May 5, 2015 0600 UTC Day 1 Convective Outlook
Updated: Tue May 5 06:00:28 UTC 2015 (20150505 1200Z Day 1 shapefile | 20150505 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20150505 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 111,484 1,962,361 Lubbock, TX...Amarillo, TX...Abilene, TX...Midland, TX...San Angelo, TX...
MARGINAL 149,805 12,696,733 San Antonio, TX...Dallas, TX...Austin, TX...Fort Worth, TX...Arlington, TX...
Probabilistic Tornado Graphic
20150505 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 % 58,299 1,010,697 Lubbock, TX...Amarillo, TX...Clovis, NM...Plainview, TX...Pampa, TX...
2 % 118,184 4,682,209 San Antonio, TX...Abilene, TX...Wichita Falls, TX...Midland, TX...Odessa, TX...
Probabilistic Damaging Wind Graphic
20150505 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
15 % 111,165 1,984,191 Lubbock, TX...Amarillo, TX...Abilene, TX...Midland, TX...San Angelo, TX...
5 % 149,678 12,659,895 San Antonio, TX...Dallas, TX...Austin, TX...Fort Worth, TX...Arlington, TX...
Probabilistic Large Hail Graphic
20150505 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
15 % 110,550 1,954,825 Lubbock, TX...Amarillo, TX...Abilene, TX...Midland, TX...San Angelo, TX...
5 % 149,782 12,666,839 San Antonio, TX...Dallas, TX...Austin, TX...Fort Worth, TX...Arlington, TX...
   SPC AC 050600

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0100 AM CDT TUE MAY 05 2015

   VALID 051200Z - 061200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS EASTERN NM...OK/TX
   PANHANDLES...FAR SOUTHWEST OK...AND NORTHWEST INTO PORTIONS OF
   CENTRAL TX...

   ...THERE IS A MRGL RISK OF SVR TSTMS SURROUNDING THE SLIGHT RISK
   AREA ACROSS THE SOUTHERN PLAINS...

   ...SUMMARY...
   ISOLATED TO SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED
   TUESDAY AFTERNOON INTO THE EVENING ACROSS PORTIONS OF THE SOUTHERN
   PLAINS FROM EASTERN NEW MEXICO INTO WESTERN OKLAHOMA...AND SOUTHWARD
   ACROSS MUCH OF TEXAS.

   ...SYNOPSIS...
   A LONGWAVE TROUGH WILL BEGIN TO EVOLVE ACROSS THE WRN HALF OF THE
   CONTIGUOUS UNITED STATES THIS FORECAST PERIOD AS A LOWER LATITUDE
   SHORTWAVE TROUGH TRACKS NEWD FROM AZ/NM/NRN MEXICO TO THE SRN AND
   CENTRAL PLAINS...AND AN UPSTREAM COLD UPPER LOW DIGS SSEWD ACROSS
   SRN BRITISH COLUMBIA AND THE PACIFIC NORTHWEST.  FARTHER EAST...AN
   UPPER RIDGE WILL SHIFT SLOWLY EWD OF THE MS VALLEY...WITH HEIGHT
   RISES EXPECTED FROM WI/LOWER MI INTO NRN ONTARIO.

   AT THE SURFACE...A NORTH-SOUTH LOW PRESSURE TROUGH ATTENDANT TO THE
   AZ/NM SHORTWAVE TROUGH WILL DEVELOP E/NEWD...BECOMING BETTER DEFINED
   IN LEE OF THE ROCKIES ACROSS THE SRN AND CENTRAL HIGH PLAINS BY THIS
   AFTERNOON.  MEANWHILE...A NORTH-SOUTH DRY LINE SHOULD MIX/SHIFT EWD
   ACROSS PARTS OF THE SRN HIGH PLAINS /WRN PARTS OF THE OK/TX
   PANHANDLES THROUGH W AND SW TX/.

   ...SRN HIGH PLAINS...
   A LARGE CLUSTER OF TSTMS...MAINLY NON-SEVERE...IS EXPECTED TO BE
   ONGOING AT THE BEGINNING OF THE FORECAST PERIOD ACROSS ERN NM INTO
   WEST TX TO SERN CO AND SW KS.  THIS ACTIVITY SHOULD SPREAD NWD INTO
   THE CENTRAL HIGH PLAINS...WITH VERY WEAK INSTABILITY PRECLUDING A
   SEVERE THREAT WITH NWD EXTENT.  IN ADDITION TO THE LEE TROUGH/DRY
   LINE BEING THE FOCUS FOR POTENTIAL AFTERNOON TSTM DEVELOPMENT IN THE
   SRN HIGH PLAINS...DIFFERENTIAL HEATING BOUNDARIES ALONG THE WEST AND
   EAST PERIPHERIES OF THE MORNING TSTM CLUSTER COULD ALSO BE THE FOCI
   FOR NEW STORMS.

   A 30-45 KT SLY LLJ EXTENDING ACROSS THE SRN TO CENTRAL PLAINS WILL
   MAINTAIN MOISTURE RETURN WITH PW VALUES EXCEEDING 1 INCH ALONG AND
   EAST OF THE DRY LINE AND UP TO 1.5 INCHES FROM DEEP SOUTH TX TO OK. 
   THIS COMBINED WITH SURFACE HEATING AND COLD 500-MB TEMPERATURES
   SPREADING EWD ACROSS THE SRN HIGH PLAINS THIS AFTERNOON WILL RESULT
   IN MODERATE INSTABILITY.  INITIAL STORMS MAY TEND TO BE HIGH-BASED
   WITH HAIL AND DAMAGING WINDS THE PRIMARY THREATS.  EFFECTIVE BULK
   SHEAR WILL BE SUFFICIENT FOR SUPERCELLS WITH A TORNADO THREAT
   EXISTING EAST OF THE DRY LINE AS STORMS ENCOUNTER GREATER
   MOISTURE/LOWER LCLS AND STRONGER LOW-LEVEL SHEAR.

   THIS ACTIVITY MAY ORGANIZE INTO ONE OR MORE LOOSELY ORGANIZED MCS/S
   THAT WILL CONTINUE NEWD ACROSS PARTS OF OK INTO KS THROUGH THE
   OVERNIGHT HOURS...BUT DECREASING INSTABILITY WITH NEWD EXTENT IS
   EXPECTED TO LIMIT OVERALL NOCTURNAL SEVERE POTENTIAL.

   ...PORTIONS OF CENTRAL AND SOUTH TX...
   ALTHOUGH MIDLEVEL LAPSE RATES WILL TEND TO BE WEAKER WITH EWD EXTENT
   INTO CENTRAL AND SOUTH TX...DIABATIC HEATING WILL SUPPORT MODERATE
   INSTABILITY WITHIN THE RETURN FLOW REGIME.  INCREASING FORCING FOR
   ASCENT AS THIS REGION IS GLANCED BY HEIGHT FALLS WITH THE SRN HIGH
   PLAINS TROUGH AND DIFLUENT UPPER LEVEL FLOW REGIME SHOULD PROVE
   FAVORABLE FOR SHOWERS AND TSTM DEVELOPMENT THIS AFTERNOON. 
   EFFECTIVE BULK SHEAR OF 30-35 KT WILL SUPPORT ORGANIZED STORMS WITH
   HAIL AND DAMAGING WINDS BEING THE PRIMARY THREATS.  MEANWHILE...
   FARTHER SOUTH...THIS SYNOPTIC SETUP WITH A MOIST...UPSLOPE FLOW FROM
   THE LOWER RIO GRANDE VALLEY SHOULD PROVE FAVORABLE FOR TSTM
   DEVELOPMENT ACROSS THE HIGHER TERRAIN IN NRN COAHUILA MEXICO.  THIS
   ACTIVITY TRACKING E/SEWD INTO SOUTH TX WILL ENCOUNTER A MODERATELY
   UNSTABLE ENVIRONMENT WITH STRONG EFFECTIVE BULK SHEAR FOR SUPERCELLS
   WITH ALL SEVERE HAZARDS POSSIBLE.  ISOLATED COVERAGE FOR THIS
   SCENARIO MAINTAINS LOW SEVERE PROBABILITIES AT THIS TIME.

   ...IA/NRN IL AND IND THROUGH OH TO THE MID ATLANTIC STATES...
   A QUASI-STATIONARY BOUNDARY EXTENDING GENERALLY W-E ACROSS THIS
   REGION WILL BE THE FOCUS FOR SHOWER AND TSTM DEVELOPMENT THIS
   AFTERNOON INTO THE EARLY EVENING.  WEAK INSTABILITY/SHEAR PARAMETER
   SPACE INDICATES THE POTENTIAL FOR SEVERE STORMS WILL BE TOO LOW TO
   INTRODUCE ANY SEVERE PROBABILITIES.

   ..PETERS/MOSIER.. 05/05/2015

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