WPC Met Watch |
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Mesoscale Precipitation Discussion: #0619 |
(Issued at 1022 AM EDT Tue Jul 08 2025
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MPD Selection |
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Mesoscale Precipitation Discussion 0619
NWS Weather Prediction Center College Park MD
1022 AM EDT Tue Jul 08 2025
Areas affected...Eastern OK...Western/Northern AR...Southern MO
Concerning...Heavy rainfall...Flash flooding likely
Valid 081422Z - 082015Z
SUMMARY...Locally slow-moving clusters of heavy showers and
thunderstorms will tend to increase in coverage going into the
afternoon hours. High rainfall rates and slow cell-motions will
likely yield isolated to scattered areas of flash flooding, which
will include a concern for locally significant/dangerous flash
flooding impacts near areas of rugged terrain.
DISCUSSION...The morning GOES-E IR satellite imagery shows a
small-scale vort center drifting gradually east along the OK/AR
border in close proximity to the Ozark Plateau. This energy is
embedded in a very moist and unstable environment as evidenced by
the 12Z KLIT RAOB sounding along with RAP analyses, and is already
producing slow-moving clusters of very heavy showers and
thunderstorms.
Much of the convection is somewhat elevated in nature, but is
embedded within MUCAPE values ranging from 1000 to 2000 J/kg, and
with PWs that are near 2 inches. The activity is also seen locally
backbuilding along the OK/AR border in an environment with
relatively notable low-level moisture convergence.
Some expansion of heavy shower and thunderstorm activity is
expected over the next several hours as the diurnal heating cycle
evolves and promotes more surface-based convection. The
aforementioned vort energy will continue to be slow-moving going
into the afternoon hours, but will be interacting with greater
surface-based instability along with differential heating
boundaries that will favor small-scale convergence zones/forcing
for additional convective development.
Corfidi vectors depict a strongly favorable environment for
backbuilding convection over the next several hours, and with such
a strongly moist and increasingly unstable airmass pooled across
the region, there will be notable concerns for slow-moving showers
and thunderstorms with very high rainfall rates.
The last couple of runs of the HRRR guidance shows potential for
rainfall rates to reach 2 to 3+ inches/hour, with locally some
rainfall totals by mid-afternoon of as much as 3 to 6+ inches
given the slow cell-motions. Some of the 06Z HREF guidance also
supports similar rates and totals.
While the antecedent conditions are very dry, and reflective of
high FFG values, the very high rainfall rate potential and
localized storm potential suggests an elevated flash flood threat.
Some of these rains will also potentially be occurring over rugged
terrain which suggests an enhanced threat for runoff potential.
Therefore, going into the afternoon hours, at least isolated to
scattered areas of flash flooding will be likely. Some concern
will exist for locally significant/dangerous flash flooding
impacts nears areas of rugged terrain.
Orrison
ATTN...WFO...LSX...LZK...MEG...OUN...PAH...SGF...SHV...TSA...
ATTN...RFC...KRF...MSR...ORN...TUA...NWC...
LAT...LON 37559266 37559084 36808969 35609021 34559200
33839433 34419578 35669604 36669506
Download in GIS format: Shapefile
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Last Updated: 1034 AM EDT Tue Jul 08 2025
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