MUWIC Newsletter - July 2003

(Issued: July 3, 2003)

Millersville University Weather Information Center (MUWIC)

Eric J. Horst, Director

************************************************************************

LEAD STORY: “Rainfall Keeping Pace”

After three consecutive years of below normal rainfall, the Lancaster area is finally receiving the rainfall needed to remain the Garden Spot of America. In fact, copious showers in recent weeks have equally frustrated farmers and outdoor enthusiasts as fifteen out of the last thirty days featured measurable rainfall. Not since September of 2000 has so much rain fallen over a 30-day period.

Year-to-date, nearly 20 inches of precipitation (rain and melted snow) has been recorded at the Millersville University Weather Center. Less than 15 inches fell during the same period last year, and only 12 inches of precipitation occurred during the first half of 2001.

With the warmest month of the year now upon us, high evaporation rates will certainly lower the amount of surface moisture and result in some browning of lawns and slower crop growth. Given the abundant rainfall this year, however, there’s little risk of slipping into a late-summer drought.

Rainfall Statistics (MU Weather Center):

Normal 2002 2003

January 3.01 2.38 1.81

February 2.47 0.27 4.65

March 3.09 3.38 2.91

April 3.47 1.79 2.12

May 3.62 3.51 3.01

June 3.88 3.63 5.35

Total 19.83 14.71 19.85

************************************************************************

EVENT OF THE MONTH

Heavy rainfall on June 20^th produced flooding in parts of Lancaster County. Two to four inches of rain fell across eastern sections and drained into the main branch of the Conestoga. Sadly, a flood-related fatality was reported in West Earl Township as numerous roads became flooding near Hunsicker and Talmage.

************************************************************************

JUNE CLIMATOLOGY (MU Weather Center)

Average High Temp: 77.5 F

Average Low Temp: 60.0F

Average Monthly Temp: 68.8 F

(Departure from Normal: -1.6 F)

Precipitation: 5.35 inches

(Departure from Normal: +1.47)

Annual Precipitation: 19.85 inches

(Departure from Normal: +0.02)

************************************************************************

JULY NORMALS, RECORDS & FACTS

Climatologically the warmest month of the year, daily average temperatures peak on July

18th and 19th with a normal high/low of 88/63. The record high for July is 104 degrees set on three different occasions (July 3, 1966, July 10, 1936, and July 21, 1930) and the

record low is 42 set on Independence Day in 1918. Normal precipitation for the month is

4.51 inches. The rainiest July on record occurred in 1941 when 9.48 inches fell. The

driest July was in 1955 when only 0.60 inches fell.

************************************************************************

JULY OUTLOOK

After a chilly first three weeks, June finally yielded some significant heat with three consecutive days in the 90s. Early July will feature another bout of hot, humid conditions as temperatures warm into the low 90s over the July 4^th weekend.

An unusually active jet stream, however, promises to keep the warm spells brief as frequent cold fronts will drop into the area from the northwest. Such northwest flow this time of year is famous for producing showers and gusty thunderstorms. I expect we’ll have a chance of showers every few days, yet not the persistent showers of last month.

Should the pattern described above last for most of the month it would yield near normal temperatures and precipitation, in aggregate. Week-to-week, you might expect a couple of 90-degree days to occur ahead of approaching cold fronts, while a shift to less humid, more pleasant weather in the days following the front. In the end, it may be that July will not feature any extended heatwaves (5 or more consecutive days above 90 degrees).