RSS Mesoscale Discussions from Storm Prediction Center
WW 487 SEVERE TSTM AZ 122200Z - 130400Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 487
NWS Storm Prediction Center Norman OK
400 PM MDT Sun Jul 12 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Central and south central Arizona
* Effective this Sunday afternoon and evening from 400 PM until
1000 PM MDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
SUMMARY...Storms clusters are forming over the Mogollon Rim and the
mountains in southeast Arizona, and the storms are expected to
spread westward through late evening. The storm environment favors
severe outflow gusts of 60-70 mph as the primary threat as storms
propagate into the lower deserts, especially where outflow mergers
occur. Otherwise, the strongest initial cells could also produce
isolated large hail near 1 inch diameter.
The severe thunderstorm watch area is approximately along and 60
statute miles east and west of a line from 60 miles north of Phoenix
AZ to 60 miles south southwest of Tucson AZ. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU7).
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 485...WW 486...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
08020.
...Thompson
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WW 0487 Status Updates
STATUS REPORT ON WW 487
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 60 WSW PRC
TO 30 NE PHX TO 45 NNW TUS TO 40 WSW TUS TO 125 SW TUS.
..LYONS..07/13/26
ATTN...WFO...PSR...TWC...FGZ...
STATUS REPORT FOR WS 487
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
AZC013-019-025-130240-
AZ
. ARIZONA COUNTIES INCLUDED ARE
MARICOPA PIMA YAVAPAI
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
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WW 0486 Status Updates
STATUS REPORT ON WW 486
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NNW SAV
TO 10 SE AGS TO 10 ESE CAE TO 25 E SPA.
..HALBERT..07/12/26
ATTN...WFO...FFC...CAE...GSP...CHS...
STATUS REPORT FOR WS 486
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
SCC005-009-011-017-023-025-027-039-049-055-057-061-075-079-085-
130040-
SC
. SOUTH CAROLINA COUNTIES INCLUDED ARE
ALLENDALE BAMBERG BARNWELL
CALHOUN CHESTER CHESTERFIELD
CLARENDON FAIRFIELD HAMPTON
KERSHAW LANCASTER LEE
ORANGEBURG RICHLAND SUMTER
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
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WW 0485 Status Updates
STATUS REPORT ON WW 485
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 SE TLH TO
10 SSW VLD TO 15 E MGR TO 15 NNW MGR TO 35 SSW CSG.
..CHALMERS..07/12/26
ATTN...WFO...TAE...
STATUS REPORT FOR WS 485
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
FLC067-079-123-122140-
FL
. FLORIDA COUNTIES INCLUDED ARE
LAFAYETTE MADISON TAYLOR
GAC019-071-075-095-173-177-185-273-277-321-122140-
GA
. GEORGIA COUNTIES INCLUDED ARE
BERRIEN COLQUITT COOK
DOUGHERTY LANIER LEE
LOWNDES TERRELL TIFT
WORTH
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
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No Mesoscale Discussions are in effect as of Mon Jul 13 02:31:15 UTC 2026.
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0801 PM CDT Sun Jul 12 2026
Valid 130100Z - 131200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN ATLANTIC SEABOARD...AND IN SOUTHERN ARIZONA...
...SUMMARY...
Thunderstorms with severe wind gusts will be possible this evening
across parts of the southern Atlantic Seaboard and in southern
Arizona. Severe gusts and hail may also occur in parts of the
western Great Lakes. A few strong gusts will also be possible in
northeast Montana, and from the southern Plains into the Southeast.
...Southern North Carolina/South Carolina/Far Eastern Georgia...
A mid-level shortwave trough is evident on water vapor imagery from
the Mid-Atlantic into the Carolinas. At the surface, a cold front is
located over southern North Carolina. To the south of the front, a
very moist air is in place with dewpoints in the 70s F, which is
contributing to moderate instability. Scattered thunderstorms are
ongoing across much of this airmass from southern North Carolina
into eastern Georgia. The latest WSR-88D VWPs at Wilmington, North
Carolina and Colubmia, South Carolina have 0-6 km shear in the 20 to
30 knot range. This environment may support a threat for severe wind
gusts for another hour early this evening.
...Southern Plains/Lower Mississippi Valley/Southeast...
A very moist airmass is in place from the southern Plains eastward
into the Southeast. Over much of the region, the RAP has moderate
instability, with surface dewpoints in the 70s F. Numerous
thunderstorms are ongoing from north-central Texas eastward into
southern Alabama. Along this corridor, the instability combined with
steep low-level lapse rates will support a threat for isolated
severe gusts for another hour or two.
...Southern Arizona...
At the surface, a sufficiently moist airmass is in place over
southern and central Arizona. In this area, the RAP has an axis of
moderate instability analyzed with SBCAPE estimated in the 1000 to
2000 J/kg range. Thunderstorms are ongoing just to the west of the
instability axis, and these storms will continue to move westward
across southern and western Arizona this evening. Large surface
temperature-dewpoint spreads and steep low-level lapse rate will
continue to support a potential for severe wind gusts...see MCD
1609.
...Western Great Lakes...
North-northwesterly mid-level flow is located over the western Great
Lakes, where a moist airmass is present. Surface dewpoints are in
the 60s and lower 70s F, and the RAP has an axis of moderate
instability from northern Wisconsin into Upper Michigan. Scattered
strong to severe storms are ongoing further north over southern
Ontario. One of these cells could remain intact and move southward
across Lake Superior into Upper Michigan this evening. In that case,
the instability combined with moderate deep-layer shear would
support an isolated threat for severe wind gusts and hail.
...Northern Montana...
Southwest mid-level flow is in place over the northwestern U.S. At
the surface, a cold front is located over central and northeast
Montana, where isolated thunderstorms are ongoing. Near and ahead of
the front in northeast Montana, the RAP is analyzing moderate
instability. Thunderstorms that move in and toward the stronger
instability over the next couple of hours, may produce isolated
severe wind gusts...see MCD 1610.
..Broyles.. 07/13/2026
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SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0439 PM CDT Sun Jul 12 2026
Valid 141200Z - 201200Z
...Synopsis...
A strong upper high will develop and persist over the
central/northern Plains into the Midwest through at least Day
5/Thursday. Upper-level troughing will continue near and off the
Pacific Northwest coast with monsoonal moisture streaming northward
across much of the Intermountain West early to midweek. Daily
monsoonal thunderstorms are likely across the Southwest into the
Great Basin, but an upper-level trough is forecast to move into the
Pacific Northwest and northern Rockies beyond Day 4/Wednesday,
helping suppress moisture south and eastward. Farther east, a deep
upper-level trough is expected to weaken the ridge over the Great
Lakes and Northeast as it digs southward on Days
3-4/Wednesday-Thursday, leading to unsettled conditions across the
region through the remainder of the forecast period.
...Northern California, much of Oregon, and northwestern Nevada...
Monsoonal moisture (PWAT values of 0.8-1.5") is continuing to advect
west and north across the Great Basin, eastern California, and into
portions of the Inland Northwest and northern Rockies. On the
western/northern fringes of the deeper moisture, a mix of wet/dry
thunderstorms are likely. On Day 3/Tuesday, 10% dry thunderstorm
probabilities were maintained across far northern California into
central-eastern Oregon. Forecast PWAT values of 0.8-1" and surface
dewpoints of 35-50F will likely to lead to at least pockets of
wetting rain. However, storm motions of 25-40 knots, 30% or less
probabilities of rainfall exceeding 0.1", and receptive fuels should
uphold a concern for lightning ignitions. Additionally, deeper
moisture will move out of these areas by mid-week with dry/breezy
conditions to follow.
...Central to northern High Plains...
Hot, dry, and breezy conditions are likely across portions of
eastern Wyoming, western South Dakota, western Nebraska and eastern
Colorado on Day 3/Tuesday through at least Day 5/Thursday. While RH
will recover overnight, south-southeast winds are likely to remain
breezy amid dry fuels. 40% Critical probabilities have been
maintained on Days 3-4/Tuesday-Wednesday, and introduced on Day
5/Thursday.
...California Central Valley...
Warm daytime temperatures and low RH will contribute to drying fuels
across the Coastal Ranges into the Central Valley. ERCs are forecast
to approach the 90-95th percentile mid-week amid dry and breezy
conditions, supporting any new ignitions and the emergence of any
lightning holdovers from sporadic wet/dry thunderstorms early in the
forecast period. 40% Critical probabilities were withheld on Day
3/Tuesday for now, but have been introduced on Day 4/Wednesday where
ensembles depict a broader overlap of meteorological fire weather
conditions.
..Elizalde-Garcia.. 07/12/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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