Valid 171200Z – 181200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
…SUMMARY…
Potential for organized severe thunderstorms will be very low across
the contiguous United States today.
…Synopsis…
A potent cyclone across the Northeast will occlude and slowly
progress to the northeast through the period. A cold front trailing
from this system is expected to stall across the southern Florida
Peninsula westward to the South Texas coast. In the West, a broad
upper trough will move across the Great Basin to near the Four
Corners region. A secondary shortwave trough will impact the Pacific
Northwest coast by late afternoon.
Isolated thunderstorm development is possible during the afternoon
along the stalled boundary in portions of south Florida. Convergence
along the boundary will not be very strong. Greater potential for
storm development will exist with the sea breeze interacting with
the front. Modest mid-level flow may loosely organize thunderstorms,
but weak mid-level lapse rates and low-level flow will limit severe
potential.
Cold temperatures aloft and approaching mid-level ascent will foster
isolated thunderstorm development within portions of eastern Utah,
western Colorado, and southwest Wyoming during the late afternoon
and into the evening. Mid-level lapse rates will be very steep, but
very limited buoyancy will limit storm intensity. A few storms may
occur along the Pacific Northwest coast as mid-level temperatures
cool in response to the shortwave trough. Buoyancy will be even more
limited in this region and no severe weather is expected.
..Wendt.. 10/17/2019
$$