September Brings a Bumpy Ride to Temperatures
by KDLT Weather
August 31, 2011 8:56 PM
With Summer beginning to wind down we begin to look down the road into Fall to see what kind of weather we may have to endure. Unfortunately, we never really know for sure even though the long range forecasts are showing a pretty typical and maybe even somewhat dry looking Fall. But one thing we can be sure of is the slope of temperatures facing downward and that we are in for some pretty drastic temperature swings. Going from 95° one day to 60° the next can take a pretty big toll on not only your spirits but your immune system as well. But the wide variety in temperatures are pretty common September through November and Kelly Smith explains why in the video on your left as well as in the story below.
"THE JET STREAM, WHICH SEPARATES A COOL AIR MASS FROM A WARM AIR MASS RETREATS NORTH DURING THE SUMMER MONTHS.
BY SEPTEMBER, SHORTER DAYS ALLOW TEMPERATURES TO START COOLING AT A FASTER RATE IN THE NORTH THEN THE SOUTH.
THIS LEADS TO BUCKLING OF THE JET STREAM WHEN COOLER AIR SURGES SOUTH AND COLLIDES WITH WARMER AIR THATS ALREADY PRESENT.
THESE EVENTS ARE RESPONSIBLE FOR OUR WILD TEMPERATURE SWINGS THAT START THIS TIME OF THE YEAR.
THE COLD FRONT EXPECTED TO MOVE THROUGH THE AREA BY WEEKS END WILL BE THE FIRST OF MANY GIANT DIPS IN THE JET STREAM OVER THE FALL.
IN FACT, THE FIRST WINTER WEATHER ADVISORIES IN THE CONTINENTAL U.S. WERE JUST POSTED FOR GLACIER NATIONAL PARK IN MONTANA WEDNESDAY.
BUT DONT FREAK OUT JUST YET BECAUSE WE ARE STILL MORE THEN 3 WEEKS AWAY FROM OUR AVERAGE FIRST FREEZE WHICH GENERALLY OCCURS AT THE END OF SEPTEMBER.
NOT TO MENTION THAT OUR AVERAGE FIRST SNOWFALL IS MORE THEN 2 MONTHS AWAY IN NOVEMBER ANDTHE EARLIEST SNOWFALL EVER WAS NOT UNTIL THE END OF SEPTEMBER AND THAT WAS OVER EIGHT YEARS AGO.
ALTHOUGH LABOR DAY IS THE UNOFFICIAL END OF SUMMER THERE IS STILL PLENTY OF TIME BEFORE THE FIRST SNOWFLAKE FALLS BUT UNTIL THEN I HOPE YOU ENJOY THE WILD RIDE."
Well it looks like the end of the week and the weekend are going to be our first wild swing for the fall season. Check out the mid level temperatures (850 mb) on Thursday in the first picture and then look at the same level but on Sunday and see if you notice a big difference.
Pretty huge difference!! Now it does look like the largest single day temperature swings will be from Thursday to Friday where highs will go from the 80's and 90's to the 70's, but a slow drop from there could have a lot of us struggling just to get to the upper 60's by Sunday.