Last Ten Days of October Bring Gusty Winds, Roller Coaster Temperatures

October 22nd to 31st:  Dry and windy conditions prevailed over the past week as a northwest flow regime brought several dry cold fronts across the region.  Temperatures were on a roller coaster with alternate warming and cooling ahead of and behind each front.

 

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At 6:16 PM, Sunday, October 29th: Looking west from Clinton Lake just before sunset.  Some alto-cumulous precipitate some of what little moisture they contain just ahead of the next dry cold front – just a few hours away.  The temperature was a balmy 65 degrees with a light south breeze. This followed an afternoon high at my residence of 68 after a morning low of 28.  At the Lawrence Airport, the late afternoon high was 67 and the morning low 23.

After the big rain of Saturday, October 21st, conditions were pleasant until the first in the series of dry cold fronts pushed through on Monday, October 23rd.  The cold air lagged behind the front as the high Monday, as on Sunday, reached the upper 60s.  However gusty northwest winds behind the midday frontal passage reached up to 41 MPH at the Lawrence Airport – enough to buffet cars around pretty good on the highways.

Tuesday, October 24th, was quite windy and much cooler as ‘cold air advection’ pushed across the local area in ernest. The high reached 57 degrees under sunny skies.   The maximum sustained wind (average over two minutes) was 36 MPH at the airport with a peak gust of 44 MPH.  This was windy enough to fell a few medium to large tree branches across town and lots of smaller branches, twigs and leaves, as some of the gusts seemed to arrive in strong little whirl winds.  With an average wind for the entire day of 17.3 MPH, this was the windiest day of the month.

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700 MB Chart (about 10,000 ft ASL) Tuesday morning, October 24th.  The windiest day of the month (on average), note the 60-knot north wind at the Topeka upper air site at this level.  In the afternoon, daytime heating and mixing of the lower atmosphere tended to bring these stronger winds aloft right down to the surface, at least in gusts.   The solid blue line is the freezing line (0 degrees Celsius) at the 700mb pressure level.  Topeka is already down to – 10 C.  The storm front that brought heavy rainfall to Lawrence late Saturday has moved only slowly due to the closed off nature of the parent upper system now over the Great Lakes.  At and at this time, 60 hours later, the front is finally nearing New York City.

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Satellite Image at 12:45 PM CDT, Tuesday, October 24th.  Nary a cloud is to be seen from North Dakota to Texas and across all the western states as strong high pressure out west and a north flow of cool, dry air over the plains keeps skies remarkably clear across the entire western half of the country.

The morning of the 25th brought the first freezing temperature of the season to the Lawrence Airport, where the low was 32 degrees out on the Kansas River flood plain.  However, at my residence in southwest Lawrence, the morning low was a milder 37 degrees.  Temperatures rebounded Wednesday afternoon however with a high of 71 at the airport and 72 at my residence.  Skies were clear once again with generally light west winds.

On Thursday, the 26th, the high reached a balmy 72 at the Lawrence Airport and 70 at my residence ahead of the next rapidly advancing cold front.  Late in the day, following a second dry cold front passage, northwest winds gusted up to 45 MPH at the airport, the strongest wind recorded the entire month.  Peak sustained winds were 35 MPH.  As with the previous front, the cold air lagged behind the initial frontal passage.

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Thursday, October 26th at 12:45 PM.  Clouds associated with the next blast of cool air from Canada are pushing southeastward.  The front moved in very late in the day bringing gusty northwest winds up to 45 MPH in the late evening.

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700 MB chart Friday morning, October 27th:  The second in a series of dry cold fronts has brought another surge of cool dry air in.  It’s deja vu all over again!

Friday, the 27th was another cool, blustery day behind the front that pushed in the previous evening.  The morning low was in the mid 30s winds with the afternoon high only reaching into the mid 40s.   Blustery northwest winds continued.  Winds managed a peak gust of 40 MPH at the Lawrence airport with a maximum sustained wind of 33 MPH.  The winds died down rapidly in the evening, allowing for strong radiational cooling conditions Friday night.  By midnight the temperature dropped to 31 at the airport (35 at my residence).  The Saturday morning low at the airport reached 23 degrees (28 at my home weather station in southwest Lawrence).   On Saturday afternoon, the high only recovered to 51 degrees at both the airport and my home.

Sunday, the 29th was more pleasant with temperatures rebounding into the mid to upper 60s with just a few mid and high level clouds, as seen below:

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At 6:29 PM Sunday, October 29th, just after sunset (and 13 minutes after the photo above).   The sun still shines on the ‘virga’ (precipitation falling from the clouds but not reaching the ground) from below as the mid level clouds dissipate into the dry air ahead of the third in a series of dry cold fronts soon to come.

On Sunday night, the third in the series of dry cold fronts moved in, bringing in gusty winds and cooler temperatures for Monday.

The temperature on Monday, October 30th, more or less flatlined with a morning low of 48 and afternoon high of 53.  Northwest winds gusted to 38 MPH at the Lawrence Airport with a maximum sustained wind of 30 MPH.  Winds were decreasing Monday evening ahead of another cold night as strong radiational cooling ensued.  This lead to a very cool day on Halloween.

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700 MB chart Monday evening, October 30.  Cool air is over the region from the northwest flow.  However a weak trough over Arizona moving eastward and another over Montana moving southeastward promise to bring more clouds and a chance of sprinkles on the last day of the month – along with quite cool temperatures for the trick-or-treaters.

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Surface Isobars at 6 AM Tuesday, October 31st.  Surface high pressure over eastern Kansas will keep cool temperatures over the area on the last day of the month.

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The October 31st 7:15 AM water vapor image shows plenty of high cloudiness poised to move across the area Tuesday as a weak, closed-off low moves into west-central Texas and a short-wave trough pushes southeastward across the central Rockies, as well.  However, low-level moisture will be lacking in this situation, so any precipitation that manages to fall from the mid level clouds later today should be very light.

On the morning of the 31st, strong radiational clearing under clear skies and calm winds allowed the overnight low to drop to 21 degrees at the airport.  A thick deck of mid and high level clouds then moved across for the daytime hours.  The overcast combined with high pressure at the surface allowed a minimal recovery from the cold overnight low to an afternoon high of only 38 degrees.  A few flakes of snow fell around town in the afternoon but not enough to wet the streets.  Topeka received a few tenths of an inch of snowfall.  However, the scattered accumulating light snow swaths in the area missed Lawrence.  Winds were light out of the southeast.  The coldest day of the month, the deviation from average for October 31st was 21 degrees below normal.

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