Published: April 25, 2008 08:13 am         

Weather watch

By MARK HANOK

It looks like the extremely dry weather pattern will continue with a slight cooling trend In last week’s weather column, I predicted that the extremely dry weather pattern would go on and on with no end in sight. I explained how an upside-down temperature pattern is one of the very best key indicators for sunny, exceptionally dry weather in Otsego County.

From Sunday afternoon, April 13, through Wednesday afternoon, April 23, there wasn’t so much as a trace of precipitation in our area, and temperatures have averaged 15 to 20 degrees above normal. This will be one of the warmest April on record.

April is actually the most likely month of the year for “reverse temperature anomalies,” and that’s because of the Atlantic Ocean. Since the ocean temperature is still very cool in April, places from the Virginia coast to Long Island, New York City, the lower Hudson Valley and southern New England, can be much cooler than central and northern New York whenever the wind is out of a southerly, southeasterly, or easterly direction. When low pressure is cut off from the jet stream, it can become stationary offshore, and this will enhance an east to southeast flow, bringing cooler air to the south while there’s much more sunshine and much warmer air to the north. That’s exactly what occurred this week, and since the upside-down temperature pattern has continued for so long, it will be difficult to break the cycle and get much rain.

Although a cooling trend is on the way for the upcoming week, temperatures will only get back to normal or a few degrees above normal by early next week.

On Friday, a major storm system will track eastward to the upper Midwest, and bring showers and thunderstorms eastward to the Ohio Valley and wet snow north to the northern Great Plains.

We’ll get a southwesterly flow ahead of the low, so temperatures will again be 15 to 20 degrees above normal, with bright sunshine and highs in the mid-70s. The showers associated with a cold front will try to get here on Saturday, but the front will weaken and a blocking high to the east will continue the dry weather along the East Coast. Skies will be partly sunny with highs in the low 70s.

We may get a few showers Saturday night and early Sunday morning, but skies will be partly sunny on Sunday with a cooler northwesterly flow; highs in the low 60’s will seem cool, but actually that’s about five degrees above normal for late April. We’ll get another opportunity for showers on Monday, although skies will be partly sunny with only the chance of a shower, and highs around 60 degrees.

Temperatures will finally get closer to normal on Tuesday, and after the chance of showers in the morning, skies will be partly sunny, with highs from 52 to 57 degrees. On Thursday, a large storm in the middle of the Atlantic Ocean blocked a large high that extended from Maine to the Florida Panhandle. The atmosphere went wild again, with practically unheard of relative humidity levels again in the Southern Tier and Western Catskills, between 10 and 15 percent.

A cold front in the upper Midwest moved very slowly eastward, blocked by the high. Severe thunderstorms developed from Iowa and Missouri to north Texas. A summer-like high pressure area along the East Coast moved very slowly eastward on Friday, as a storm system developed over the center of the nation. A southwesterly flow in between these weather systems, and unlimited sunshine, sent the mercury soaring to 83 degrees at New York City, 81 degrees at Elmira, and 80 degrees at Albany. The high was 77 degrees at our weather station in Otego.

Ahead of a cold front, severe thunderstorms developed across the Deep South. With a northwesterly flow of cooler air wrapping around the low, the high was only 61 degrees at Little Rock, Ark. and 65 degrees at Memphis. At the same time, highs were in the low 70s in North Dakota. When it’s ten degrees warmer in North Dakota and 16 degrees warmer in Elmira than in Memphis, an already extremely dry, sunny weather pattern will be reinforced in central and eastern New York. For this reason, it was a certainty that all the local forecasts calling for cloudy skies Sunday and Monday would be completely wrong. The upside-down temperature pattern was so extreme on Saturday that Syracuse, where the high was 87 degrees, ended up with the highest temperature anywhere in the nation except for Arizona and Texas. That kind of “reverse temperature anomaly” reinforces extraordinary dryness in the Cooperstown area, where blazing sunshine continued, and the high was 84 degrees at our weather station in Otego. Low pressure tracked eastward to near Chicago by late afternoon, and its associated cold front extended southward to the Florida Panhandle. On Sunday, the high was 82 degrees at Watertown, while only 56 degrees in New York City. When a “reverse temperature anomaly” is this extreme, very dry conditions can continue for weeks in Otsego County. A storm system, completely cut off from the jet stream, sliced southeastward from the Ohio Valley to North Carolina, while high pressure backed southwestward from the Canadian Maritimes to eastern New England. This is one of the classic weather patterns for upside-down temperatures, and the more northerly locations in New York were the warmest places, while the southernmost areas were the coolest places. That’s because there was bright sunshine all day in northern New York and along Lake Ontario, while stratocumulus clouds wrapped around the cut-off low further to the south, where the wind was off the cool waters of the Atlantic Ocean. In fact, low cloudiness and a cool breeze kept temperatures in the upper 50s in New York City. Skies were partly to mostly sunny in the Cooperstown area, with highs in the low 70s.

The upside-down temperature pattern became even more extreme from central and northern New York to Virginia on Monday, as the cut-off low and its associated upper-level trough remained nearly stationary over eastern North Carolina. With moderate to heavy rain for much of the day in southeastern Virginia, and a cool easterly flow off the Atlantic Ocean, the high was only 59 degrees at Norfolk.

At the same time, with high pressure continuing to back westward to northern New England, brilliant sunshine sent the mercury soaring to 15 to 25 degrees above normal from western, central, and northern New York, to northern Vermont. The high was 78 degrees at Syracuse and 77 degrees at Burlington, Vt. It was just another day of unlimited sunshine in Otsego County, with a high of 76 degrees at our weather station in Otego, and relative humidity as low as 20 percent.

On Tuesday, Skies were brilliantly sunny all day in the Cooperstown area, with highs in the upper 70s. Mark Hanok is an Otegobased meteorologist. You can visit him on the World Wide Web at http://members. aol.com/weathergazette.