...Expected Local Impacts by Category...
Transportation: Widespread
Power: Isolated-Scattered
Tree Damage: Isolated
Impact categories and definitions:
Isolated: less than 25 percent of the category may be impacted
Scattered: 25-40 percent of the category may be impacted
Regional: 40-60 percent of the category may be impacted
Widespread: greater than 60 percent of the category may be impacted
...Overview and Timing...
Freezing drizzle and periods of freezing rain and/or sleet will continue to develop/increase across the local area through the morning hours. If you like to watch weather radar during these types of events, it is very important to keep in mind that freezing drizzle is not detectable by weather radar as the precipitation droplets are too small. Many areas that seem to show "no precipitation" on radar are actually receiving a freezing mist or freezing drizzle, which over time creates an ice glazing condition just like freezing rain will do.
As temperatures continue to fall this morning, the precipitation will likely change mainly to sleet and/or a sleet/snow combination from near 9-10am into the midday/early afternoon hours. Present indications suggest that measurable precipitation will end from Northwest to Southeast across the area by 2-3pm.
Elevated roadways such as bridges, overpasses, etc., will see deteriorating conditions first this morning, followed by some secondary and/or lesser traveled roadways (especially in areas that receive more freezing rain vs. simply freezing drizzle). We are already seeing rapidly deteriorating conditions in the Austin metro area at this time, especially on the elevated/flyover roadways including several accidents and some road closures. Temperatures were colder in that area first, so we are likely to see similarly deteriorating conditions across the remainder of the local area as temperatures continue to fall into the morning hours.
...Ice Accumulation Forecast...
Ice accumulation of up to 0.1 inch is expected with this event, most of which will likely occur before 9-10am. If more sleet begins to mix in with the precipitation toward mid-morning, then this amount could be lower in some parts of the area. On the other hand, locations that receive more frequent periods of freezing rain early to mid morning could see slightly higher amounts in spots as well.
Ice accumulation of up to 0.1 inch would mainly form a light glaze on exposed surfaces, especially metallic surfaces, colder elevated surfaces such as bridges, overpasses, etc., (especially if they are untreated), and roadways that are lesser traveled and/or untreated. Tree limbs and exposed power lines may also start to see a light glaze-over especially if the near 0.1 inch ice amounts are realized.
...Sleet and/or Snow Accumulation Forecast...
A combined sleet/snow accumulation of up to 0.5 inch is possible in some parts of the area. This would most likely occur from near 9-10am through about 1-2pm, with decreasing amounts into the mid-afternoon hours. The sleet and/or snow will be able to accumulate more rapidly on surfaces that have a light ice glaze from earlier in the morning hours.
...Transportation Impacts - Widespread...
Transportation impacts are likely to reach "widespread" status across much of the local area with this event. Elevated surfaces such as bridges and overpasses will be impacted first, followed by some lesser traveled/untreated surface roadways depending upon the extent of any heavier precipitation (i.e., freezing rain vs. simply freezing drizzle). Please also note that although accumulating winter precipitation will end during the early to mid-afternoon hours today, temperatures will remain well below freezing into tonight and much of Wednesday. This could result in icy patches and/or localized areas of ice to remain well after the precipitation has ended in some parts of the area.
...Power Impacts - Isolated-Scattered...
Power impacts are expected to reach "isolated-scattered" status across the local area with this event. Areas with exposed power lines would be most vulnerable, and especially if any concentrated spots of even slightly more than 0.1 inch ice accumulation are observed in those areas. North winds will continue to gust at 25-35 mph throughout much of the day today, and this could aggravate the condition at times in at least parts of the area, especially where the higher end of the ice accumulation occurs and where there is more open exposure to a Northerly wind.
...Impacts on Trees - Isolated...
Impacts on trees are expected to reach "isolated' status across the local area with this event. Ice glazing of up to 0.1 inch does not typically cause significant issues with downing of tree limbs, so this would primarily be of concern in any areas that may receive slightly more than 0.1 inch of glaze, and on any trees that were in poor condition to begin with. North winds will continue to gust 25-35 mph throughout the day today, and this could aggravate the condition at times in at least parts of the area, especially where the higher end of the ice accumulation occurs and where there is more open exposure to a Northerly wind.
...Other Impacts...
Please note that in addition to hazardous conditions that are expected as a result of wintry precipitation, cold temperatures and bitter cold Wind Chills will also create additional hazards throughout this period and extending into Wednesday as well as portions of Thursday. Please refer to the latest update of the Wind Chill Advisory product for additional details on this aspect of the storm system.
We will continue monitoring the situation and issue updates as conditions warrant.
Transportation: Widespread
Power: Isolated-Scattered
Tree Damage: Isolated
Impact categories and definitions:
Isolated: less than 25 percent of the category may be impacted
Scattered: 25-40 percent of the category may be impacted
Regional: 40-60 percent of the category may be impacted
Widespread: greater than 60 percent of the category may be impacted
...Overview and Timing...
Freezing drizzle and periods of freezing rain and/or sleet will continue to develop/increase across the local area through the morning hours. If you like to watch weather radar during these types of events, it is very important to keep in mind that freezing drizzle is not detectable by weather radar as the precipitation droplets are too small. Many areas that seem to show "no precipitation" on radar are actually receiving a freezing mist or freezing drizzle, which over time creates an ice glazing condition just like freezing rain will do.
As temperatures continue to fall this morning, the precipitation will likely change mainly to sleet and/or a sleet/snow combination from near 9-10am into the midday/early afternoon hours. Present indications suggest that measurable precipitation will end from Northwest to Southeast across the area by 2-3pm.
Elevated roadways such as bridges, overpasses, etc., will see deteriorating conditions first this morning, followed by some secondary and/or lesser traveled roadways (especially in areas that receive more freezing rain vs. simply freezing drizzle). We are already seeing rapidly deteriorating conditions in the Austin metro area at this time, especially on the elevated/flyover roadways including several accidents and some road closures. Temperatures were colder in that area first, so we are likely to see similarly deteriorating conditions across the remainder of the local area as temperatures continue to fall into the morning hours.
...Ice Accumulation Forecast...
Ice accumulation of up to 0.1 inch is expected with this event, most of which will likely occur before 9-10am. If more sleet begins to mix in with the precipitation toward mid-morning, then this amount could be lower in some parts of the area. On the other hand, locations that receive more frequent periods of freezing rain early to mid morning could see slightly higher amounts in spots as well.
Ice accumulation of up to 0.1 inch would mainly form a light glaze on exposed surfaces, especially metallic surfaces, colder elevated surfaces such as bridges, overpasses, etc., (especially if they are untreated), and roadways that are lesser traveled and/or untreated. Tree limbs and exposed power lines may also start to see a light glaze-over especially if the near 0.1 inch ice amounts are realized.
...Sleet and/or Snow Accumulation Forecast...
A combined sleet/snow accumulation of up to 0.5 inch is possible in some parts of the area. This would most likely occur from near 9-10am through about 1-2pm, with decreasing amounts into the mid-afternoon hours. The sleet and/or snow will be able to accumulate more rapidly on surfaces that have a light ice glaze from earlier in the morning hours.
...Transportation Impacts - Widespread...
Transportation impacts are likely to reach "widespread" status across much of the local area with this event. Elevated surfaces such as bridges and overpasses will be impacted first, followed by some lesser traveled/untreated surface roadways depending upon the extent of any heavier precipitation (i.e., freezing rain vs. simply freezing drizzle). Please also note that although accumulating winter precipitation will end during the early to mid-afternoon hours today, temperatures will remain well below freezing into tonight and much of Wednesday. This could result in icy patches and/or localized areas of ice to remain well after the precipitation has ended in some parts of the area.
...Power Impacts - Isolated-Scattered...
Power impacts are expected to reach "isolated-scattered" status across the local area with this event. Areas with exposed power lines would be most vulnerable, and especially if any concentrated spots of even slightly more than 0.1 inch ice accumulation are observed in those areas. North winds will continue to gust at 25-35 mph throughout much of the day today, and this could aggravate the condition at times in at least parts of the area, especially where the higher end of the ice accumulation occurs and where there is more open exposure to a Northerly wind.
...Impacts on Trees - Isolated...
Impacts on trees are expected to reach "isolated' status across the local area with this event. Ice glazing of up to 0.1 inch does not typically cause significant issues with downing of tree limbs, so this would primarily be of concern in any areas that may receive slightly more than 0.1 inch of glaze, and on any trees that were in poor condition to begin with. North winds will continue to gust 25-35 mph throughout the day today, and this could aggravate the condition at times in at least parts of the area, especially where the higher end of the ice accumulation occurs and where there is more open exposure to a Northerly wind.
...Other Impacts...
Please note that in addition to hazardous conditions that are expected as a result of wintry precipitation, cold temperatures and bitter cold Wind Chills will also create additional hazards throughout this period and extending into Wednesday as well as portions of Thursday. Please refer to the latest update of the Wind Chill Advisory product for additional details on this aspect of the storm system.
We will continue monitoring the situation and issue updates as conditions warrant.
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