Update on Texas Rainfall
The following image is a “meso-analysis” of the on-going rain event over Texas and surrounding states. Note the position of the area of Low Pressure (L). Heaviest precipitation has formed in the east through northeast quadrants of the low, which is typical. The red arrows indicate vectors of moisture transport with the color-coded regions indicating pockets of deep moisture. You might note that the area of red (very high levels of moisture) is being transported directly into Southeast Texas.
Here is a summary of rainfall over the past 24-hours. While amounts are piling up in spots, generally I don’t think the coverage is quite as widespread as expected. The radar image, at least at the current time, is showing a linear alignment of rainfall tracks a bit more than a widespread precipitation shield.
While most of this rain will be welcome, there will be the possibility of flooding, especially urban and low-lying flooding.
After this system pushes north and northeast, another weaker system will arrive this weekend. By that time the front will have moved slowly east, thus heaviest precipitation this weekend will be over parts of Arkansas, Mississippi, Tennessee, and Kentucky.
Heads Up for Cold Air Push
As I mentioned in my Weekly Water Outlook, I expect the currently-positive-phased Arctic Oscillation to sharply turn negative next week. Cold air is pooling in Canada. It has been held in check by the northern branch of the jet stream but as the negative AO takes hold, it should abruptly sag south. While there can be a bit of a lag between changes in phase in the AO, I expect a significant cold snap over the majority of the nation—especially central sections—starting next week and continuing at least through the third week of January.
2012- Warmest Year on Record
It’s official. According to the latest statistics from NOAA’s National Climatic Data Center, the average temperature for the contiguous United States for 2012 was 55.3° Fahrenheit, which was 3.2° Fahrenheit above the twentieth-century average and 1.0° Fahrenheit above the previous record from 1998. The year consisted of the fourth-warmest winter, a record-warm spring, the second-warmest summer, and a warmer-than-average autumn.
The map below shows where the 2012 temperatures were different from the 1981–2010 average. Shades of red indicate temperatures up to 8° Fahrenheit warmer than average, and shades of blue indicate temperatures up to 8° Fahrenheit cooler than average—the darker the color, the larger the difference from average temperature. (source: NOAA)
Lack of Chicago Snow
Chicago’s lack of snowfall is set to tie a record set in 1940.
Three hundred and nineteen days have passed without an inch of snow falling in Chicago, according to the Chicago Tribune.