Special Weather Statement, NWS Jacksonville, FL

Area Forecast Discussion
National Weather Service Jacksonville FL
223 AM EDT Sun Jun 20 2021

...STRONG TO SEVERE STORMS POSSIBLE IN RAINBANDS TODAY...

.NEAR TERM [Through Tonight]...

Tropical Depression Claudette was across Alabama early this
morning. The Depression will track across Georgia to the north of
the area this morning into the afternoon before moving into South
Carolina. Deep tropical moisture to the south of Claudette will
move across the area this morning into the afternoon, and numerous
light showers were moving across the area early this morning.
Model soundings show low level southerly flow with southwesterly
40-45 knot 850mb winds across southeast Georgia and the I-10
corridor. Guidance shows 0-1km helicity values of 200-350 m2/s2 as
far south as the I-10 corridor. Model soundings are hinting that
there could be steeper low level lapse rates as well across
southeast Georgia and into portions of northeast Florida. Any
storms that are able to develop will likely be rotating, and mini
supercells could produce damaging winds and isolated tornadoes
today. SPC has upgraded southeast Georgia to a Slight Risk of
Severe Storms for today, with much of northeast Florida in a
Marginal Risk.

Numerous to widespread bands of showers and embedded storms will
move across the area this morning into the early afternoon hours.
Guidance is suggesting a heavy band of showers and embedded storms
will move into the Suwannee Valley from the Gulf of Mexico before
daybreak, and locally heavy rainfall is possible in the Suwannee
Valley this morning. Other heavy rainbands may form across the
area as well through the morning and into the mid afternoon, and
ponding on roadways and localized flooding is possible with any
training heavy showers/storms. Subsidence is expected in the mid
to late afternoon as the Claudette moves into South Carolina. This
will bring lower rain chances from the late afternoon and into the
evening and overnight hours.

Went in the middle to lower side of guidance for high temperatures
today since there is already considerable amounts of showers
across the region. Highs will likely remain in the low to mid 80s
for much of the area, with areas seeing clearing in the late
afternoon possibly reaching as high as 90 degrees. Overnight lows
will be mild in the low to mid 70s.

.SHORT TERM [Monday Through Wednesday]...

Tropical low will move toward the northeast Monday, with high
pressure to the southeast. Southwest flow will prevail Monday,
keeping east coast sea breeze from moving in. Convection Monday will
be driven by diurnal heating and convergence along gulf coast sea
breeze as it moves inland. Activity will diminish toward midnight.

On Tuesday, the region will be between high pressure to the east
southeast and a trough to the northwest. The region will be in the
base of a 500mb trough. Once again the surface flow will prevail
from the southwest, allowing the gulf coast sea breeze to move well
inland, while the east coast sea breeze has little impact. The
trough aloft will provide an additional source of instability. So,
Tuesday is expected to be an active convective day. Convection
will decrease toward midnight.

The surface trough will diminish as it moves toward the area Tuesday
night into Wednesday, while the region remains in an upper trough.
Another fairly active convective day anticipated Wednesday.

Temperatures will trend near normal at night, and near to a little
below during the day time.

.LONG TERM [Wednesday Night Through Sunday]...

Surface high pressure will be northeast Wednesday night through
Friday. The surface high will build more toward the east Saturday,
as an upper trough dips into region.

The surface flow will prevail from the southeast this period,
allowing the east coast sea breeze to push well inland each day.

Daily rounds of showers and storms expected this period, with
greatest chances during the afternoon and evening hours.

Temperatures will be near normal this period.

&&

.AVIATION...
[Through 06Z Monday]

Showers were moving across the area early this morning, and
showers and embedded storms will increase in coverage through the
morning hours and into the early afternoon. Restrictions are
possible at the TAF sites, especially from mid morning through
early afternoon. South to southwest winds 10-15 knots will prevail
through the day, with winds diminishing near the end of the TAF
period.

&&

.MARINE...

Tropical Depression Claudette is expected to move northeast
towards the Carolinas today and tonight and exit into the Western
Atlantic on Monday. Winds will increase from the south to Small
Craft Advisory levels this morning over southeast Georgia waters.
High pressure will shift to the southeast through early next week
and winds will shift to become southwesterly. A frontal boundary
will approach the area from the northwest midweek and is expected
to stall over the area waters late in the week.

Rip Currents: Moderate risk of rip currents at the beaches today.
Low risk of rip currents at the beaches on Monday.

&&

.PRELIMINARY POINT TEMPS/POPS...

AMG  85  72  90  72  83 /  90  50  40  10  70
SSI  85  76  90  76  85 /  70  40  30  10  60
JAX  84  74  93  73  87 /  80  20  30  10  60
SGJ  86  74  91  74  87 /  60  20  20  10  50
GNV  85  73  89  73  85 /  70  30  40  10  60
OCF  86  74  89  73  89 /  60  30  40  10  60

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...Small Craft Advisory from 10 AM this morning to 5 AM EDT Monday
     for Coastal waters from Altamaha Sound to Fernandina Beach
     FL out 20 NM-Waters from Altamaha Sound GA to Fernandina
     Beach FL from 20 to 60 NM.

&&

Special Weather Statement
National Weather Service Jacksonville FL
508 AM EDT Sun Jun 20 2021

FLZ020-021-GAZ162-200945-
Hamilton FL-Suwannee FL-Echols GA-
508 AM EDT Sun Jun 20 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN SUWANNEE...HAMILTON
AND ECHOLS COUNTIES UNTIL 545 AM EDT...

* At 507 AM EDT, National Weather Service meteorologists were
  tracking a strong thunderstorm near Lake Park, moving northeast at
  40 mph.

* Winds in excess of 45 mph, funnel clouds, and minor flooding due to
  heavy rainfall is possible with this storm.

* Locations impacted include...
  Jasper, Jennings, Suwannee Springs, Statenville, Suwannee River
  State Park, Mayday, Blue Springs and Crossroads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

These winds can down small tree limbs and branches, and blow around
unsecured small objects. Seek shelter in a safe building until the
storm passes.

Torrential rainfall is occurring with this storm, and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

This activity was also developing in an environment favorable for the
formation of funnel clouds. Stay tuned to NOAA weather radio and
local media for additional updates and possible warnings.

To report severe weather, contact your nearest law enforcement
agency. You can also share your report with NWS Jacksonville on
Facebook and Twitter.

&&

LAT...LON 3063 8314 3079 8313 3085 8306 3085 8301
      3087 8297 3084 8286 3081 8283 3036 8279
      3028 8324 3031 8321 3035 8321 3035 8319
      3038 8319 3039 8317 3041 8318 3042 8322
      3046 8322 3047 8324 3062 8327 3063 8331
TIME...MOT...LOC 0907Z 239DEG 33KT 3061 8326

AK