Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
309 AM EST Tue Nov 08 2022

Valid 12Z Tue Nov 08 2022 - 12Z Thu Nov 10 2022

...Heavy rain and flash flooding likely across parts of southwestern
California today...

...Heavy mountain snow to continue through Wednesday for the Sierra
Nevada, Intermountain West, and northern Rockies...

...Impacts from Subtropical Storm Nicole expected to begin late today in
eastern Florida...

...Heavy snow and blizzard conditions possible for portions of the
northern High Plains, Great Plains, and Upper Mississippi River Valley
Wednesday through Thursday...

A deep upper level low over the western U.S. will continue to drive active
weather across most of the region through mid-week. Several frontal
boundary will pass through, supporting widespread precipitation, falling
as rain at lower elevations and mixed precipitation and snow at mid and
high elevations. Anomalous moisture will focus over California today as a
low pressure system slides down the coast. There is a Slight risk of
Excessive Rainfall (level 2/4) in effect for a large portion of
southwestern California with a smaller embedded Moderate Risk (level 3/4)
for the Transverse Ranges from Los Angeles into southwestern San
Bernardino counties. Heavy precipitation will likely lead to flash
flooding, especially near steep terrain and burn scars. Rapid runoff may
also lead to isolated flash flooding in urban areas along the coast. In
the higher elevations in California, heavy mountain snow is expected, and
Winter Storm Warnings are in effect.

Precipitation will spread from California through the Intermountain West
and northern and central Rockies today and Wednesday. Heavy mountain snow
will be possible across higher elevations, and widespread Winter Weather
Advisories and Winter Storm Warnings are in effect. A strong cold front
will begin to push inland from the coast late tonight into Wednesday as
the upper level low shifts eastwards and will emerge into the Plains on
Thursday. Behind the front, cooler air and decreasing precipitation
chances are expected.

As the strong cold front emerges into the High Plains, low pressure will
strengthen along the boundary and a warm front will lift north across the
Upper Midwest. Showers and thunderstorms are likely on Wednesday and
isolated heavy rainfall and flash flooding will be possible. The front
will continue east Wednesday into Thursday, and precipitation will be
falling through cold air on the backside of the system. This will likely
result in swath of heavy snow, and a corridor of sleet and freezing rain,
in portions of the northern High Plains, Great Plains, and Upper
Mississippi River Valley. Intense snow rates will likely produce
significant snowfall accumulations in some areas. Strong gusty winds will
accompany the system and could also cause blizzard conditions with low
visibility.

In the Southeast, Subtropical Storm Nicole continues to approach the
Florida peninsula and is forecast to strengthen to a Hurricane when
crossing the northwest Bahamas. The center of the storm is expected to
make landfall in Florida late Wednesday then track northwest across the
state before curving to the northeast and moving up along the East Coast.
Marine impacts will spread far north ahead of the storm with hazardous
marine and beach conditions expected along the entire Southeast coast.
Strong winds and heavy rainfall will directly impact Florida through the
event, and Tropical Storm Warnings and Watches are in effect from South
Florida to coastal Southeast Georgia and Hurricane Watches are in effect
for portions of Central and South Florida. Impacts are expected to begin
later today in South Florida, then spread northwards Wednesday and
Thursday as the storm progresses. See nhc.noaa.gov for the latest
information regarding Nicole.

As far as the temperature outlook for the CONUS, well above average
temperatures are forecast for much of the Central U.S. Wednesday and
Thursday with widespread highs in the 70s. Well below normal temperatures
are expected in the West behind the strong cold front and will push
eastwards through the week as the system progresses.


Dolan


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