May 25, 2019 0600 UTC Day 1 Convective Outlook
Updated: Sat May 25 05:53:08 UTC 2019 (20190525 1200Z Day 1 shapefile | 20190525 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20190525 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 56,808 744,774 Amarillo, TX...Plainview, TX...Altus, OK...Liberal, KS...Pampa, TX...
SLIGHT 141,918 13,889,708 Wichita, KS...Pittsburgh, PA...Buffalo, NY...Lubbock, TX...Rochester, NY...
MARGINAL 301,721 32,987,129 Detroit, MI...Indianapolis, IN...Columbus, OH...Oklahoma City, OK...Kansas City, MO...
Probabilistic Tornado Graphic
20190525 1200 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 56,669 744,590 Amarillo, TX...Plainview, TX...Altus, OK...Liberal, KS...Pampa, TX...
2 % 129,134 13,773,025 Cleveland, OH...Wichita, KS...Pittsburgh, PA...Buffalo, NY...Lubbock, TX...
Probabilistic Damaging Wind Graphic
20190525 1200 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
30 % 56,652 736,459 Amarillo, TX...Plainview, TX...Altus, OK...Liberal, KS...Pampa, TX...
15 % 128,657 13,576,743 Wichita, KS...Pittsburgh, PA...Buffalo, NY...Lubbock, TX...Rochester, NY...
5 % 314,420 33,268,562 Detroit, MI...Indianapolis, IN...Columbus, OH...Oklahoma City, OK...Kansas City, MO...
Probabilistic Large Hail Graphic
20190525 1200 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 23,421 479,845 Amarillo, TX...Plainview, TX...Liberal, KS...Pampa, TX...Hereford, TX...
30 % 37,139 552,259 Amarillo, TX...Plainview, TX...Liberal, KS...Pampa, TX...Hereford, TX...
15 % 159,929 13,853,383 Cleveland, OH...Wichita, KS...Pittsburgh, PA...Buffalo, NY...Lubbock, TX...
5 % 301,075 33,066,809 Detroit, MI...Indianapolis, IN...Columbus, OH...Oklahoma City, OK...Kansas City, MO...
   SPC AC 250553

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1253 AM CDT Sat May 25 2019

   Valid 251200Z - 261200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
   AND EVENING ACROSS THE TEXAS PANHANDLE INTO WESTERN OKLAHOMA AND
   ADJACENT SOUTHWEST KANSAS...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
   EVENING NEAR THE LOWER GREAT LAKES INTO THE ALLEGHENY PLATEAU AND
   UPPER OHIO VALLEY...

   ...SUMMARY...
   Severe thunderstorms appear likely today across the Texas and
   Oklahoma Panhandle region, northward into Kansas, and also south of
   the lower Great Lakes region into the Allegheny Plateau and portions
   of the upper Ohio Valley.

   ...Synopsis...
   Mid/upper subtropical ridging centered near the Gulf coast appears
   likely to remain prominent through this period.  However, models do
   indicate flattening of a ridge axis extending to its north, as a
   significant short wave impulse within the mid-latitude westerlies
   turns northeastward then eastward across eastern Ontario and the
   upper Great Lakes region into Quebec and portions of the Northeast. 
   An associated surface cyclone may continue to deepen as it migrates
   across James Bay into northern Quebec, with a trailing surface cold
   front advancing southeastward across the Great Lakes while stalling
   over the central Plains.

   Upstream, large-scale troughing will persist within the mid-latitude
   westerlies across much of the West.  Within this regime, models
   indicate that a vigorous short wave trough and embedded deep
   mid-level low will continue to dig along the southern Oregon through
   northern California coast.  As this occurs, a downstream trough axis
   is forecast to take on a negative tilt orientation while pivoting
   across Baja.  While downstream ridging may build to the lee of the
   Rockies through the High Plains, models continue to indicate that a
   short wave perturbation emanating from the Western troughing will
   progress through the ridging across the southern High Plains late
   this afternoon into tonight.

   Moderate to strong instability along the northwestern through
   northern periphery of the subtropical ridging appears likely to
   again provide support for considerable strong to severe thunderstorm
   development today.  The stalled frontal zone across the central
   Plains into portions of the mid/lower Missouri Valley is expected to
   provide the general northern limit of any appreciable severe weather
   potential.  A convectively generated or reinforced boundary
   preceding it may provide the focus, or northwestern limit, of any
   appreciable severe weather potential across the middle Mississippi
   Valley into the lower Great Lakes region.

   ...Southern/central Plains into the lower Missouri Valley...
   Considerable spread exists among the various model output concerning
   possible convective evolution for this period.  However, there
   appears general consensus that the evolving mid/upper pattern will
   support an area of strengthening large-scale forcing for ascent
   across the Texas Panhandle region into portions of western Oklahoma
   by late this afternoon.  This likely will be associated with
   strengthening lower/mid tropospheric warm advection, beneath a
   focused area of increasingly divergent high level flow.  In the
   presence of moderate to strong instability, which probably will
   include a destabilizing boundary layer characterized by CAPE in
   excess of 2000 J/kg, this is expected to support considerable
   thunderstorm development, perhaps as soon as early afternoon.  In
   the presence of continuing strong deep layer shear, convection
   probably will include supercells with a risk for severe hail.

   Subsequent development is more unclear, but there appears potential
   for convection to grow upscale into one or two larger clusters,
   spreading northeastward and eastward into western Oklahoma and
   southern Kansas, accompanied by a risk for strong surface gusts. 
   Potential for tornadoes also remains unclear, but it would seem at
   least a bit more favorable if storms remain more discrete in nature.
    As a southerly low-level jet remains focused across the Texas South
   Plains, and strengthens late this afternoon and evening, it is also
   possible that an outflow boundary left by initial convection may
   remain a focus for continuing discrete storm development, including
   a risk for supercells with tornadoes.

   If convection farther south does not become an inhibiting factor, a
   cold front/dryline intersection across northwest Kansas may also
   provide a focus for the initiation of at least isolated late
   afternoon storms, including supercells.

   ...Lower Great Lakes/Allegheny Plateau/upper Ohio Valley region...
   Focus for organized severe weather potential today remains somewhat
   unclear, but models suggest that this may be most probable in
   association with a convectively generated or enhanced perturbation
   migrating around the flatten mid/upper ridge.  It appears that this
   feature could help focus thunderstorm development along the lake
   breeze to the south/east of Lakes Erie, and perhaps Ontario, by late
   afternoon.  In the presence of 30-50+ kt lower/mid tropospheric flow
   and moderate  CAPE, one or two upscale growing convective clusters
   appear possible, accompanied initially by a risk for severe hail,
   then, primarily, a risk for potentially damaging wind gusts.

   ..Kerr/Squitieri.. 05/25/2019

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