The Weather Prediction Center

Short Range Forecast Discussion

[Abbreviations and acronyms used in this product]
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Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
335 AM EDT Tue Apr 13 2021

Valid 12Z Tue Apr 13 2021 - 12Z Thu Apr 15 2021

...A slow-moving storm will bring widespread snows to the Great
Basin and central Rockies, with heavy accumulations for the
mountains...

...Strong to severe storms, including damaging winds, large-hail
and heavy rain are expected for portions of eastern Texas and
Louisiana...

...Critical Fire Weather conditions are expected across portions
of the Southwest...

A slow-moving area of low pressure will continue to produce
widespread precipitation across the northern Great Plains and
Upper Midwest, including some late-season accumulating snows from
Montana to the Upper Great Lakes.  Precipitation is expected to
continue through Tuesday before diminishing from west to east
across the Plains as the system moves east on Wednesday.  As the
system moves east, scattered precipitation will begin to develop
across the Mid-Atlantic and Northeast on Wednesday, with organized
heavier precipitation forecast to develop over the northern
Mid-Atlantic and Northeast by Thursday morning.

A slow-moving frontal boundary to the south, interacting with
increasing moisture, is expected to encourage shower and
thunderstorm development across the southern Plains and lower
Mississippi valley on Tuesday and Wednesday.  There is the
potential that some of these storms may become strong to severe,
especially across eastern Texas and Louisiana.  In addition to
concerns for large hail and damaging winds, these storms may also
produce heavy rainfall amounts.  Given the high stream flows and
saturated soils due to recent heavy rains across the lower
Mississippi Valley and central Gulf Coast, the threat for
additional heavy rains will also likely lead to increasing
flooding concerns across the region on Tuesday and Wednesday.

As the lead system over the Midwest drifts east, a second
slow-moving system will develop over the Pacific Northwest on
Tuesday and sink slowly southward into the northern Great Basin by
Wednesday.  Increasing precipitation coverage across the Great
Basin and Rockies will include late-season snows the region.  Snow
developing on Tuesday and continuing through Wednesday into
Thursday is expected to result in heavy accumulations for portions
of the region, including the central and to southeastern Wyoming
ranges, as well as the central Colorado and northern Utah ranges.

In contrast to the wet conditions along the central Gulf Coast
into the lower Mississippi Valley, dry conditions, low relative
humidities and gusty winds will support an Elevated to Critical
Fire Weather Threat over the Southwest Tuesday and Wednesday.  Red
Flag Warnings will be in effect on Tuesday for a significant
portion of the California deserts, southern Nevada, northwestern
Arizona and southern Utah. 

Pereira

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




Last Updated: 335 AM EDT Tue Apr 13 2021