Apr 14, 2018 0100 UTC Day 1 Convective Outlook
Updated: Sat Apr 14 00:55:50 UTC 2018 (20180414 0100Z Day 1 shapefile | 20180414 0100Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...Severe thunderstorms expected over parts of the lower Mississippi Valley this afternoon and tonight....   Please read the latest public statement about this event.  View What is a Watch? clip.

Categorical Graphic
20180414 0100 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MODERATE 23,643 1,906,042 Shreveport, LA...Little Rock, AR...Bossier City, LA...North Little Rock, AR...Pine Bluff, AR...
ENHANCED 73,453 4,024,436 Memphis, TN...Tyler, TX...Longview, TX...Jonesboro, AR...Monroe, LA...
SLIGHT 150,549 13,506,371 Dallas, TX...Austin, TX...Kansas City, MO...Garland, TX...Des Moines, IA...
MARGINAL 213,728 26,768,796 Houston, TX...San Antonio, TX...Fort Worth, TX...Tulsa, OK...Arlington, TX...
Probabilistic Tornado Graphic
20180414 0100 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
SIG SEVERE 60,959 3,271,923 Shreveport, LA...Little Rock, AR...Longview, TX...Bossier City, LA...North Little Rock, AR...
15 % 23,670 1,877,660 Shreveport, LA...Little Rock, AR...Bossier City, LA...North Little Rock, AR...Pine Bluff, AR...
10 % 53,682 2,097,714 Longview, TX...Jonesboro, AR...Monroe, LA...Greenville, MS...Lufkin, TX...
5 % 88,990 7,469,692 Dallas, TX...Memphis, TN...Garland, TX...Springfield, MO...Mesquite, TX...
2 % 177,992 24,861,920 Houston, TX...Austin, TX...Fort Worth, TX...Kansas City, MO...Tulsa, OK...
Probabilistic Damaging Wind Graphic
20180414 0100 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
45 % 26,552 1,874,045 Memphis, TN...Little Rock, AR...North Little Rock, AR...Jonesboro, AR...Pine Bluff, AR...
30 % 69,934 4,037,479 Shreveport, LA...Tyler, TX...Longview, TX...Bossier City, LA...Monroe, LA...
15 % 139,184 12,701,984 Dallas, TX...Austin, TX...Kansas City, MO...Garland, TX...Jackson, MS...
5 % 174,463 23,615,710 Houston, TX...San Antonio, TX...Fort Worth, TX...Tulsa, OK...Arlington, TX...
Probabilistic Large Hail Graphic
20180414 0100 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
15 % 179,560 15,199,398 Dallas, TX...Austin, TX...Kansas City, MO...Garland, TX...Shreveport, LA...
5 % 210,513 24,854,447 Houston, TX...San Antonio, TX...Fort Worth, TX...Tulsa, OK...Arlington, TX...
   SPC AC 140055

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0755 PM CDT Fri Apr 13 2018

   Valid 140100Z - 141200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM THE
   ARKLATEX TO CENTRAL ARKANSAS...

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN
   TEXAS TO SOUTHERN MISSOURI...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL TEXAS
   TO IOWA...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTH TEXAS
   TO THE UPPER MIDWEST...

   ...SUMMARY...
   Numerous severe storms will continue this evening into tonight from
   east Texas to the lower/mid Mississippi Valley. Tornadoes (some
   strong), large hail, and damaging winds will remain possible,
   primarily from the Arklatex to the Mid-South.

   ...Discussion...
   A relatively expansive corridor of severe weather is evolving from
   central Texas northward to the upper Midwest this evening. As a cold
   front continues to spread east and progressively overtake a dry
   line, convection will advance eastward from the central/southern
   Plains to the Mississippi Valley.

   ...Texas to the mid/lower Mississippi Valley...
   From the Arklatex eastward, low-level shear will further amplify
   through the evening, owing to a strengthening 850mb jet (around
   60-70 kt). 00Z regional soundings sampled around 1500-2000 J/kg of
   MLCAPE, and these values should only slowly decrease through the
   evening, owing to a moist boundary-layer environment. Therefore,
   semi-discrete cells gradually deepening in confluent bands from
   Texas/Louisiana into Arkansas will continue to pose a threat for
   tornadoes (some of which could be strong) and damaging winds. Large
   hail will also remain a threat with cells that possess at least
   semi-discrete elements. Through the evening hours, upscale growth
   will yield a greater coverage of QLCS structures from southern
   Missouri southward to Louisiana, with the primary threat
   transitioning to damaging winds. A few embedded tornadoes will
   remain possible as well.

   ...Mid Missouri Valley and vicinity...
   Farther north, convection is becoming progressively focused
   near/north of the warm front, where large-scale ascent is maximized.
   Drier conditions and long, straight hodographs have yielded less
   organized convective modes, versus those farther south. In turn, the
   threat appears to have transitioned to primarily pockets of large
   hail and gusty winds. Therefore, enhanced probabilities have been
   removed from this area.

   ..Picca.. 04/14/2018

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z