VISIT: Meteorological Interpretation Blog

(From SPC MCD 1327 - Concerning Tornado Watch #509) 

Wednesday night, June 11, 2008, at just after 6:30 PM, some 93 boys, ages 13 to 18, along with 25 adult BSA staff members, were fighting for their lives as a deadly tornado roared through the Little Sioux Boy Scout Camp. Four of the Boy Scouts ended up losing their lives in this fight against Mother Nature while attending what was to be a weeklong leadership training camp.  Over 40 others were also injured and were either rescued and/or attended to by other staff and scouts who used their emergency/first aid training to the best of their abilities.  You couldn’t ask for a better bunch in a situation like this…and even then there were some terrible results.

The synoptic/mesoscale set-up had a cold front extending from a surface low pressure center over eastern South Dakota, south through eastern Nebraska and into central portions of Kansas.  A warm front stretched from the surface low eastward across southern Minnesota (not far north of the Iowa border).  In between these two features lay the warm (and moist) sector with surface temperatures ranging from the mid 70s (north) to nearly 90 (south) and dew points in the upper 60s to lower 70s.  There was also a slowly moving (westward) mesoscale boundary (through Iowa).  Mixed layer CAPE ranged from around 1500 j/kg (north) to nearly 3000 j/kg (south) by this time with lapse rates above 700mb  were running between 7 and 8 deg C/km (there was just a bit of a cap present near and above 600mb that kept the lid on long enough to make things explosive).  Effective shear was running between 40 (far south) and 60 (north in Minnesota) kts with low level storm relative helicities ranging from 200 (south into Kansas) to nearly 500 m²/s² (north into southern Minnesota and northern Iowa).

Movement of the cold front was to the east…with storms initiating ahead of the cold front along a (pre-frontal) trough from southeastern South Dakota into northeastern Nebraska by 4 PM LDT…back-building south southwestward into south central Nebraska by 5 PM (southwest Kansas also had storms going up by 5 PM).

Many of these storms became tornadic within in the first hour since initiation – first starting over portions of northwestern Iowa and southwestern Minnesota…then with reports following, down the line, into eastern Nebraska and western Iowa soon after.  Kansas then finished off the evening with continued reports up to just after midnight.  All told there were at least 53 separate reports of tornadoes (some reports, however, may be of the same storm) covering the four states of Minnesota, Iowa, Nebraska, and Kansas.  There were five fatalities total (the four in Iowa and one in Kansas) and many, many more injured.       

Please give the kids a second (and third) thought.  

Below are some links to, or copies of, some perhaps lesser known meteorological training materials.  Many of these have been born out of Aviation Weather programs either here in the USA through the military Air Force Weather Agency (AFWA) or the FAA, or from up north and our Canadian Neighbors.  Although some of the information is based on region specific examples, all of it (the principles, etc.) can be applied to most of our own geographic areas. 

First up is a link to NAV Canada, a privately run non-profit organization that operates Canada’s Civil Air Navigation Service.  This section contains an in depth training manuals section that is broken into six geographic regions that cover the whole of Canada.  Truly indispensable stuff here for all but tropical forecasters: NAV Canada Maunuals

Next up is the Air Force Weather Agency’s “Meteorological Techniques” which is an in depth compilation of many various weather forecasting parameters and techniques.  It is another truly indispensable item to be used for review, support, rules of thumb (tricks of the trade).   Also by AFWA, great training, practice, and supplemental review is the manual of the Mesoscale Forecast Process. 

This paper by John Mecikalski and Kristopher Bedka titled, “Forecasting Convective Initiation by Monitoring the Eveolution of Moving Cumulus in Daytime GOES Imagery” is a little long in the tooth (title-wise), but is definitely worth a read. 

More in the way of research papers / training materails will be posted here from time to time.  If you know of some lesser known, but valuable training for those of us in the weather business, please send us the information so that we may pass in on to others.�