9.8F
Current conditions from King Hill
Updated every 5 minutes
 
  Tuesday December 11, 2018

RSS Mesoscale Discussions from Storm Prediction Center

SPC - No watches are valid as of Tue Dec 11 13:02:02 UTC 2018

No watches are valid as of Tue Dec 11 13:02:02 UTC 2018.


No Mesoscale Discussions are in effect as of Tue Dec 11 13:02:02 UTC 2018.

SPC Dec 11, 2018 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook
      
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0652 AM CST Tue Dec 11 2018

Valid 111300Z - 121200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not expected across the contiguous U.S.
today through tonight.

...Western WA/northwest OR...
A shortwave trough off the coast of British Columbia early today
will steadily amplify and spread southeastward toward the coastal
Pacific northwest, reaching the WA/OR coast by 00Z and advancing
inland across the Pacific Northwest through late tonight. Steepening
lapse rates will occur by evening as sub -30 C temperatures aloft
spread inland. Forecast soundings suggest buoyancy will become deep
enough for some lightning within the post-frontal regime across
coastal areas of WA and northwest OR this evening, and possibly
inland toward the WA and northern OR Cascades.

..Guyer/Goss.. 12/11/2018

Read more

SPC Dec 11, 2018 0830 UTC Day 3 Severe Thunderstorm Outlook

SPC 0830Z Day 3 Outlook
      
Day 3 Outlook Image
Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0225 AM CST Tue Dec 11 2018

Valid 131200Z - 141200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THURSDAY INTO
THURSDAY NIGHT ACROSS THE SABINE AND LOWER MISSISSIPPI VALLEYS...AND
NORTH CENTRAL GULF COAST VICINITY...

...SUMMARY...
Strong thunderstorms may impact parts of eastern Texas into the
lower Mississippi Valley and north central Gulf coast vicinity
Thursday into Thursday night, accompanied by at least some risk for
severe weather.

...Synopsis...
Models suggest that mid/upper flow could amplify further through
this period, with troughing and ridging within split belts of
westerlies emanating from the mid-latitude Pacific largely in phase
across the eastern pacific into western North America.  Downstream
of the ridging, models indicate that a vigorous short wave trough
within the southern stream will dig southeast of the southern
Rockies, before turning eastward across the southern Plains, where a
significant embedded lower/mid-tropospheric cyclone may evolve and
deepen while progressing toward the lower Mississippi Valley. 

While the ensemble mean output of the various models are fairly
similar with the depiction of the evolving pattern, spread among the
ensemble members and among the deterministic output of the various
models has been, and remains, rather large.  This not only includes
the evolution of the mid-latitude perturbation, but also its
interaction with a belt of westerlies emanating from the subtropical
eastern Pacific.

Further complicating matters concerning the assessment of any
associated severe weather potential, the boundary layer over the
Gulf of Mexico will only be in the process of beginning to modify in
the wake of antecedent cooling and drying.  And substantive warm
sector low-level moistening inland of coastal areas remains in
doubt.

...East Texas/lower Mississippi Valley/Gulf coast...
Models suggest that an influx of upper 50s to lower 60s F surface
dew points across southeast Texas into Louisiana is possible during
the day Thursday.  It appears that this probably will occur in the
wake of an early period band of convection that will progress across
and east of the lower Mississippi Valley.  However, an evolving dry
slot may allow for sufficient insolation to contribute to weak to
modest boundary layer destabilization, beneath fairly cold mid-level
temperatures across parts of eastern Texas into Louisiana.  If this
occurs, deep layer shear probably will be sufficient to support a
risk of severe storms, possibly including a couple of supercells.

Otherwise, somewhat better boundary layer moisture return appears
possible ahead of an evolving secondary surface low near coastal
areas, from southeast Louisiana into the western Florida Panhandle
Thursday night.  This may also contribute to an environment
conducive for supercells, including the risk for a tornado or two.

..Kerr.. 12/11/2018

Read more

SPC Dec 11, 2018 Day 4-8 Severe Weather Outlook

Day 4-8 Outlook
      
Day 4-8 Outlook Image
Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0355 AM CST Tue Dec 11 2018

Valid 141200Z - 191200Z

...DISCUSSION...
Medium-range models suggest that a surface frontal wave migrating
inland off the northeastern Gulf of Mexico could be accompanied by
forcing for ascent and shear supportive of organized severe
thunderstorm potential on Friday.  This currently seems most likely
to impact portions of northern Florida, from the Big Bend into the
Gainesville/Jacksonville areas (and perhaps as far south as the
Interstate 4 corridor of the central Peninsula), into southern
Georgia.  Guidance indicates that Gulf boundary layer modification
may allow for an influx of mid 60s+ F surface dewpoints across this
region during the day, however this may still only result in very
weak destabilization.  Given, also, sizable spread still evident
among the models, and within their respective ensemble output,
concerning the evolution and progression of the deep lower/mid
tropospheric cyclone initially approaching the lower Mississippi
Valley at 12Z Friday, the extent of any severe weather potential
remains unclear.

Otherwise, generally stable conditions appear likely to prevail
across much of the U.S. this weekend through early next week,
resulting in negligible risk for severe thunderstorms.

Read more


 
 
Current Radar Loop:

Copyright © WestfordWeather.net 2007-2018. All rights reserved.