RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Thu Jul 9 14:03:02 UTC 2026.
No Mesoscale Discussions are in effect as of Thu Jul 9 14:03:02 UTC 2026.
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0755 AM CDT Thu Jul 09 2026
Valid 091300Z - 101200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE NORTHERN AND CENTRAL PLAINS...FROM THE LOWER MISSOURI VALLEY
INTO THE LOWER OHIO VALLEY...AND PORTIONS OF THE MID-ATLANTIC...
CORRECTED FOR INCORRECT GEOGRAPHIC REFERENCE
...SUMMARY...
Thunderstorms with severe wind gusts and hail will be possible this
afternoon and evening across parts of the central and northern
Plains. Severe wind gusts may also occur in parts of the Ozarks, mid
Mississippi Valley, lower Ohio Valley, Mid-Atlantic and Arizona.
...Central High Plains into the Central Plains...
A similar thermodynamic environment to yesterday is expected across
the central Rockies today, with scattered afternoon thunderstorm
development anticipated. The presence of a low-amplitude shortwave
trough could lead to greater storm coverage today versus yesterday.
Moist post-frontal easterlies will help offset mixing across much of
the region, keeping dewpoints in the upper 50s/low 60s across
east-central/northeast CO, with higher dewpoints farther east into
southern NE and western/central KS. Moderate westerly flow aloft
will support organized storm structures into this more buoyant
environment, with an attendant threat for strong to severe gusts
with the stronger bowing segments. There is some potential for a
contiguous line of storms from the NE Panhandle across eastern CO if
widespread cold pool amalgamation is realized. Uncertainty regarding
convective evolution precludes higher probabilities with this
outlook, but increased probabilities may be needed later if forecast
confidence increases.
...Northern Plains...
A somewhat separate convective regime is expected across the
northern Plains versus farther south. Here, strong heating of a
moist airmass beneath steep mid-level lapse rates will support
robust buoyancy this afternoon, with MLCAPE over 2000 J/kg
anticipated. The better forcing for ascent will remain north of the
region and some convective inhibition may linger, but convergence
along a modest cold front and/or pre-frontal trough/low will likely
result in at least isolated thunderstorms. Strong buoyancy combined
with effective bulk shear around 30-35 kt should support a few
supercells. Large to isolated very large hail and strong downdrafts
are possible within the more organized storms.
...Lower MO Valley into the Lower OH Valley...
An MCS is currently tracking southeastward through central MO, with
occasionally strong gusts noted on its leading edge. Continued
eastward progression away from the low-level jet, coupled with the
decreasing strength of the jet, will likely lead to a weakening of
this MCS this morning. However, the moist airmass downstream will
diurnally destabilize, likely resulting in a reintensification of
the MCS and/or development of new storms along its leading edge.
Additional development is possible in the wake of this MCS, amid
low-level moisture convergence along a potential differential
heating boundary. Vertical shear will be weak, but moderate/strong
buoyancy and steep low-level lapse rates will support strong cold
pools and the potential for damaging gusts.
...Mid-Atlantic...
A moist airmass will remain in place across the Mid-Atlantic today,
characterized by afternoon dewpoints in the upper 60s to mid 70s.
Airmass destabilization is expected by the early afternoon, with
moderate to strong buoyancy (i.e. MLCAPE from 1500 to 2000 J/kg)
likely. A low-amplitude shortwave trough currently over TN/KY is
forecast to progress northeastward, interacting with the moist and
unstable airmass to support thunderstorms. While the thermodynamic
characteristics of the airmass remain similar to the last few days,
increased large-scale ascent and slightly stronger mid-level flow
attendant to the shortwave will likely support greater storm
coverage and intensity. Moderate vertical shear will support a
predominantly outflow-dominant multicellular mode, with damaging
wind gusts as the primary risk, particularly in areas where few
clouds allow for more heating and steeper low-level lapse rates.
...Lower Great Lakes into northern New England...
Moderate westerly/southwesterly flow aloft at the base of a
shortwave trough moving across Ontario and Quebec will extend from
the Lower Great Lakes region through New England this afternoon. A
modest cold front associated with the shortwave will shift
eastward/southeastward into the region as well, interacting with the
warm, moist and unstable airmass in place to support scattered
thunderstorms this afternoon. Poor mid-level lapse rates will keep
buoyancy modest, but the moderate westerly/southwesterly flow aloft
could still support some stronger bowing segments capable of
damaging gusts.
...Southeast Arizona...
Mid-level moisture will support afternoon thunderstorm development
across the higher terrain of southeast AZ/southwest NM.
Southwestward storm motion associated with modest mid-level
easterly/northeasterly flow could take a few of these storms into
the hot and deeply mixed airmass across southeast AZ. Strong
downdrafts are possible with any stronger storms.
..Mosier/Thornton.. 07/09/2026
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