The University of Tulsa

Mountain Cedar Pollen Forecast

Metropolitan Area	Exposure Risk
Oklahoma City	Severe
Tulsa	Severe
St. Louis MO	Moderate

Date Issued: 19 December 2002

Mountain Cedar Location(s): Arbuckle Mountains, OK

Regional Weather: Friday, December 20 TX/OK/AR: Conditions across the region will be under the influence of high pressure as the severe weather to the east moves out over the Atlantic. Clear, cool conditions will occur throughout the region this morning with sunny conditions today and tomorrow for much of the region. Of coarse with clear skies also comes cool temperatures with much of the area in the 30s. High temperatures will be in the upper 50s to mid 60s today and tomorrow. Humidity will be low as conditions continue to dry out. Moderate winds will blow across the region from the west to southwest increasing overnight into tomorrow with strong winds during the afternoon especially in north Texas. To the north sunny, dry conditions will prevail today but with increasing clouds tonight, late, and into tomorrow. High temperatures today will be in the upper 50s cooling by 5 degrees tomorrow. Overnight temperatures will cool to the low 40s. Winds will be from the west to southwest both days with moderate conditions today increasing to strong tomorrow.

Trajectory weather: The air mass trajectories from the Arbuckle Mountains move due east then abruptly turn north over eastern Oklahoma and western Arkansas, eventually moving over Missouri and towards the Great Lakes. The trajectories show characteristics of movement at near ground level as the cooler, heavier air moves through the region with little lift therefore any entrained particle should not travel significant distances. Sunny skies will prevail this morning with temperatures in the upper 50s and low humidity. Moderate winds from the west to southwest today will increase overnight to strong conditions tomorrow afternoon in southern Oklahoma and northern Texas. Cloudy conditions will move into the area overnight and into tomorrow with a general cooling of temperatures by about 5 degrees.

OUTLOOK: ***Severe Threat today***favorable conditions for pollen release today. Conditions in the Arbuckle Mountains will be stable with temperatures reaching the upper 50s and relatively dry conditions with moderate winds. These characteristics will result in favorable conditions for pollen release today and tomorrow. Cooler, heavier air results in atmospheric conditions being not great for entrainment and travel significant distances. However, regional incursions into eastern Oklahoma and Arkansas are likely.. Therefore a sever threat for entrainment and travel downwind of significant quantities exists for eastern Oklahoma and western Arkansas. A moderate threat exists for further downwind communities such as St. Louis.

Trajectory Start (s) (shown by black star on map): Sulfur, OK.

Prepared by: Peter K. Van de Water (Department of Geosciences, 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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