FROM: Bob Weisman, Earth Sciences
DATE: 3 May 1999
SUBJECT: A wet start, a dry finish
St. Cloud April 1999 Weather Summary
After only having 7 days combined in February and March with measurable
precipitation, the trend quickly changed during April according to statistics
compiled at the St. Cloud Regional Airport. The first 15 days of the month
produced 2.22 inches of mostly rainfall, almost the normal precipitation
for the entire month. However, things dried out considerably after that.
Only 0.07 inch fell during the second half of April and none in the 10 days,
so April 1999 actually ended up slightly below normal in precipitation. This
brings the annual precipitation to 4.14 inches, an inch below normal.
The reason for the change? During the first half of the month,
a large number of low pressure systems which hit the Southwestern US were
pulled northeastward by the jet streams. Since these storms begin closer
to the Gulf of Mexico, they tend to carry a lot of moisture with them.
During the second half of the month, there were still a lot of Southwestern
US low pressure systems (remember the golf tournament which was snowed out
in Phoenix and many Colorado Rockies games were postponed?), but the jet
stream shifted to a little more of a west-east orientation. Therefore, these
moist systems tended to go further south, so the northern edge of the
precipitation shield tended to be located along the Minnesota/Iowa border
or further southward.
April temperatures averaged more than two degrees above normal. The
first half of the month produced cool high temperatures (avg high
of 53.2 degrees with 5 days with a high only in the 40's), but mild low
temperatures due to the frequent cloudiness and rainfall). During the
second half of the month, conditions dried out and high temperatures
rose (avg high of 60 deg and no high colder than 50 degrees during the
last 13 days).
We did pick up 0.8 inch of snow on the 5th, bringing the seasonal
snowfall total to 36.4 inches. If this becomes the final 1998-99 amount,
it will below the lowest snowfall total in 9 years (we had 32.5 inches
in 1989-90). Since St. Cloud has not received a measurable May snowfall
since 1979, I can look at this two ways: 1) No snow in May for the past
19 years, so this favors the end of the snow season. 2) This is the
longest streak without measurable May snowfall St. Cloud has on record
so are we due?
MONTHLY STATISTICS APR 1999 NORMAL
TEMPERATURE (DEG F)
Average high temp 56.6 55.0
Average low temp 34.9 32.0
Overall average 45.8 43.5
Warmest high temperature 77 on the 30th
Coolest high temperature 40 on the 3rd
Mildest low temperature 47 on the 27th
Coldest low temperature 25 on the 18th
Records set: none
PRECIPITATION
Total melted precip (in) 2.29 2.36
Most in 24 hours .68 on the 7th
SNOWFALL (in) 0.8 2.7
Most in 24 hours 0.8 on the 5th
Seasonal snowfall (Oct-Apr) 36.4 45.6
=============================================================================
Bob Weisman, Meteorology Professor SUPERVISOR: Shirley (age 7)
Earth Sciences Department PHONE: (320) 255-3247 (V)
MS 48 (800) 627-3529 (TTY via
Saint Cloud State University Minnesota Relay Service)
720 4th Avenue South FAX: (320) 255-4262
Saint Cloud, Minnesota 56301-4498 EMAIL: scsweisman@tigger.
stcloudstate.edu
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