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

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National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana