May 25, 2015 2000 UTC Day 1 Convective Outlook
Updated: Mon May 25 19:32:07 UTC 2015 (20150525 2000Z Day 1 shapefile | 20150525 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

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

Categorical Graphic
20150525 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MODERATE 51,798 8,549,538 Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...Garland, TX...
ENHANCED 68,381 5,984,053 Austin, TX...Shreveport, LA...Killeen, TX...Round Rock, TX...Fort Smith, AR...
SLIGHT 256,024 20,199,318 Houston, TX...San Antonio, TX...Oklahoma City, OK...Omaha, NE...Tulsa, OK...
MARGINAL 232,931 19,998,780 Detroit, MI...Memphis, TN...Kansas City, MO...Madison, WI...Baton Rouge, LA...
Probabilistic Tornado Graphic
20150525 2000 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
10 % 42,756 8,141,709 Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...Garland, TX...
5 % 96,889 8,176,484 San Antonio, TX...Austin, TX...Omaha, NE...Lincoln, NE...Shreveport, LA...
2 % 186,006 16,421,432 Houston, TX...Oklahoma City, OK...Tulsa, OK...Corpus Christi, TX...Laredo, TX...
Probabilistic Damaging Wind Graphic
20150525 2000 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
SIG SEVERE 63,459 9,274,580 Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...Garland, TX...
45 % 51,774 8,530,433 Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...Garland, TX...
30 % 57,805 4,427,048 Austin, TX...Shreveport, LA...Killeen, TX...Round Rock, TX...Fort Smith, AR...
15 % 265,777 21,719,562 Houston, TX...San Antonio, TX...Oklahoma City, OK...Omaha, NE...Tulsa, OK...
5 % 233,486 20,339,249 Detroit, MI...Memphis, TN...Kansas City, MO...Madison, WI...Baton Rouge, LA...
Probabilistic Large Hail Graphic
20150525 2000 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
30 % 103,799 13,903,461 San Antonio, TX...Dallas, TX...Austin, TX...Fort Worth, TX...Arlington, TX...
15 % 266,870 20,619,459 Houston, TX...Oklahoma City, OK...Omaha, NE...Tulsa, OK...Wichita, KS...
5 % 234,922 20,651,807 Detroit, MI...Memphis, TN...Kansas City, MO...Madison, WI...Baton Rouge, LA...
   SPC AC 251932

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0232 PM CDT MON MAY 25 2015

   VALID 252000Z - 261200Z

   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF NCNTRL AND NE
   TX...SRN OK...FAR NW LA AND SW AR...

   ...THERE IS AN ENH RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS
   AND ARKLATEX...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
   PLAINS...CNTRL PLAINS...MID MO VALLEY AND LOWER MS VALLEY...

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
   PLAINS...CNTRL PLAINS...MID MO VALLEY...MS VALLEY AND GREAT LAKES
   REGION...

   ...SUMMARY...
   WIDESPREAD SEVERE THUNDERSTORMS ARE FORECAST TODAY INTO TONIGHT
   ACROSS PORTIONS OF NORTH CENTRAL AND NORTHEAST TEXAS AND SOUTHERN
   OKLAHOMA.  DESTRUCTIVE OUTFLOW WINDS...A FEW TORNADOES AND HAIL ARE
   LIKELY WITH THESE STORMS.  MORE ISOLATED SEVERE WEATHER IS EXPECTED
   OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSOURI VALLEY.

   THE FIRST CHANGE TO OUTLOOK FOR THIS ISSUANCE IS TO TRIM PARTS OF
   NORTHWEST AND NCNTRL TX FROM THE SLIGHT AND MODERATE RISK AREAS. THE
   AIRMASS HAS STABILIZED IN THE WAKE OF A LINEAR MCS MOVING ACROSS NRN
   AND CNTRL TX. NO SEVERE THREAT IS ANTICIPATED BEHIND THE LINEAR MCS
   ACROSS WCNTRL TX LATER THIS AFTERNOON. THE SECOND CHANGE TO THE
   OUTLOOK IS TO EXTEND THE 10 PERCENT TORNADO PROBABILITY A BIT
   FURTHER SOUTHWEST TO INCLUDE PARTS OF THE TX HILL COUNTRY WHERE A
   COUPLE OF TORNADIC SUPERCELLS ARE ONGOING. THE FINAL CHANGE TO THE
   OUTLOOK IS TO REMOVE THE SIGNIFICANT HAIL PROBABILITY FROM CNTRL AND
   NE TX.

   ..BROYLES.. 05/25/2015

   .PREV DISCUSSION... /ISSUED 1130 AM CDT MON MAY 25 2015/

   ...SYNOPSIS...

   BROAD...CYCLONIC FLOW WILL BE MAINTAINED WEST OF THE MS VALLEY
   THROUGH THE DAY ONE PERIOD WITH THE PRIMARY FEATURE OF INTEREST
   BEING A SHORT-WAVE TROUGH WHICH WILL TRANSLATE FROM THE SRN HIGH
   PLAINS INTO THE MID MS VALLEY AND MID SOUTH.  THIS IMPULSE WILL BE
   LOOSELY PHASED WITH A SLOWER-MOVING VORTICITY MAXIMUM TRACKING
   ACROSS NEB.

   AT THE SURFACE...MID-MORNING SURFACE ANALYSIS REVEALS A COUPLE OF
   MORE PROMINENT CYCLONES...ONE OVER WRN NEB AND THE OTHER OVER NWRN
   TX.  THE FORMER WILL DEVELOP GENERALLY EWD ACROSS NEB IN TANDEM WITH
   A COLD FRONT MOVING EWD/SEWD THROUGH THE NRN AND CNTRL PLAINS. 
   MEANWHILE...THE LATTER WILL DEVELOP NEWD TOWARD THE
   ARKLATEX...LIKELY IN CONCERT WITH THE EVOLVING MCS OVER W-CNTRL TX.

   --WIDESPREAD DESTRUCTIVE WIND EVENT FORECAST OVER THE SOUTHERN
   PLAINS THIS AFTERNOON INTO TONIGHT--

   ...SRN PLAINS INTO LOWER MS VALLEY TODAY THROUGH TONIGHT...

   A BOWING ECHO IS CURRENTLY STRENGTHENING OVER W-CNTRL TX IN ADVANCE
   OF THE ABOVE-MENTIONED SHORT-WAVE TROUGH EJECTING NEWD 
   ACROSS THE SRN PLAINS.  CONVECTION-ALLOWING MODEL GUIDANCE IS QUITE
   CONSISTENT IN SUGGESTING THAT THIS MCS WILL EXPAND IN LONGITUDINAL
   BREADTH AS IT ACCELERATES EWD/NEWD ACROSS THE SRN PLAINS TODAY AND
   INTO AR/LA TONIGHT.  

   12Z ROAB DATA INDICATE THAT THE INFLOW AIR MASS IS QUITE MOIST WITH
   DEWPOINTS IN THE UPPER 60S/LOWER 70S AND WHEN COUPLED WITH RATHER
   STEEP LAPSE RATES ALOFT /SEE 12Z DRT SOUNDING/...THE ENVIRONMENT
   WILL BECOME MODERATE TO STRONGLY UNSTABLE BY AFTERNOON WITH MLCAPE
   OF 2000-3000 J/KG.  THIS INSTABILITY WILL ALIGN WITH A BELT OF
   STRENGTHENING SWLY FLOW IN THE 700-500-MB LAYER TO SUPPORT FURTHER
   FORWARD PROPAGATION/ACCELERATION OF THE BOW WITH WIDESPREAD DAMAGING
   WINDS AND SEVERE HAIL ANTICIPATED ACROSS THE MDT RISK AREA. 
   TORNADOES WILL ALSO BE POSSIBLE...BOTH WITH
   MESOVORTICES/MESOCYCLONES EMBEDDED IN THE MCS...AS WELL AS WITH ANY
   SUPERCELLS WHICH MAY FORM DOWNSTREAM FROM IT.

   EXPECT THE THREAT FOR MAINLY DAMAGING WINDS TO CONTINUE INTO THE
   OVERNIGHT HOURS ACROSS PORTIONS OF AR/LA.


   ...CNTRL PLAINS INTO UPPER MIDWEST THIS AFTERNOON/EVENING...

   FORCING FOR ASCENT/DCVA ATTENDANT TO THE EWD-MOVING NEB VORTICITY
   MAXIMUM WILL EFFECTIVELY DEEPEN CIRCULATIONS ALONG THE ASSOCIATED
   SURFACE FRONTAL SYSTEM SUCH THAT WIDELY SCATTERED TSTMS SHOULD
   DEVELOP BY AFTERNOON FROM PORTIONS OF NEB INTO PARTS OF IA/MN/WI. 
   OTHER STORMS ARE ALSO ANTICIPATED TO DEVELOP LATER TODAY AHEAD OF
   THE WEAK DRYLINE/FRONT IN KS AS THE REGION BECOMES INFLUENCED BY THE
   MID-LEVEL WAVE TRACKING THROUGH THE SRN PLAINS.

   THE STRONGEST AFTERNOON DESTABILIZATION IS EXPECTED TO OCCUR FROM
   CNTRL/ERN KS INTO THE MID MO VALLEY WHERE THE COMBINATION OF
   INCREASING BOUNDARY LAYER MOISTURE AND A RIBBON OF STEEPER MID-LEVEL
   LAPSE RATES YIELD MLCAPE APPROACHING 1500-2500+ J/KG.  AND WHILE
   DEEP-LAYER SHEAR WILL NOT BE PARTICULARLY STRONG...IT WILL BE
   SUFFICIENT...GIVEN THE INSTABILITY...TO SUPPORT ORGANIZED STORM
   MODES CAPABLE OF MAINLY SEVERE HAIL AND DAMAGING WINDS.  A BRIEF
   TORNADO OR TWO WILL BECOME INCREASINGLY POSSIBLE THIS
   EVENING...MAINLY OVER THE MID MO VALLEY...AS A STRENGTHENING LLJ
   ENHANCES LOW-LEVEL SHEAR.

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z