The period December 24, 2005 to January 4th, 2006 is the 3rd gloomiest 12 day stretch in the Twin Cities in 42 years according to solar radiation records at the University of Minnesota St. Paul Campus. Incoming solar radiation records begin at the U of M St. Paul Campus Climate Observatory in 1963. The only other spells of cloudiness that beat this stretch are: October 30 to November 10, 1972 coming in first place, and December 28, 1991 to January 8, 1992 in second place.
The other site with a measure of sunshine in the Twin Cities is a device that records minutes of sunshine at the National Weather Service in Chanhassen. Zero minutes of sunshine were recorded at Chanhassen for eight consecutive days from December 24 to December 31, 2005. The sun made an appearance on January 1, 2006 at Chanhassen thus ending the streak.
The culprit for this stretch of clouds and fog has been an abundance of moisture in the lower levels of the atmosphere and lack of any strong area of arctic high pressure to sweep the moisture and clouds away. The mild air has been a disappointment to snow lovers with the erosion of the snow pack. On the plus side, the warmth is undoubtedly helping out heating bills. Mean temperatures for the past few days have been right around freezing, which is more typical for mid-November.
The longest record of consecutive days with zero minutes of sunshine is fifteen days from October 30, 1972 to November 13, 1972. The 1972 streak is remarkable that on November 14 there was less than an hour of sunshine, then two more days of zero minutes of sunshine! The sunshine recorder was at the Twin Cities International Airport before June 1996 and moved to Chanhassen after that.
In 1991-1992 the skies were cloudy in the Twin Cities for fourteen days in a row from December 26, 1991 to January 8, 1992. The days were marked with clouds obscuring the tops of the skyscrapers in downtown Minneapolis, drizzle and of course, copious amounts of fog. The temperature for those fourteen days ranged between 27 and 37 degrees at the Twin Cities Airport, which is very unusual for winter. Back during that streak, the chairman of Fingerhut hired a plane to take their employees on a trip above the clouds to find the sun. An odd feature during this event was an "ice fog" that would freeze and thaw on power lines, shorting them out in west central Minnesota.
Since 1906, there have been two other long stretches of general cloud cover: Oct. 31 to Nov. 15, 1922 and a comparable stretch from Nov. 15 to 28, 1944. But those times were marked by at least a partial break in the clouds. A more recent consecutive cloudy streak in the Twin Cities was eight days from November 6th to November 13, 2000.
The gloom is being felt in other areas as well. University of Minnesota climatologist and meteorologist Mark Seeley in the January 6, 2006 edition of "Weather Talk" describes conditions in the Twin Cities and other places in the region.
Topic: Gloomy weather continues in Minnesota.... The National Weather Service Forecast Office in Chanhassen reports that for the period from December 24, 2005 to January 4, 2006 the percent possible sunshine was only 2 percent. On eleven days it was virtually zero while on New Year's Day it was reported to be 26 percent. Over the same 12 day period, the Weather Service in Duluth reported only 3 percent possible sunshine, while their office in Sioux Falls, SD reported nearly 10 percent possible sunshine over the same period. Average values for this time of year are 45 to 55 percent possible sunshine, so these are indeed significant negative departures. The 12 day spell of gloomy weather, with a virtual absence of any direct sunshine (Dec 24, 2005 to Jan 4, 2006) in the Twin Cities has few analogies. Only winter of 1972 and 1992 show similar prolonged periods of gloominess according to solar radiation measurements on the St Paul Campus. On the other hand temperatures during this spell have been quite mild, averaging 15 to 20 degrees F above normal at the MSP airport. La Crosse has not dipped below the 30 degrees F mark since December 24th, a remarkable run of warmth for them. Such dramatic temperature departures this time of year are equivalent to having a run of 100 degrees F or higher for 12 days in July.
Below is a statement from the National Weather Service in Duluth with more information on the cloudiness.
PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE DULUTH MN 1000 AM CST FRI JAN 6 2006 HOW LONG HAVE THESE CLOUDS BEEN AROUND? EXCEPT FOR A FEW HOURS OF SUNSHINE ON THE 25TH OF DECEMBER IN DULUTH...THE NORTHLAND HAS BEEN CLOUDY SINCE DECEMBER 23RD. FOR THE MONTH OF DECEMBER 2005...THE NATIONAL WEATHER SERVICE IN DULUTH RECEIVED ONLY 29% OF THE TOTAL POSSIBLE SUNSHINE...WHICH MAKES IT THE 4TH CLOUDIEST DECEMBER IN THE PAST SIXTEEN YEARS. THE NORMAL* AMOUNT OF POSSIBLE SUNSHINE FOR DECEMBER IS 40%. (ONE HUNDRED PERCENT CORRESPONDS TO THE LENGTH OF THE SOLAR DAY...FROM SUNRISE TO SUNSET.) SO...WHY IS THE NORTHLAND SO CLOUDY? THE CULPRIT IS THE CONTINUED WARM AND MOIST AIR MASS IN PLACE. THE WARM AIR ABOVE THE SURFACE TRAPS MOISTURE NEAR THE SURFACE AND RESULTS IN WIDESPREAD LOW CLOUDS. THE SECOND HALF OF DECEMBER WAS MUCH WARMER THAN NORMAL ACROSS THE NORTHLAND...WHICH AIDED THE PERSISTENT CLOUD COVER. IT WILL LIKELY TAKE A COLD ARCTIC AIR MASS TO SCOUR OUT THESE LOW CLOUDS...AND WITH CONTINUED MILD TEMPERATURES FORECASTED AT LEAST THROUGH THE WEEKEND...AN END TO THE CLOUDS REMAINS OUT OF SIGHT. HOW DOES THIS CLOUDY STRETCH COMPARE TO OTHERS? IN THE PAST SIXTEEN YEARS...THE LONGEST STRETCH OF CLOUDY DAYS RECORDED AT THE DULUTH NATIONAL WEATHER SERVICE WAS 12 DAYS...FROM OCTOBER 25TH TO NOVEMBER 5TH OF 2003. AS OF JANUARY 6TH, 2006...CLOUDY CONDITIONS HAVE PERSISTED FOR 12 DAYS IN A ROW AT THE NATIONAL WEATHER SERVICE IN DULUTH. A SMALL AREA OF CLOUDS ERODED ALONG THE HEAD OF LAKE SUPERIOR ON CHRISTMAS DAY DURING THE AFTERNOON WHICH ALLOWED FOR A FEW HOURS OF SUNSHINE. OTHERWISE...THE CLOUDY STREAK WOULD BE 14 DAYS (SINCE THE 23RD OF DECEMBER). THE FOLLOWING IS A LIST OF CLOUDY STREAKS OF A WEEK OR LONGER SINCE 1990 AT THE DULUTH NWS. THE ALL-TIME RECORD IS UNKNOWN. 1. 12 DAYS DECEMBER 26TH - AT LEAST JANUARY 6TH 2005-2006 1. 12 DAYS OCTOBER 25TH - NOVEMBER 5TH 2002 3. 11 DAYS NOVEMBER 22ND - DECEMBER 2ND 2001 3. 11 DAYS NOVEMBER 5TH - NOVEMBER 15TH 2000 3. 11 DAYS DECEMBER 13TH - DECEMBER 23RD 1993 3. 11 DAYS NOVEMBER 16TH - NOVEMBER 26TH 1992 7. 9 DAYS DECEMBER 26TH - JANUARY 3RD 1991-1992 8. 8 DAYS DECEMBER 15TH - DECEMBER 22ND 2002 8. 8 DAYS NOVEMBER 28TH - DECEMBER 5TH 1993 8. 8 DAYS APRIL 18TH - APRIL 25TH 1992 8. 8 DAYS MARCH 1ST - MARCH 8TH 1992 12. 7 DAYS DECEMBER 6TH - DECEMBER 12TH 2004 12. 7 DAYS JANUARY 18TH - JANUARY 24TH 1999 12. 7 DAYS JANUARY 4TH - JANUARY 10TH 1998 12. 7 DAYS OCTOBER 30TH - NOVEMBER 5TH 1997 THE FOLLOWING IS A LIST OF THE PERCENTAGE OF TOTAL POSSIBLE SUNSHINE RECEIVED IN THE MONTH OF DECEMBER FOR THE PAST SIXTEEN YEARS. 1990 50.0% 1991 41.0% 1992 31.0% 1993 26.0% 1994 45.0% 1995 37.0% 1996 28.0% 1997 43.0% 1998 67.0% 1999 32.0% 2000 39.1% 2001 22.1% 2002 36.0% 2003 41.0% 2004 34.0% 2005 29.0% NORMAL* 40.0% *THE NORMAL IS THE 30 YEAR AVERAGE FROM 1971 TO 2000