Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1128 AM CDT Tue Aug 19 2025
Valid 191630Z - 201200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE OHIO VALLEY TO THE SOUTHERN/CENTRAL PLAINS...AND OVER PORTIONS
OF WESTERN/NORTHERN MONTANA...
...SUMMARY...
Scattered thunderstorms capable of producing occasional damaging
winds will be possible across parts of the south-central Plains and
Ozarks to the Ohio Valley this afternoon and evening. Isolated
severe thunderstorms may also occur this evening across parts of
western and northern Montana.
...Ohio Valley to the Central/Southern Plains...
Upper ridging will remain prominent today across the Southwest and
southern/central Rockies, as a weak mid/upper-level trough moves
east-southeastward across the Great Lakes and OH Valley regions. At
the surface, a weak cold front is forecast to advance
east-southeastward across parts of the OH Valley and mid MS Valley
today, and more slowly southward over portions of the
central/southern Plains while weakening. This boundary should aid in
at least scattered thunderstorm development through the afternoon as
diurnal heating of a moist airmass along/south of the front occurs.
While deep-layer flow and related shear are expected to remain
generally weak, moderate to strong instability and the steepening of
low-level lapse rates may support occasional strong to damaging
winds with water-loaded downdrafts within the stronger cores. Only
minor adjustments have been made to the broad Marginal Risk based on
latest observational and short-term guidance trends.
...Northern Rockies/High Plains...
An embedded mid-level shortwave trough will advance northeastward
this evening and overnight across parts of the northern Rockies and
adjacent High Plains on the western to northern periphery of
prominent upper ridging over the Southwest. Isolated to perhaps
widely scattered thunderstorms should develop through the evening
hours across parts of western MT and vicinity as large-scale ascent
associated with the shortwave trough overspreads the northern
Rockies. Instability is forecast to remain rather limited, but
steepened lapse rates aloft and a well-mixed boundary layer could
still aid in some convective downdraft enhancement, with isolated
strong to severe gusts possible as convection spreads northeastward
towards the international border.
...Coastal Texas...
A weak mid-level perturbation with ongoing thunderstorms along parts
of the middle TX Coast should continue south-southwestward this
afternoon and evening. Low/mid-level flow should remain modest,
which will generally limit thunderstorm organization. Still, some
clustering could support isolated strong/gusty winds in the presence
of increasing instability this afternoon across parts of
south-central TX and the lower TX Coast. Confidence in
severe-caliber gusts remains too low to include any severe
probabilities at this time.
..Gleason/Wendt.. 08/19/2025
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TMZV5g
