Weekly/Special Severe Weather 4/14/2011
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Transcript of Weekly/Special Severe Weather 4/14/2011
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Weekly/Special Severe Weather4/14/2011Keith StellmanWarning Coordination MeteorologistNational Weather Service Shreveport, LouisianaSlides Available atwww.srh.noaa.gov/shv/briefing
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SummaryModerate Risk for severe storms late today/tonightvery large hailStrong to violent tornadoes possibleDamaging windsSE OK, NE TX, SW AR afternoon/eveningNW/N LA, S AR Late tonightUpper level pattern very similar to April 9, 2009Possible Red Flag conditions on Friday20-25 mph windsRelative humidity 20-25%
National Weather Service Shreveport, Louisiana
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OverviewNational Weather Service Shreveport, LouisianaLCurrentMidnightLDeep MoistureGulf Moisture140 knot Jetstreak
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Slight Risk AreaHighest Probability of Severe WeatherThreatsLarge HailTornadoes (Some could be strong/violent)Damaging WindsSevere Weather ThursdayModerate Risk Area
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Timing 3 PM Today Dryline west of the region moving inStorms soon developing along the lineNAM Model
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Timing 6 PM Today Dryline still west of the region moving inStorms developing ahead of the line in NE TX/SE OKNAM Model
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Timing 9 PM Today Dryline still west of the regionPrefrontal line providing enough lift to break capStorms moving into NW LA/SW ARNAM Model
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Wind Shear at 9 PMVery high wind shear values to support supercells /rotating updraftsInstability forecast to be very high 2000-3000 j/kgFrom 6PM-3AM values are sufficient
0-3 KM HelicityOrange =
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Timing 6 AM FridayMoving throughStorms should fill in southward along the lineBecoming a damaging wind threat
- Forecast Rainfall TotalsHeaviest rain in OK/ARNot enough to touch the drought0.50- 0.750.25-0.500.75- 1.25
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Threats/ImpactsDamaging WindsHighest threat in the moderate risk areaTransitioning across N LA in the early AM
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Threats/ImpactsLarge HailRed outlined area includes Significant hail threat >2Probability of Severe hail within 25 miles of a point
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Threats/ImpactsTornadoPink area denotesIncreased probability For strong/violent tornadoes (EF2+)Probability of a tornadowithin 25 miles of a point
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FridaySlight Risk for storms Eastern LAEarly AM..ending by mid morningDamaging Winds primary threat
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FridayVery dry air filtering inVery strong and gusty west windsPossible Red Flag conditions for the first time in many years
Relative Humidity values Friday PMSustained WindsWinds 20-25 mphGusting over 30
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WeekendPleasantDry
Saturday HighsSunday Highs
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Next Weather Maker Tuesday/WednesdayPattern changes next weekFront moves into I-40 corridor and stallsPossible relief from droughtSevere weather
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DROUGHT SITUATION
Drought is worsening in some areas! A D4 rating (Exceptional) area is being included for southern sections of Deep East Texaswhile the remainder of much of the area is in the D3 rating (Extreme) area.Multiple county/parish burn bans in effect.
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SummaryModerate Risk for Severe Weather over the north late today/tonightImpactsTornadoes (some Strong)Very Large HailDamaging WindsThreat shifts east by early AM
Friday High Fire Danger
National Weather Service Shreveport, LouisianaSlight Risk AreaHighest Probability of Severe WeatherModerate Risk Area
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NEXT CONFERENCE CALL:Thursday 04/21/2011 @ 10 AM
www.srh.noaa.gov/shv/briefing
National Weather Service Shreveport, Louisiana
*OPTIONAL SLIDE!