Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1016 AM CST Fri Feb 28 2020

Valid 281630Z - 291200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
The risk of severe storms appears negligible through tonight.

...Mid-South to Southern Appalachians...
A shortwave impulse over the Lower MO Valley will progress
southeast, aiding in scattered shower development during the late
afternoon across the Mid-South. Despite surface dew points only in
the low to mid 30s, steep lapse rates through a combination of
boundary-layer heating and very cold 500 mb temperatures near -32 C
may support scant buoyancy (SBCAPE up to 250 J/kg). Here, convection
could become sufficiently deep and cloud tops sufficiently cold to
support mixed phase and charge separation, with a threat for
isolated thunderstorms containing small hail and gusty winds.
Farther east, shallow convection is expected during the late
afternoon across the southern Appalachians with a leading shortwave
impulse, but even less buoyancy and shallower convective depths
suggest that thunderstorm probabilities are below 10 percent. 

...Coastal WA/northern OR...
An offshore shortwave trough near 48 N and 132 W will move inland
near the WA/BC border area by evening. Cooling mid-level
temperatures and steepening lapse rates in the post-frontal
environment should be sufficient for scant buoyancy near the coast,
and an associated threat for isolated lightning flashes after 03Z.

..Grams.. 02/28/2020

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0129 PM CST Fri Feb 28 2020

Valid 282000Z - 291200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
No severe storms are expected through tonight.

...Discussion...

Only minor adjustments have been made to previous forecast. A few
thunderstorms remain possible from the middle to lower MS Valley and
TN Valley this afternoon into early evening and along the Pacific NW
coast tonight.

..Dial.. 02/28/2020

.PREV DISCUSSION... /ISSUED 1016 AM CST Fri Feb 28 2020/

...Mid-South to Southern Appalachians...
A shortwave impulse over the Lower MO Valley will progress
southeast, aiding in scattered shower development during the late
afternoon across the Mid-South. Despite surface dew points only in
the low to mid 30s, steep lapse rates through a combination of
boundary-layer heating and very cold 500 mb temperatures near -32 C
may support scant buoyancy (SBCAPE up to 250 J/kg). Here, convection
could become sufficiently deep and cloud tops sufficiently cold to
support mixed phase and charge separation, with a threat for
isolated thunderstorms containing small hail and gusty winds.
Farther east, shallow convection is expected during the late
afternoon across the southern Appalachians with a leading shortwave
impulse, but even less buoyancy and shallower convective depths
suggest that thunderstorm probabilities are below 10 percent. 

...Coastal WA/northern OR...
An offshore shortwave trough near 48 N and 132 W will move inland
near the WA/BC border area by evening. Cooling mid-level
temperatures and steepening lapse rates in the post-frontal
environment should be sufficient for scant buoyancy near the coast,
and an associated threat for isolated lightning flashes after 03Z.

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1050 AM CST Fri Feb 28 2020

Valid 291200Z - 011200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Isolated thunderstorms will be possible Saturday along a portion of
the Pacific Northwest.

...Pacific Northwest...

A shortwave trough embedded within a synoptic trough currently
situated off the Pacific Northwest coast will move onto the WA coast
tonight. A secondary shortwave trough will rotate through the base
of the trough and into OR Saturday. Cold temperatures aloft with
steep lapse rates and forcing for ascent accompanying this feature
will result in weak instability (150-300 J/kg MUCAPE) especially
along and west of the coastal range where influence of the marine
layer will be maximized. Scattered showers will develop within this
environment along with a possibility of isolated lightning flashes.

..Dial.. 02/28/2020