Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
410 PM EDT Tue Jun 21 2022

Valid 00Z Wed Jun 22 2022 - 00Z Fri Jun 24 2022

...Monsoonal moisture will continue to support widespread showers and
thunderstorms across parts of the Southwest and southern Rockies over the
next few days, with additional concerns for flash flooding...

...Some severe weather possible through this evening across parts of the
Midwest, with a severe weather and flash flood threat focusing farther
east on Wednesday toward the Ohio Valley and Mid-Atlantic...

...Cooler temperatures arriving over the Midwest while high heat and
humidity builds from the Mid-South to the Gulf Coast and Southeast...

Monsoonal moisture continues to stream northward from Mexico into areas of
the Southwest and the southern Rockies given deep layer southerly flow in
between an upper-level trough near California and a strong ridge of high
pressure focused over the lower Mississippi Valley. This moisture has been
well entrenched over the last several days and should remain pooled over
the region going into the latter part of the week. The result will again
be multiple rounds of heavy showers and thunderstorms each day, with
concerns that some of the rainfall totals will be excessive. Increasingly
moist soil conditions and increasing streamflows across these areas from
the recent rainfall, coupled with locally a few additional inches of rain
over the next couple of days will favor areas of flash flooding. Going
through tonight and Wednesday morning, the Weather Prediction Center has
depicted a Moderate Risk of excessive rainfall across parts of southwest
New Mexico which is within a broader Slight Risk category more regionally
extending from southeast Arizona into south-central Colorado.

Meanwhile, a cold front crossing the Great Lakes, Midwest, and central
Plains through this evening will produce heavy showers and thunderstorms
from the northern Great Lakes to the central High Plains. Some localized
pockets of severe weather with concerns for large hail and damaging winds
will be possible going through tonight and early Wednesday. In fact, the
Storm Prediction Center has a Slight Risk of severe thunderstorms depicted
along an axis from southeast Kansas through southeast Iowa. This cold
front later Wednesday and into Thursday will cross through the Ohio Valley
and get into the central Appalachians and Mid-Atlantic region. This will
bring the threat of heavy showers and thunderstorms into these areas, and
there will be concerns for some severe thunderstorms and pockets of flash
flooding. The Storm Prediction Center and Weather Prediction Center have
introduced Slight Risk areas across portions of this region, and
especially the Mid-Atlantic, to address these concerns.

Regarding the most recent heatwave across the Midwest, the arrival and
passage of the aforementioned cold front will allow for much cooler
temperatures to arrive with temperatures dropping back down to near normal
and locally below normal for the next couple of days. Some of the coolest
temperatures compared to normal will be down across areas of Southwest and
the southern Rockies where clouds and rain from the active monsoonal
pattern will be in place. Cool temperatures will also be noted over the
Northeast and portions of the Mid-Atlantic where proximity of an upper low
off the East Coast and a surface low pressure center near the coastal
Mid-Atlantic region will favor cooler onshore flow. However, there will be
areas of very hot weather still continuing, and this will especially be
the case over the next couple of days over the Mid-South, Gulf Coast
region, and Southeast U.S. where temperatures will likely reach the upper
90s to low 100s. This will likely be hot enough to break some daily
temperatures records.

Increasingly hot conditions are also expected to set up for parts of the
West and especially in northern California and adjacent areas of the
northern Great Basin. Some temperatures in the Sacramento Valley may reach
the century mark. Dry weather is expected overall along the West Coast and
into the Great Basin, however, a few dry, high-based thunderstorms will be
possible across southern California and the southern Great Basin given
closer proximity to some of the monsoonal moisture to the southeast. Some
wildfire concerns will exist from lightning strikes associated with these
generally dry thunderstorms.

Orrison

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