erratic winter weather

On December 24 2022, Atlanta experienced a historic single digit 8°F (-13.3°C) minimal temperature.  This cold snap turned green ground cover brown and delayed or canceled flights.  In mid to late December the arctic oscillation (AO) was in a negative part of its cycle.  Strongly negative AO values are consistent, or should I say necessary, for achieving a historic low in an Atlanta winter.  

The December 2022 cold snap was an outlier and then came a historically warm January 2023.   Currently, the AO is in the positive part of its cycle and as the AO changes slowly, it seems likely that Atlanta will be spared a historic cold snap in February.   This story brings me to share a few lucky iPhone photos of bees on winter-flowering ornamental cherry trees. I was walking the dog on a sunny 57°F (13.9°C) afternoon.   I stood still and soaked in the loud buzz of bees foraging on cherry tree flowers.

Monthly Lowest Min Temperature for Atlanta Area, GA (ThreadEx)
Year	Jan	Dec
2023	29	M
2022	26	8
2021	28	34
2020	23	22
2019	22	29
2018	13	28
2017	15	26
2016	20	26
2015	11	29
2014	6	30
2013	29	27
2012	22	30
2011	19	29
2010	13	14
2009	12	26
2008	15	18
2007	18	26
2006	28	19
2005	16	24
2004	18	16
2003	8	26
2002	21	25
2001	17	23
2000	19	13
Mean	19	24
Max	29	34
	2023	2021
Min	6	8
	2014	2022

insulated hive wrap and cloake board stack

 

In Atlanta, cold 20°F temperatures arrived on Christmas Day and the ensemble of 11 arctic oscillation forecast a large negative downturn. I used these metrics as significant evidence that winter temperatures are here to stay.  Since 2010, I have reused my NOD Bee Cozy R8 insulated hive wraps  and believe hive wraps improved the chance of overwintered bee hive survival. As a lazy (aka stubborn) beekeeper and despite warm winter fluctuations, I'll leave the Bee Cozy on till spring 2021.

Photo shows joined hives - overwintered hive below and a March 23rd spring swarm capture above an open Cloake Board. The bee cozy is designed for 10-frame equipment, so it easily slipped over the Bloake Board without removing 8-frame boxes. 

I'm encouraged to see warm moist air (bee respiration) condense outside the hive at the top vent and Cloake Board Entrance. 

Here are current the hive elements:

• screen bottom board with no counting board insert
• NOD Bee Cozy R8 insulated hive wraps surrounding the May 25 hive reorganization
• inner cover with top notch up ventilation
• two 3/4 inch sheets of XPS foam board insulation between inner cover and telescoping cover
• white corrugated plastic sheet overhang
• concrete pavers on top

2019 Bee Cozy

Ants create tunnels and nest in the extruded polystyrene foam boards in warmer weather, so I postponed insulating the hives until now. In Atlanta, first frost arrived on November 12th which is just on the early side of historical average.  November 12 also marked the first subtle Arctic Oscillation downturn this winter.

Here are current the hive elements:

• screen bottom board with no counting board insert
• bee cozy hive wrap surrounding the August hive down-sizing
• inner cover with notch up ventilation
• two 3/4 inch sheets of XPS foam board insulation between inner cover and telescoping cover
• white corrugated plastic sheet overhang
• concrete bricks on top

Arctic Oscillation Jan '17

Here's my go-to metric, Arctic Oscillation, for anticipating history making low winter temperatures in Atlanta.  I can hold-off no longer, today I added the bee cozy for the first time this winter.

Listed from the bottom upwards, here are the hive elements at this time.

• screen bottom board with no counting board insert
• bee cozy hive wrap surrounding the late August hive re-sizing
• inner cover with top notch ventilation
• two 3/4 inch sheets of XPS insulation
• telescoping cover
• white over-hanging corrugated plastic sheet
• concrete pavers

Arctic Oscillation & Bee Cozy Hive Wrap

This might not be the optimal time to add the bee cozy hive wrap, but I'm itching to acknowledge winter.   As you can see from the Arctic Oscillation forecast, this is the first significant negative downturn this winter.  Atlanta December temperatures have been mild and I held off adding the bee cozy. My concerns include limited winter forage and a larger than seasonally appropriate bee population. Here are the hive elements at this time.

• screen bottom board with no counting board insert
• bee cozy hive wrap surrounding the June-July hive re-sizing
• inner cover with top notch ventilation
• two 3/4 inch sheets of XPS insulation between inner cover and telescoping cover
• white corrugated plastic sheet overhang with concrete pavers on top

winter-flowering ornamental cherry tree

Sorting through my latest camera work, I found a few lucky photos which overcome bright back-lighting, shooting through a window and fast moving honey bees.  In the backyard, the winter-flowering ornamental cherry tree bloom looks great and attracts honey bees too.  In some sunny locations, mahonia is or is about to bloom and spiderwort are still in bloom.

In Atlanta, November and the first half of December have been warm. NOAA climatology based on El Niño have yet to develop into cooler mid-Atlantic weather.  I'm watching the Arctic Oscillation 7 day forecast closely for a negative downturn before adding the bee cozy hive wrap. 

my 2013 spring experience

On March 16th, I removed the bee cozy and added one medium super too each hive.  Blue nitrile gloves worked great - fantastic zero sting outcome.   Discovered many small hive beetles (SHB) above the inner cover which only fed my SHB concerns coming out of a warm winter.  I also readied my swarm traps with new pheromone lures.

The bee cozys were kept off the hives for my beekeeping convenience - I unilaterally declared spring had arrived.  In hindsight, bee cozy removal timing was too enthusiastic as March in Atlanta was cooler than usual. Using the Georgia Automated Environmental Monitoring Network data, I compared this year's minimum temperatures with two other years.

I'm fooled again - next time, I will ignore the NOAA spring climate forecast and watch the NOAA Arctic Oscillation (AO index) for short term Atlanta winter temperature trends. My apologies about the crude correlation of graphs - notice how the negative cycle of the AO index correlates with the cool/low 2013 minimum temperature curve.  A few days after the removal of the bee cozy marks the lowest point in the AO index - oh well.

Winter Outlook (December through February)

NOAA's winter outlook for Atlanta reads as "Northeast and Mid-Atlantic: equal chances for above-, near-, or below-normal temperatures and precipitation. Winter weather for these regions is often driven not by La Niña but by the Arctic Oscillation."  

November seemed very warm and this was confirmed using Georgia Automated Environmental Monitoring Network.  An average Atlanta November temperature of 58.6°F has not been seen since 2003.  

Nov-1    To    Nov-30          Max[°F], Min[°F], Avg[°F]
2011                 2011               70.4       46.7        58.6
2010                 2010               63.5       45.3        54.4
2009                 2009               64.2       45.2        54.7
2008                 2008               59.8       41.0        50.4
2007                 2007               63.6       43.4        53.5
2006                 2006               62.9       44.2        53.5
2005                 2005               65.0       46.1        55.5
2004                 2004               64.1       48.7        56.4
2003                 2003               68.1       47.9        58.0
2002                 2002               59.6       41.6        50.6
2001                 2001               70.3       51.4        60.9
2000                 2000               59.1       44.1        51.6

The Arctic Oscillation has been in a positive phase and forecast to remain so for the next few weeks.  I speculate that odds are now tilted towards above normal December through February temperatures. 

Last Saturday, I added the Bee Cozy, but last year, the bee Cozy was added on the 4th of November.   I like to believe that the prolonged cold during Snowpocalypse reduced the number of small hive beetles this summer, but with a potentially warmer winter, I'm happy that I painted the Beetle Jail for use in summer of 2012. 

arctic oscillation versus La Niña pattern

December 2010 and January 2011 were breathtakingly cold and attributed to a large amplitude negative phase of the arctic oscillation according to the state climatologist David Emory Stooksbury. As the arctic oscillation phase is now positive, perhaps a more typical La Niña pattern (warmer and dryer) will predominate for Atlanta.

Or perhaps NOT....you can start laughing now.....to date, mid-March 2011, rainfall nearly equals the March average. The soil is completely saturated with the latest 1.4" of rain. So, I will cross-out dryer. Will the March 2011 temperature be warmer than average?.....you can start laughing again.

My plan is to keep the bee cozy on till consistently warm (50 °F) dawn temperatures arrive. The bee cozy may be a bee hive management inconvenience, but the bee cozy does not harm the bees. In the photo, imagine a chilly 44 °F morning with several drone pupa dragged onto the landing board.