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Special Severe Weather Briefing 4/3/2011. Slides Available at www.srh.noaa.gov/shv/briefing. Keith Stellman Warning Coordination Meteorologist. National Weather Service Shreveport, Louisiana. Overnight/Monday. Slight Risk for Severe Weather over entire region
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Special Severe Weather Briefing4/3/2011 Slides Available at www.srh.noaa.gov/shv/briefing Keith Stellman Warning Coordination Meteorologist National Weather Service Shreveport, Louisiana
Overnight/Monday Slight Risk for Severe Weather over entire region Cold Front moving across region Both high wind shear and ample instability forecast thru the event..with higher amounts east in LA/S AR Hail/High Winds…Isolated tornadoes (Best Chances North LA/South Central AR mid to late AM with higher low level shear) National Weather Service Shreveport, Louisiana
Overview Current L 6 AM Monday L Deep Moisture National Weather Service Shreveport, Louisiana
Severe Weather Monday Highest Probability of Severe Weather Slight Risk Area Threats Damaging Winds Hail Isolated Tornadoes
Timing – 6 AM Monday • Front west of the region moving in • Storms developing along the line
Where Deep moisture moves in… instability increases Even though its early… instability will be sufficient Need to break Cap Instability at 6 AM Pink > 1000 J/KG Red > 1500 J/KG
Timing – 9 AM Monday • Front Nashville-> Mt Pleasant -> Tyler • Storms continue developing along the line
Values 1 - 3 Isolated Tornadoes/ Damaging Winds >3 - 6 Strong to Violent Tornadoes 9 AM EHI = Instability and Wind Shear Yellow = 1-2 Orange = 2-3 Red = 3-4
Timing – Noon Monday • Front Magnolia-> Shreveport -> Lufkin • Line filling in • Greater instability from here eastward
Instability increases east as things warm up and even more moisture moves in Very little cap to overcome Instability at Noon Pink > 1000 J/KG Red > 1500 J/KG Yellow > 2000 J/KG Green > 3000 J/KG * ~1000 is all that is needed
Values decrease dramatically ahead of the front Due to wind shear decreasing even though instability is increasing Values 1 - 3 Isolated Tornadoes/ Damaging Winds >3 - 6 Strong to Violent Tornadoes Noon EHI = Instability and Wind Shear Yellow = 1-2 Orange = 2-3 Red = 3-4
Timing – 3 PM Monday • Front East of Monroe -> Colfax • Greatest instability as it moves into this region • Damaging winds/Hail
Heaviest rain in LA / South AR Eastern Parishes heaviest rainfall. Forecast Rainfall Totals 0.25”-0.50” 0.50”- 0.75” 0.75”- 1.25”
Summary Slight Risk for Severe Weather over entire region Impacts Damaging Winds Hail Isolated Tornadoes Front will move across the region from 6 AM West – 3 PM East Highest Probability of Severe Weather Slight Risk Area Threats Damaging Winds Hail Isolated Tornadoes National Weather Service Shreveport, Louisiana
NEXT CONFERENCE CALL: Thursday 04/7/2011 @ 10 AM www.srh.noaa.gov/shv/briefing National Weather Service Shreveport, Louisiana