Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 09/29/22
Area Forecast Discussion
National Weather Service Melbourne FL
Issued by National Weather Service Corpus Christi TX
754 PM EDT Wed Sep 28 2022
...New AVIATION...
.UPDATE...
Issued at 327 PM EDT Wed Sep 28 2022
At 305 PM EDT (1800 UTC), the eye of Hurricane Ian was located by
an Air Force Reserve Hurricane Hunter aircraft and Tampa radar
data near latitude 26.7 North, longitude 82.2 West over Sanibel
Island. Ian is moving toward the north-northeast near 9 mph. This
general motion with a reduction in forward speed is forecast
tonight, followed by a turn toward the northeast on Thursday. The
center of Ian moved onshore at Sanibel Island around 305 PM.
Maximum sustained winds remain near 150 mph with higher gusts.
Ian is a high end category 4 hurricane on the Saffir-Simpson
Hurricane Wind Scale. Ian remains a catastrophic hurricane and
weakening can be expected now that landfall has occurred, but Ian
could be near hurricane strength when it moves over the Florida
East coast Thursday.
&&
.DISCUSSION...
Tropical storm conditions will continue this evening and
overnight mainly in squalls. Additionally, a tornado or two will
be possible, associated with squalls into the nighttime period.
The Tornado Watch presently in effect for most of the region
through 5 PM will likely be expanded northward to some degree into
tonight. Widespread rain coverage with the chance of additional
flooding, especially across north central FL and the I-4 corridor,
with highest rainfall totals projected along and north of the
track of Ian as it slowly moves inland west of the area. Gusty
winds up to Tropical Storm force, along with a few tornadoes will
be the main concern for the bands through tonight. Creeks and
rivers that are already approaching bankfull will overflow,
leading to substantial flooding. Urban locations and low lying
areas are especially susceptible, with inundation of major
roadways and flooding of structures possible.
With considerable clouds, temperatures will remain mild with overnight
lows in the low to mid 70s.
Thursday...The most significant local wind impacts from Hurricane
Ian are expected to begin by daybreak Thursday morning and
continue through the day, as the center tracks slowly northeastward
over east central Florida, and pushes offshore by evening. Per
the latest NHC advisory, Ian is expected to cross into the
northern MLB forecast area near hurricane strength, and weaken to
a tropical storm while approaching the east coast. Sustained
winds near the center are expected to be around or just below
65kt/74mph in the early morning, then decrease to around
50kt/58mph by the afternoon as the center begins to move offshore.
Tropical storm force conditions continue through the afternoon
and into the evening. Gusts to hurricane strength will be possible
through the day in all counties except Indian River, Saint Lucie
and Martin counties. Further away from the center, expecting
occasional tropical storm force gusts through the day. Tropical
storm force winds continue through the evening, then begin to
subside as Ian pushes further offshore. Stronger squalls will
still be capable of gusts to hurricane force over the northeast
coast.
Friday-Wednesday...Breezy to locally windy conditions with
lingering showers/squalls expected early Friday, especially the
northern half of the forecast area, as Ian lifts northward into
the Atlantic waters off Florida and Georgia. Guidance continues to
show a significant dry air punch crossing Florida as it wraps
into the system late Friday into Saturday, resulting in much lower
PoPs through mid next week.
Afternoon highs increase from the L-M80s in Ian`s rains and cloud
cover, to the M-U80s Friday onward, thanks to the considerably drier
and cooler air getting wrapped across Florida. Overnight lows become
fairly comfortable, in the U60s-L70s.
&&
.MARINE...
Issued at 327 PM EDT Wed Sep 28 2022
Considerable squalls moving from south to north will produce
tropical storm gusts along with a possible waterspout. Seas will
build well above hazardous level over the open Atlantic.
Thursday-Sunday...Dangerous seas up to 20 ft and tropical storm
force conditions expected Thursday as Hurricane Ian pushes
offshore the east central Florida coast, and exit the local
Atlantic waters to the north. Winds over 40 kts, backing from S
over the Treasure Coast waters to E over the Volusia waters around
Ian. Seas begin to subside Friday, but remain hazardous at 6-9 ft
across the Treasure Coast waters and 7-13 ft across the Volusia
waters. Advisories and Cautionary statements are likely to
continue through the end of the week.
Boating conditions expected to become more favorable during the
weekend as cool dry air gets wrapped across Florida and the local
Atlantic waters in the wake of Ian. Winds SW-S around 15 kts,
decreasing to 10 kts from the W Sunday. Seas 3-5 ft, occasionally 6
ft, subsiding to 2-4 ft this weekend.
&&
.AVIATION...
(00Z TAFS)
Provided by NWS Corpus Cristi at 740 PM EDT Wed Sep 28 2022
Conditions are expected to continue to deteriorate through tonight
into Thursday morning as Hurricane Ian continues moving north-
northeast across central Florida. All TAF sites across the region
will be impacted, especially as bands move across the area
resulting in gusts ranging from 45-65 knots, possibly higher.
Strongest winds are expected to effect MLB northward with even
stronger winds for MCO/ISM/DAB overnight into Thursday. Have gone
with prevailing IFR/MVFR conditions with periods of LIFR,
especially as Hurricane Ian moves across the area.
&&
.HYDROLOGY...
Issued at 327 PM EDT Wed Sep 28 2022
.HYDROLOGY...
Historic rainfall is expected to spread across the area over the
next 48 hours as Hurricane Ian pushes inland over southwest Florida.
Updated guidance now suggests a range of 12 to 20 inches with
locally higher amounts up to 30 inches as the center of Ian tracks
northeast across Central Florida. These highest totals are generally
concentrated along and north of I-4, spreading along an axis from
Lakeland to Daytona Beach. Elsewhere across east central FL,
rainfall totals will range from 4 to 12 inches with isolated higher
amounts depending on where heavy rainbands set up. A Flood Watch
remains in effect for all of east central Florida.
This amount of rainfall will cause major and catastrophic
flooding for portions of the area. Creeks and rivers that are
already approaching bankfull will overflow, leading to the
possibility of unprecedented flooding given these forecast rain
amounts for the metro Orlando corridor and Saint Johns River
basin. Numerous water rescues and substantial inundation of
structures is likely beginning tonight and throughout the day
Thursday, especially across traditionally flood prone urban and
suburban areas around Orlando.
Levels along the Saint Johns River will continue to rise, with
greater significant rises expected later in the week as rainfall
from Hurricane Ian drains into the basin. The forecast points at
Astor, Lake Harney above Geneva and Deland are all expected to
rise to Major Flood Stage and increasing likelihood and confidence
in reaching Record Flood Stage, with comparable crests near or
above Irma levels in 2017. Levels on the Little Wekiva River could
rise well above Major Flood, also nearing Record Flood Stage
tonight into tomorrow, with Shingle Creek near Campbell also
reaching Hurricane Irma levels in Moderate to Major flood stage.
All river forecasts are highly dependent on rainfall amounts that
reach the basin, so less or more rainfall will cause variability
in observed stages.
Interests along the Saint Johns north of Cocoa, Shingle Creek and
Little Wekiva River should prepare for major flood impacts,
substantial flooding of structures along the river.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 74 82 70 80 / 100 100 90 60
MCO 75 82 70 81 / 90 90 70 40
MLB 76 85 70 84 / 90 90 70 40
VRB 76 86 70 86 / 80 80 50 40
LEE 72 77 67 77 / 100 90 70 40
SFB 74 80 69 79 / 100 100 80 50
ORL 75 80 70 81 / 100 90 70 40
FPR 76 85 70 86 / 80 80 50 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Tornado Watch until 1 AM EDT Thursday for FLZ041-045-046-053-058-
141-154-159-164-247-254-259-264-347-447-547-647-747.
Tropical Storm Warning for FLZ041-141-154-159-164-247-254-259-
264-347-447-547-647-747.
Hurricane Warning for FLZ041-044>046-053-058-141-144-247-347-447-
547-647-747.
Flood Watch through late Thursday night for FLZ041-044>046-053-
058-141-144-154-159-164-247-254-259-264-347-447-547-647-747.
AM...Tornado Watch until 1 AM EDT Thursday for AMZ550-552-555-570-572-
575.
Tropical Storm Warning for AMZ550-552-555-570-572-575.
Hurricane Warning for AMZ550-552-570-572.
&&
$$
DIGITAL FORECASTS...Pendergrast/Schaper
HYDROLOGY...Smith
AVIATION...NWS Corpus Cristi
IDSS...Weitlich/Ulrich/Sharp/Volkmer
DATAC/DATA MINING...Tollefsen/Leahy
NWS SAVI Activated at this time