Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
315 PM EDT Wed Jun 17 2026

Valid 00Z Thu Jun 18 2026 - 00Z Sat Jun 20 2026

...Tropical Storm Arthur to bring heavy rainfall across the Gulf Coast
states over the next couple of days...

...Numerous severe thunderstorms are expected in the Midwest to Ohio
Valley today...

...A frontal system will continue eastward, bringing possible severe
weather for parts of the Ohio Valley, Northeast, and Mid-Atlantic on
Thursday...

An active middle of the week is set to continue for much of the eastern
half of the country through the remainder of the week. The newly
categorized Tropical Storm Arthur remains the main story for the Gulf
Coast states as it progresses farther inland. The continued interaction
between the tropical moisture associated with Arthur and the fast-moving
weather pattern to the north will perpetuate multiple days of heavy
rainfall across the Gulf Coast states. Through the remainder of today,
Arthur is anticipated to continue moving farther inland over southeastern
Texas and southwestern Louisiana through tonight. Tropical-storm-force
winds will continue for these areas, and Tropical Storm Warnings remain in
effect for parts of Texas and Louisiana. Additionally, heavy rainfall will
continue from much of the Texas coast into parts of Louisiana,
Mississippi, and Alabama, along with western portions of Georgia and the
Florida Panhandle. Rainfall totals around 5 to 10 inches are expected in
these areas, with isolated higher totals near 20 inches. This will result
in potentially life-threatening flash and urban flooding, along with
scattered minor river flooding, with isolated moderate to major river
flooding possible. As such, a Moderate Risk (level 3/4) of excessive
rainfall is highlighted in the Weather Prediction Centerâ€s Excessive
Rainfall Outlook (ERO) for this region over each of the next three days.
Additional hazards associated with Arthur will include a dangerous storm
surge and the possibility of a couple of tornadoes.

Meanwhile, a severe weather outbreak is set to begin today for portions of
the Mid-Mississippi and Ohio Valleys, particularly across parts of central
Illinois and northwestern Indiana. A strong mid-level trough and an
associated jet streak will continue quickly moving eastward, reaching the
Great Lakes while a strong surface low-pressure system approaches the
region by the evening hours. With a strong southerly low-level jet ahead
of the trough, thunderstorms will develop during the afternoon and evening
hours. Numerous thunderstorms are likely to be severe, carrying a risk of
large hail, damaging winds, and intense tornadoes. Winds could reach up to
75 mph in some areas. As a result, the Storm Prediction Center (SPC) has
outlined a Moderate Risk (level 4/5) of severe weather for central
Illinois and northwestern Indiana for today. At the same time, rainfall
will be heavy at times and will bring the possibility of scattered flash
flooding. Consequently, there is also a Moderate Risk (level 3/4) of
excessive rainfall in central Indiana and east-central Illinois, with a
Slight Risk (level 2/4) spanning much of the Midwest and lower Great Lakes.

By Thursday, an unseasonably deep low-pressure system will move through
the Great Lakes and into Quebec, Canada. Increasing southerly flow will
bring heat and humidity back to the Mid-Atlantic on Thursday, with severe
thunderstorms possible for portions of the Ohio Valley, Northeast, and
Mid-Atlantic ahead of the cold front trailing from the low center.
Damaging winds will be possible with these storms, and the SPC has
outlined a Slight Risk (level 2/5) for the area. Temperatures are forecast
to rise into the 90s and lower 100s in the Mid-Atlantic, where record-high
temperatures will be challenged on Thursday. By Friday morning, the cold
front will be moving off the New England coast, ushering cooler air into
the Northeast and the Great Lakes. Much of the West will generally be
quiet through the next couple of days, with highs reaching the 100s in the
Great Basin and the 110s in the Desert Southwest. Triple-digit
temperatures are also forecast for the central to southern High Plains
before the arrival of a cold front from the north by Thursday.


Blanco-Alcala/Kong


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