Special Winter Weather Briefing 1/9/2010 slides: srh.noaa/shv/briefing
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Transcript of Special Winter Weather Briefing 1/9/2010 slides: srh.noaa/shv/briefing
Special Winter Special Winter Weather BriefingWeather Briefing
1/9/20101/9/2010slides:slides:
www.srh.noaa.gov/shv/briefingwww.srh.noaa.gov/shv/briefing
Keith StellmanKeith Stellman
National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana
Overview Today(Sunday)Today(Sunday) East TX south of I-20: East TX south of I-20: Rain mixing with sleet through early Rain mixing with sleet through early
afternoon. Changing to all snow after noon. Accumulations afternoon. Changing to all snow after noon. Accumulations of 2-4” possibleof 2-4” possible
NE TX north of I-20: NE TX north of I-20: Sleet early changing to snow. Sleet early changing to snow. Accumulations 3-6” with higher amounts possible toward TXKAccumulations 3-6” with higher amounts possible toward TXK
SW AR and SE OK: SW AR and SE OK: Mostly snow. Accumulations highest in I-Mostly snow. Accumulations highest in I-30 of 4-6” with some higher possible30 of 4-6” with some higher possible
North LA I-20 corridor north: North LA I-20 corridor north: Freezing rain, sleet, snow mix. Freezing rain, sleet, snow mix. Freezing rain/sleet early through early Afternoon..becoming Freezing rain/sleet early through early Afternoon..becoming all snow. Accumulations highest along AR/LA line of 4-5” I-all snow. Accumulations highest along AR/LA line of 4-5” I-20 corridor 1-3”. Ice Accumulations of 0.5 – 1.00” (includes 20 corridor 1-3”. Ice Accumulations of 0.5 – 1.00” (includes sleet)sleet)
Lufkin->Many->Jena: Lufkin->Many->Jena: Mostly rain. Some sleet mixing in. Mostly rain. Some sleet mixing in. Brief changeover at the end. Maybe a dusting. Freezing Brief changeover at the end. Maybe a dusting. Freezing rain/sleet in Grant/Winn/rain/sleet in Grant/Winn/
MondayMonday Freezing drizzle possible after midnight through early AMFreezing drizzle possible after midnight through early AM Light flurries early AM across I-30 corridorLight flurries early AM across I-30 corridor AM Temperatures ≤ 32 areawide, AM Temperatures ≤ 32 areawide, Upper 20’s along/north US 82 (Clarksville ->El Dorado)Upper 20’s along/north US 82 (Clarksville ->El Dorado)
National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana
Radar/Observations Radar/Observations (830AM)(830AM)
National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana
Freezing line
Winter Storm WarningsWinter Storm Warnings
All included All included except except southern row.southern row.
Snow threat Snow threat greatest north.greatest north.
Freezing Freezing rain/sleet/snorain/sleet/snow central (I-w central (I-20)20)
Sleet/snow/Freezing rain Sleet/snow/Freezing rain changechange
Temperature profile at Noon Sunday - Temperature profile at Noon Sunday - ShreveportShreveport
Free
zing
line
Warm Warm nose 200-nose 200-4000 feet 4000 feet a little a little coolercooler
Will likely Will likely see mixed see mixed bag bag through through noonnoon
Further Further north..all north..all snow. snow. West, West, rain/sleet rain/sleet as warm as warm nose is nose is biggerbigger
Height
Surface Tempeatures 28-31
Sleet/snow/Freezing rain Sleet/snow/Freezing rain DilemmaDilemma
Temperature profile at 3 PM Sunday - Temperature profile at 3 PM Sunday - ShreveportShreveport
Free
zing
line
Warm Warm Nose Nose disappearsdisappears
Precip Precip would would become all become all snow Noonsnow Noon
Snow Snow would fall would fall onto any onto any ice/sleet ice/sleet accumulatiaccumulationsons
Northern Northern LALA
HeightSurface Tempeatures 28-31
Ice Accumulation Ice Accumulation ProbabilitiesProbabilities Greatest risk Greatest risk
along I-along I-20..especially 20..especially in North LA. in North LA. Risk Risk increases increases east.east.
Amounts Amounts generally generally 0.25-0.50” in 0.25-0.50” in green area…green area…higher higher amounts amounts possible possible eastern eastern Parishes up Parishes up to 1”to 1”
Through 4PMThrough 4PM
Snow Probabilities > 4”Snow Probabilities > 4” Greatest risk Greatest risk
along I-along I-30..especially 30..especially in North LA. in North LA. Risk Risk increases increases north.north.
Amounts Amounts generally 4-6” generally 4-6” RedRed
2-4” Green2-4” Green 1-2” Blue1-2” Blue
North all North all snowsnow
Middle Middle change change ~noon-3PM~noon-3PM
Timing: NoonTiming: NoonNAM Model NAM Model Rain East Rain East
TX mixing TX mixing in in
Mix Mix elsewhere elsewhere except except northnorth
Timing: 3 PMTiming: 3 PMNAM Model NAM Model
Becoming Becoming mostly snow mostly snow as upper low as upper low moves inmoves in
Heavy snows Heavy snows near the near the upper low upper low (blue (blue banded banded areasareas
Timing: 6PMTiming: 6PMNAM Model NAM Model Precip Precip
tapering tapering off west off west and and southwest.southwest.
Heaviest Heaviest snows in I-snows in I-3030
Mixed bag Mixed bag easteast
National Center Snow National Center Snow Forecast Forecast
(issued 6 AM Sunday)(issued 6 AM Sunday) Higher Higher amounts north amounts north where warm where warm nose keeps nose keeps precip mostly precip mostly snowsnow
Amounts Amounts lesser where lesser where sleet/freezing sleet/freezing rain mixes inrain mixes in
Overall Forecast Overall Forecast (issued 6 AM Sunday)(issued 6 AM Sunday)
Higher Higher amounts north amounts north where warm where warm nose keeps nose keeps precip mostly precip mostly snowsnow
Amounts Amounts lesser where lesser where sleet/freezing sleet/freezing rain mixes inrain mixes in
Monday Monday (with snowpack, highs/lows could be (with snowpack, highs/lows could be
colder)colder)
Arctic Air Moving In
Highs Weather
Freezing Drizzle possible as Freezing Drizzle possible as temperatures aloft warm temperatures aloft warm
above freezingabove freezing
ImpactsImpacts Heavy snows possible Heavy snows possible late Sunday AM through late Sunday AM through early Monday AM (I-20 early Monday AM (I-20 north)north)
Lower visibilitiesLower visibilities
Slushy roads in heavier Slushy roads in heavier sleet/snowssleet/snows
Heavy wet snows can Heavy wet snows can weigh on pine trees and weigh on pine trees and come down on come down on powerlinespowerlines
Cold temperatures Cold temperatures through mid-week keep through mid-week keep snows around snows around
Pipe freezing issues, if Pipe freezing issues, if temperatures remain temperatures remain <35 through mid week<35 through mid week
If Freezing I-20 If Freezing I-20 corridor: 0.25-0.50”corridor: 0.25-0.50”
Snow will fall onto Snow will fall onto FZRA SundayFZRA Sunday
Mainly North LA, Mainly North LA, but could spill into but could spill into NE TX and NE TX and Southern ARSouthern AR
Obvious travel Obvious travel issuesissues
Power outagesPower outages Freezing Drizzle Freezing Drizzle
overnight areawide overnight areawide possiblepossible
NEXT CONFERENCE CALL:
Thursday 10 AM (regular briefing)Thursday 10 AM (regular briefing)
Unless otherwise notedUnless otherwise noted
www.srh.noaa.gov/shv/www.srh.noaa.gov/shv/briefingbriefing
National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana