...June 2009 Begins on a Rainy Note - Severe Weather Summary...
A stalled frontal boundary across southern Nebraska and Southern Iowa provided the focus for shower and thunderstorm activity as we began the month of June. Thunderstorms erupted along and south of this boundary across northeast Kansas and across extreme northern Missouri (north of Highway 36), during the afternoon hours of Monday, June 1st. Due to an increasing amount of instability and moisture in the afternoon, these storms were often severe in nature, with damaging winds and very large hail reported at times. These storms also packed quite a punch where rainfall was concerned. Holt county of Missouri experiences the heaviest rainfall with radar and observations indicating upwards of 5 inches of rain in some areas.
As earlier noted, large, severe hail was also common in many of these storms. The largest hail report came in near Coffey, Missouri along Interstate 35. In this area, hail up to the size of baseballs was commonly reported. Below you will find radar images at the peak time when this storm was producing its largest hail. These images show the reflectivity of 8 different levels of this storm, with the lowest level at 0.5 degrees (7500ft AGL at storm location) and the highest level at 5.1 degrees (around 53,000 ft AGL) near the top of the thunderstorm. Meteorologists use these different "tilts" of the radar to inspect storms for their strength and access the potential for severe impacts. The extremely high reflectivity values of this storm with very high levels of reflectivity (bright whites and pinks) extended well above 40'000 ft AGL, indicative of extremely large and damaging hail very high in the storm itself.
For more information on how Doppler Radar works and how large hail can be detected, please feel free to read the following article on the topic:
|Lower Level Storm Reflectivity||Mid Level Storm Reflectivity|
This frontal boundary slowly drifted southward during the daytime hours of the 2nd of June. As it moved southward, additional heavy rain fell in portions of the area, however instability was not high enough to produce additional severe thunderstorms. Below you will find an estimated rainfall map from the afternoon hours of Monday June 1st, to the overnight hours of June 2nd. Note how the heaviest rainfall was location across northeastern Kansas, southeastern Nebraska, and across northern Missouri. Rainfall estimates may be slightly overestimated due to excessive hail in portions of northwestern Missouri. The second map displays local storm reports from northern Missouri and northeastern Kansas during this event.
|Storm Total Estimated Rainfall - June 1-2, 2009||Local Storm Reports - June 1, 2009|
Local Storm Reports
|Time (UTC)||Size (inches)||Location||County||State||Lat||Lon||Comments|
|2125||1.25||7 NE GALLATIN||DAVIESS||MO||39.98||-93.87||(EAX)|
|2125||0.88||CRAIG||HOLT||MO||40.19||-95.37||PEA TO NICKEL SIZE HAIL. (EAX)|
|2140||0.75||2 E BRIMSON||GRUNDY||MO||40.14||-93.7||(EAX)|
|2142||0.88||1 N MOUND CITY||HOLT||MO||40.15||-95.23||(EAX)|
|2200||1.25||2 E GILMAN CITY||HARRISON||MO||40.14||-93.83||(EAX)|
|2225||1.00||2 N COFFEY||DAVIESS||MO||40.13||-94.01||(EAX)|
|2241||2.75||7 S BETHANY||HARRISON||MO||40.17||-94.03||HAIL REPORTED NEAR THE I-35 AND HWY H INTERSECTION. (EAX)|
|2250||0.75||5 W PRINCETON||MERCER||MO||40.4||-93.68||HAIL COVERING THE GROUND. (EAX)|
|2252||0.88||4 SSW MILAN||SULLIVAN||MO||40.15||-93.15||(EAX)|
|Time (UTC)||Speed (mph)||Location||County||State||Lat||Lon||Comments|
|2227||UNK||2 W OREGON||HOLT||MO||39.98||-95.18||TREES AND POWERLINES DOWN ON HWY 11 BETWEEN OREGON AND FOREST CITY. (EAX)|