RSS Mesoscale Discussions from Storm Prediction Center
WW 249 SEVERE TSTM ID MT WA 282220Z - 290700Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 249
NWS Storm Prediction Center Norman OK
320 PM PDT Thu May 28 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northern Idaho
Western Montana
Central and Eastern Washington
* Effective this Thursday afternoon from 320 PM until Midnight
PDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 75
mph possible
Isolated large hail events to 1.5 inches in diameter possible
SUMMARY...Strong to severe thunderstorms are expected to develop
late this afternoon through early evening, initially across
west-central/northern-central Idaho as well as western Montana and
interior Washington. The strongest storms will be capable of large
hail and locally damaging winds, and over time, some semi-organized
storm clusters could evolve into northern Idaho and eastern
Washington later this evening as storms spread north-northwestward.
The severe thunderstorm watch area is approximately along and 180
statute miles east and west of a line from 100 miles north northeast
of Spokane WA to 50 miles east southeast of Walla Walla WA. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU9).
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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 248...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
13025.
...Guyer
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WW 248 SEVERE TSTM ID OR 281950Z - 290300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 248
NWS Storm Prediction Center Norman OK
1250 PM PDT Thu May 28 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Western Idaho
Central and Eastern Oregon
* Effective this Thursday afternoon and evening from 1250 PM
until 800 PM PDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 75
mph likely
Scattered large hail events to 1.5 inches in diameter possible
A tornado or two possible
SUMMARY...Thunderstorms will develop and intensify across the watch
area through the afternoon, in a moderately unstable air mass. The
strongest storms will pose a risk of damaging winds and large hail
through the early evening.
The severe thunderstorm watch area is approximately along and 110
statute miles north and south of a line from 35 miles south
southwest of Redmond OR to 80 miles southeast of Baker OR. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU8).
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
1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
13030.
...Hart
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WW 0249 Status Updates
STATUS REPORT ON WW 249
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..MEAD..05/28/26
ATTN...WFO...OTX...MSO...PDT...
STATUS REPORT FOR WS 249
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IDC009-017-021-035-049-055-057-061-069-079-290040-
ID
. IDAHO COUNTIES INCLUDED ARE
BENEWAH BONNER BOUNDARY
CLEARWATER IDAHO KOOTENAI
LATAH LEWIS NEZ PERCE
SHOSHONE
MTC029-039-047-053-061-063-077-081-089-290040-
MT
. MONTANA COUNTIES INCLUDED ARE
FLATHEAD GRANITE LAKE
LINCOLN MINERAL MISSOULA
POWELL RAVALLI SANDERS
WAC001-003-005-007-013-017-019-021-023-025-037-039-043-047-051-
063-065-071-075-077-290040-
WA
. WASHINGTON COUNTIES INCLUDED ARE
Read more
WW 0248 Status Updates
STATUS REPORT ON WW 248
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..MEAD..05/28/26
ATTN...WFO...BOI...PDT...PQR...MFR...
STATUS REPORT FOR WS 248
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IDC001-003-027-045-073-075-087-290040-
ID
. IDAHO COUNTIES INCLUDED ARE
ADA ADAMS CANYON
GEM OWYHEE PAYETTE
WASHINGTON
ORC001-013-017-021-023-025-027-031-037-045-049-055-059-061-063-
065-069-290040-
OR
. OREGON COUNTIES INCLUDED ARE
BAKER CROOK DESCHUTES
GILLIAM GRANT HARNEY
HOOD RIVER JEFFERSON LAKE
MALHEUR MORROW SHERMAN
UMATILLA UNION WALLOWA
WASCO WHEELER
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
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MD 0885 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF CENTRAL AND NORTH-CENTRAL TEXAS
Mesoscale Discussion 0885
NWS Storm Prediction Center Norman OK
0550 PM CDT Thu May 28 2026
Areas affected...portions of central and north-central Texas
Concerning...Severe potential...Watch unlikely
Valid 282250Z - 290015Z
Probability of Watch Issuance...5 percent
SUMMARY...Isolated large hail will be possible with the strongest
storms in a cluster of storms developing across portions of central
and north Texas. A watch is currently not expected, but the area
will be monitored.
DISCUSSION...A cluster of multicell thunderstorms is ongoing across
portions of southern North Texas and northern portions of central
Texas. This region is downstream of the western North American
long-wave trough and upstream of the central US short-wave trough.
This places the area just east of the rising heights noted across
the southern Rockies.
The overall large scale environment is very unstable with MUCAPE in
excess of 2500 J/kg and locally greater than 3000 J/kg. Although,
deep layer shear is generally less than 30 knots, but pockets of
25-30 knots will support at least some organization to the strongest
of the multicell cores. Additionally, this region is downstream of
an upper-level subtropical jet on the southwest side of the large
western US trough, which is at minimum resulting in diffluent
upper-level flow and may provide some large-scale ascent.
Individual cells within this larger cluster have produced isolated
large hail around 1-1.5". The current degree of instability will
continue to support this threat with the strongest storms.
Although overall organization of the entire cluster is currently
somewhat limited, the area will be monitored for signs of individual
cell outflows merging together and functioning as a single,
collective outflow. Should this occur, the potential for some
damaging wind may develop as the overall cluster sags
south/southeast this evening.
Generally speaking, the overall severe potential should remain
relatively limited in space and time. As such, a watch is currently
not anticipated, but conditions will be monitored.
..Marsh/Guyer.. 05/28/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...SJT...LUB...
LAT...LON 32440029 33169987 33409802 33129657 32299629 31769635
31409711 31369853 31839984 32440029
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
Read more
MD 0884 CONCERNING SEVERE THUNDERSTORM WATCH 248... FOR SOUTHWEST IDAHO INTO EASTERN AND CENTRAL OREGON
Mesoscale Discussion 0884
NWS Storm Prediction Center Norman OK
0515 PM CDT Thu May 28 2026
Areas affected...southwest Idaho into eastern and central Oregon
Concerning...Severe Thunderstorm Watch 248...
Valid 282215Z - 290015Z
The severe weather threat for Severe Thunderstorm Watch 248
continues.
SUMMARY...The severe-weather threat continues across the watch area.
A potentially more focused area of severe storms will impact the
Harney Basin in the vicinity of Burns, OR and points west through
northwest for the next couple of hours.
DISCUSSION...As of 22:00 UTC, radar and IR satellite data indicated
a cluster of intense storms, including embedded supercell
structures, over Harney County, OR in the vicinity of Burns. Storm
movement was to the northwest at around 30 kt. Mesoanalysis places
that convection along a west-southwest to east-northeast-oriented
surface boundary that delineates a drier air mass to the south, and
a more moist and unstable environment to the north. The air mass to
the north is characterized by steep low to mid-level lapse rates,
which are yielding 1000-1500 J/kg MLCAPE amidst a kinematic
environment featuring 35-40 kt of effective bulk shear.
In addition to radar-observed rotation in the mid levels, some of
the storms have exhibited forward-propagating characteristics,
suggestive of damaging wind potential, in addition to the large hail
threat.
Elsewhere, convective outflow trailing additional storms across far
southwest ID has recently pushed through the Boise area, and may
serve as the focus for additional strong to severe storm
development. An additional strong thunderstorm over Washington
County ID may pose a large hail threat while moving into Baker
County OR.
..Mead.. 05/28/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MSO...BOI...LKN...OTX...PDT...MFR...PQR...
LAT...LON 42011499 41981725 42002085 42712092 42772131 43582131
43632196 45672190 46061786 45941677 45391636 44731617
43871615 42821507 42011499
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
Read more
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0300 PM CDT Thu May 28 2026
Valid 282000Z - 291200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ...
...SUMMARY...
Scattered severe thunderstorms remain possible this afternoon and
evening over western Idaho and east of the Cascades in Washington
and Oregon, capable of damaging gusts, large hail, and perhaps a
tornado.
...20Z Update...
The previous forecast (see below) remains on track.
..Squitieri.. 05/28/2026
.PREV DISCUSSION... /ISSUED 1108 AM CDT Thu May 28 2026/
...WA/OR/ID...
Morning water vapor imagery shows an upper low over central CA, with
a strong shortwave trough rotating around the low over central NV.
This feature is forecast to move into ID/OR later today, with an
associated 40-50 knot mid level jet affecting the area. Strong
heating, dewpoints in the upper 40s-lower 50s, and steepening
mid-level lapse rates will lead to moderate CAPE values over much of
western ID into central WA/OR, setting the stage for afternoon
thunderstorms. Activity is expected to first develop across
southwest ID/southern OR, where sufficient vertical shear would
support supercell structures capable of large hail and damaging wind
gusts. Morning CAM guidance suggests activity will organize into
multiple clusters by evening, tracking northwestward across the
Columbia Basin into western/central WA. These storms would continue
to pose a damaging wind threat.
...CO...
Strong heating and sufficient low-level moisture will likely result
in widely scattered thunderstorms in the foothills of the Front
Range this afternoon. The strongest cells could produce hail.
...KS...
A remnant weak vorticity max is tracking northward near the OK/KS
border. Southeasterly low-level winds to the north of the vort max
may result in sufficient shear for weak rotation in a few storms
later today. While a brief spin-up over north-central KS cannot be
ruled out, the overall threat appears too weak for outlook
probabilities today.
Read more
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0236 PM CDT Thu May 28 2026
Valid 291200Z - 301200Z
...Colorado Plateau and Southwest...
Dry and breezy conditions are expected across portions of the CO
Plateau and Southwest as an upper-level trough across the Great
Basin accelerates northeastward through the day. Limited cloud cover
will reinforce efficient mixing of a dry boundary layer with minimum
RH falling to between 15 and 20% (locally 10%) by mid afternoon.
Southwest winds of 15-25 mph, low RH and receptive fuels will
support several hours of elevated fire weather conditions Friday,
with a slight eastward expansion of Elevated highlights warranted
based on latest forecast guidance and expected drier fine fuels.
..Williams.. 05/28/2026
.PREV DISCUSSION... /ISSUED 1248 AM CDT Thu May 28 2026/
...Synopsis...
An upper-level low over the Great Basin will translate into an open
wave as persistent ridging continues across the central CONUS. A
compact upper low will move out of southern Quebec into New England
on Friday night, transporting ample moisture and a southward
progressing cold front. Fire weather concerns are expected to remain
limited to the eastern Great Basin and Southwest as the upper-level
trough advances northward.
...Great Basin and Southwest...
Dry, southerly flow is expected to continue into Day 2/Friday as
upper level troughing lifts over the region. At peak heating, RH
reductions to 15-20% and south-southwesterly winds of 15-25 mph are
expected to promote Elevated fire weather conditions across the
eastern Great Basin, Colorado Plateau, and portions of the
Southwest. A 50-60 kt mid-level jet will emerge at the base of the
lifting trough, supporting a narrow region of locally critical fire
weather conditions in terrain-favored areas of the Four Corners
where wind gusts of up to 35 mph and less than 15% RH may coalesce.
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0412 PM CDT Thu May 28 2026
Valid 301200Z - 051200Z
...Synopsis...
An upper trough pushes northeastward into the Northern Rockies by
early next week as blocking ridge remains over the central U.S.
Surface high pressure and associated dry conditions amid light winds
will dominate over the Great Lakes and Midwest while troughing
across the Northeast. Much of the Plains and Southeast will continue
to see good opportunities for showers and thunderstorms with deeper
boundary layer moisture in place, keeping fire weather concerns low.
The exiting upper-level trough into the Northern Rockies will
promote a gradual warming and drying trend across much of the
Intermountain West and Southwest through the middle of next week.
Diffuse surface pressure gradients will keep winds on the light side
with above normal temperatures and dry conditions supporting drying
and curing of fuels. Longer term model guidance suggests intrusion
of deeper atmospheric moisture into southern AZ and NM, west of the
Divide, as early as Tuesday as weak troughing sets up over Baja
California. However predictability remains low which precludes
introduction of dry thunderstorm probabilities at this time.
..Williams.. 05/28/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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