265
FXUS21 KWNC 161814
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT June 16 2025

SYNOPSIS: Strong mid-level high pressure is predicted across the northeastern
quadrant of the contiguous U.S. (CONUS) from the end of week-1 into the
beginning of week-2. There is good agreement in model guidance and associated
tools indicating enhanced chances for extreme heat for this region. A high risk
of extreme heat is posted for the Ohio Valley, Great Lakes region, Northeast,
and Mid-Atlantic, for Jun 24. Broader areas are highlighted across the
northeastern CONUS including the Mid-Atlantic with slight and moderate risks of
extreme heat early in week-2. A front is predicted to extend from the Upper
Mississippi Valley to the Central Plains, bringing potentially heavy
precipitation and isolated strong thunderstorms to parts of the Upper Midwest
early in the period.

HAZARDS

High risk of extreme heat for the Ohio Valley, Great Lakes region, Northeast,
and Mid-Atlantic, Tue, Jun 24.

Moderate risk of extreme heat for parts of the northeastern CONUS including the
Mid-Atlantic, Tue-Wed, Jun 24-25.

Slight risk of extreme heat for portions of the eastern half of the CONUS,
Tue-Thu, Jun 24-26.

Slight risk of heavy precipitation for parts of the Upper Midwest, Tue-Wed, Jun
24-25.

Slight risk of high winds across portions of the Southern and Central High
Plains, Tue-Wed, Jun 24-25.

DETAILED SUMMARY

FOR THURSDAY JUNE 19 - MONDAY JUNE 23:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR TUESDAY JUNE 24 - MONDAY JUNE 30: There is good model agreement indicating
amplified mid-level ridging peaking across the northeastern CONUS at the end of
week-1, lingering at the beginning of week-2 before weakening by the middle of
the period. This pattern is expected to bring increased likelihood of extreme
heat to many parts of the eastern CONUS. A high risk of extreme heat is
designated for the Ohio Valley, Great Lakes region, Northeast, and
Mid-Atlantic, Jun 24, where multiple Probabilistic Extremes Tools (PETs)
indicate at least a 50% chance of maximum temperatures exceeding the 85th
percentile compared to normal, and at least a 20% chance of exceeding the 95th
percentile. A moderate risk area is posted for parts of the northeastern CONUS
including the Mid-Atlantic, Jun 24-25, while a broader area is highlighted with
a slight risk across parts of the eastern CONUS, Jun 24-26. The National Blend
of Models (NBM) shows many of these areas nearing or breaking record
temperatures both in the maximum and minimum temperatures. Maximum air
temperatures may exceed 95 deg F across the Mid-Atlantic and 90 F elsewhere in
the highlighted risk areas, although with anticipated high dewpoints, the heat
index values would likely be higher. Minimum heat index values could reach or
exceed 80 deg F in some areas.



Mid-level troughing is predicted across the northwestern CONUS, supporting a
front developing ahead of it, from the end of week-1 into the beginning of
week-2. This front may bring enhanced precipitation to the upper Midwest, thus
a slight risk of heavy precipitation is posted for this region, Jun 24-25. The
PETs indicate at least a 20% chance of 3-day accumulated rainfall totals
exceeding the 85th percentile and one inch. Enhanced warm moist flow from the
Gulf may provide favorable conditions for localized severe thunderstorms in the
highlighted risk area.



The National Hurricane Center (NHC) indicates at least a 90% chance of cyclone
formation offshore of Central America and Mexico over the next seven days, as
of 11am PDT. This disturbance combined with possible low formation over Baja
California and the Southwest may bring enhanced moisture to parts of the
Southwest which could bring localized enhanced rainfall and thunderstorms to
the area. Additionally, a dry line may set up across the eastern Four Corners
that could support thunderstorms in the region. There is no specified
precipitation hazard, although a slight risk of high winds is designated over
western portions of the Southern and Central High Plains, Jun 24-25. PETs show
at least a 20% chance of maximum wind speeds exceeding the 85th percentile and
20 mph.



Ice-bound rivers are beginning to break up in the North Slope of Alaska.
Flooding is possible by the end of week-1 and into week-2 across much of the
region as a result of ice jams, aufeis, snow melt, and associated flooding. A
flood risk is not designated for today due to conditions anticipated to start
to wane during the week-2 period.

FORECASTER: Melissa Ou

$$