Severe Thunderstorm Warning 161, NWS Jacksonville, FL

Area Forecast Discussion
National Weather Service Jacksonville FL
158 PM EDT SAT AUG 13 2016

.NEAR TERM...This afternoon through Sunday...

Both sea breezes were developed and advancing inland this afternoon
with NNW to SSE oriented cloud streaks indicative of the low level
ridge axis just north of the local area and prevailing steering
flow pushing convection to the NNW. A few cells were starting to
pop across Flagler and St. Johns counties this hour...and
anticipate additional  initiation farther west across NE Florida
through the afternoon. Area of enhanced cumulus near our western
Ga zones will also start to precipitate soon. Through the
afternoon and into the early evening...sea breeze and convective
outflow forcing will focus across the interior of the CWA with
outflow/boundary mergers between the I-75 and Highway 301
corridors with clearing across our zones generally east of the St.
Johns River basin into the evening. Drier and cooler mid/upper
level air over the area on the WNW side of an upper level low
retrograding across S Fl will keep convection scattered in
coverage...but could also enhance downburst potential with
evaporative cooling and steeper lapse rates present in stronger
cells. The main convective concerns will be strong gusty winds of
40-50 mph and excessive lightning across interior locations late
this afternoon and evening. High temps will top out in the low/mid
90s inland with the coast already cooling into the mid 80s with
the east coast sea breeze pushing inland.

Tonight convective will fade in coverage and intensity after sunset
across our western zones with clearing skies after midnight. Could
see some patchy fog and low stratus form inland across the Suwannee
River Valley after midnight as low temps fall into the low/mid 70s
inland to upper 70s/near 80 along the Atlantic coast and St. Johns
River basin.

Sunday the upper level low will be across the eastern Gulf with a
deeper and more moist southerly upper level flow over the area on
the eastern side of the vortex. In addition to cooler temps and a
moisture surge from the south...increasing PVA rotating northward
around the low will sweep across our Fl zones during peak
heating...then progress northward across our SE Ga zones into the
evening. In the lower levels a stronger easterly flow is
expected...which will push the east coast sea breeze inland a bit
faster than today and focus the highest rain chances across our
inland zones toward the I-75 corridor where sea breezes/outflows
will converge as upper level dynamical support pivots above and
low level instability is maximized. In total...appears convective
ingredients will be more favorable for strong to isolated severe
storms Sunday afternoon across our inland zones which could
produce strong downbursts. Temperatures will remain near recent
values with highs in the low/mid 90s inland to upper 80s coast.

.SHORT TERM /Monday through Tuesday Night/...

High pressure at surface and aloft strengthen somewhat while moving very little
during this period...enhancing onshore component of low-level flow. This
should continue pattern with better rainfall chances over the interior counties
compared to coastal counties. Consensus guidance following this with chance POP
values well inland...slight chance values closer to the coast due to lesser
expected coverage. High temps both days will range from upper 80s coast to
around 90 i-95 corridor and 90-95 range further inland.

.LONG TERM...Wednesday Through Saturday/...

Little change in surface/upper pattern until Thursday...as
shortwave trough moves eastward over mid-Atlantic region
Thursday/Friday...causing upper ridge over our area to weaken and
shift south/east..leading to a more southerly surface flow over
our area Fri/Sat. This will support better rain chances for
coastal counties. Near normal temperatures are forecast for
coastal counties...slightly above normal further inland.

&&

.AVIATION...

Prevailing VFR conditions with restrictions possible this afternoon
and evening in scattered convection at inland terminals. Atlantic
coast sea breeze was west of SGJ...SSI and soon CRG with TS not
advertised...while VCTS was still included at the other terminals
through this evening. Precip will fade inland with a NNW drift
with clearing skies overnight. SREF model guidance suggested a low
potential for some patchy shallow ground fog and low stratus
mainly near and west of the I-75 corridor Sunday morning but
confidence not high enough at this time to include in forecast for
GNV.

&&

.MARINE...

Surface high pressure will dominate northeast of the local waters
which will continue a prevailing southeast flow over the local
waters. Daytime sea breezes will increase magnitudes to near 15
kts at times along the coast with nocturnal land breezes shifting
the winds offshore early in the morning. Combined seas will
generally range below 3 ft.

Rip Currents: Low risk today and Sunday.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  72  95  74  94 /  30  20  10  30
SSI  78  89  79  89 /  10  10  10  20
JAX  74  92  75  92 /  10  30  10  30
SGJ  76  89  78  88 /  10  30  10  30
GNV  72  92  74  92 /  40  60  20  50
OCF  72  92  74  93 /  40  60  30  40

&&

.JAX Watches/Warnings/Advisories...
FL...None.
GA...None.
AM...None.
&&

Enyedi/Wolf/Nelson

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSONVILLE FL
949 AM EDT SAT AUG 13 2016

AMZ450-452-454-470-472-474-FLZ020>025-030>033-035>038-040-124-125-
GAZ132>136-149>154-162>166-141400-
COASTAL WATERS FROM ALTAMAHA SOUND TO FERNANDINA BEACH FL OUT
20 NM-
COASTAL WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL OUT
20 NM-
COASTAL WATERS FROM ST. AUGUSTINE TO FLAGLER BEACH FL OUT 20 NM-
WATERS FROM ALTAMAHA SOUND GA TO FERNANDINA BEACH FL FROM 20 TO
60 NM-
WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL FROM 20 TO 60 NM-
WATERS FROM ST. AUGUSTINE TO FLAGLER BEACH FL FROM 20 TO 60 NM-
HAMILTON-SUWANNEE-COLUMBIA-BAKER-INLAND NASSAU-INLAND DUVAL-UNION-
BRADFORD-CLAY-ST. JOHNS-GILCHRIST-ALACHUA-PUTNAM-FLAGLER-MARION-
COASTAL NASSAU-COASTAL DUVAL-COFFEE-JEFF DAVIS-BACON-APPLING-
WAYNE-ATKINSON-WARE-PIERCE-BRANTLEY-INLAND GLYNN-COASTAL GLYNN-
ECHOLS-CLINCH-CHARLTON-INLAND CAMDEN-COASTAL CAMDEN-
949 AM EDT SAT AUG 13 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST FLORIDA...
SOUTHEAST GEORGIA AND THE ADJACENT COASTAL WATERS.

.DAY ONE...TODAY AND TONIGHT...

SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EARLY
EVENING...MAINLY OVER INLAND AREAS. STORM MOTION WILL GENERALLY BE
TOWARDS THE NORTH NORTHWEST AROUND 10 TO 15 MPH. A FEW STRONG
STORMS WITH GUSTY WINDS...FREQUENT LIGHTNING AND LOCALLY HEAVY
RAINFALL CAN BE EXPECTED.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY...

SCATTERED THUNDERSTORMS ARE POSSIBLE EACH DAY...PRIMARILY DURING
THE AFTERNOON AND EARLY EVENING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

FOR ADDITIONAL INFORMATION...VISIT THE NATIONAL WEATHER SERVICE
IN JACKSONVILLE WEBSITE ON THE INTERNET AT WEATHER.GOV/JAX.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
511 PM EDT SAT AUG 13 2016

FLZ032-132200-
CLAY FL-
511 PM EDT SAT AUG 13 2016

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL CLAY COUNTY UNTIL 600 PM
EDT...

AT 511 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
MIDDLEBURG...MOVING NORTHWEST AT 10 MPH.

HAIL UP TO NICKEL SIZE IN DIAMETER...EXCESSIVE CLOUD-TO-GROUND
LIGHTNING AND GUSTY WINDS OF 45 TO 55 MPH CAN BE EXPECTED ALONG WITH
POSSIBLE MINOR DAMAGE.

LOCATIONS IMPACTED INCLUDE...
MIDDLEBURG...PENNEY FARMS AND ASBURY LAKE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...
REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY
EMERGENCY MANAGEMENT.

LAT...LON 3002 8177 2990 8182 2996 8200 3014 8187
TIME...MOT...LOC 2111Z 120DEG 7KT 3000 8182

PETERSON