Blast of cold air with unusually low pressure

Last week was chilly with light snow about every other day; culminating in a low of -1°F on Friday (25 Jan). Temperatures moderated over the next couple of days, and then steadily warmed from Monday until 20:25 Tuesday evening (29 Jan).

At that point, with the temperature at its high of the day of 52.8°F, the barometric pressure bottomed out at 28.95", the wind picked up, and an intense downpour moved through. By 21:00, we had nearly 0.2" rain, the winds were gusting to nearly 25mph, and the temperature had dropped to 46°F. For the next hour, light rain was blown about by gusty 20-25mph winds, and the temperature continued dropping to 35°F at 22:00. The rain ended, replaced with occasional light snow blown around by winds gusting up to 30mph for the next couple of hours as the temperature continued to fall, reaching 14.4°F at midnight.

The winds howled all night, with a maximum gust of 32mph, as the temperature continued drifting lower, bottoming out at 6.1°F by 07:30 this morning (30 Jan).

The temperature dropped 38.4°F in 3½ hours, or nearly 1 degree every 5½ minutes. The pressure reading of 28.95" was the lowest I've recorded here in Fort Wayne (data collection began in Dec 2005), smashing the previous low of 29.10".

The NWS had previously issued a Winter Storm Watch for our area for last night; but late yesterday afternoon canceled it. The snow line, as seen on the natural color MODIS image shown here, was fairly sharp, and stayed about 40 miles to the west and then north of us.

The NWS is making big promises for Thursday night into Friday morning:

NATIONAL WEATHER SERVICE NORTHERN INDIANA
413 PM EST WED JAN 30 2008

…SIGNIFICANT WINTER STORM POSSIBLE THURSDAY NIGHT INTO FRIDAY…

ANOTHER WINTER STORM WILL TAKE SHAPE OVER OKLAHOMA ON THURSDAY AND TRACK INTO THE OHIO VALLEY BY FRIDAY MORNING. A SWATH OF MODERATE TO HEAVY SNOW IS EXPECTED TO AFFECT MUCH OF THE FORECAST AREA…WITH SNOW DEVELOPING THURSDAY EVENING AND INCREASING IN INTENSITY THURSDAY NIGHT INTO FRIDAY MORNING. WHILE THE EXACT LOCATION OF THE HEAVIEST SNOWFALL REMAINS IN QUESTION…6 TO 10 INCHES OF SNOW IS POSSIBLE ACROSS THE WATCH AREA ALONG WITH BLOWING AND DRIFTING SNOW. LISTEN TO NOAA WEATHER RADIO OR YOUR LOCAL MEDIA FOR THE LATER UPDATES ON THIS SITUATION.

…WINTER STORM WATCH REMAINS IN EFFECT FROM THURSDAY EVENING THROUGH FRIDAY EVENING…

ANOTHER WINTER STORM WILL AFFECT THE AREA THURSDAY NIGHT AND FRIDAY WITH SIGNIFICANT SNOW ACCUMULATIONS POSSIBLE. THERE WILL BE THE POTENTIAL FOR HEAVY SNOW ACCUMULATIONS OF 6 TO 10 INCHES… AS WELL AS STRONG GUSTY WINDS CREATING BLOWING AND DRIFTING SNOW.

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awc 2008-01-30 16:24:35