The abundant rain that began falling on March 28 (the day The Sun ran my story on the state's deepening drought) is beginning to have an impact on groundwater supplies across the state, according to the U.S. Geological Survey.

USGS hydrologist Wendy McPherson reports today that water levels in monitoring wells and streams tracked by the agency are rising nicely. Many groundwater wells are now near normal levels for this time of year, and seem likely to continue rising.

That's the streamflow map at left. Dark blue indicates streams flowing at 90 percent of record levels for the date. Black indicates record flows. 

Wells that typically respond more slowly to rain events are behind the pace in their recovery, McPherson says. She cites a monitoring well in Baltimore County that has risen only a half-inch in the past week. It remains two feet below the level considered normal for this time of year.

"Fresh water is our most valuable resources because it is needed for all life on Earth to survive. The supply is not unlimited and we need to give water the respect it deserves and use it wisely, even when it is raining," she said.

April has so far produced 5.65 inches of rain at Baltimore-Washington International Thurgood Marshall Airport. That makes it the wettest April for Baltimore in 27 years, still short of the 6.55 inches that fell during the next-wettest April, in 1983. The long-term average for April is 3 inches, Baltimore's driest month.

Ten of the 15 wettest Aprils since 1871 occurred before 1950:

1889:  8.70 inches

1952:  8.15 inches

1937:  7.92 inches

1910:  7.76 inches

1933: 7.58 inches

1895:  7.42 inches

1940:  6.99 inches

1918:  6.79 inches

1929:  6.73 inches

1874:  6.65 inches

1983:  6.55 inches 

1973:  6.41 inches

1928:  6.26 inches

1924:  5.89 inches

2009*:  5.65 inches

* Through April 21

That said, the rain is expected to continue today and this evening in the form of scattered showers and perhaps a stray thunderstorm or two late today - much like last night's window-rattler.

We're also looking at a couple of cold nights as temperatures drop toward 40, and maybe into the 30s in some spots.

But the big picture is bright. These cold, rainy disturbances being dragged out of the northwest by the northern jet stream are on their way out with the jet itself. High pressure is on tap, with sunny skies Thursday and right through the weekend. As winds around the high shift to the south and southwest, daytime highs will start to rise, reaching the 60s on Thursday, the 70s on Friday and the 80s through the weekend and on into next week.

Break out the shorts!