Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
427 AM EDT Mon Jun 20 2022

Valid 12Z Mon Jun 20 2022 - 12Z Wed Jun 22 2022

...Severe thunderstorms and flash flooding possible from the northern
Rockies to the northern Plains Monday...

...Widespread showers and thunderstorms will continue with early season
Monsoon moisture across parts of the Southwest and southern Rockies,
posing the risk for flash flooding...

...Excessive, well above average heat over the Heartland to advance east
into the Great Lakes and Southeast during the first half of the week...

An upper-level low over the Great Basin will begin to slowly eject into
the northern High Plains as a surface cold front meanders eastward through
the northern Plains and southward through the High Plains and Rockies on
Monday. Thunderstorms are forecast to develop along and ahead of the
front. Some of these storms may be severe, and the Storm Prediction Center
has issued a Slight Risk (level 2/5) of severe weather for portions of the
Northern Plains. Scattered instances of large hail and damaging winds
produced by more organized clusters of storms are the main threats. 
Meanwhile, periods of heavy rain will remain a concern across parts of
western Montana as widespread moderate rainfall develops within moist
upslope flow behind the cold front, underneath and on the backside of the
closed upper-level low. A Slight Risk (level 2/4) of excessive rainfall
has been issued for broad total rainfall amounts of around 1", locally as
high as 3".

For the Southwest, an influx of Monsoon moisture will continue to produce
scattered showers and thunderstorms, along with the risk for flash
flooding, through at least Wednesday. Areal average daily rainfall totals
of 0.5 to 1", locally higher, are forecast for portions of New Mexico,
southern Colorado, and eastern Arizona. Slight Risks (level 2/4) of
excessive rainfall have been issued for the region Monday, Tuesday, and
Wednesday, and Flood watches are in place for the Rio Grande Valley of New
Mexico. Areas near recent burn scars will be at most risk for rapid runoff
and debris flows, as well as areas where the rainfall occurs on successive
days.

Dangerous heat will continue to make headlines from the central U.S. to
the Southeast. One more day of well above normal, near-record and
record-breaking heat is expected from the central Plains to the Upper
Midwest. Excessive Heat Warnings remain in effect for the Red River Valley
of the North and the greater Minneapolis area. High temperatures up to 100
degrees along with high humidity will lead to head indices into the
mid-100s. Heat Advisories for well above average temperatures in the mid-
to upper 90s are in place for the rest of the region. The center of the
heat wave begins to transition further east on Tuesday into the Great
Lakes, with forecast highs in the mid- to upper 90s, up to 15-20 degrees
above normal. In addition to hot high temperatures, very warm, near-record
and record-breaking low temperatures in the 70s will provide little relief
from the heat overnight. Temperatures will also warm up across the
Southeast on Wednesday, with highs into the low 100s expected. Maximum
heat indices may reach as high as 110 degrees along the central Gulf Coast
when factoring in high humidity. High temperatures in general will be hot
and a bit above normal across most of the central and eastern U.S. outside
of the Northeast and Mid-Atlantic.

Elsewhere, well below average temperatures are expected underneath
anomalous upper-level troughs over the Northeast/Mid-Atlantic and West.
Highs in the 70s will be common for the Interior Northeast and
Mid-Atlantic on Monday and will remain in the low 70s through at least
Wednesday for New England. As a warm front pushes eastward through the
Great Lakes and towards the East Coast Monday into Tuesday, above average
temperatures will return to interior portions of the Northeast and
Mid-Atlantic. The front is forecast to stall inland, and there are
Marginal Risks (level 1/4) for excessive rainfall on Tuesday and Wednesday
as showers and thunderstorms may tend to cluster and move over the same
areas, leading to locally heavy rainfall totals. Forecast high
temperatures will also be well below normal Monday for most of the Rockies
and Great Basin, with highs in Montana struggling to get out of the 50s.
Temperatures will begin to heat up across the area on Tuesday and
Wednesday, except for portions of the Southwest and Southern Rockies where
showers associated with the monsoon will keep temperatures cooler. Highs
in the central California valleys stand out in particular as they reach
into the low 100s, about 10 to 15 degrees above normal.

Putnam/Snell

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