575
FXUS02 KWBC 060626
PMDEPD

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
226 AM EDT Sun Oct 6 2024

Valid 12Z Wed Oct 09 2024 - 12Z Sun Oct 13 2024


...Milton could bring potentially catastrophic impacts across
parts of Florida through Wednesday...


...Overview...

Tropical Storm Milton, currently located in the western Gulf of
Mexico and is forecast to continue to track east-northeast across
the Gulf while strengthening to possibly major hurricane strength.
Milton should be approaching the west coast of the Florida
Peninsula by early Wednesday with significant rainfall/flooding,
high wind, and storm surge threats. Elsewhere, an upper trough
(anchored by an upper low that may track over or near New England)
will move through the East mid next week as an upper ridge upstream
tracks from the West to Central U.S. bringing a period of
climatologically warm weather. By later next week, a Pacific trough
will push inland over the West with some generally light
precipitation to accompany.


...Guidance/Predictability Assessment...

Model guidance continues to suggest Milton will strengthen into a
possibly major hurricane as it tracks east across the Gulf. There
remain some north-south wobbles and uncertainty in the timing, with
plenty of run to run variability. The CMC remains the slowest of
the deterministic models, with the UKMET on the faster side. The
GFS and ECMWF are a good middle ground solution and are closest to
the official track from the NHC. Timing variability also evident in
the latest runs of the AI/ML models as well. Milton may transition
to extratropical quite quickly after it crosses the Florida
Peninsula into Thursday.

Farther north with the main jet stream, models are reasonably
agreeable with the pattern described above. The Pacific trough
shows the most spread especially with regards to timing, but some
weekend uncertainty regarding cut off energy meandering over the
Southwest. Prefer a blend of the ensemble means with the ECMWF for
this feature.


...Weather/Hazards Highlights...

Milton is forecast to be a major hurricane as it approaches the
West Coast of Florida by the start of the period on Wednesday.
There is an increasing risk of life- threatening storm surge and
wind impacts for portions of the west coast of the Florida
Peninsula beginning even before Wednesday. Residents in these areas
should ensure they have their hurricane plan in place, follow any
advice given by local officials, and check back for updates to the
forecast. 6 to 12 inches of rainfall is not out of the question for
parts of the FL peninsula, but where that exact axis of heavy
rainfall sets up, is still quite uncertain and entirely dependent
on the exact track Milton takes across FL. Regardless, significant
rainfall and impacts are expected to accompany Milton, and the Day
4 ERO period (Wednesday) now shows a moderate risk for flash
flooding across the north- central portion of the Peninsula,
including the major population regions of Tampa Bay, Orlando, and
Jacksonville. By Thursday, the heaviest rainfall associated with
Milton should be offshore of FL, but did continue a marginal risk
for northeast FL to account for possibly slower speed.

Elsewhere, the upper low over/near New England should allow for
some lake-enhanced rain within in westerly flow across the Great
Lakes. A mean frontal zone with one or more embedded waves should
reach near the northern Pacific Northwest by early-mid week,
producing some periods of light to locally moderate rain and non-
zero chances of snow in the highest elevations. Widely scattered
showers are possible at times across the Four Corners states into
parts of the south-central U.S., but anything beyond light rain is
unlikely.

The strong and persistent western-central U.S. upper ridge will
promote an extended period of well above normal temperatures over
that part of the country. Gradual eastward drift of the ridge axis
will shift the highest anomalies into the north central Plains by
Wednesday, and some locations could reach 20-30F above normal
persisting into late week. Meanwhile height falls slowly pushing in
over the West Coast will support a trend toward near normal
temperatures by Wednesday or Thursday. Temperatures over most of
the East should be cooler as upper troughing sets up near the East
Coast, trending back to normal next weekend. Frost/Freeze may be a
concern across portions of the Upper Great Lakes region and
interior Northeast mid week before the upper low scoots out of the
region.

Santorelli


Additional 3-7 Day Hazard information can be found on the WPC medium
range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php

WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation forecast (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/#page=ero
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml
https://www.wpc.ncep.noaa.gov/#page=ovw









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