Date Issued: 23 December 1999
Mountain Cedar location(s): Edwards Plateau, Texas
Regional weather: Thursday, December 23 - TX/OK: Surface high pressure will continue to govern the weather in the region. Interaction of the High with an upper-level Low in Old Mexico is bringing in clouds and moisture to parts of southern and western Texas. Slight chance of rain there today and Friday. Otherwise, clear to partly cloudy skies and slowly-moderating temperatures are the rule. Highs today in the 40's and 50's. Lows tonight mostly 20's and 30's. Highs Friday mostly in the 50's with some 40's northern sections.
Trajectory weather: Austin/Junction: Partly cloudy west; mostly cloudy east with a chance of light rain late this afternoon. Highs in the 50's. Mostly cloudy tonight with a slight chance of rain or drizzle, low near 40. Mostly cloudy with a chance of light rain Friday, high in the 50's. San Angelo: Partly cloudy today, high in the low 50's. Partly to mostly cloudy tonight, slight chance of rain, low near 30. Decreasing cloudiness Friday, high in the 40's.
Trajectory confidence: High despite the dramatic difference in the Junction and San Angelo trajectories. The presence of diverging winds in this area today is quite reasonable.
OUTLOOK: *** Mild Threat *** Some release expected. Conditions for pollen release are mixed today. Afternoon temperatures will be in the favorable range. Humidities vary across the Plateau. Most areas have shown a drop in relative humidity during the late morning hours. However, the drops have been slow for the most part and current (12 noon) levels are at or just below the 50% benchmark. As mentioned Wednesday, a portion of the cones are probably ready to release pollen. Airborne amounts shouldn't be significant for today's event. Residents of the Texas hill country and south-central Texas...including San Antonio and westward toward the Big Bend region.... may feel some ill effects. TK
Trajectory Start(s) (shown by * on map): Austin, TX; Junction, TX; San Angelo, TX
Austin, TX
Junction, TX
San Angelo, TX
Prepared by: Thomas Keever (Department of Marine, Earth and Atmospheric Sciences, NCSU), Estelle Levetin (Faculty of Biological Science, The University of Tulsa, 600 S. College, Tulsa, OK 74104), and C.E. Main (Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695-7618). This forecast gives the anticipated future track of released Mountain Cedar pollen, weather conditions over the region and along the forecast pathway, and an estimated time of arrival for various metropolitan areas.
Questions: Aerobiology Lab e-mail: pollen@utulsa.edu
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