To: MPR's Morning Edition From: Mark Seeley Re: Topics for MPR's Morning Edition, Friday, Mar 25, 2005 HEADLINES: - Classes Without Quizzes - March 18th snow storm - Hurricane track forecasts - Easter Sunday climatology - Almanac for March 25th - Soundings - Outlook Topic: Classes Without Quizzes on April 2nd.... The College of Agricultural, Food, and Environmental Sciences will be hosting the Annual Classes Without Quizzes on Saturday, April 2nd from 8:30 am to 2:00 pm on the St Paul Campus. I will be presenting a lecture at 9:00 am entitled "Torrid, Tornadic, and Traumatic: Perceptions and Trends in Minnesota's Severe Weather." There will be other sessions during the morning on pet nutrition, renewable energy, tax law, woody plants and gardening, dietary supplements, improved crops, and food safety. The event is open to the public and just $20 for adults, $15 for alumni, and $10 for students. More information can be found at the COAFES web site: http://www.coafes.umn.edu/cwq or by calling (612)-624-1745. Topic: Final comments on snow storm of March 18, 2005 Kiester in Faribault County reported a grand total of 21 inches of snowfall last Friday, March 18th, breaking the statewide record for that date, formerly held by Albert Lea where it snowed 20 inches in 1933. Numerous locations in southern Minnesota reported between 15 and 20 inches, including Rochester which reported an all-time single date record of 19.8 inches. For several locations, that storm will be noted as one of the heaviest falls of snow ever in the month of March, yet coming in essentially a snow deprived winter. Topic: Hurricane track forecasts to remain as a drawn line NOAA administrators attending the National Hurricane Conference this week in New Orleans reported that survey results suggested that they keep using the narrow black line on a map to depict their best estimate of a hurricane track. This method was criticized last year, especially when Hurricane Charely took a sharp right turn in its path, diverting away from the Tampa, FL area and striking instead into Punta Gorda. It seems the public should perceive that any storm path forecast probably has error bands of 100 miles on either side of the line. Certainly Minnesotans understand this to be the case with the forecasted track of winter storms, so why should it not be implied in hurricane track forecasts as well? MPR listener question: What is the climatology of Easter Sunday in the Twin Cities area? I know that the date varies considerably, but what can you tell us about the historical weather on Easter Sunday. Answer: Indeed, the date of Easter has varied from March 23rd to April 25th, and we can certainly have huge differences in weather across such a range of dates. On average a March date for Easter Sunday brings highs in the 40s F and lows in the 20s F. Since the establishment of the National Weather Service in the Twin Cities in 1891, Easter Sunday has occurred in March twenty-five times. Of those dates, eight have been wet, and six have brought snowfall, the most 2.5 inches on March 31, 1929. Since 1891, Easter Sunday has occurred in April 89 times. By the way it has never occurred on April 24th, but has occurred once as late as April 25th in 1943. Of the April Easter Sundays, 27 have been wet, and 4 have brought snowfall. Two Easter Sundays have seen thunderstorms in the Twin Cities area, both 1941 and 1998. Average daytime highs for Easter Sunday in April are in the 50s and 60s F, with lows in the 40s. Climate extremes for Easter Sunday include a high of 88 degrees F on April 10, 1977, a low of -2 degrees F on March 25, 1894, and a maximum total precipitation of 0.49 inches on April 13, 1941. The last dense fog on Easter was in 1993, and the worst wind chill conditions were in 1894 and 1920 when readings of -15 degrees F were noted. Looking for Easter eggs was difficult in 1975 as there was still 10 inches of snow on the ground Easter Sunday, March 30th. Twin Cities Almanac for March 25th: The average MSP high temperature for this date is 45 degrees F (plus or minus 14 degrees F standard deviation), while the average low is 28 degrees F (plus or minus 11 degrees F standard deviation). MSP Local Records for March 25th: MSP weather records for this date include: highest daily maximum temperature of 78 degrees F in 1939; lowest daily maximum temperature of 12 degrees F in 1955; lowest daily minimum temperature of -8 degrees F in 1867; highest daily minimum temperature of 51 degrees F in 1945; record precipitation of 1.43 inches in 1890; and record snowfall of 3.6 inches in 1996. There have been 14 measurable snowfalls on this date since 1891. Greatest snow depth on this date was 20 inches in 1951. The worst wind chill conditions occurred in 1894 and 1955 with a reading of -20 F. Average dew point for March 25h is 24 degrees F, with a maximum of 58 degrees F in 1945 and a minimum of -12 degrees F in 1955. All-time state records for March 25th: Scanning the state climatic data base: the all-time high for this date is 83 degrees F at Canby (Yellow Medicine County) and Tracy (Lyon County) in 1939; the all-time low is -31 degrees F at Bigfork (Itasca County) in 1965. The heaviest snowfall statewide on this date occurred in 1914 at Bemidji where they recorded 14 inches. The all-time state record for precipitation (liquid equivalent) on this date is 3.31 inches at Halstad (Norman County) in 1996. Word of the Week: Sounding This term derives from both Latin and Anglo Saxon terms meaning to submerge something in order to detect depth. In meteorology the term sounding refers to an upper air observation or a complete radiosonde report. Balloons equipped with instrumentation are launched twice each day (12 hours apart) from upper air stations. There are over 900 such stations scatterd around the world. They transmit back data about temperature, pressure, wind, and humidity as they pass through various vertical layers of the atmosphere. These are referred to as radiosondes. Another type of balloon is a rawinsonde, which carries no instruments, but is tracked by either radar or a radio direction finder such that wind direction and speed aloft can be plotted for various vertical layers. Radiosondes provide the basic data that feed into forecast models. These balloons rise to heights of 80,000 to 100,000 feet before they burst. A small parachute allows for the instrument package to fall to Earth and not be destroyed. Sometimes farmers and others find the instrument package in their fields. There are instructions on the container to mail the package back to the government so the instruments can be reconditioned and reused. Outlook: A warming trend begins this weekend with highs in the 40s for Easter Sunday, then even warmer next week. There is a slight chance for snow showers in the far north later on Sunday. Warm temperatures much of next week with a chance for showers on Tuesday and Thursday, may be even some thunderstorms.