Special Special Winter Weather Winter Weather

BriefingBriefing2/3/20112/3/2011slides:slides:

www.srh.noaa.gov/shv/briefingwww.srh.noaa.gov/shv/briefingKeith StellmanKeith Stellman

National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana

Overview Tonight/FridayTonight/Friday

Arctic air in place across the regionArctic air in place across the region Upper level system moves in and draws moisture in Upper level system moves in and draws moisture in

from the gulf over the cold air.from the gulf over the cold air. Accumulations of 1-3 inches snow/minor sleet Accumulations of 1-3 inches snow/minor sleet

accumulations possible I-20 Corridor and south accumulations possible I-20 Corridor and south (Winter Weather Advisory area) (Winter Weather Advisory area) Tyler>Longview>Shreveport>Magnolia>El Dorado Tyler>Longview>Shreveport>Magnolia>El Dorado and points south. and points south.

Ice accumulations of 0.25-0.50 inches possible…Ice accumulations of 0.25-0.50 inches possible…(Winter Storm Warning area) Lufkin-(Winter Storm Warning area) Lufkin->Nacogdoches>Natchitoches->Nacogdoches>Natchitoches->Winnfield>Monroe>Columbia>Colfax>Jena>Winnfield>Monroe>Columbia>Colfax>Jena

Beginning this evening 6 pm ending by 6 pm Friday. Beginning this evening 6 pm ending by 6 pm Friday. (Winter precipitation north of the Winter Storm (Winter precipitation north of the Winter Storm Warning area may begin a little later than 6 pm this Warning area may begin a little later than 6 pm this evening.) evening.)

National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana

Big PictureBig Picture

National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana

TodaTodayy

TngtTngt

FridFridayay

Strong Upper Level

Low Pressure Area

HH

Regional ViewRegional View

Snow

Pack

Temperatures ThursdayTemperatures ThursdayWind Chills Highs

Winter Storm Winter Storm Warning/Advisory (6 pm Warning/Advisory (6 pm this evening through 6 this evening through 6

pm Fridaypm Friday Winter Winter

Precipitation Precipitation expected expected across the across the entire Four entire Four State Region. State Region.

Warning areas Warning areas in blue. in blue.

Advisory areas Advisory areas in purple.in purple.

Sleet/snow/Freezing rain Sleet/snow/Freezing rain DilemmaDilemma

Temperature profile at 6 AM Friday - Temperature profile at 6 AM Friday - ShreveportShreveport

Free

zing

line

High Res High Res models models suggest all suggest all snow in snow in NW LA NW LA and and portions of portions of East TexasEast Texas

Warm Warm nose not nose not as as prevalent prevalent as the air as the air is too cold is too cold to startto start

Height

Surface Tempeatures 25-28

Sleet/snow/Freezing rain Sleet/snow/Freezing rain DilemmaDilemma

Temperature profile at 6 AM Friday - Temperature profile at 6 AM Friday - MonroeMonroe

Free

zing

line

High Res High Res models models suggest all suggest all snow in snow in NW LA NW LA and and portions of portions of East TexasEast Texas

Warm Warm nose not nose not as as prevalent prevalent as the air as the air is too cold is too cold to startto start

Height

Surface Tempeatures 27-30

Sleet/snow/Freezing rain Sleet/snow/Freezing rain DilemmaDilemma

Temperature profile at 6 AM Friday - Temperature profile at 6 AM Friday - MonroeMonroe

Free

zing

line

Warm Warm Nose Nose appears appears and looks and looks deep deep enough to enough to melt the melt the snowsnow

Could Could either be either be sleet or sleet or freezing freezing rainrain

Lufkin -> Lufkin -> NatchitocNatchitoches -hes ->Columbia>Columbia

Height

Surface Tempeatures 28-31

Model Forecast 3 AM Model Forecast 3 AM FridayFriday

Snow to Sleet/Freezing Rain Line

• Models Models waver on waver on the mix the mix line. line.

• Blue Blue barbs barbs indicate indicate south south winds winds transporttransporting ing moisture moisture northnorth

Total Liquid Equivalent (precip Total Liquid Equivalent (precip amounts) amounts)

High Res ModelHigh Res Model

Model has Model has been been trending trending toward toward higher higher amounts in amounts in the the SoutheasterSoutheastern Parishes n Parishes (0.50-1.00”) (0.50-1.00”)

Sabine, Sabine, NatchitocheNatchitoches, Grant, s, Grant, Winn, La Winn, La Salle, Salle, CaldwellCaldwell

Total Liquid Equivalent (precip Total Liquid Equivalent (precip amounts) amounts)

Model Concensus (SREF)Model Concensus (SREF)

This blend This blend shows the shows the highest highest swath in the swath in the Southeast Southeast and south and south (0.50-1.00”) (0.50-1.00”)

Sabine, Sabine, NatchitocheNatchitoches, Grant, s, Grant, Winn, La Winn, La Salle, Salle, CaldwellCaldwell

The 2” lineThe 2” line

Overall Forecast Overall Forecast

Thu PM/FridayThu PM/FridayLows

Highs

ImpactsImpacts Swath of 1”-4” of snow Swath of 1”-4” of snow south of a Jacksonville-south of a Jacksonville->Marshall->Magnolia >Marshall->Magnolia lineline

Sleet/Snow/Freezing Sleet/Snow/Freezing Rain along a Lufkin -Rain along a Lufkin ->Natchitoches->Natchitoches->Columbia Line>Columbia Line

Lower visibilitiesLower visibilities

Ground temps cold…precip Ground temps cold…precip will stick to will stick to bridges/overpasses and bridges/overpasses and main roadwaysmain roadways

Cold temperatures Cold temperatures through Saturday AM to through Saturday AM to keep it aroundkeep it around

If Freezing rain If Freezing rain materializes, could materializes, could be talking about be talking about 0.25-0.75” in the 0.25-0.75” in the southeast…possibly southeast…possibly higher in Grant/La higher in Grant/La Salle/NatchitochesSalle/Natchitoches

Over 0.50” would Over 0.50” would cause widespread cause widespread Power outagesPower outages

Instant freeze on all Instant freeze on all surfaces with temps surfaces with temps in the 20sin the 20s

NEXT CONFERENCE CALL:

Thursday 10 AM Thursday 10 AM www.srh.noaa.gov/shv/briewww.srh.noaa.gov/shv/brie

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National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana