilities
should be expected under MVFR ceilings. Gusty winds associated
with TS Colin will be most likely over our southeastern most
terminals (TLH and VLD) and should be in the 20 to 25 knot range
later this afternoon. Rain will taper off gradually from west to
east starting late this afternoon, possibly clearing all of our
terminals to the east just before the end of the TAF.

&&

.PRELIMINARY POINT TEMPS/POPS...

Tallahassee   79  72  92  70  94 / 100  70  20   0   0
Panama City   84  75  87  75  85 /  80  40  10   0   0
Dothan        82  70  90  68  89 /  80  30  10   0   0
Albany        79  71  91  68  89 /  80  60  10   0   0
Valdosta      79  72  89  68  91 / 100  90  20   0   0
Cross City    80  74  89  72  92 / 100  90  30  10  10
Apalachicola  81  74  88  74  88 / 100  60  20   0   0

&&

.TAE WATCHES/WARNINGS/ADVISORIES...

FL...Flood Watch through late tonight for Calhoun-Central Walton-
     Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-
     Coastal Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden-
     Inland Bay-Inland Dixie-Inland Franklin-Inland Gulf-Inland
     Jefferson-Inland Taylor-Inland Wakulla-Jackson-Lafayette-
     Leon-Liberty-Madison-South Walton-Washington.

     Tropical Storm Warning for Coastal Dixie-Coastal Franklin-
     Coastal Jefferson-Coastal Taylor-Coastal Wakulla-Inland
     Dixie-Inland Franklin-Inland Taylor-Inland Wakulla-
     Lafayette.

     High Rip Current Risk through Tuesday morning for Coastal Bay-
     Coastal Gulf-South Walton.

     High Surf Advisory until 8 AM EDT /7 AM CDT/ Tuesday for Coastal
     Bay-South Walton.

GA...Flood Watch through late tonight for Baker-Ben Hill-Berrien-
     Brooks-Colquitt-Cook-Decatur-Dougherty-Grady-Irwin-Lanier-
     Lowndes-Miller-Mitchell-Seminole-Thomas-Tift-Turner-Worth.

AL...None.

GM...Tropical Storm Warning for All Zones.

&&

LAMERS/HARRIGAN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1231 PM EDT MON JUN 06 2016

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1228 PM     HEAVY RAIN       5 E TALLAHASSEE         30.44N 84.20W
06/06/2016  M0.00 INCH       LEON               FL   PUBLIC

            FORMER NWS EMPLOYEE MEASURED 6.35 INCHES STORM TOTAL AND
            5.2 INCHES SINCE 7AM.

&&

CAMP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1253 PM EDT MON JUN 06 2016

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1250 PM     HEAVY RAIN       5 SE TALLAHASSEE        30.39N 84.22W
06/06/2016  M0.00 INCH       LEON               FL   COCORAHS

            FORMER NWS EMPLOYEE REPORTS 3.86 INCHES OVER THE PAST 4
            HOURS.

&&

CAMP