WPC Frontal Systems Short Term Forecast

The forecasts depicted below combine WPC forecasts of fronts, isobars and high/low pressure centers with the NDFD depiction of expected weather type for days .5 to 2.5 ahead. Each frame represents 6 hours. A short range forecast discussion for the CONUS is available below the short term loop.

FXUS01 KWBC 190737
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
336 AM EDT Sat Apr 19 2025

Valid 12Z Sat Apr 19 2025 - 12Z Mon Apr 21 2025

...Moderate to heavy snow over parts of the Central/Southern
Rockies on Saturday...

...There is a Moderate Risk of excessive rainfall over parts of
the Middle Mississippi Valley to the Southern Plains on Saturday...

...There is a Slight Risk of severe thunderstorms over parts of
the Middle/Lower Mississippi Valley and the Southern Plains on
Saturday and an Enhanced Risk of severe thunderstorms over parts
of the Middle/Lower Mississippi Valley on Sunday...

A front extending from the Great Lakes/Ohio Valley and then across
the Middle/Lower Mississippi Valley into the Southern Plains will
move eastward off the Northeast Coast and from the Mid-Atlantic to
the Southern Plains by Sunday morning. On Saturday, the system
will produce showers and thunderstorms from parts of the Northeast
to the Southern Plains and severe thunderstorms from the
Middle/Lower Mississippi Valley to the Southern Plains. Therefore,
the SPC has issued a Slight Risk (level 2/5) of severe
thunderstorms over parts of the Middle/Lower Mississippi Valley to
the Southern Plains through Sunday morning.  The hazards
associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a few tornadoes. Furthermore,
there is an added threat of hail, two inches or greater, over the
Southern Plains.

In addition, the showers and thunderstorms will produce heavy rain
over parts of the Middle Mississippi Valley and the Southern
Plains on Saturday. Therefore, the WPC has issued a Moderate Risk
(level 3/4) of excessive rainfall over parts of the Middle
Mississippi Valley into the Southern Plains through Sunday
morning. Numerous flash flooding events are possible and many
streams may flood, potentially affecting larger rivers.

Further, an upper-level low associated with the western end of the
front will produce moderate to heavy snow over parts of the
Central/Southern Rockies. Rain will also develop over the lower
elevations of the Southwest and Central High Plains. The snow will
end over the region by Sunday morning.

On Sunday, a wave of low pressure along the boundary moves
northward from the Southern Plains to the Upper Mississippi Valley
by Monday morning.  The front will produce showers and severe
thunderstorms over parts of the Middle/Lower Mississippi Valley.
Therefore, the SPC has issued an Enhanced Risk (level 3/5) of
severe thunderstorms over the Middle/Lower Mississippi Valley from
Sunday into Monday morning.  The hazards associated with these
thunderstorms are frequent lightning, severe thunderstorm wind
gusts, hail, and a few tornadoes.

In addition, the threat of excessive rainfall will decrease on
Sunday over parts of the Middle/Lower Mississippi Valley to a
Marginal Risk. Moreover, showers and thunderstorms will expand
into the Great Lakes/ Ohio Valley. Furthermore, an area of wet
snow will develop near Lake Superior on Monday morning.

Meanwhile, on Saturday, a front over the Pacific Northwest will
move eastward to the Northern High Plains to the Northern
Intermountain Region/Great Basin and dissipate by Sunday morning.
The system will produce light rain over parts of the Northwest,
moving into the Northern Intermountain Region by Saturday evening.
By Sunday morning, additional light rain will move into the
Pacific Northwest. As the associated energy moves eastward, rain
and highest elevation snow will develop over parts of the Northern
Intermountain Region and Northern Rockies overnight Sunday.


Ziegenfelder


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

• NDFD Rain (Chance) – There is chance of measurable rain (≥0.01″) at the valid time.
• NDFD Rain (Likely) – Measurable rain (≥0.01″) is likely at the valid time.
• NDFD Snow (Chance) – There is chance of measurable snowfall (≥0.01″ liquid equivalent) at the valid time.
• NDFD Snow (Likely) – Measurable snow (≥0.01″ liquid equivalent) is likely at the valid time.
• NDFD Mix (Chance) – There is a chance of measurable mixed precipitation (≥0.01″ liquid equivalent) at the valid time.  “Mixed” can refer to precipitation where a combination of rain and snow, rain and sleet, or snow and sleet are forecast.
• NDFD Mix (Likely) – Measurable mixed precipitation (≥0.01″ liquid equivalent) is likely at the valid time.  “Mixed” can refer to precipitation where a combination of rain and snow, rain and sleet, or snow and sleet are forecast.
• NDFD Ice (Chance) – There is a chance of measurable sleet and/or freezing rain (≥0.01″ liquid equivalent) at the valid time.
• NDFD Ice (Likely) – Measurable sleet and/or freezing rain (≥0.01″ liquid equivalent) is likely at the valid time.
• NDFD T-Storm (Chance) – There is a chance of thunderstorms at the valid time.   Areas are displayed with diagonal hatching enclosed in a dark red border.
• NDFD T-Storm (Likely and/or Severe) – Thunderstorms are likely and/or the potential exists for some storms to reach severe levels at the valid time.