Special Severe Weather Briefing 4/3/2011
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Transcript of Special Severe Weather Briefing 4/3/2011
Special Severe Special Severe Weather BriefingWeather Briefing
4/3/20114/3/2011
Keith StellmanKeith StellmanWarning Coordination Warning Coordination
MeteorologistMeteorologistNational Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana
Slides Available atSlides Available atwww.srh.noaa.gov/shv/briefingwww.srh.noaa.gov/shv/briefing
Overnight/Monday Slight Risk for Severe Weather Slight Risk for Severe Weather
over entire regionover entire region Cold Front moving across regionCold Front moving across region Both high wind shear and ample Both high wind shear and ample
instability forecast thru the instability forecast thru the event..with higher amounts east in event..with higher amounts east in LA/S ARLA/S AR
Hail/High Winds…Isolated tornadoes Hail/High Winds…Isolated tornadoes (Best Chances North LA/South (Best Chances North LA/South Central AR mid to late AM with higher Central AR mid to late AM with higher low level shear)low level shear)
National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana
OverviewOverview
National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana
LL
CurrentCurrent
6 AM Monday6 AM MondayLL
Deep Moist
ure
Slight R
isk A
rea
Slight R
isk A
rea
Highest Highest Probability Probability of Severe of Severe WeatherWeather
ThreatsThreats1.1. Damaging Damaging
WindsWinds2.2. Hail Hail 3.3. Isolated Isolated
TornadoesTornadoes
Severe Weather Severe Weather MondayMonday
Timing – 6 AM MondayTiming – 6 AM Monday
Front west of Front west of the region the region moving inmoving in
Storms Storms developing developing along the linealong the line
Instability at 6 AM Instability at 6 AM Where Deep Where Deep
moisture moisture moves in… moves in… instability instability increasesincreases
Even though Even though its early… its early… instability instability will be will be sufficientsufficient
Need to Need to break Capbreak Cap
Pink > 1000 J/KGPink > 1000 J/KGRed > 1500 J/KGRed > 1500 J/KG
Timing – 9 AM MondayTiming – 9 AM Monday
Front Front Nashville-> Mt Nashville-> Mt Pleasant -> Pleasant -> TylerTyler
Storms Storms continue continue developing developing along the linealong the line
9 AM 9 AM EHI = Instability and Wind EHI = Instability and Wind
ShearShear ValuesValues
1 - 3 1 - 3 Isolated Isolated TornadoesTornadoes/ / Damaging Damaging WindsWinds
>3 - 6 >3 - 6 Strong to Strong to Violent Violent TornadoesTornadoes
Yellow = 1-2Yellow = 1-2Orange = 2-3Orange = 2-3
Red = 3-4Red = 3-4
Timing – Noon MondayTiming – Noon Monday
Front Magnolia-Front Magnolia-> Shreveport -> > Shreveport -> LufkinLufkin
Line filling inLine filling in Greater Greater
instability from instability from here eastwardhere eastward
Instability at NoonInstability at Noon Instability Instability
increases increases east as east as things warm things warm up and even up and even more more moisture moisture moves inmoves in
Very little Very little cap to cap to overcomeovercome
Pink > 1000 J/KGPink > 1000 J/KGRed > 1500 J/KGRed > 1500 J/KG
Yellow > 2000 J/KGYellow > 2000 J/KGGreen > 3000 J/KGGreen > 3000 J/KG
* ~1000 is all that is needed* ~1000 is all that is needed
NoonNoon EHI = Instability and Wind EHI = Instability and Wind
ShearShear Values decrease Values decrease dramatically dramatically ahead of the frontahead of the front
Due to wind Due to wind shear decreasing shear decreasing even though even though instability is instability is increasingincreasing
ValuesValues 1 - 3 Isolated 1 - 3 Isolated
Tornadoes/ Tornadoes/ Damaging Damaging WindsWinds
>3 - 6 Strong to >3 - 6 Strong to Violent Violent TornadoesTornadoes
Yellow = 1-2Yellow = 1-2Orange = 2-3Orange = 2-3
Red = 3-4Red = 3-4
Timing – 3 PM MondayTiming – 3 PM Monday Front East of Front East of
Monroe -> Monroe -> ColfaxColfax
Greatest Greatest instability as it instability as it moves into this moves into this regionregion
Damaging Damaging winds/Hailwinds/Hail
Forecast Rainfall TotalsForecast Rainfall Totals HeaviesHeavies
t rain in t rain in LA / LA / South South AR AR
Eastern Eastern ParisheParishes s heaviest heaviest rainfall. rainfall.
0.50
”- 0
.75”
0.50
”- 0
.75”
0.25”-0.50”0.25”-0.50”
0.75
”- 1
.25”
0.75
”- 1
.25”
Summary Slight Risk for Slight Risk for
Severe Weather Severe Weather over entire regionover entire region ImpactsImpacts
Damaging WindsDamaging Winds HailHail Isolated TornadoesIsolated Tornadoes
Front will move Front will move across the region across the region from 6 AM West – from 6 AM West – 3 PM East3 PM East
National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana
Slight R
isk A
rea
Slight R
isk A
rea
Highest Highest Probability Probability of Severe of Severe WeatherWeather
ThreatsThreats1.1. Damaging Damaging
WindsWinds2.2. Hail Hail 3.3. Isolated Isolated
TornadoesTornadoes
NEXT CONFERENCE CALL:
Thursday Thursday
04/7/2011 @ 10 AM04/7/2011 @ 10 AM
www.srh.noaa.gov/shv/www.srh.noaa.gov/shv/briefingbriefingNational Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana