SPC - No watches are valid as of Sat Feb 23 08:26:02 UTC 2019

No watches are valid as of Sat Feb 23 08:26:02 UTC 2019.


SPC - No MDs are in effect as of Sat Feb 23 08:26:02 UTC 2019

No Mesoscale Discussions are in effect as of Sat Feb 23 08:26:02 UTC 2019.


SPC Feb 23, 2019 0600 UTC Day 1 Convective Outlook

SPC 1200Z Day 1 Outlook
      
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1122 PM CST Fri Feb 22 2019

Valid 231200Z - 241200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
NORTHERN MISSISSIPPI...SOUTHWEST TENNESSEE AND FAR NORTHWEST
ALABAMA...

...SUMMARY...
Scattered severe thunderstorms are expected to develop today from
the Arklatex region and lower to mid Mississippi Valley eastward
into the Tennessee and Ohio Valleys. Tornadoes, wind damage and
isolated large hail will be possible across much of the area.

...Significant tornado and wind damage event expected across parts
of the lower to mid Mississippi and Tennessee Valleys today...

...Arklatex/Lower to Mid Mississippi Valley/Tennessee and Ohio
Valleys...
A well organized negatively-tilted upper-level trough will move
across the southern Plains today as a 90 to 100 kt mid-level jet
moves through the base of the trough. At the surface, a low will
gradually deepen and move northeastward across the central Plains
into the lower Missouri Valley. A surface trough is forecast to
extend southward into the lower Mississippi Valley with a moist
airmass located across the region. Surface dewpoints in the upper
60s and lower 70s F will overspread northern Louisiana, southeast
Arkansas and most of Mississippi by midday. At the start of the
period, a cluster of thunderstorms should be ongoing from northern
Mississippi into western and middle Tennessee. The stronger storms
embedded in the cluster may have an isolated severe threat. This
activity is forecast to move northeastward away the moderate risk
area allowing for the moist sector to warm up late this morning. In
response, a corridor of moderate instability is expected to be in
place by midday from northeast Louisiana into far southeast Arkansas
and western Tennessee. As large-scale ascent increases ahead of the
southern Plains upper-level trough, thunderstorms are forecast to
develop during the morning along the surface trough in the Arklatex
with this convection moving northeastward into southeastern Arkansas
by midday. More isolated thunderstorms will be possible across the
moist sector from northern Louisiana into north-central Mississippi.
During the early to mid afternoon, convective coverage should
increase with scattered thunderstorms moving east-northeastward
across the Enhanced and Moderate Risk areas.

RAP forecast soundings across the Moderate Risk area from
north-central Mississippi into southwest Tennessee at 21Z show
moderate instability and impressive kinematic profiles. MLCAPE is
forecast to be from 1000 to 1200 J/kg with 0-6 km shear in the 50 to
55 kt range. This will support supercell formation with cells that
remain discrete. In addition, hodographs are long and looped with
0-3 km storm relative helicity values in the 350 to 450 m2/s2 range.
This low-level shear environment will be favorable for tornadoes. A
potential for long-track significant tornadoes will exist across the
Moderate Risk area from late this morning through much of the
afternoon. Wind damage and isolated large hail will also be possible
with supercells. A squall-line is also expected to develop and move
across the Enhanced and Moderate risk areas during the late
afternoon and early evening. Wind damage, isolated large hail and a
few tornadoes will also be possible with the stronger thunderstorms
embedded in the line. This squall-line with wind damage potential
should move across middle Tennessee and north-central Alabama during
the evening.

Further north across the Ohio Valley, scattered thunderstorms are
forecast to move northeastward into western Kentucky and southern
Indiana during the afternoon. Forecast soundings at 21Z for Paducah
show MLCAPE near 800 J/kg with 0-6 km shear of 65 kt. This combined
with strong low-level shear will be sufficient for severe storms
capable of producing tornadoes and wind damage. Most of the severe
convection should remain south of the Ohio River. Due to the weaker
instability in the Ohio Valley, severe coverage is expected to be
less.

..Broyles/Bentley.. 02/23/2019

Read more

SPC Feb 23, 2019 0700 UTC Day 2 Convective Outlook

SPC 0700Z Day 2 Outlook
      
Day 2 Outlook Image
Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1144 PM CST Fri Feb 22 2019

Valid 241200Z - 251200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHEAST...

...SUMMARY...
A few strong storms may occur Sunday morning along a cold front
across portions of the Southeast.

...Southeast...

Intense 12hr mid-level height falls will spread across the upper
Midwest into the Great Lakes region early in the period as a 110kt+
500mb speed max translates across the OH Valley. Associated surface
front will progress to a position from OH - southern Appalachians -
FL Panhandle at 24/12z. Remnants of organized deep convection that
materializes during the day1 period is expected to advance across
the northern Gulf States during the overnight hours. This activity
will slowly weaken as frontal convection encounters less favorable
thermodynamic environment along southern fringe of large-scale
forcing for ascent. Latest short-range guidance and HREF data
support a gradual weakening, likely due to weakening frontal
convergence as upper trough ejects well north of this region.
Forecast soundings ahead of the wind shift exhibit MUCAPE on the
order of 500 J/kg with only modest mid-level lapse rates. Latest
thinking is broken squall line should advance across eastern
AL/northwest GA  into the MRGL risk area with some attendant wind
threat. This activity is expected to continue weakening as the front
progresses across GA.

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

..Darrow.. 02/23/2019

Read more

SPC Feb 23, 2019 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
0141 AM CST Sat Feb 23 2019

Valid 251200Z - 261200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Some thunder potential is possible with weak convection from the
upper Texas coast to southwest Louisiana.

...Upper TX Coast/Southwest LA...

Neutral/weak height rises are forecast across the south-central
US/northern Gulf Basin Monday. As a result, early-day surface
anticyclone is expected to remain influential through the period.
Low-level trajectories are not expected to be particularly favorable
for appreciable moisture to advance inland as east-northeast surface
winds should persist much of the day along the Gulf coast. Latest
guidance does suggest a weak mid-level short-wave trough will eject
across northern Mexico toward deep south TX during the latter half
of the period. In response, weak LLJ is expected to develop across
the northwest Gulf basin into the upper TX coast. Warm advection
atop retreating/weakening surface high could prove sufficient for
weak convection and the possibility for some thunder late in the
period.

..Darrow.. 02/23/2019

Read more

SPC Feb 23, 2019 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
0223 AM CST Sat Feb 23 2019

Valid 261200Z - 031200Z

...DISCUSSION...
Large-scale pattern will become decidedly less amplified during the
medium-range period, though several notable short-wave troughs will
traverse the CONUS. In the mean, ridging will be anchored over the
Rockies which will favor multiple frontal intrusions across the
country east of the Rockies. As a result, moisture/instability will
struggle to advance inland and the prospects for organized deep
convection will remain low this period.

Read more

SPC Day 1 Fire Weather Outlook

SPC Day 1 Fire Weather Outlook
          
Day 1 Fire Weather Outlook Image
Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1245 AM CST Sat Feb 23 2019

Valid 231200Z - 241200Z

...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN NEW MEXICO THROUGH
SOUTH TEXAS...

...Synopsis...
A strong surface low across the Texas panhandle Saturday morning
will deepen and quickly move northeast through the day. The
combination of the increasing surface pressure gradient and deep
mixing with strong mid-level winds will lead to 25 to 30 mph
sustained surface winds across much of West Texas. South of the cold
front, which is expected to be somewhere just south of the Red River
Saturday afternoon, relative humidities are expected to be in the 8
to 15 percent range. Therefore, critical fire weather conditions are
expected across a large portion of West Texas Saturday afternoon.
The duration of these critical conditions may be somewhat limited as
surface winds weaken considerably during the late afternoon as the
surface low and mid-level jet move northeast. However, the duration
is expected to be long enough, and the wind speeds are expected to
be strong enough to warrant a critical fire weather delineation.

..Bentley.. 02/23/2019

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

Read more

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
1246 AM CST Sat Feb 23 2019

Valid 241200Z - 251200Z

...Synopsis...
Cool and wet fuels will limit overall fire weather risk across the
CONUS on Sunday. Dry conditions are expected across portions of the
southern High Plains, but winds are expected to be mostly light.
There is potential for 10 to 15 mph winds in addition to 12 to 15
percent relative humidities in eastern New Mexico and the western
Texas panhandle, but ongoing precipitation across this area will
likely limit fuel receptiveness. Therefore, no areas have been drawn
for this outlook.

..Bentley.. 02/23/2019

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

Read more