Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
356 AM EDT Mon Apr 17 2023

Valid 12Z Mon Apr 17 2023 - 12Z Wed Apr 19 2023

...Heavy snow over the Upper Great Lakes begins to wind down...

...Temperatures will be 10 to 20 degrees below average over parts of the
Upper/Middle Mississippi Valley, Upper Great Lakes, and Ohio Valley...

...There is a Marginal Risk of excessive rainfall over parts of the
Northeast...

On Sunday, an area of low pressure over the Upper Great Lakes will slowly
move northeastward into Canada by Monday evening. The associated front
will move off the East Coast by Monday evening. The system will produce
rain over the Northeast and parts of the Ohio Valley. Moderate to heavy
rain will accompany the rain over parts of the Northeast. Therefore, the
WPC has issued a Marginal Risk of excessive rainfall over parts of the
Northeast through Tuesday morning. The associated heavy rain will create
localized areas of flash flooding, affecting areas that experience rapid
runoff with heavy rain. Moreover, showers and thunderstorms will develop
over parts of Florida through Monday evening.

On the northwest side of the storm, heavy snow will develop over parts of
the Upper Great, producing additional amounts near 12 inches near Lake
Superior. By Monday evening, the snow will begin to taper off. However,
snow will linger over parts of the Great Lakes through Tuesday evening.
Furthermore, on Monday, temperatures will be 10 to 20 degrees below
average over parts of the Upper/Middle Mississippi Valley, Upper Great
Lakes, and Ohio Valley. Rain and snow will linger over parts of the
Northeast through Wednesday morning.

Meanwhile, a front over the Northern Rockies to the Great Basin will move
eastward to the Upper Midwest and Central Plains by Wednesday. Weak
onshore flow and upper-level energy will create coastal rain and higher
elevation snow over the Pacific Northwest and Northern California, with
snow extending into parts of the Sierra Nevada Mountains that will begin
to taper off on Tuesday into Tuesday evening. On Tuesday, rain and snow
will develop over parts of the Northern Rockies and Northern High Plains.

As the system begins to move out of the Rockies, moisture will flow
northward over the Southern Plains overnight Monday. As a result, early on
Tuesday, showers and thunderstorms will start to develop over the
Central/Southern Plains. In addition, overnight Tuesday, showers and
thunderstorms will develop over parts of the Northern/Central Plains into
parts of the Middle Mississippi Valley.


Ziegenfelder



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