Prognostic Meteorological Discussion
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FXUS21 KWNC 291813
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT May 29 2026

SYNOPSIS: Today`s primary hazard concern is the increased potential of extreme
heat and Rapid Onset Drought (ROD) across parts of the central and east-central
contiguous U.S. (CONUS) associated with strong mid-level high pressure across
these regions. An area of mid-level low pressure is forecast to move into the
western CONUS early in week-2. This may bring episodes of high winds to parts
of the West.

HAZARDS

Moderate risk of extreme heat across parts of the Northern and Central Plains,
Upper and Middle Mississippi Valley, and Great Lakes region, Sat-Sun, June 6-7.

Slight risk of extreme heat for portions of the Northern and Central Plains,
Upper and Middle Mississippi and Ohio Valleys, and Great Lakes region, Sat-Fri,
June 6-12.

Slight risk of high winds for parts of the West, Sat-Mon, June 6-8.

Possible Rapid Onset Drought for parts of the Upper and Middle Mississippi
Valley and Great Lakes region.

DETAILED SUMMARY

FOR MONDAY JUNE 01 - FRIDAY JUNE 05:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR SATURDAY JUNE 06 - FRIDAY JUNE 12: A mid-level ridge across the West at the
end of week-1 is anticipated to shift eastward to the central CONUS early in
week-2, with multiple model ensemble means indicating this ridge amplifying
across the central CONUS. Recent deterministic GFS and ECMWF model solutions
indicate positive 500 hPa height normalized anomalies reaching greater than 3
standard deviations across the Northern Plains and Upper Mississippi Valley
early in the period. This pattern amplification translates to increased signals
for heat across the north-central CONUS in the model solutions and associated
tools. Therefore a moderate risk (40-60% chance) of extreme heat is designated
for parts of the Northern and Central Plains, Upper and Middle Mississippi
Valley, and Great Lakes region, June 6-7. The PETs indicate at least a 20 to
30% chance of temperatures exceeding the 85th percentile climatologically and
90 deg F (85 deg F across more northern regions), with uncalibrated guidance
indicating areas further north exceeding 90 deg F. A broader area of slight
risk is highlighted for these regions in addition to the Ohio Valley, June
6-12. Southerly enhanced moist flow is possible as surface high pressure forms
across the East, resulting in higher relative humidity which could result in
higher heat index temperatures across the risk area. Recent model guidance
shows 2-m dewpoint temperatures reaching the 70s (deg F) in the extreme
temperature risk areas.



Following a very wet spring across the Great Lakes and Upper Mississippi
Valley, precipitation has been limited over the past several weeks. The most
recent release of the U.S. Drought Monitor shows expansion of abnormally dry
conditions across parts of the region. WPC`s week-1 forecast indicates below
normal precipitation and above normal temperatures in this area. Above normal
temperatures are forecast to continue into week-2 and near to below normal
precipitation is favored as well. Therefore, a possible risk of ROD is posted
for parts of the Upper and Middle Mississippi Valley and Great Lakes region.



As the 500-hPa positive height anomalies progress eastward at the start of
week-2, an area of mid-level troughing is forecast to develop near the West
Coast. This system brings elevated chances for high winds to much of the West
Coast and into the Great Basin. There is broad support for winds exceeding the
85th climatological percentile across this area and uncalibrated guidance also
highlights elevated winds early in week-2 as this feature moves into the
region. Therefore, a slight risk of high winds is posted for these regions June
6-8.



In Alaska, river ice breakup season is ending, but many rivers north of the
Brooks Range remain icebound. River breakup flooding can occur with little or
no notice as conditions on frozen rivers can change quickly, so please check
with the Alaska Pacific River Forecast Center for the latest conditions and
advisories.

FORECASTER: Ryan Bolt

$$