Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
350 AM EDT Thu Sep 22 2022

Valid 12Z Thu Sep 22 2022 - 12Z Sat Sep 24 2022

...There is a Moderate Risk of excessive rainfall over parts of the
Central Rockies through Friday morning...

...There is a Slight Risk of excessive rainfall over parts of the Northern
Rockies and the Southwest through Friday morning...

...Temperatures will be 10 to 15 degrees above average over parts of the
Southern Plains/Lower Mississippi Valley to the Southeast...

Tropical moisture streaming northward over the Southwest into parts of the
Great Basin/Central Rockies begins to wane on Thursday evening.
Upper-level energy will interact with the moisture to produce shows and
thunderstorms with heavy rain. Therefore, the WPC has issued a Moderate
Risk of excessive rainfall with these thunderstorms over parts of the
Central Rockies through Friday morning. The associated heavy rain will
create numerous areas of flash flooding, including burn scars.
Furthermore, many streams may flood, potentially affecting larger rivers.

Moreover, an upper-level low over the Pacific Northwest and an associated
front over parts of the Northern Rockies will aid in producing heavy rain
showers and thunderstorms. Therefore, the WPC has issued a Slight Risk of
excessive rainfall over parts of the Northern Rockies through Friday
morning. The associated heavy rain will create mainly localized areas of
flash flooding, with urban areas, roads, small streams, and burn scars the
most vulnerable.

Furthermore, the tropical moisture streaming over the Southwest will also
produce showers and thunderstorms with heavy rain over the area.
Therefore, the WPC has issued a Slight Risk of excessive rainfall over
parts of the Southwest through Friday morning. The associated heavy rain
will create mainly localized areas of flash flooding, with urban areas,
roads, small streams, and burn scars the most vulnerable.

On Friday, the threat of excessive rainfall decreases as the moisture flow
is limited. However, there will still be showers and thunderstorms with
the possibility of heavy rain over parts of the Southwest/Southern
Rockies. Therefore, the WPC has issued a Marginal Risk of excessive
rainfall over parts of the Southwest/Southern Rockies from Friday into
Saturday morning. The associated heavy rain will create localized areas of
flash flooding, affecting areas that experience rapid runoff with heavy
rain and burn scars.

Meanwhile, a front extending across the Northeast to the Southern
Appalachians, then westward to the Southern Plains, will move off most of
the Eastern Seaboard overnight Thursday. The front will trigger showers
and strong to severe thunderstorms along and ahead of the boundary from
the Northeast to the Mid-Atlantic. Therefore, the SPC has issued a
Marginal Risk of severe thunderstorms over parts of Southern New England
to the Mid-Atlantic through Friday morning. The hazards associated with
these thunderstorms are frequent lightning, severe thunderstorm wind
gusts, and a minimal threat of tornadoes and hail.

Moreover, the possibility of heavy rain will accompany the showers and
thunderstorms over the region. Therefore, the WPC has issued a Marginal
Risk of excessive rainfall over parts of the Northeast through Friday
morning. The associated heavy rain will create localized areas of flash
flooding, affecting areas that experience rapid runoff with heavy rain.

The threat of severe thunderstorms and excessive rainfall ends on Friday.

Additionally, a sub-tropical upper-level high over parts of the
south-central portion of the country remain through Saturday. The
sub-tropical high will allow temperatures will be 10 to 15 degrees above
average over parts of the Southern Plains/Lower Mississippi Valley into
the Southeast on Thursday. The temperatures will be in the 90s to near 100
over the region, possibly setting records on Thursday.

Ziegenfelder

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