1 / 14

Special Winter Weather Briefing 1/7/2010

Special Winter Weather Briefing 1/7/2010. Keith Stellman. National Weather Service Shreveport, Louisiana. Overview. Sunday Low pressure system moving across Texas will bring precipitation to the region as early as Saturday night/Sunday

piera
Download Presentation

Special Winter Weather Briefing 1/7/2010

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Special Winter Weather Briefing1/7/2010 Keith Stellman National Weather Service Shreveport, Louisiana

  2. Overview Sunday Low pressure system moving across Texas will bring precipitation to the region as early as Saturday night/Sunday May start as rain, but will transition to a mix of sleet/snow rain by Sunday AM (West) Sunday PM (East) Accumulations of 4 or more inches snow/sleet possible especially I-30 and possibly down to I-20 Monday Precip ends before dawn at most locations Light flurries early AM across I-30 corridor AM Temperatures ≤ 32 I20 north, Upper 20’s along/north US 82 (Clarksville ->El Dorado) National Weather Service Shreveport, Louisiana

  3. Scenario H L Strong Upper Level Low Pressure Area L Mon L L Today Sun Sat National Weather Service Shreveport, Louisiana

  4. Sleet/snow/rain DilemmaTemperature profile at 6 PM Sunday • Some models suggest a warm nose ~4-5kt ranging 33-35 ºF • If that occurs sleet is more likely (model 1). • If not, snow (model 2). • Different sites vary in this profile • Note the winds advecting colder air from the NE Model #1 Model #2 Freezing line Height

  5. Scenario #1 (noon – 6 PM) NAM Model • Liquid equivalent amounts 0.25-0.50” behind the snow line Snow/sleet line

  6. Scenario #1 (6 PM - Midnight) NAM Model • Liquid equivalent amounts 0.25-0.50” north of the snow line Snow/sleet line

  7. Scenario #2 (6 PM) • Coldest model, worst case scenario • Liquid equivalent amounts 0.50 – 1.25” north of the snow line • Heaviest swath from Tyler - > El Dorado Euro Model Snow/sleet line

  8. National Center Snow Forecast (Friday Afternoon) • Swath of heavier snows from Tyler -> NW LA/ Southern AR • Generally along I-20 except TX • We think the extent is too far south…but under worst case scenario some could extend further south

  9. Previous Forecast (issued 6 AM Friday) • Less in Texas, focus more in southern AR

  10. Forecast, for now

  11. Forecast amounts, for now • **This is a conservative forecast based on the uncertainties in the temperature profiles • If an all snow event… amounts could be doubled

  12. Monday (with snowpack, highs will be colder than this forecast Lows Highs Arctic Air Moving In

  13. Impacts • Heavy snows possible late Sunday AM (west) through early Monday AM (north) • Lower visibilities • Slushy roads in heavier snows • Heavy wet snows can weigh on pine trees and come down on powerlines • Cold temperatures through mid-week keep snows around • pipe freezing issues, if temperatures remain <35 through mid week

  14. NEXT CONFERENCE CALL: TBD….Possibly Sat AM www.srh.noaa.gov/shv/briefing National Weather Service Shreveport, Louisiana

More Related