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Storm Prediction Center Forecast


RSS Mesoscale Discussions from Storm Prediction Center

SPC - No watches are valid as of Tue Nov 20 21:04:02 UTC 2018

No watches are valid as of Tue Nov 20 21:04:02 UTC 2018.


SPC - No MDs are in effect as of Tue Nov 20 21:04:02 UTC 2018

No Mesoscale Discussions are in effect as of Tue Nov 20 21:04:02 UTC 2018.


SPC Nov 20, 2018 1630 UTC Day 1 Convective Outlook

SPC 1630Z Day 1 Outlook
      
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1015 AM CST Tue Nov 20 2018

Valid 201630Z - 211200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Isolated thunderstorms are possible today across the Florida
Peninsula, and late tonight in the vicinity of southern New Mexico
and far west Texas.

...Florida Peninsula...
A low-amplitude shortwave trough over the northeastern Gulf of
Mexico will continue eastward across north FL today. A relatively
moist/modestly unstable air mass exists along and south of a
slow-moving front. A couple of strong/more organized storms may
occur today, such as recently (~1545Z) along the FL east coast,
especially near the front in the presence of relatively strong
deep-layer shear. However, it seems likely that weak winds in the
lower troposphere, along with weak mid-level lapse rates and
weakening low-level convergence, will keep severe-weather potential
at a minimum. The thunderstorm threat across FL is generally
expected to diminish by mid/late evening.

...Far west Texas/southeast New Mexico tonight...
A southern-stream shortwave trough over northern Baja will continue
to move eastward toward far west TX by early Wednesday. Some
low/mid-level moistening is expected in the zone of ascent preceding
this trough as it reaches far west TX/southern NM tonight. Weak
buoyancy rooted near or just above 700 mb will be possible
overnight, when a few lightning flashes may occur with the weak
elevated convection.

..Guyer/Wendt.. 11/20/2018

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SPC Nov 20, 2018 2000 UTC Day 1 Convective Outlook

SPC 2000Z Day 1 Outlook
      
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0156 PM CST Tue Nov 20 2018

Valid 202000Z - 211200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Isolated thunderstorms are possible today across the Florida
Peninsula, and late tonight in the vicinity of southern New Mexico
and far west Texas.

The only change to the previous outlook was to adjust the Florida
thunderstorm area based on the current position of the front. 
Otherwise, the previous outlook reasoning remains valid.

..Bunting.. 11/20/2018

.PREV DISCUSSION... /ISSUED 1015 AM CST Tue Nov 20 2018/

...Florida Peninsula...
A low-amplitude shortwave trough over the northeastern Gulf of
Mexico will continue eastward across north FL today. A relatively
moist/modestly unstable air mass exists along and south of a
slow-moving front. A couple of strong/more organized storms may
occur today, such as recently (~1545Z) along the FL east coast,
especially near the front in the presence of relatively strong
deep-layer shear. However, it seems likely that weak winds in the
lower troposphere, along with weak mid-level lapse rates and
weakening low-level convergence, will keep severe-weather potential
at a minimum. The thunderstorm threat across FL is generally
expected to diminish by mid/late evening.

...Far west Texas/southeast New Mexico tonight...
A southern-stream shortwave trough over northern Baja will continue
to move eastward toward far west TX by early Wednesday. Some
low/mid-level moistening is expected in the zone of ascent preceding
this trough as it reaches far west TX/southern NM tonight. Weak
buoyancy rooted near or just above 700 mb will be possible
overnight, when a few lightning flashes may occur with the weak
elevated convection.

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SPC Nov 20, 2018 1730 UTC Day 2 Convective Outlook

SPC 1730Z Day 2 Outlook
      
Day 2 Outlook Image
Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1119 AM CST Tue Nov 20 2018

Valid 211200Z - 221200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Isolated thunderstorms are possible along the California coast on
Wednesday, however severe thunderstorms are not expected.

...Synopsis...
An upper-level trough and associated surface cold front over the
eastern Pacific will move inland late Wednesday.  Cool mid-level
temperatures will contribute to modest instability on the order of
100-200 J/kg despite substantial cloud cover.  Lift with the front
will result in showers and isolated thunderstorms offshore and near
the coast.  Although shear will be sufficient for some degree of
storm organization, the lack of more substantial buoyancy will limit
the potential for stronger storms.

A southern-stream shortwave trough will move across Texas towards
the lower Mississippi Valley Wednesday, contributing to surface
cyclogenesis along a stationary front over the western Gulf of
Mexico.  Although the developing warm sector will remain well
offshore, very weak elevated instability north of the
front/developing low combined with large-scale lift may result in an
occasional lightning strike.  Overall potential appears too low to
warrant areal delineation.

...MAXIMUM RISK BY HAZARD...
Tornado:  <2%     - None
Wind:     <5%     - None
Hail:     <5%     - None

..Bunting.. 11/20/2018

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SPC Day 2 Fire Weather Outlook

SPC Day 2 Fire Weather Outlook
          
Day 2 Fire Weather Outlook Image
Day 2 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1223 PM CST Tue Nov 20 2018

Valid 211200Z - 221200Z

...NO CRITICAL AREAS...

Fire weather concerns will be minimal today, especially as scattered
clouds/precipitation begin to overspread dry areas of the western
U.S. (particularly California).  See the previous discussion below
for additional information.

..Cook.. 11/20/2018

.PREV DISCUSSION... /ISSUED 1231 AM CST Tue Nov 20 2018/

...Synopsis...
An upper-level shortwave trough moves into the western CONUS on
Wednesday bringing much needed rain/snow to the West Coast with the
heaviest precipitation expected across portions of the Coast
Ranges/Sierra Nevada. Overall, fire weather concerns will be minimal
across the western CONUS as large-scale troughing will prevail
across the region. Some locally elevated conditions may develop
across the Great Basin, especially southern/central Nevada. However,
cooler temperatures and precipitation are expected to move into much
of western/northern Great Basin by Wednesday night mitigating fire
weather concerns.

...Please see www.spc.noaa.gov/fire for graphic product...

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