Weekly/Special Severe Weather4/14/2011Keith StellmanWarning Coordination MeteorologistNational Weather Service Shreveport, LouisianaSlides Available atwww.srh.noaa.gov/shv/briefing

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

OverviewNational Weather Service Shreveport, LouisianaLCurrentMidnightLDeep MoistureGulf Moisture140 knot Jetstreak

Slight Risk AreaHighest Probability of Severe WeatherThreatsLarge HailTornadoes (Some could be strong/violent)Damaging WindsSevere Weather ThursdayModerate Risk Area

Timing 3 PM Today Dryline west of the region moving inStorms soon developing along the lineNAM Model

Timing 6 PM Today Dryline still west of the region moving inStorms developing ahead of the line in NE TX/SE OKNAM Model

Timing 9 PM Today Dryline still west of the regionPrefrontal line providing enough lift to break capStorms moving into NW LA/SW ARNAM Model

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 =

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

Threats/ImpactsDamaging WindsHighest threat in the moderate risk areaTransitioning across N LA in the early AM

Threats/ImpactsLarge HailRed outlined area includes Significant hail threat >2Probability of Severe hail within 25 miles of a point

Threats/ImpactsTornadoPink area denotesIncreased probability For strong/violent tornadoes (EF2+)Probability of a tornadowithin 25 miles of a point

FridaySlight Risk for storms Eastern LAEarly AM..ending by mid morningDamaging Winds primary threat

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

WeekendPleasantDry

Saturday HighsSunday Highs

Next Weather Maker Tuesday/WednesdayPattern changes next weekFront moves into I-40 corridor and stallsPossible relief from droughtSevere weather

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.

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

NEXT CONFERENCE CALL:Thursday 04/21/2011 @ 10 AM

www.srh.noaa.gov/shv/briefing

National Weather Service Shreveport, Louisiana

*OPTIONAL SLIDE!