URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 491
NWS Storm Prediction Center Norman OK
620 PM CDT Thu Jul 16 2026

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Northeast North Dakota

* Effective this Thursday night from 620 PM until Midnight CDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2
    inches in diameter possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...A cluster of thunderstorms will likely develop this
evening and track eastward across the watch area.  The strongest
cells will pose a risk of large hail and damaging wind gusts.

The severe thunderstorm watch area is approximately along and 60
statute miles north and south of a line from 55 miles west of Devils
Lake ND to 15 miles north northeast of Grand Forks ND. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU1).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
28030.

...Hart

STATUS FOR WATCH 0491 HAS NOT BEEN ISSUED YET

Mesoscale Discussion 1635
NWS Storm Prediction Center Norman OK
0511 PM CDT Thu Jul 16 2026

Areas affected...north-central and northeast North Dakota

Concerning...Severe potential...Watch possible 

Valid 162211Z - 170015Z

Probability of Watch Issuance...40 percent

SUMMARY...The threat for at least isolated occurrences of large hail
and severe wind gusts is expected to increase this evening.
Convective trends are being monitored for a possible severe
thunderstorm watch.

DISCUSSION...Visible satellite imagery depicts a deepening cumulus
field across portions of Bottineau and McHenry Counties in the
vicinity of a subtle meso-low triple point. Latest deterministic and
time-lagged CAM guidance suggests that storm initiation will become
increasingly likely by 00Z (7 PM CDT) as the remaining convective
inhibition is eroded by continued heating and low-level convergence.
An additional storm or two is possible farther south on a surface
trough/weak front south of Bismarck. 

In the absence of appreciable large-scale forcing for ascent, it
remains unclear what the eventual areal coverage of storms will be.
Nonetheless, latest objective analyses suggest that the local
environment features moderate to strong instability with MLCAPE as
high as 3000-3500 J/kg. When coupled with a vertically veering wind
profile with 30-40 kt of effective bulk shear, the setup appears
favorable for some organized storm modes, including supercells
initially with a subsequent transition to a cold-pool driven
convective system. The primary hazards in that scenario would be
large hail and severe wind gusts. Forecast storm motions for a
right-moving supercell suggest that residence time along an existing
outflow boundary in the area will remain limited, which is expected
to preclude a more robust tornado threat.

As mentioned above, eventual storm coverage remains uncertain, which
will dictate the need for a watch. If it becomes apparent that
multiple severe storms will develop, a severe thunderstorm watch may
be considered.

..Mead/Hart.. 07/16/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FGF...BIS...

LAT...LON   48210088 48900059 48979945 48989794 48519760 47689774
            47229800 47129918 47080049 47460094 48210088 

MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0251 PM CDT Thu Jul 16 2026

Valid 162000Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
WESTERN MONTANA...

...SUMMARY...
Severe thunderstorms capable of producing large hail and gusty winds
will be possible across parts of the northern Rockies this afternoon
and evening. Isolated to scattered damaging winds may also occur
over portions of northern New England, the Upper Midwest, and
Mid-Atlantic. A brief tornado could occur across a small part of
south-central/southwest Texas later today or tonight.

...20z Update...
The primary adjustment was to reduce wind probabilities across
portions of the Northeast behind a leading line of convection
attendant to a weak surface front. Falling temperatures and more
stable conditions in the wake of this front should preclude
additional thunderstorm development through the evening, though some
lingering threat persists across parts of New England as convection
continues to push east towards the Atlantic coast. 

...Mid-Atlantic...
GOES visible imagery shows building cumulus across parts of
southeast PA within a favorable environment for organized
convection. Although guidance continues to suggest much of this
activity will mature along and off the coast, some potential for
severe wind, as well as large hail, is apparent based on latest RAP
mesoanalyses and forecast guidance. 

...North Dakota...
The 2% tornado risk probability line was expanded eastward along a
surface warm front evident in visible imagery and surface
observations. Warm and moist conditions and ambient low-level
vorticity along this boundary may support some potential for brief
tornadoes as thunderstorms begin to develop later this evening.

Elsewhere, the previous forecast remains on track. See the previous
discussion below for additional details.

..Moore.. 07/16/2026

.PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 16 2026/

...Northern Rockies...
A closed upper low will move slowly northward along the coastal
Pacific Northwest through tonight. Upper ridging will persist across
much of the Rockies to the Plains. Between these features, a belt of
modestly enhanced south/southwesterly deep-layer flow will
overspread the northern Rockies. Modest easterly low-level winds
will transport generally 50s to low 60s F surface dewpoints across
this region beneath steep mid-level lapse rates. As daytime heating
occurs, moderate instability should develop. Scattered thunderstorms
are forecast to initially form over the higher terrain during the
afternoon. Veering wind profiles with height through mid/upper
levels and gradually strengthening flow aloft will support around
30-40 kt of effective bulk shear. Organized cells will pose a risk
for gusty winds and severe hail across much of the region. The
greatest risk for 1+ inch hail appears to be across parts of western
Montana.

...Northern New England...
A vigorous mid-level shortwave trough will move quickly
southeastward from southern Ontario/Quebec across New England today
with strong west/northwest deep-layer flow. Boundary layer moisture
will be somewhat limited compared to prior days, with surface
dewpoints generally in the 50s F. Still, somewhat greater daytime
heating is expected to the north of the more prominent smoke plume
across southern New England, which should help steepening low-level
lapse rates by late morning/early afternoon. While MLCAPE will
remain modest (around 250-500 J/kg), the strong low/mid-level
westerly flow and steepened low-level lapse rates should support
scattered damaging winds as low-topped convection spreads southeast
from Quebec and across portions of northern New England through the
afternoon near a secondary/weak front.

...Mid-Atlantic...
Enhanced west-northwesterly mid/upper-level winds will overspread
the Mid-Atlantic today on the southern periphery of the mid-level
shortwave trough moving across New England. A surface front is
expected to sag southward through the day, approaching the
Pennsylvania/Maryland border vicinity by late afternoon. Rich
low-level moisture will be in place ahead of the surface front and
beneath steepening mid-level lapse rates spreading in from the Ohio
Valley. This, along with diurnal heating, will foster a corridor of
moderate to locally strong instability this afternoon. Furthermore,
various NAM/RAP forecast soundings show 30-40 kt of effective bulk
shear and steep low-level lapse rates present south of the front.
This environment would generally support organized cells/line
segments. However, overall thunderstorm coverage remains uncertain
given that stronger forcing for ascent should remain mostly north of
the warm sector. Additionally, it is uncertain to what extent that
smoke may continue to have a negative impact on an otherwise
favorable environment for severe thunderstorms. 

...Northeast North Dakota/Northern Minnesota...
A series of convectively enhanced vorticity maxima will migrate
across the Canadian Prairies north of the prominent upper ridge over
the Plains/Rockies, and through northwesterly flow aloft into parts
of North Dakota and northern Minnesota this afternoon into tonight.
At the surface, a weak low and surface front will move across North
Dakota into northern Minnesota during the evening and overnight
hours. South/southeasterly low-level flow will maintain a
moisture-rich boundary layer, supporting a narrow corridor of
instability. NAM/RAP forecast soundings show supercell wind
profiles, but also increasing capping through the late
afternoon/evening. Even so, most high-resolution guidance develops
convection across southern Manitoba into northern North Dakota
during the evening, spreading east/southeast across northern
Minnesota overnight. Isolated severe hail and damaging winds may
occur with this activity, and a tornado risk cannot be ruled out.

...South-Central Texas...
While low-level shear/SRH has weakened since last night, and ongoing
convection remains extensive/repetitive, a northward drift of the
MCV and potential re-establishment of stronger low-level winds later
today into tonight could account for non-zero/brief tornado
potential.

...Arizona...
Thunderstorms will develop over the higher terrain of the Mogollon
Rim and southeast Arizona this afternoon/evening, and subsequently
spread westward across portions of central/southern Arizona. Modest
instability and steep lapse rates amid strong heating could support
sporadic strong gusts.

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0227 PM CDT Thu Jul 16 2026

Valid 181200Z - 191200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
OHIO VALLEY AND LOWER GREAT LAKES INTO THE MID-ATLANTIC...

...SUMMARY...
Strong to severe thunderstorms are expected across portions of the
Ohio Valley and lower Great Lakes into the Mid-Atlantic, mainly
Saturday afternoon into the evening. Some threat may linger into
late Saturday night.

...Ohio Valley into the Mid Atlantic and vicinity...
Some amplification of a mid/upper-level trough is expected over the
northeastern CONUS on Saturday, as multiple shortwaves move through
the base of the trough. The primary surface low is expected to
deepen as it moves across southern Quebec toward northern Maine. A
trailing cold front will move through parts of the Ohio Valley and
Northeast. A remnant surface front initially draped from western PA
toward the Delmarva region is forecast to lift northeastward as a
warm front through the period. 

As deep-layer flow strengthens atop a richly moist and destabilizing
warm sector, organized severe potential is expected to develop
across a relatively broad region from the Ohio Valley into the Mid
Atlantic, with at least an isolated threat potentially reaching
parts of New England. Uncertainties include the influence of
early-day convection and potential persistent smoke on the
northeastward extent of substantial surface-based destabilization. 

Along the cold front, the greatest relative threat is currently
expected from the lower Great Lakes into eastern parts of the Ohio
Valley, where stronger 850-700 mb flow (around 25-40 kt) is
forecast. Organized cells/clusters capable of damaging wind and
isolated hail may evolve along/ahead of the front and spread
eastward. Rich boundary-layer moisture and modest enhancement to
low-level SRH may also result in some tornado threat, depending on
storm-mode evolution. Favorable moisture/buoyancy will also extend
westward along/ahead of the front into parts of the Midwest and
lower Ohio Valley, but there may be more of a tendency for
convection to be undercut by the front with westward extent. 

Farther south/east, organized convection may evolve or reintensify
near the effective warm front by afternoon into parts of PA/NJ, and
also develop into parts of MD/VA along/east of a surface trough.
Very warm temperatures and steepening low-level lapse rates will
become supportive of damaging-wind potential, and isolated hail may
also occur. Some tornado threat could also evolve in closer
proximity to the warm frontal zone. 

An extensive frontal QLCS may develop by evening, and continue to
pose some wind-damage threat for as long as it persists into
Saturday night. 

...Northern Rockies vicinity...
Compared to previous days, some drying from the west is expected
across parts of MT on Saturday, as a mid/upper-level shortwave
trough moves across parts of BC/AB through the day. High-based
convection is still expected from ID into southwest MT and vicinity,
though relatively weak buoyancy and deep-layer shear should limit
storm organization. Some overlap of stronger deep-layer shear and
moderate buoyancy is forecast to occur across parts of northern MT,
but storm coverage within this regime is uncertain, with stronger
large-scale ascent currently expected to remain north of the
international border.

..Dean.. 07/16/2026

Day 2 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0213 PM CDT Thu Jul 16 2026

Valid 171200Z - 181200Z

...Afternoon Update...
A few thunderstorms may linger into the early morning hours of Day
2/Friday across northeastern Washington and the Idaho Panhandle. By
midday, a dry airmass will return to the Columbia Basin with locally
breezy winds. Mostly clear skies will allow for strong surface
heating and deep vertical mixing, resulting in RH values declining
to less than 20% and sustained south-southwesterly winds of 10-20
mph (localized gusts up to 25 mph). Preceding days of wet/dry
thunderstorms has resulted in many lightning ignitions, with the
potential for additional fires to emerge as a result of combined
meteorological conditions and receptive fuels (90th percentile
ERCs). Elevated highlights were introduced across far northern
Oregon and central-eastern Washington to account for this threat.
The rest of the forecast remains on track; see the previous
discussion for more information.

..Elizalde-Garcia.. 07/16/2026

.PREV DISCUSSION... /ISSUED 1231 AM CDT Thu Jul 16 2026/

...Synopsis...
An upper ridge will amplify over much of the Intermountain West and
central U.S. Evacuation of deeper monsoon moisture hastened by dry
southwest flow south of a Pacific Northwest trough will bring dry
and breezy conditions to portions of CA, OR and NV Friday.
Similarly, daily shower and thunderstorm activity will generally be
shifted farther east with dry conditions returning to the Pacific
Northwest.

...Northeastern California, south-central OR and far northwestern
NV...
Dry southwest flow aloft coupled with a diffuse surface low in the
Great Basin will enhance low-level southwest winds across
northeastern CA and adjacent OR and NV areas. Efficient boundary
layer mixing under sunny skies will manifest in southwest winds at
the surface of around 15 mph during Friday afternoon. The winds
coupled with RH of 10-15% will bring an elevated fire weather
concern to the area amid dry fuels. 

...Columbia Basin...
Dry south to southwest flow is expected to return Friday across
portions of the Columbia Basin and Okanogan Valley as an upper low
ejects into British Columbia. South/southwest winds of around 15 mph
and RH dropping to 15% should briefly elevate fire weather concerns
Friday. However, preceding rainfall could mitigate the fire weather
threat, precluding introduction of highlights for this outlook
issuance.

...Please see www.spc.noaa.gov/fire for graphic product...

Day 3-8 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0416 PM CDT Thu Jul 16 2026

Valid 181200Z - 241200Z

...Discussion...
A shortwave trough will move across British Columbia/Alberta on Day
3/Saturday, encouraging a dry airmass to translate northeastward
into the Pacific Northwest and Northern Rockies through the weekend.
Through the remainder of the forecast period, guidance indicates an
upper ridge (currently atop the northern Plains) will gradually
shift westward to encompass much of the western CONUS, while the
eastern US is expected to remain in a progressively active troughing
pattern. Daily chances of thunderstorm activity are possible across
the eastern CONUS with several embedded shortwaves within the larger
troughing pattern, and across the Intermountain West as monsoonal
moisture advects northward once again. Portions of the Northwest,
Pacific Coast, and central/northern High Plains are forecast to
remain hot and mostly dry within the overall pattern, possibly
leading to increasing fuel receptivity. 

Strong south-southwesterly flow aloft behind an exiting shortwave
trough will encourage dry and windy conditions across northeastern
California, northwestern Nevada, and central Oregon/Washington on
Day 3/Saturday. With preceding days of thunderstorms and numerous
lightning ignitions across the region, 15-25% RH values and locally
gusty winds could permit additional lightning holdovers to emerge.
Meteorological conditions may further intensify the increasingly dry
fuelscape, potentially impacting new/ongoing wildfires and control
efforts. 40% Critical probabilities have been introduced to account
for this threat.

..Elizalde-Garcia.. 07/16/2026

...Please see www.spc.noaa.gov/fire for graphic product...