December 2002 Saint Cloud Weather Summary

DATE: 1 January 2003

SUBJECT: December 2002 and 2002 annual St. Cloud weather summary

The Byrds may have sung, “To everything (turn, turn, turn), there is a season (turn, turn, turn)…” but they weren’t living in Saint Cloud during the past year. December 2002 was another month that didn’t really fiit our idea of what December is supposed to be like. This December, according to the statistics from the Saint Cloud Regional Airport, continued to make up for the very cold October. The average temperature of 23.2°F was more than eight and a half degrees above the normal temperature. These statistics made December 2002 the 14th warmest December in the 122 years of Saint Cloud temperature records. This might seem remarkable, but both December 2001 (23.9°F) and December 1997 (24.0°F) were warmer. Two record temperatures were set during this past December, but neither of them were high temperatures. A record mild low was set on the 18th when the temperature never dropped below 32 degrees and a record warm average temperature was set on the 28th, thanks to a 40-degree high and a 26-degree low. Saint Cloud came within two degrees of a record high on the 14th (51°F, the highest temperature during the month) and within one degree of a record high on the 28th.

There were two factors in the continuing mild weather seen during the past month. First, the persistent high over British Columbia f inally dissipated early in the month, so the weather pattern no longer sent air from the Arctic Circle into Minnesota. The second factor was the lack of snow cover, not only over the southern two-thirds of Minnesota, but also in southern Saskatchewan and Alberta, most of South Dakota, and Montana. The lack of snow cover meant that cold air masses that moved into the United States f rom Canada had less sunlight reflected back to space by the snow, allowing temperatures to climb more than usual, even during the cold periods.

The lack of snow cover was the other weather factor that was out of season. Only 1.7 inches of snow fell during December 2002 in Saint Cloud. This total, which was 7.5 inches below normal, tied December 1965°For the 14th lowest December snowfall out of 104 years on record. The most snow received on any day was 0.5 inch on the 20th. Because of this, Saint Cloud only had a measurable snow cover for 6 days out of the month. Since this snow cover was never at least 0.5 inch, no more than a trace will appear in the records (snow depth on the ground is rounded to the nearest inch). The “out of season” factor is that there has been only one other year (1959) when October had more snow than either November or December.

The lack of snow also meant a lack of liquid precipitation. The December 2002 total was 0.22 inch, about one-quarter of the normal amount. The low precipitation amount tied for the 16th lowest December amount with 1980 and 1999.

December’s lack of moisture, either wet or white, was a reflection of the December storm track. There were two main storm tracks in December. The southern track tended to lie from the West Coast across the southwest and south central US, then curved northeastward to the Middle Atlantic States and the Northeast. This track was responsible for the heavy rains on the West Coast and several snowstorms in the south and Northeast, including the storm of December 23-25 that dropped up to 10 inches of snow in Oklahoma and Arkansas and up to 3 feet of snow in New York and Vermont. The northern storm track tended to stay either in southern Canada or across northern Minnesota. Saint Cloud and most of the southern half of Minnesota ended up in between the two tracks and got nothing. Some of this pattern is reminiscent of the average pattern during an El Nino event, mainly the heavy West Coast and southern U.S precipitation. On the other hand, the Northeast tends to be warm and dry during El Nino and this hasn’t been the case. So, our weather won’t be easily explained by El Nino this winter.

The statistics for the year 2002 are now complete. Weather wise, 2002 will be remembered for some wild temperature fluctuations, mostly out of season, and the incredible wetness of the year. The total Saint Cloud precipitation in 2002 was 35.16 inches, more than 7 1/2 inches above normal. This total made 2002 the ninth wettest year in the 98 years of complete rainfall records. The most notable rains came on July 10 and September 5-6. The rainfall of the September storm totaled 4.39 inches, the 5th highest 24-hour rain event on record in Saint Cloud. The rainfall on July 10 produced widespread flooding in Sauk Centre, Saint Cloud, Foley, and many other areas mainly along and north of Hwy. 23 from Glenwood to Milaca. While the Saint Cloud total seems to be very high, it was lower than the statewide average of 38.45 inches, the 4th highest average rainfall in Minnesota of the 111 years on record. When noting these statistics, I must again point out the 2.38 inch difference between the SCSU manual rain gauge and the Saint Cloud Airport rain gauge between 7:00 and 8:30 AM on July 10. If 2 inches were added to the annual rainfall, 2002 would jump from the 9th wettest to the 4th wettest year.

Temperature-wise, Saint Cloud experienced quite a roller coaster. The final statistics showed an annual mean temperature of 43.3°F, 1.8°F warmer than normal. However, the seasonal fluctuations were much wilder. January and February were part of the warmest winter on record and the warmest November through February period on record. By the end of January, Saint Cloud was on track For near normal snowfall. Then, in March and April, Saint Cloud got the winter it had avoided during the winter season. March was nearly 10 degrees below normal, the 8th coldest March on record. Snow storms in March and April combined to produce 35.1 inches, the second snowiest spring total on record. This included the snowstorm of March 14, which produced 10.4 inches in Saint Cloud and 15-20 inches generally through central Minnesota, and three April storms that dropped at least 5 inches on Saint Cloud. The April snowfall of 15.3 inches missed the snowiest April on record by 0.3 inch (1928). The persistently cold weather, especially in March and May, produced the 4th coldest spring in Saint Cloud history and the coldest since 1950. The March and April snow brought the total snowfall of 2001-2002 to 64.0 inches, the 11th snowiest cold season on record.

However, the cold spring could not prevent two records. There were only 12 days with a low of zero or colder, breaking the record for fewest number of below zero lows (16 in 1997-1998). Also, the coldest temperature recorded during the winter was -9°F. Every previous winter in Saint Cloud records had at least one low temperature of -13°F or colder.

By June, the primary weather mode had changed to high humidity with frequent outbreaks of slow-moving thunderstorms. This continued into early October and produced the two major rains on July 10 and September 5-6 as well as numerous other significant rain storms. The September storm accounted for more than two-thirds of the September total (the 4th wettest September on record) and more than 40% of the fall rainfall total (7th wettest fall on record). However, we switched to a much colder weather pattern in October. Two early season snowstorms produced 6.4 inches of snow in October, just missing the snowiest October on record by 0.4 inch (1936). October 2002 was also the second coldest October on record, but it was a distant runner-up to October 1925.

In November, the cold weather pattern continued, but with little snow on the ground, so the temperatures remained nearly the same, but the normal temperatures were much colder. As a result, November had above normal temperatures.

So, what is in our future? I looked at our low seasonal snowfall so far to try and make a guess. There have been 31 previous cold seasons with reliable records that had no more than 9 inches of snow through the end of December. Only 7 of those 31 winters ended up with at least 40 inches of snow for the year (the normal is 45.5 inches). The average season snowfall from those winters was 28.3 inches with the most frequent amount of snowfall between 20 and 29.9 inches (15 of the 31 winters). Now, this analog method of forecasting really blew it when I tried to predict the spring weather. However, it does appear likely that we will have below normal snowfall for the winter of 2002-2003.

(DETAILS OF DEC 2002 FOLLOW, THEN COMES A SUMMARY OF 2002)

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            DECEMBER 2002 ST CLOUD STATISTICS

TEMPERATURE(°F)                  DEC 2002       NORMAL

Average high                      31.8           23.2

Average low                       14.6            5.5

Monthly average                   23.2           14.4

Warmest high                    51 on the 14th 

Coldest high                    18 on the 4th 

Mildest low                     32 on the 18th (set record; see below)

Coldest low                     -1 on the 3rd

Daily temperature records set:              

Record warm mean temp:          33 on the 28th (old record: 32 in 1999)          

Record warm lows:               32 on the 18th (old record: 30 in 1957,1993)

MELTED PRECIPITATION (in)       DEC 2002       NORMAL

Total melted precip                .22            .83

Most in 24 hours                   .12 on the 18th

SNOWFALL (in)

Total snowfall                     1.7            9.2

Most in 24 hours                   0.5 on the 20th

Seasonal (2001-2002)               8.5           16.3

             SEASONAL ST. CLOUD SNOWFALL(IN)

            OCT  NOV  DEC  JAN  FEB  MAR  APR  MAY  TOTAL

2001-2002   0.5 11.8  2.8  3.5 10.3 19.8 15.3  0.0   64.0

2002-2003   6.4  0.4  1.7                             8.5

NORMAL      0.5  6.8  8.9 10.1  7.0  9.8  2.3  0.1   45.5

            ANNUAL 2002 ST CLOUD STATISTICS

TEMPERATURE (F)                   2002          NORMAL

Average high                      53.0           52.7

Average low                       33.5           30.4

Annual average                    43.3           41.5

Warmest high                     95 on June 30; July 6

Coldest high                      3 on March 3 

Mildest low                      75 on June 3

Coldest low                      -9 on Jan 18; March 1,3

Days with highs of 90 or higher    8             12

Days with highs of 32 or lower    80             86

Days with highs of 0 or lower      0              3.3

Days with lows of 75 or higher     1              0.5

Days with lows of 70 or higher     6              3.1

Days with lows of 32 or lower    187            170

Days with lows of 0 or colder     16             43

Days with lows of –20 or colder    0             5.4

MELTED PRECIPITATION (in)          2002         NORMAL

Total melted precipitation        35.16*         27.43

Most in 24 hours                   4.39 on Sept 5-6 (5th highest 24 hour rainfall

                                                     total in Saint Cloud history)

Most in calendar day               2.74 on Aug 3 

Days with at least  .01 in         121            96.8

Days with at least  .10 in          59

Days with at least  .50 in          22            16.7

Days with at least 1.00 in           8             5.6

*9th wettest year in Saint Cloud history

SNOWFALL (in)                     2002          NORMAL

Total snowfall                    57.4           45.5

Most in 24 hours                  10.4 on March 14 

Days with at least 0.1 in          30            

Days with at least 1.0 in          13            14.4

Days with at least 3.0 in           7            

Days with at least 6.0 in           1             

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