Special Weather Statement, NWS Jacksonville, FL

Area Forecast Discussion
National Weather Service Jacksonville FL
320 AM EDT Mon Mar 19 2018

...SEVERE THUNDERSTORMS POSSIBLE TODAY AND TUESDAY...

.SHORT TERM...Today and Tonight...First wave of showers moved
across the area around midnight and weakened. Another area of
convection now upstream over the Fl panhandle and sw Ga will move
across ne Fl/se GA early this morning as short wave aloft moves
east. After this early morning convection the area should get a
break during the late morning and early afternoon until heating
and increasing vertical wind shear aid additional convection late
this afternoon into tonight. A few storms may become severe
mainly over se Ga where a surface front will start to lift north
as a warm front. CAPES are progged to exceed 2000 J/kg with
increasing shear and helicity by late afternoon. Severe threats
will include the possibility of damaging winds...tornadoes...and
large hail.

.SHORT TERM (Tuesday through Thursday)...
Monday's convection (especially if it persists into early Tuesday
morning) could affect what transpires on Tuesday, but the
dynamics remain strong and Tuesday remains the most concerning
timeframe for severe weather (especially across northeast Florida)
as the cold front moves through our area. Theta-E ridge axis
moves into Florida Tuesday morning, and PWATs will rise to near
1.50-1.60 inches - well above the 90th percentile and at or above
daily max value for most dates in mid-March. A potent shortwave is
progged to dive into the lower Mississippi River Valley and into
the Florida Panhandle by early afternoon. Deep layer shear remains
strong with 50 to 60 knots between 0-6km (and 30+ knots between
0-3km) as the front moves through during this timeframe. Breezy
southwest winds could reach wind advisory levels, and with the
surge of moisture in this flow, cloud cover could limit SBCAPE
some. However, MLCAPE/MUCAPE values are still on the order of
2000+ J/kg so there doesn't look to be much trouble with
instability barring the influence of ongoing morning convection.
As a result, a squall line is expected to develop along the front
with embedded severe thunderstorms. Isolated supercell development
is possible ahead of the front, especially south of I-10 by early
to mid-afternoon. Forecast soundings south of the I-10 corridor
this timeframe look similar to yesterday's solutions with enough
SRH capable of strong rotating updrafts. Damaging winds, large
hail and a few tornadoes are all possible. Localized flooding from
heavy rainfall could also become a concern, though storm motion
should remain fairly fast. The severe threat will end from
northwest to southeast with the front clearing north central
Florida counties and the southeast Georgia coast by early evening.

Low pressure deepens as it moves offshore and toward the Northeast,
while the upper level trough also deepens as it moves southward.
Clearing skies and gusty northwesterly winds expected throughout
the day with high temperatures in the low to mid 60s. Northwest
flow aloft and at the surface will continue through Thursday,
though winds will be a lighter. Guidance for overnight lows both
nights have come up a few degrees, with lows generally around 38
to 40 degrees inland, mid 40s along the coast.

.LONG TERM (Friday through Monday)...
Upper level flow will remain northwesterly through Saturday, and
surface flow will shift around and become light and variable as
surface high pressure moves eastward on Friday.  Temperatures will
 rebound to near 70, with overnight lows in the mid 40s to near
50. Surface high moves southeast into the Atlantic on Saturday as
another surface low pressure develops and moves into the mid-
Atlantic. High temperatures will warm into the mid 70s to low 80s
Saturday through Monday, with localized Atlantic seabreeze keeping
temperatures at the coast slightly cooler. Upper level flow turns
more zonal as an upper level trough deepens across the Northeast.
Trailing cold front from the surface low may be able to reach our
northern zones but looks to dry out before it does. Have some
slight chance PoPs Sunday and Monday to account for this
uncertainty.

&&

.AVIATION...Periods of showers and thunderstorms will affect ne
Fl/se Ga TAF sites today and tonight. IFR and MVFR conditions
expected this morning especially in shower activity which will
become likely between 08z-12z. Expect a break with VFR conditions
prevailing late this morning and early afternoon before showers
redevelop by mid-afternoon .

&&

.MARINE...SW winds will increase tonight with Small Craft Advisory
conditions expected to develop Tuesday...extending through at
least Wednesday night. Shower and thunderstorm activity will
become likely today through Tuesday with a cold front pushing
across the waters Tuesday night. Winds and seas will decrease
late Thursday through Friday.

Rip Currents: Low risk through Tuesday due to offshore winds.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  77  65  79  47 /  40  50  70  10
SSI  74  64  76  53 /  70  50  60  10
JAX  80  66  82  50 /  90  40  60   0
SGJ  79  66  79  50 /  90  30  60   0
GNV  79  67  79  48 /  90  50  70   0
OCF  80  68  79  50 /  90  40  70   0

&&

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

Zibura/Elsenheimer/

Special Weather Statement
National Weather Service Jacksonville FL
447 AM EDT MON MAR 19 2018

FLZ021-190915-
Suwannee FL-
447 AM EDT MON MAR 19 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN SUWANNEE COUNTY
UNTIL 515 AM EDT...

At 445 AM EDT, Doppler radar was tracking a strong thunderstorm near
Dowling Park, or 10 miles northwest of Mayo, moving east at 40 mph.
Small hail and frequent lightning strikes are expected with this
storm.

Locations impacted include...
Live Oak, Dowling Park, Luraville, Mcalpin and Newburn.

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 3030 8323 3034 8296 3010 8290 3010 8311
      3011 8312 3010 8314 3011 8316 3010 8317
      3010 8318 3011 8322 3014 8323 3016 8324
      3017 8323 3019 8325
TIME...MOT...LOC 0845Z 273DEG 35KT 3019 8325

ZIBURA