The University of Tulsa

Mountain Cedar Pollen Forecast

 

 

 

Date Issued: 18 January 2003

 

Mountain Cedar Location(s): Edwards Plateau, Texas

 

Regional Weather: Saturday, January 18 and Sunday, January 19 TX/OK/AR: High pressure has moved in across the region but with cold temperatures only beginning to moderate.  Clear skies will occur over much of Texas today and tomorrow.  Today winds from the north to northwest will be moderate to strong from southern to northern Texas.  The current jet stream is positioned over southern Oklahoma and Northern Texas so those areas will see very windy conditions today and moderately gusty conditions tomorrow.  Wind direction will shift tomorrow coming from the west to southwest.  Temperatures across Texas will remain cold today with regional conditions below the mid 50s and northern Texas only reaching the high 40s.  Tomorrow will be warmer as high temperatures rebound by 5 to 10 degrees depending on your location.  The cold air is also dry resulting in low relative humidity conditions both days.  Overnight low temperatures will be in the 30s with below freezing conditions on the Plateau and to the west.  In Oklahoma, a weather system is building over the Ozark Mountains but will move to the east during the day.  There is a slight possibility for some backside precipitation in eastern Oklahoma.  Temperatures will be cold today with highs only in the 40s and lows tonight well below freezing.  Winds will be moderate to strong today and tomorrow from the northwest switching to a southwesterly flow overnight and into tomorrow.  Sunny and clear skies will occur in southern Oklahoma with partly cloudy  skies both days to in northeastern Oklahoma and over the Ozark Mountains.  As in Texas temperatures will ameliorate on Sunday with a 5 to 10 degree or greater warm-up during the two periods.

 

Trajectory weather: The air mass trajectories from eastern Texas move  toward the east then northeast being drawn toward the system moving out of Arkansas.  At the western source sites the trajectories start towards the southeast but move steadily northward into northern Texas and southern Oklahoma.  All of the trajectories show poor atmospheric characteristics for pollen entrainment and travel away from the source regions with the heavy, dense cold air moving at ground level.  Cold conditions overnight and into today should dampen pollen release today.  Sunday:  Sunday conditions will improve with a 5 to 10 degree warm up across the region.  In addition, overnight low temperatures will not be as cold with the southern Texas populations above freezing.  Sunny skies with low humidity and moderate to light winds will prevail across the region.  The trajectories move towards the north to northeast with stable or sinking atmospheric conditions along the pathway.  Monday morning the air parcels are turned towards the west traveling over southern Oklahoma or back into Texas.

 

OUTLOOK: *** Saturday: Low to Moderate Threat today***Mixed conditions for pollen release today. ***Sunday: Moderate Threat today ***favorable conditions for pollen release today. Clear skies and dry conditions but very cold temperatures overnight and during the day today result in a forecast of mixed conditions for pollen release today.  The more northern populations are less at risk because temperatures will be cold during most of the day, but the more southern populations may see conditions reach the mid 50s before the day is done.  Because of the warmer conditions there is a potential for some limited release.  However, the trees should be nearing the end of the pollination season and therefore there may not be significant amounts of pollen to be dispersed. The trajectory characteristics show poor conditions for entrainment and travel today coupled with the marginal conditions for release results in a low threat to downwind communities. Sunday:  On Sunday similar conditions will exist but temperatures will ameliorate with a 5 to 10 degree warm up across the region.  Therefore favorable conditions for pollen release are expected.  Similarly, the trajectories show good conditions for entrainment and travel therefore the potential for significant deposition of pollen along the trajectories is possible and a Moderate threat to downwind communities is forecast.  The pathways move north to northeast off of the Plateau putting northern Texas (Dallas/Ft. Worth to Wichita Falls) and southeastern Oklahoma at risk.

 

Trajectory Start (s) (shown by * on map): Austin, TX; Junction, TX; San Angelo, TX.

 

Austin, TX

 

 

Junction, TX

 

 

San Angelo, TX

 

 

 

Prepared by: Peter K. Van de Water (Department of Geoscience, Oregon State University), and Estelle Levetin (Faculty of Biological Science, The University of Tulsa, 600 S. College, Tulsa, OK 74104). 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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