National Weather Service Weather Forecast Office

June 2004 - a Review of Weather, Temperatures, and Precipitation for the Quad State Region.

 

Weather Summary for June 2004

 

Weather Summary information is taken from the June AMonthly Report of River and Flood ConditionsA for the Quad State Region.

 

Showers and thunderstorms broke out ahead of a cold front during the first couple of days of June.  The stronger storms were capable of producing brief heavy rainfalls.  Three Flash Flood Warnings were issued on the 1^st for portions of southeast Illinois and northwest Kentucky.  Numerous roads were flooded or closed.  More scattered showers and thunderstorms developed before the upper level trough passed by the 9^th.  After the first, additional reports of flooding were minimal.

 

High pressure then set up across the southeast U.S. with a warm and moist southwest flow across the middle Mississippi Valley through mid-month.  A quasi-stationary boundary to the north of the HSA helped initiate several rounds of showers and thunderstorms between the 12^th and the 18^th.  High precipitable water values and an unstable atmosphere contributed to isolated very heavy rainfall amounts.  Radar estimates of 2-4" per hour rainfall rates were  common during this period.  Total rainfall amounts were highly variable but some locations reported almost 4 inches of rain.  Numerous Flash Flood Warnings and Urban and Small Stream Flood Advisories were issued.  Reports of flooded roadways, road closures and stream flooding were common.  The Wabash and Big Muddy Rivers rose and crested slightly above their respective flood stages by the 21^st.

 

After this event, the upper level flow became more zonal to slightly northwest.  Several weak upper level disturbances passed over the region during the second half of the month touching off a few showers and thunderstorms.  On the average, rainfall amounts were minimal but some locations did report localized flooding.

 

June Temperatures Across the Quad State Region

 

The following table (Figure 1) displays average June 2004 temperatures at five locations across the Quad State Region where this information is consistently collected. For comparison, historical average daily temperatures for June are also given for these locations. The Normal period used to calculate normal high, low, and average daily temperatures and rainfall is currently 1971 through 2000.

 

The high, low and average daily temperatures are averaged for all days of June 2004. Column 5 allows a comparison of the 2004 average temperature to the highest and lowest June average temperatures recorded during the Normal Period (1971 through 2000). High and Low daily temperatures were not compared.

 

The last column indicates the difference of the June 2004 average temperature from the average temperature observed during the Normal Period, and the percentile of the June 2004 mean temperature compared to June mean temperatures during the Normal Period.

 

Percentile is the percentage of years during the Normal Period that had mean June temperatures equal to or below the 2004 mean temperature. In most cases, this is based on the entire 30-year Normal Period, but in some cases data was missing that only allowed comparison to 28 or 29 years of the Normal Period. 

 

Figure 1. June Average Daily Temperature Summaries (Degrees F) for Several Quad State Region Locations.

 

Location	Temp >	High	Low	Avg.	Range of Mean Temperatures*	Degrees from Mean /percentile
Carbondale    IL	Normal > 2004 >	84.7 83.9	62.3 62.5	73.7 73.2	max: 78.6 in 1971 min:  69.6 in 1974	-0.5 43%-ile
Cape Girardeau    MO	Normal > 2004 >	86.4 84.3	65.5 62.9	76.2 73.6	max: 79.6 in 1971 min:  71.4 in 1974	-2.6 18%-ile
Evansville    IN	Normal > 2004 >	85.6 83.7	64.2 64.2	75.2 74.2	max: 79.3 in 1971 min:  70.7 in 1982	-1.0 38%-ile
Paducah    KY	Normal >     2004 >	86.0 83.9	65.1 64.0	75.8 74.0	max: 78.6 in 1984 min:  71.1 in 1974	-1.8 28%-ile
Poplar Bluff    MO	Normal > 2004 >	86.9 84.2	65.0 65.2	76.2 74.7	max: 78.9 in 1987 min:  70.9 in 1974	-1.5 21%-ile

* Range of averages is the highest and lowest June average temperature observed

        from 1971 to 2000.    

 

As the table indicates, average temperature for June 2004 was below normal at all five locations. The warmest location was Carbondale, where the average temperature for June 2004 was 0.5 degrees below normal, placing it in the 43^rd percentile – meaning that 43 percent of the June average temperatures during the normal period were lower than 2004. For Carbondale, the 2004 average low temperature for June was slightly higher than the normal low, while the 2004 average high temperature was slightly below normal.

 

For the other four locations, 2004 June temperature ranged from 1.0 degree below normal in Evansville, to 2.3 degrees below normal in Cape Girardeau. Percentile ranks of these locations ranged from 18 to 38, respectively. Overall, the temperatures at most locations were well below normal.

 

June Precipitation Across the Quad State Region

 

The next table (Figure 2) displays normal precipitation and the observed precipitation for June 2004. The historical time periods are the same as those in Figure 1. Frozen precipitation – if any – is not available from this data except as liquid equivalent, which is included in the total precipitation for the month.

 

Figure 2. June 2004 Observed Precipitation and Normal June Precipitation (inches) for Several Quad State Region Locations

 

* Range is the highest and lowest June precipitation observed from1971 to 2000.

 

Figure 2 indicates that precipitation was below normal at four of the five locations. Only Paducah was near normal at only -0.34 inch, and at the 55^th percentile.

 

The other four locations ranged from 1.68 inch below normal in Carbondale (at the 32nd percentile) to 2.44 inch below normal at Evansville (at the 17^th percentile). Overall, June was considerably drier than normal.