Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0630 PM CST Fri Feb 28 2025

Valid 010100Z - 011200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are unlikely tonight.

...01z Update...

Dry, mostly stable conditions are noted across the lower 48 early
this evening. While a strong upper low is digging southeast, just
off the southern CA Coast, buoyancy should remain inadequate along
the northeastern periphery of this feature to warrant any meaningful
risk for thunderstorms tonight.

..Darrow.. 03/01/2025

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0153 PM CST Fri Feb 28 2025

Valid 282000Z - 011200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are unlikely through tonight.

...20z Update...
No adjustments are needed as latest observations and short-term
guidance suggest that thunderstorm potential will remain negligible
over the CONUS through tonight.

..Guyer.. 02/28/2025

.PREV DISCUSSION... /ISSUED 1015 AM CST Fri Feb 28 2025/

...Synopsis and Discussion...
An upper trough over Ontario and the Upper Midwest is forecast to
further amplify today as it eventually encompasses much of the
eastern CONUS. With a surface cold front having cleared the
Gulf/Atlantic Coasts, dry and/or stable conditions are likely to
preclude thunderstorms across the central/eastern CONUS through
tonight. Farther west, a closed upper low will approach coastal
southern CA through the period. While showers may occur across parts
of this region as the upper low approaches, thermodynamic profiles
are forecast to remain generally unfavorable for lightning
production.

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0106 PM CST Fri Feb 28 2025

Valid 021200Z - 031200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Widely scattered, generally weak thunderstorm activity is possible
across parts of central California into the Great Basin, and across
parts of the central Great Plains, Sunday through Sunday night.

...Synopsis and Discussion...
An amplified upper trough will move east across the West Coast on
Sunday, with a strong backside speed max digging into the Four
Corners states into Monday morning. Minimal elevated instability is
forecast to develop primarily from southern NV into northern AZ and
southern UT, supporting isolated weak thunderstorms late.

To the east, a compact shortwave trough/upper low is forecast to
move quickly into the central Plains, with low pressure developing
over eastern CO into western KS. Given dry surface trajectories due
to a surface high to the east, minimal low-level moisture return
will occur. However, steep lapse rates especially during the late
afternoon and cool temperatures aloft will support scattered
thunderstorms, most prominent near the surface low over KS.
Therefore despite strong shear profiles with this otherwise
synoptically favorable system, severe weather is not expected.

..Jewell.. 02/28/2025

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1118 AM CST Fri Feb 28 2025

Valid 011200Z - 021200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Isolated thunderstorms cannot be ruled out over parts of northern
Arizona.

...Synopsis...
On Saturday, a deep and compact upper low will move across southern
CA/northern Baja into AZ during the day, and into NM by Sunday
morning. Strong cooling aloft with this system combined with daytime
heating and upslope flow may yield afternoon/evening convection,
likely weak as instability will remain minimal. However, the
favorable ascent coupled with very steep lapse rates may support a
few general thunderstorms.

Elsewhere, a large upper trough will exist across the eastern CONUS,
with high pressure spreading southeastward out of the upper MS
Valley, maintaining stable conditions.

..Jewell.. 02/28/2025

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1015 AM CST Fri Feb 28 2025

Valid 281630Z - 011200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorm are unlikely through tonight.

...Synopsis and Discussion...
An upper trough over Ontario and the Upper Midwest is forecast to
further amplify today as it eventually encompasses much of the
eastern CONUS. With a surface cold front having cleared the
Gulf/Atlantic Coasts, dry and/or stable conditions are likely to
preclude thunderstorms across the central/eastern CONUS through
tonight. Farther west, a closed upper low will approach coastal
southern CA through the period. While showers may occur across parts
of this region as the upper low approaches, thermodynamic profiles
are forecast to remain generally unfavorable for lightning
production.

..Gleason/Thornton.. 02/28/2025

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0620 AM CST Fri Feb 28 2025

Valid 281300Z - 011200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorm probabilities are very low Friday.

Relatively dry and stable conditions will preclude organized
thunderstorm development across the continental US today.

..Hart/Grams.. 02/28/2025

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0358 AM CST Fri Feb 28 2025

Valid 031200Z - 081200Z

...DISCUSSION...
Medium-range guidance suggests that an initially zonal, intense
mid/upper jet across the western into central mid-latitude Pacific
may undergo considerable amplification into and through this period.
It remains a bit unclear how emerging waves will impact the
downstream pattern by the middle to latter portion of next week. 

However, it still appears that one significant preceding short wave
trough, migrating inland of the Pacific coast by early Monday, will
progress into and across the southern Rockies, before accelerating
east-northeastward through mid week.  And guidance remains
suggestive that this will be accompanied by strong surface
cyclogenesis, perhaps most notably across portions of the east
central Great Plains toward the lower Great Lakes region late
Tuesday through Tuesday night.  This may include an evolving warm
sector with intensifying low-level and deep-layer shear (in the
presence of southerly to southwesterly flow strengthening to 50-100
kt in the 850 to 500 mb layer), coincident with an influx of
moistening and destabilizing boundary-layer air off the northwestern
Gulf.  

Spread typical at this extended time frame (day 5) lingers among the
various model output concerning the sub-synoptic, and even synoptic,
details across the southeastern Great Plains through Ohio Valley and
Southeast, which may considerably impact the severe weather risk
area and potential.  However, the medium-range guidance depicts an
environment at least conditionally supportive of an organized severe
weather event, including potential for a few strong tornadoes and
damaging straight line winds.

It is possible, but perhaps a bit more uncertain, that this could
continue across parts of the southern and middle Atlantic Seaboard
on Wednesday.

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0117 AM CST Fri Feb 28 2025

Valid 021200Z - 031200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Widely scattered, generally weak, thunderstorm activity is possible
across parts of central California into the Great Basin, and across
parts of the central Great Plains, Sunday through Sunday night.

...Discussion...
Split westerlies will remain amplified across the eastern Pacific,
and characterized by generally high mean mid-level heights extending
inland within a broadly confluent belt across the Rockies and east
of the Mississippi Valley by late Sunday night, in the wake of
large-scale troughing slowly progressing east of the Atlantic
Seaboard.  Within this regime, a significant, cold mid/upper trough
is forecast to progress inland of the Pacific coast into the Great
Basin and Southwest, preceded by a less prominent perturbation
crossing the southern Rockies and through the central Great Plains
by 12Z Monday.

In lower levels, modest surface cyclogenesis appears likely to
commence across eastern Wyoming and Colorado into the adjacent high
plains.  Models indicate that this will be accompanied by
strengthening southerly return flow, in the wake of cold/dry surface
ridging shifting east of the Mississippi Valley into Atlantic
Seaboard.  Stronger flow is forecast to develop inland of a
gradually modifying boundary-layer over the western Gulf Basin, but
modest moistening in lower/mid-levels is still probable across the
southern through central Great Plains, beneath (at least initially)
relatively warm/dry layers farther aloft.

...Central Great Plains...
There remains notable spread concerning the motion of the lead short
wave perturbation.  However, guidance suggest that associated
forcing for ascent and mid-level cooling, coupled with the limited
moisture return, probably will contribute to sufficient
destabilization to support scattered thunderstorm development late
Sunday afternoon through Sunday night.  This is likely to be
generally rooted above a stable boundary layer.  While the
environment might become conducive to small hail in stronger cells,
the risk for severe weather appears negligible at this time.

...Central California into Great Basin...
Beneath stronger mid-level cooling and forcing for ascent
overspreading the region, models suggest that destabilization will
become sufficient for widely scattered weak thunderstorms Sunday
into Sunday night.

..Kerr.. 02/28/2025

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1100 PM CST Thu Feb 27 2025

Valid 011200Z - 021200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
The risk for thunderstorms appears negligible across much of the
U.S. Saturday through Saturday night.

...Discussion...
Models indicate that an amplified split flow, characterized by
generally high mid/upper heights, will be maintained across the
eastern Pacific into western North America through this period. 
Within this regime, it appears that an initially slow moving
mid-level low near the southern California/northern Baja coast will
accelerate inland across the Southwest Saturday through Saturday
night, as a more prominent short wave trough digs toward the
northern and central California coast.  However, there remains
notable spread among the various model output concerning how rapidly
the lead perturbation transitions to an open wave, and how soon a
closed low develops within the trailing perturbation.

Downstream, large-scale mid/upper troughing likely will be
maintained across much of eastern North America, reinforced by a
number of digging short wave perturbations, as far south as the
northeastern Gulf Basin through Florida Peninsula.  This is forecast
to be accompanied by substantive further lower/mid-tropospheric
drying across much of the northern and eastern Gulf Basin.

In response to the evolving upstream pattern, a developing southerly
return flow may contribute to some lower/mid-tropospheric moistening
east of the Texas Big Bend toward deepening surface troughing to the
lee of the southern Rockies.  However, this is likely to be capped
by relatively warm and dry layers farther aloft.  

Dry and/or stable conditions are expected to generally prevail
across much of the remainder of the U.S., as well, with little
appreciable risk for thunderstorm development.

...Southern Great Basin/Southwest...
There remains sizable spread among the various model output
concerning the track of the modest mid-level cold core of the inland
advancing lead short wave trough.  Given initially dry conditions,
and limited moisture return as it progresses inland, latest guidance
indicates only very weak destabilization beneath the coldest
mid-level temperatures.  Based on NAM/RAP forecast soundings, any
convection which may become capable of producing lightning probably
will need forcing augmented by the higher terrain.  While a brief
weak thunderstorm or two might not be out of the question across the
higher terrain of northwestern Arizona late Saturday afternoon, NCEP
SREF and HREF calibrated thunderstorm guidance currently suggest
that 10 percent thunderstorm probabilities might be to high.

..Kerr.. 02/28/2025

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1126 PM CST Thu Feb 27 2025

Valid 281200Z - 011200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorm probabilities are very low Friday.

...Discussion...

Large-scale pattern is not expected to favor appreciable
moistening/destabilization through 01/12z as a dominant upper trough
settles south across the Great Lakes/OH Valley region. This feature
will not prove favorable for Gulf moisture to advance inland as
west-northwesterly flow should prevail through the period.

Farther west across southern CA, a notable upper low is forecast to
dig southeast, just off the southern CA Coast, as a strong 500mb
speed max translates toward the northern Baja Peninsula. While
profiles will cool, and mid-level lapse rates steepen, scant
moisture should be noted with this system across inland southern CA.
Forecast soundings suggest the most-buoyant parcels will struggle to
exhibit enough instability to warrant any meaningful risk for deep
convection capable of generating lightning. For these reasons
thunderstorms will not be forecast today.

..Darrow/Squitieri.. 02/28/2025