MUWIC Newsletter - July 2005

(Issued: July 5, 2005)

Millersville University Weather Information Center (MUWIC)

Eric J. Horst, Director

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LEAD STORY: “Weather Pattern Turns Dry…for Now”

After two wetter-than-normal years, late spring into early summer 2005 has shifted decidedly drier-than-normal across much of the Northeast. Persistent northwest wind flow in May produced below normal temperatures and only about one-third of normal precipitation. While June turned dramatically warmer, precipitation remained somewhat scant with only isolated showers and no widespread soaking rain events.

Consequently, soil conditions are drying out and crops will soon begin to suffer given a continuation of the current pattern. Fortunately, increasing tropical cyclone activity may increase rainfall in the coming weeks. More important, frequent rainfall over the last two-plus years has elevated most water resources above long-term average levels—reservoirs, wells, streams, and ground water levels remain in good shape. Therefore, a bonafide drought is not imminent, despite the drying soil and increasingly brown lawns.

2005 Rainfall (MUWIC)

January - 3.76”

February - 2.11”

March - 3.01”

April - 3.76”

May - 1.14”

June - 2.96”

Year-to-date - 16.74

DFN - -3.09

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EVENT OF THE MONTH

On June 6^th, severe thunderstorms crossed the county producing heavy downpours, gusty winds, hail, and even some isolated flash flooding. Rainfall reports of one to three inches were common, with 4.15 inches being measured at the Lancaster airport.

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JUNE CLIMATOLOGY (MU Weather Center)

Average High Temp: 84.3 F

Average Low Temp: 64.4 F

Average Monthly Temp: 74.3 F

(Departure from Normal: +4.0 F)

Precipitation: 2.96 inches

(Departure from Normal: -0.92)

Annual Precipitation: 16.74 inches

(Departure from Normal: -3.09)

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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.

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JULY OUTLOOK

July is climatologically the warmest month with an average high temperature of 86 degrees and a long-term average of ten days that warm into 90s. This year, I do not see us exceeding these values, and I do not expect any extended periods of extreme heat (five or more consecutive days above 90 degrees). Instead, I believe the hottest weather will remain over the Plains region and only occasionally pulse eastward. Therefore, warm spells will likely occur two or three days at a time, punctuated with a cold front passage and a round of storms. In the end, temperatures for the month should average within a degree or two of normal.

The tough forecast relates to precipitation. A recent increase in tropical cyclone activity is a positive sign for farmers (and anyone else who likes rain) across the eastern third of the country. It looks likely that two or three tropical systems will make landfall along the Gulf or East coasts this month, so there’s a good chance of a soaking rain storm or two here--something we did not receive in either May or June. Furthermore, scattered thunderstorms are possible every few days as a weak jet stream trough persists across southeastern Canada and sends a few cold fronts our way. Given the above factors, I expect that total rainfall for July will be in the range of three and six inches.