Jun 12, 2014 2000 UTC Day 1 Convective Outlook
Updated: Thu Jun 12 20:03:40 UTC 2014 (20140612 2000Z Day 1 shapefile | 20140612 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20140612 2000 UTC Day 1 Outlook Graphic
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 208,522 24,839,191 Houston, TX...San Antonio, TX...Dallas, TX...Austin, TX...Fort Worth, TX...
Probabilistic Tornado Graphic
20140612 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.
Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 62,125 6,587,739 San Antonio, TX...Austin, TX...Huntsville, TX...Copperas Cove, TX...Pflugerville, TX...
2 % 114,697 15,867,469 Houston, TX...Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...
Probabilistic Damaging Wind Graphic
20140612 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.
Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
30 % 40,803 8,547,960 Houston, TX...Austin, TX...Huntsville, TX...Atascocita, TX...Mission Bend, TX...
15 % 167,285 16,268,986 San Antonio, TX...Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...
5 % 755,395 65,036,656 Jacksonville, FL...Memphis, TN...Denver, CO...Washington, DC...New Orleans, LA...
Probabilistic Large Hail Graphic
20140612 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.
Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 52,582 8,546,870 San Antonio, TX...Austin, TX...Huntsville, TX...Mission Bend, TX...Copperas Cove, TX...
30 % 40,651 5,178,804 San Antonio, TX...Austin, TX...Huntsville, TX...Copperas Cove, TX...Pflugerville, TX...
15 % 134,064 17,518,251 Houston, TX...Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...
5 % 617,074 40,165,844 Jacksonville, FL...Memphis, TN...Denver, CO...New Orleans, LA...Colorado Springs, CO...
   SPC AC 122000

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0300 PM CDT THU JUN 12 2014

   VALID 122000Z - 131200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM CNTRL AND ERN TX INTO THE
   LOWER MS VALLEY...

   ...SUMMARY...
   SEVERE THUNDERSTORMS ARE EXPECTED ACROSS PORTIONS OF TEXAS EASTWARD
   INTO THE LOWER MISSISSIPPI VALLEY. VERY LARGE HAIL AND DAMAGING
   WINDS WILL BE THE MAIN THREATS...BUT A FEW TORNADOES ARE POSSIBLE.
   ADDITIONAL...BUT MORE ISOLATED...STRONG TO SEVERE STORMS WILL BE
   POSSIBLE IN THE NORTHERN AND CENTRAL ROCKIES...THE HIGH PLAINS...AND
   ACROSS PARTS OF MID-ATLANTIC STATES TO LOWER GREAT LAKES REGION.

   ...TX THROUGH LOWER MS VALLEY AREA...

   HAVE ADJUSTED PROBABILITY AND CATEGORICAL GRAPHICS TO ACCOUNT FOR
   EFFECTS OF AN EXPANSIVE OUTFLOW BOUNDARY THAT CURRENTLY EXTENDS FROM
   CNTRL ARKANSAS SWWD THROUGH NWRN LA THEN WWD THROUGH CNTRL TX TO A
   THERMAL LOW NEAR JUNCTION. MEANWHILE A COLD FRONT EXTENDING FROM
   SWRN MO THROUGH SRN OK INTO SWRN TX IS ADVANCING SWD. DRYLINE
   EXTENDS FROM EAST OF SANDERSON NEWD TO THE THERMAL LOW JUST WEST OF
   JUNCTION. THE ATMOSPHERE IN VCNTY OF AND JUST SOUTH OF THE OUTFLOW
   BOUNDARY ACROSS MUCH OF CNTRL AND SCNTRL TX HAS BECOME VERY UNSTABLE
   WITH 3000-4000 J/KG MLCAPE AND VERY STEEP LAPSE RATES.
   MEANWHILE...NEAR SFC WINDS REMAIN ELY JUST NORTH OF THE OUTFLOW
   BOUNDARY AND SELY IN WARM SECTOR BENEATH MODEST /30-35 KT/ MID LEVEL
   FLOW RESULTING IN VEERING LOW WIND PROFILES AND 30-35 KT EFFECTIVE
   BULK SHEAR. THE MOST LIKELY AREA FOR INITIAL ROBUST THUNDERSTORM
   INITIATION APPEARS TO BE NEAR JUNCTION WHERE CUMULUS IS INCREASING
   IN VICINITY OF THE DRYLINE-OUTFLOW BOUNDARY INTERSECTION. ONCE
   STORMS INITIATE...THEY WILL LIKELY TAKE ON SUPERCELL STRUCTURES WITH
   A THREAT FOR VERY LARGE HAIL AND POSSIBLY A FEW TORNADOES AS THE
   STORMS MOVE EAST AND INTERACT WITH THE MODIFYING OUTFLOW BOUNDARY.
   EVENTUALLY STORMS MAY CONGEAL INTO AN MCS WITH AN INCREASING THREAT
   FOR DAMAGING WIND.

   ADDITIONAL STRONG TO SEVERE STORMS MAY DEVELOP ALONG SWD ADVANCING
   FRONT OVER NRN AND NERN TX INTO EARLY EVENING...BUT THE ATMOSPHERE
   HAS BEEN OVERTURNED BY PREVIOUS CONVECTION IN THIS REGION WITH
   LIMITED REMAINING RECOVERY TIME.

   ..DIAL.. 06/12/2014

   .PREV DISCUSSION... /ISSUED 1132 AM CDT THU JUN 12 2014/

   ...SOUTHERN PLAINS TO LOWER MS RIVER VALLEY...
   THE DECAYING REMNANTS OF AN MCS/TRAILING COLD POOL CONTINUE TO
   SPREAD SOUTHEASTWARD ACROSS PARTS OF NORTH TX/FAR SOUTHERN OK LATE
   THIS MORNING. INITIAL SEVERE THREAT THIS AFTERNOON WILL BE IN
   ASSOCIATION WITH WHAT MAY BE AN UPSCALE DEVELOPING QUASI-LINEAR
   COMPLEX AND/OR AN MCV ACROSS PARTS OF EAST TX INTO LA AND PERHAPS
   OTHER PARTS OF THE MID-SOUTH/LOWER MS RIVER VALLEY. THE PRECEDING
   AIR MASS ACROSS THE CORRIDOR WILL CONTINUE TO STEADILY
   WARM/DESTABILIZE COINCIDENT WITH AMPLE HEATING AND LOWER TO MIDDLE
   70S F SURFACE DEWPOINTS. DAMAGING WINDS/BOUTS OF SEVERE HAIL WILL BE
   POSSIBLE.

   FARTHER WEST...ADDITIONAL INTENSE STORM DEVELOPMENT IS ANTICIPATED
   ESPECIALLY ACROSS PARTS OF CENTRAL/WEST-CENTRAL TX INTO LATE
   AFTERNOON/EARLY EVENING. THIS WILL BE VICINITY OF THE SYNOPTIC FRONT
   IN CONJUNCTION WITH RESIDUAL INFLUENCES OF EARLY DAY
   OUTFLOW/DIFFERENTIAL HEATING. THIS SCENARIO WILL LIKELY BE AIDED BY
   THE APPROACH OF A SHORTWAVE TROUGH/SPEED MAX...WITH ATTENDANT
   STRONGER MID/HIGH-LEVEL WESTERLIES...NOTED TO BE MOVING EASTWARD
   OVER NM AT MID-MORNING. SUPERCELLS CAPABLE OF LARGE HAIL AND
   POSSIBLY A COUPLE OF TORNADOES WILL INITIALLY BE POSSIBLE...WITH
   STORMS LIKELY GROWING UPSCALE AND ADDITIONALLY POSING A DAMAGING
   WIND RISK AS THEY SPREAD GENERALLY SOUTHEASTWARD TONIGHT. PENDING
   EARLY AFTERNOON TRENDS AND GREATER CONFIDENCE IN A PEAK RISK
   CORRIDOR...AREAS SUCH AS WEST-CENTRAL/CENTRAL TX COULD WARRANT AN
   UPGRADE TO MODERATE RISK /MAINLY FOR VERY LARGE HAIL/ WITH THE 20Z
   DAY 1 UPDATE.

   ...CO/NM...
   STORMS ARE EXPECTED TO DEVELOP/INCREASE THIS AFTERNOON ACROSS THE
   FRONT RANGE/ADJACENT HIGH PLAINS IN ASSOCIATION WITH A LOW-LEVEL
   UPSLOPE REGIME. WEAK DESTABILIZATION IN CONJUNCTION WITH VEERING
   WIND PROFILES AND 40+ KT OF EFFECTIVE SHEAR MAY ALLOW FOR SOME
   SUPERCELLS CAPABLE OF SEVERE HAIL.

   ...PORTIONS OF THE MID-ATLANTIC/NORTHEAST STATES...
   ESPECIALLY GIVEN RELATIVELY PREVALENT EARLY DAY CLOUD
   COVER...RELATIVELY WEAK MID-LAPSE RATES/MODEST VERTICAL SHEAR SHOULD
   LIMIT THE OVERALL MAGNITUDE/EXTENT OF THE SEVERE RISK IN MOST AREAS
   TODAY. NONETHELESS...AS THE BOUNDARY LAYER GRADUALLY WARMS...LOCALLY
   DAMAGING WINDS AND POTENTIALLY SOME HAIL WILL BE POSSIBLE THIS
   AFTERNOON/EARLY EVENING.

   ...FL PENINSULA...
   IN THE PRESENCE OF RELATIVELY COOL MID-LEVEL TEMPERATURES...THE
   BOUNDARY LAYER WILL CONTINUE TO WARM/DESTABILIZE PARTICULARLY ACROSS
   THE CENTRAL FL TO THE SOUTH OF STORMS ONGOING THIS MORNING ACROSS
   THE NORTHERN PENINSULA. ISOLATED BOUTS OF LOCALLY DAMAGING WINDS AND
   MARGINALLY SEVERE HAIL WILL BE POSSIBLE THROUGH THE AFTERNOON.

   ...NORTHERN INTERMOUNTAIN REGION/EASTERN GREAT BASIN...
   AN UPPER TROUGH WILL CONTINUE TO MOVE INLAND/EASTWARD OVER THE
   PACIFIC NORTHWEST AND NORTHERN INTERMOUNTAIN WEST THROUGH TONIGHT.
   AHEAD OF IT...STRENGTHENING CYCLONIC WESTERLIES WILL OVERSPREAD
   AREAS AS FAR SOUTH AS THE GREAT BASIN/UT VICINITY. ISOLATED
   STRONG/SEVERE THUNDERSTORMS WILL BE POSSIBLE BY LATE AFTERNOON/EARLY
   EVENING ACROSS THE NORTHERN INTERMOUNTAIN REGION INCLUDING PARTS OF
   EASTERN ORE/WA AND ID/WESTERN MT. FARTHER SOUTH...OTHER HIGH-BASED
   THUNDERSTORMS CAPABLE OF DOWNBURSTS WILL BE POSSIBLE ACROSS PORTIONS
   OF UT.

   ...SOUTHEAST MO TO SOUTHERN IL...
   MARGINAL SEVERE WIND/HAIL MAY BE POSSIBLE ACROSS THE REGION.
   REFERENCE MESOSCALE DISCUSSION 971 FOR MORE SHORT-TERM DETAILS.

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