The first month of the official millennium began with many folks in far eastern Pennsylvania still digging out of the foot or more of snow that fell on December 30th. The first few days of January continued the cold pattern that Pennsylvania had been in all last month. Daily high temperatures were in the 20's and low 30's. Lake effect snows brought a few inches of snow to western PA during the 1st through the 5th.
On Friday the 5th, a small, vigorous and fast-moving low pressure system came out of the Great Lake states and gave most of the state anywhere from one to five inches of snow. High temps held close to (or below) freezing so the precipitation indeed mostly fell in crystal form.
Even though temperatures usually fall behind a storm, we saw the beginning of a small warming trend. On the 7th, temperatures broke 40 in some towns, including Pittsburgh, which was nine degrees above normal for the day, with a high of 43. But this trend was short-lived as a coastal storm slid north on Monday the 8th, giving a couple tenths of an inch of rain to most eastern parts of PA, and even a little snow north and west.
Temperatures fell in the northwesterly wind behind this storm, and decidedly so in western Pennsylvania, where Pittsburgh only saw 22 degrees and Erie only 25. The chill-down only lasted a couple days, however, and then we began our first real warm streak since the end of November. The upper level airflow pattern had finally changed, so that now the cold trough moved farther west toward the Plains states.
High temperatures warmed up toward the low 40's by the 11th and 12th. In fact, Philadelphia hit 50 on the 11th, and western PA got most of its warmth on the 13th through the 15th, when the temperature reached the mid 40's in Pittsburgh.
A storm out of the southern Plains almost got to us on the 12th, but slid south instead. But a strong low in the upper Plains sent moisture eastward to rain on us during the 14th and 15th. Rainfall totals were not too impressive though, with few locations getting more than a tenth of an inch or so.
The 16th and 17th were cloudy, but for the most part dry days. It continued quite warm in eastern PA, but western parts fell back to seasonable highs in the low to mid 30's.
An energetic frontal system became strung out from the Mid-Atlantic States down toward Texas by Thursday the 18th, and pulses of low pressure along the system would keep Pennsylvania's weather unsettled through the weekend. The storm began as some freezing rain in spots, but fell mostly as plain old rain during Friday and Saturday. Southeastern sections of the state got around an inch of rain out of the system. As the front moved offshore and temperatures fell into the low 30's, Pennsylvania received a quick burst of heavy snow associated with the upper level low on Saturday night and into Sunday the 21st. Five inches or more of the white stuff came down in a stripe across much of central and northern PA. Even Philly and Harrisburg got about three inches. This complex storm brought the bulk of January's total precipitation for much of PA.
Temperatures briefly fell a bit below average behind the storm but rebounded nicely, with highs getting toward about 40 degrees, for the 23rd and 24th, especially east. A little snow fell in northwestern PA during these days, but the next significant storm came late on the 26th and into Saturday the 27th. This was a quick-developing but not terribly strong system that brought some light rain and snow showers as it moved briskly west to east over Pennsylvania.
The 28th and 29th were quiet days with high temperatures in the 30's as our recent minor storm became a powerhouse over the North Atlantic.
Also during this time a monster of a storm was developing over the southwest. It marched northeastward into the Plains states, trailing its cold front south. The front produced damaging winds and heavy rains over the southeast, but conditions were not so severe in Pennsylvania. The actual low pressure center of the storm hung back over the upper Midwest, but its attendant fronts raced eastward, bringing our state a round of moderate to heavy rain on Tuesday the 30th, beginning as freezing rain in some sections early in the morning. Precipitation totals of around a half-inch were common.
After the front passed through, skies cleared rapidly during the afternoon. Although it was nominally a cold front, the storm system was so wrapped-up that warm air was actually surging northeastward ahead of the hanging-back low pressure center. All told, temperatures neared 50 degrees in much of southern and western PA by sundown, and Philadelphia hit 58!
That night, and into the last day of the month, some light rain fell as the residual low pressure from the occluded storm system swung through PA.
The month of January 2001 featured a welcome warm-up from December's persistent chill. However, Pennsylvania could have used some more rain, as precipitation totals were more than an inch below normal in most of the major reporting stations. If not for the storm that occurred during the weekend of the 20th, this month would have been very dry indeed. In fact, western and central PA fell under NOAA's lowest value of drought index.
-Evan Blaisdell