Severe Storm Outlook Narrative (AC)
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
000
ACUS02 KWNS 180345
SWODY2
SPC AC 180344

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1044 PM CDT Tue Oct 17 2017

Valid 191200Z - 201200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorm probabilities will be greatest across the southern
Rockies, along the Pacific Northwest Coast, and over parts of
Florida.

...Discussion...

Dry and stable conditions will exist across much of the contiguous
US Thursday though three distinct areas of the country will have
some threat for thunderstorms.

1) Southern Rockies region - Several low-latitude disturbances will
traverse the international border over the next few days. These
features should encourage higher PW air mass to spread across
northern Mexico into NM and the adjacent High Plains. As a result,
convection is expected to develop across this region as instability
increases ahead of short wave. Thunderstorms that form over NM will
spread toward the TX South Plains during the evening aided by
nocturnal increase in LLJ across this region after dark.

2) Pacific NW - Profiles are expected to cool significantly along
the Pacific NW coast as a strong trough moves inland around 20/03z.
Primary threat for lightning will be with post-frontal convection
influenced by relatively more buoyant onshore flow.

3) FL - Upper trough will move off the FL coast early in the period
and heights will rise slowly as ridge builds toward the state.
Large-scale surface pattern will change little over the next few
days with deep easterly flow expected to continue due to dominant
surface ridge anchored over the southern Appalachians. Showers will
focus along the east coast and sufficient buoyancy should exist for
at least a threat for lightning with the strongest updrafts.

..Darrow.. 10/18/2017

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.