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 050747
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
344 AM EDT Wed Aug 05 2026

Valid 12Z Wed Aug 05 2026 - 12Z Fri Aug 07 2026

...There is a Slight Risk (level 2/4) of excessive rainfall over
parts of the South Carolina Coast and the Upper Great Lakes,
Middle Mississippi Valley into the Central Plains on Wednesday...

...There is a Marginal Risk (level 1/4) of excessive rainfall over
parts of the Northeast, Great Lakes, and Middle Mississippi Valley
into the Central/Southern Plains and the Southwest on Thursday...

...Poor air quality for the Pacific Northwest and Great Basin...



A front dissipates over the Mid-Atlantic by Wednesday afternoon.
Moisture-rich air over the eastern third of the country will aid
in producing showers and thunderstorms from the Mid-Atlantic into
the Southeast and Florida through Friday morning. Weak onshore
flow over South Carolina will aid in producing an area of showers
and thunderstorms with heavy rain along the South Carolina Coast.
Therefore, the WPC has issued a Slight Risk (level 2/4) of
excessive rainfall with these thunderstorms over the South
Carolina Coast through Thursday morning.  The associated heavy
rain will create mainly localized areas of flash flooding, with
urban areas, roads, small streams, and low-lying areas being the
most vulnerable. 

A second front over the Upper Great Lakes, across the Middle
Mississippi Valley, and into parts of the Central/Southern Plains
and Central Rockies on Wednesday will move and become
quasi-stationary through Friday.  The boundary will trigger
showers and thunderstorms from the Upper Great Lakes, Middle
Mississippi Valley, and Central Plains on Wednesday with an area
of heavy rain. Therefore, the WPC has issued a Slight Risk (level
2/4) of excessive rainfall from Southwestern Lake Michigan into
the Middle Mississippi Valley and Central Plains from Wednesday
morning into Thursday morning. The associated heavy rain will
create mainly localized areas of flash flooding, with urban areas,
roads, small streams, and low-lying areas being the most
vulnerable.  The continued showers and thunderstorms along the
boundaries have prompted the WPC to issue a Marginal Risk (level
1/4) of excessive rainfall over the eastern third of the country
and from the Middle Mississippi Valley to the Southwest on
Thursday into Friday morning.

Moreover, monsoonal moisture will produce showers and
thunderstorms with moderate to heavy rain over parts of the
Southwest during the late afternoon into the late evening through
Friday.  A third front moving southward out of Central Canada will
move into parts of the Upper Midwest and Northern Plains Thursday
into Friday. The boundary will trigger scattered showers and
thunderstorms over parts of the Upper Midwest Thursday into Friday.

In the Northwest, ongoing fires will lead to persistent smoke in
the region, from Washington/Oregon eastward and also over the
Great Basin with separate fires. Air quality alerts are in effect
for much of the region. Some members of the public may experience
health effects. Members of sensitive groups may experience more
serious health effects. This includes children, the elderly, and
persons with respiratory problems. Temperatures will trend warmer
over the next couple of days, leading to Moderate HeatRisk levels
(3 out of 5).


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.