Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
415 PM EDT Mon Sep 26 2022

Valid 00Z Tue Sep 27 2022 - 00Z Thu Sep 29 2022

...Hurricane Ian sets path towards Florida with the threat of flooding,
high winds, and severe weather increasing...

...Heavy rain continues for portions of the Lower Great Lakes Tuesday...

...Cool and unsettled weather expected to persist across the Northeast and
Great Lakes through at least mid-week...

...Well above average temperatures forecast throughout the West, with
excessive heat impacting parts of southern California...


The focus of attention this week will be Hurricane Ian, which is forecast
by the National Hurricane Center to rapidly intensify into a major
hurricane and move northward towards the Gulf Coast of Florida. The threat
for heavy rain, high winds, and severe weather will be increasing as the
storm approaches. Showers currently across the Keys to southern Florida
are forecast to become heavier and more frequent as the outer rainbands
associated with Ian begin to overspread the state. There is a Moderate
Risk of Excessive Rainfall on Tuesday for coastal portions of the southern
Florida Peninsula and for the northern half of the Peninsula on Wednesday
as heavy rainfall from the storm, on top of already wet antecedent
conditions, may lead to scattered to widespread instances of flooding. The
Storm Prediction Center has also highlighted the same regions with Slight
Risks for the threat of tornadoes. Winds are also expected to increase as
Ian approaches, with tropical storm force winds currently forecast to
reach southern portions of the Peninsula on Tuesday.

Meanwhile, an amplifying upper-level trough is forecast to continue
bringing cool and unsettled weather from the Great Lakes to the Northeast
through mid-week.  The strength of the upper trough will be maintained by
reinforcing surges of cooler air diving across central Canada.  This
pattern will favor damp, dreary weather to persist into Wednesday.  There
is a Slight Risk of Excessive Rainfall along Lake Erie and a Marginal Risk
along Lake Ontario on Tuesday as cold air aloft flowing across the warm
waters of the Great Lakes will destabilize the atmosphere and could lead
to heavy lake-effect rain. In addition to the threat for heavy rain,
temperatures will remain unseasonably cool across the Midwest and
Northeast and spread into the Southeast Wednesday. Most of the Upper
Midwest, Great Lakes, and interior Northeast will see highs in the
upper-50s and low-60s, with some locations in the Upper Great Lakes only
reaching the upper 40s Tuesday. There are Frost Advisories in effect for
portions of the Upper Mississippi Valley Tuesday morning as lows will
bottom out in the mid-30s. Southern portions of the Midwest as well as the
coastal Northeast will see highs in the mid-60s to low 70s. Temperatures
across the Southeast will cool from the upper 70s and low 80s on Tuesday
to the mid-70s Wednesday.  

In contrast to the eastern half of the country, Summer-like, well above
normal temperatures are forecast to remain over much of the West as a
strong upper-level ridge passes over the region. The hottest weather is
expected over the Southwest and southern California with highs in the
mid-100s for the interior deserts and in the 90s for all but coastal
portions of Southern California. Excessive Heat Warnings and Heat
Advisories remain in effect for the Greater Los Angeles/San Diego regions
as well as adjacent portions of the Sonoran Desert. Elsewhere, well above
normal temperatures will stretch from the Intermountain West to the
northern Rockies and northern High Plains. Highs on Tuesday and Wednesday
are forecast to soar into the upper 80s and low 90s.

Putnam/Kong

Graphics are available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php