Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Mon Oct 09 2023

Valid 12Z Mon Oct 09 2023 - 12Z Wed Oct 11 2023

...Colder and unsettled weather to move east from the Pacific Northwest
and northern California through mid-week while above average temperatures
shift from the Interior West into the Great Plains...

...Below average temperatures continue for the Great Lakes and Ohio Valley
while lake effect showers persist through Tuesday...

...Surge of tropical moisture to bring an increased threat for heavy rain
and flash flooding for southern Texas on Tuesday...

Warm/hot and dry weather will come to an end for the West Coast today as a
Pacific cold front moves inland. Light to occasionally moderate rain will
overspread northern California, western Oregon/Washington late this
morning into the afternoon. High temperatures will also be 10 to 20
degrees colder today compared to Sunday from northern California into
western Washington, but locations from the Intermountain West to the High
Plains will continue to see above average warmth for at least one more
day. Another cold front will reach the western U.S. on Tuesday as the
first continues to advance into the central Rockies, bringing
precipitation to the northern Great Basin, central/northern Rockies and
adjacent High Plains along with snow for the higher elevations of the
West. Below average temperatures (10 to 25 degrees below average) will
gradually shift to the east across portions of the western U.S. through
mid-week.

A slow moving closed low aloft, centered just north of the Great Lakes,
will keep cooler than average temperatures in the forecast for the Great
Lakes region, Ohio Valley and portions of the Northeast today. Lake effect
rain showers will also persist downwind of the Great Lakes, but rainfall
intensity is expected to be lighter than what was observed over the
weekend. The cooler than average temperatures will linger into mid-week
for the Great Lakes and portions of the Northeast as the closed low
remains in place.

Across the southern tier of the U.S., a stationary front in the Gulf of
Mexico will begin to lift northward as a warm front on Tuesday. This will
support an increase in deep moisture along the Texas Gulf Coast.
Meanwhile, what is expected to become Hurricane Lidia in the eastern
Pacific should make landfall in western Mexico Tuesday evening. While the
system will weaken as it encounters the mountainous terrain of interior
Mexico, the mid-level disturbance tied to Lidia and tropical moisture in
the middle and upper levels of the atmosphere will spread downstream
toward Texas and the western Gulf of Mexico. While specific details remain
unknown at this time, portions of southern Texas could receive a few
inches of rain through Tuesday night, some of which could fall at a high
intensity, supporting a risk for flash flooding across southern Texas.

Otto

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