Special Weather Statement, NWS Jacksonville, FL

Area Forecast Discussion
National Weather Service Jacksonville FL
240 PM EDT Mon Jul 3 2017

...Hot and Humid with Heat Indices around 105 degrees and
Scattered afternoon/evening storms through Thursday...

.NEAR TERM /through Tuesday/...

Maintaining an hourly POP/weather evolution fairly close to
general HRRR trend...with 2 areas of precipitation focus...1st
over eastern counties of SE GA ahead of 700mb shortwave...and 2nd
over our southern counties where multiple boundaries exist and
where east coast sea breeze more likely to make some progress
inland...along with existence of high precipitable water axis per
GOES-16 derived imagery. Soundings show decent D-CAPE and
differential theta-e values that suggest potential for cold
downdrafts that could yield strong gusty winds from strongest
storms. May be a relative min of convection along I-10 corridor
north of deep moisture axis yet south of 700mb shortwave. Muggy
low temps in mid 70s.

For July 4th...Hot muggy day expected...with model low-level
thickness values a little higher than today...supports mid 90s
inland with some areas seeing upr 90s...heat index values
100-105...with high temps around 90 immediate coast. Models
suggest lesser coverage of afternoon convection compared to past
few days...best chance over our southern counties...with 20-30
POPs further north.

.SHORT TERM /Tuesday Night through Thursday/...

East to West Oriented Weak High pressure ridge remains in place
at the surface and aloft from the Northern GOMEX across the
Florida Peninsula and into the Wrn Atlantic. This will continue
very light steering flow out of the S or SW. Airmass will remain
moist enough to support isolated to scattered storms each day with
PWATS in the 1.6 to 1.8 range. The slightly less coverage of
storms each day than normal will allow for Max Temps to reach well
into the middle 90s inland and even a few upper 90s are possible.
Max Temps closer to 90 and lower 90s near the coast as weak sea
breezes push slowly inland each day. This will support daily heat
indices around 105 degrees during the afternoon hours.

.LONG TERM /Friday through Monday/...

Ridge breaks down slightly Fri/Sat as trof/old frontal boundary
moisture tracks into the SE U.S. and this increase in moisture
will slowly bring back more scattered to numerous shower/storm
activity over the weekend which will linger into early next week.
This will also allow for Max Temps to slip closer to normal with
highs in the lower/middle 90s inland and upper 80s/near 90 at the
coast with Heat Indices in the 100-105 range. Temps aloft may cool
closer to -8/-9C at 500 mb and allow for better coverage of strong
to isolated Severe Storms with wet microburst/downburst potential
increasing slightly.

&&

.AVIATION...Generally VFR conditions expected...except lower
conditions associated with scattered afternoon SHRA/TSRA. Greatest
coverage anticipated to be 20z-00z period over north-central FL
and eastern counties of se GA. Included TEMPO group for this
period at KSSI...KGNV...and KSGJ... with just VCTS JAX areas TAF
sites where lesser coverage anticipated.

&&

.MARINE...Surface ridge of high pressure will remain just S of our
waters...maintaining southerly 10-15kt winds and 2-4ft seas through
the week.

.Rip Currents...Swells are expected to continue to be minimal the
next couple of days so have continued to go with a low risk.
However...rip currents may be briefly enhanced in typical threat
areas...by piers...particularly during afternoon sea breezes.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  74  96  74  97 /  20  20  10  30
SSI  77  91  79  92 /  40  30  10  30
JAX  75  94  75  95 /  30  30  10  40
SGJ  76  91  76  91 /  30  30  10  20
GNV  74  95  73  95 /  20  50  10  50
OCF  74  94  73  94 /  20  50  20  50

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&

Wolf/Hess/McGinnis

Hazardous Weather Outlook
National Weather Service Jacksonville FL
336 AM EDT Mon Ju1 3 2017

AMZ450-452-454-470-472-474-FLZ020>025-030>033-035>038-040-124-125-
GAZ132>136-149>154-162>166-040900-
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-
336 AM EDT Mon Jul 3 2017

...AFTERNOON HEAT INDICES NEAR 105 DEGREES...

This Hazardous Weather Outlook is for Northeast Florida,
Southeast Georgia and the Adjacent Coastal Waters.

.DAY ONE...Today and Tonight...

Scattered thunderstorms will develop this afternoon with
best coverage of storms west of I-95 and across southeast
Georgia in the afternoon into the early evening. Some storms
may be strong and produce gusty winds and frequent lightning
in addition to locally heavy rain.

Prior to showers and storms...high temperatures in the lower
to mid 90s combined with the humidity will produce heat indices
near 105 degrees.

Scattered showers and thunderstorms will linger near the Atlantic
coast this evening...with a gradual decrease in coverage and
intensity through midnight.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday...

Scattered to numerous showers and thunderstorms are expected
each day mainly in the afternoon and evening. Locally heavy
rainfall...gusty winds...and frequent lightning will be possible
in the strongest thunderstorms.

High temperatures in the lower to mid 90s combined with the
humidity will create heat index values 100 to 105 degree.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not needed at this time.

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
321 PM EDT MON JUL 3 2017

FLZ040-032000-
Marion FL-
321 PM EDT MON JUL 3 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL MARION COUNTY UNTIL
400 PM EDT...

At 320 PM EDT, Doppler radar was tracking a strong thunderstorm over
The Villages, moving northwest at 5 mph.

Wind gusts of 45 to 55 mph can be expected along with possible minor
wind damage.

Locations impacted include...
Weirsdale, Ocklawaha, Silver Springs Shores, Lake Weir, Belleview and
Summerfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 2901 8223 2915 8191 2896 8185 2896 8217
TIME...MOT...LOC 1920Z 154DEG 5KT 2895 8197

ELSENHEIMER