Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 PM EDT Wed Sep 16 2026

Valid 00Z Thu Sep 17 2026 - 00Z Sat Sep 19 2026

...A moderate risk of flash flooding through tonight across portions of
Arizona and New Mexico...

...Showers and thunderstorms could lead to flash flooding over sections of
the north-central U.S. during the next few days...

...Record-challenging high temperatures continue across the south-central
U.S....

A moderate risk of flash flooding is anticipated through tonight across
portions of Arizona and New Mexico. This is in response to a low to
mid-level sub-tropical circulation being drawn northward across
northwestern Mexico toward Arizona ahead of a large scale upper-level
trough moving into the West Coast of the U.S. This circulation will lift
monsoonal moisture already in place across the Four Corners region to
enhance rainfall amounts especially near the moderate risk areas in
central Arizona and New Mexico where upwards of 2-3" of rain with locally
higher amounts are possible through tonight. By Thursday, the circulation
is forecast to move northward through Arizona and the Four Corners as it
weakens. The coverage and intensity of rainfall is forecast to lessen as
the day progresses. However, more heavy rain may be triggered if this
circulation remains stronger than expected. By Friday, the disturbance
should become much diffused but widely scattered flash flooding is still a
concern across the Four Corners states with additional showers and
thunderstorms.

Meanwhile, a meandering front will remain the focus for thunderstorms and
locally heavy rainfall across the Midwest to the Ohio Valley through
tonight. Meanwhile, the upper-level energy ejecting from the Four Corners
heavy rain will trigger the formation of a new low-pressure system over
the central High Plains by Thursday night. Expect a round of strong
thunderstorms and local heavy rainfall across the Northern Plains Thursday
night moving into the upper Midwest on Friday where WPC is highlighting a
slight risk of flash flooding.

As we get into mid-September, cooler air from Canada is beginning to dip
into the northern tier states, bringing cooler than normal temperatures.
Meanwhile, an upper-level high associated with the persistent heat dome
remains strong across the South, resulting in a pronounced north-south
temperature contrast. High temperatures in the low 70s and upper 60s can
be expected north of the meandering front in the Central Plains and
Midwest, compared to upper 90s and triple-digit highs south of the front
across the Southern Plains and Mid/Lower Mississippi Valley.
Unfortunately, the western end of the front lifting northward means that
the hazardous heat is here to stay this week across the South. In fact,
high temperatures reaching into the upper 90s to lower 100s will challenge
daily records from the Southern Plains to the lower Mississippi Valley
where Heat Advisories remain in effect. Meanwhile, instability associated
with a stationary front on the southern edge of the heat dome will
continue to bring scattered thunderstorms with heavy downpours across much
of the Sunshine State, although excessive rainfall is not expected from
this activity.


Kong/Asherman


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

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