(more data and related information from NWS Birmingham)
Does a Warm March Mean a Hot Summer?
...MARCH WARMTH, AND WHAT IT MEANS FOR THE REST OF THE SUMMER...
AN EARLY SPRING SEASON STRONG WESTWARD EXTENSION OF THE BERMUDA HIGH
PRESSURE RIDGE, COMBINED WITH LOW PRESSURE WHICH DEVELOPED OVER THE
DISTANT SOUTHWESTERN UNITED STATES, SET UP AN ATMOSPHERE OF
PREVAILING MOSTLY CLEAR SKIES OVER THE HEART OF DIXIE BY THE
MID-MONTH OF MARCH 2012. SEVERAL SUBSEQUENT RECORD BREAKING OR NEAR
RECORD BREAKING (MATCH TO PREVIOUS OCCURRENCE) TEMPERATURES WERE
REACHED AT BIRMINGHAM AND MONTGOMERY BY MID-MARCH 2012.
IN CONJUNCTION WITH THE EARLY SEASON HIGH PRESSURE WESTWARD EXTENSION
WAS THE OCCURRENCE OF A CUT-OFF LOW PRESSURE OVER THE FOUR CORNERS.
HAD THIS CUT-OFF LOW NOT OCCURRED, THERE LIKELY WOULD NOT HAVE BEEN
ANY REMARKABLE RECORDS SET. HOWEVER, THE POLAR JET STREAM STEERING
HAD REALIGNED ACROSS THE NORTHERN STATES LEAVING THE LOW PRESSURE
STAGNANT FOR DAYS OVER THE DESERT SOUTHWEST, AND PERSISTENT
SOUTHERLY FLOW PREVAILED WEST OF THE MISSISSIPPI.
THE RECORDS SHOW TEMPERATURES AT BOTH BIRMINGHAM AND MONTGOMERY HAVE
REACHED 89 AND 90 DEGREES DURING THE MONTH OF MARCH ON NUMEROUS
OCCASIONS IN THE PAST. THIS WAS NOT THE CASE THIS YEAR. THESE ARE
THE NEWEST RECORDS REACHED (SO FAR) DURING THE MONTH OF MARCH 2012.
THROUGH MARCH 24 OF THIS YEAR, THE AVERAGE TEMPERATURES AT BIRMINGHAM
AND MONTGOMERY WERE 64.8 AND 66.0 DEGREES, RESPECTIVELY. THIS IS THE
SECOND WARMEST SUCH START TO THE MONTH OF MARCH AT BIRMINGHAM, AND
THIRD WARMEST AT MONTGOMERY, BASED ON RECORDS AT BOTH CITIES THAT GO
BACK AT LEAST 110 YEARS. DOES THE WARM LATE WINTER AND EARLY SPRING
PORTEND A SUMMER OF SIMILAR RECORD-SETTING WARMTH? JUDGING FROM PAST
WEATHER RECORDS AT BIRMINGHAM AND MONTGOMERY, NOT NECESSARILY SO.
HERE ARE THE 10 YEARS WITH THE WARMEST MARCHES AT BOTH BIRMINGHAM AND
MONTGOMERY, WITH A COMPARISON OF TEMPERATURES IN JUNE, JULY, AND
AUGUST OF THOSE SAME YEARS:
IN BIRMINGHAM, 7 OF THE 10 YEARS WITH THE WARMEST MARCHES WERE
FOLLOWED BY A SUMMER (JUNE, JULY AND AUGUST) WITH TEMPERATURES NEAR
OR BELOW NORMAL. ONLY 2 OF THE 10 YEARS HAD SUBSEQUENT SUMMERS THAT
RANKED IN THE TOP 20 WARMEST (2007 RANKED 4TH, AND 1921 RANKED 11TH).
IN MONTGOMERY, 7 OF THE 10 YEARS WITH THE WARMEST MARCHES WERE
FOLLOWED BY A SUMMER (JUNE, JULY AND AUGUST) WITH TEMPERATURES NEAR
OR BELOW NORMAL. NONE OF THE 10 YEARS HAD SUBSEQUENT SUMMERS THAT
RANKED IN THE TOP 20 WARMEST -- IN FACT, THREE OF THE YEARS (1910,
1946, AND 1997) WERE RANKED AMONG THE "COOLEST" SUMMERS.
THUS, THE ONLY CONCLUSION ONE CAN MAKE IS THAT HAVING WARM
TEMPERATURES IN THE MONTH OF MARCH HAS NO PREDICTIVE VALUE FOR HOW
HOT THE FOLLOWING SUMMER WILL BE.