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WINTER 2014-15 OUTLOOK (issued November  2014)

For the first time in over a decade Shreveport failed to hit 100 degrees during the summer of 2014.  Now that we are past Halloween, it's time to think about what's in store for the upcoming winter here in the ArkLaTex.  Will the relatively cool summer lead to a cold winter like last year?  The answer may lie with what's happening in the oceans that surround North America.  Since most of the globe is covered by oceans, it's no surprise that variations in sea surface temperatures play a big role in the climate around the world.  Thus, it seems logical that one can look at the state of the oceans now and find years in the past where ocean conditions were similar and use the weather from years gone by to make a very general forecast for the future.

Oceanic Oscillations
If you study sea surface temperatures, you will find that there are many patterns during which SSTs rise and fall over a certain period of time.  The three biggest of these oscillations are the AMO (Atlantic Multi-decadal Oscillation), the PDO (Pacific Decadal Oscillation) and of course the ONI (Oceanic NINO Index).

AMO:  The AMO is in the last half of the warm part of the cycle.  Typically when the AMO is positive or above normal, it can contribute to more above normal winter temperatures.  The latest measure of the AMO indicates that it is strongly positive and very similar to last year.   

PDO:  We are in the beginning of the part of the PDO cycle where it tends to be negative.  A negative PDO can enhance the effects of La Nina.  You might remember that the extreme drought that we experienced in 2010-11 came during a double dip La Nina.  The latest measure of the PDO indicates that it is much different than last year.  Last year the PDO was negative.  Right now the PDO strongly positive.

ONI:  (UPDATED Nov 2014) The ONI is an oscillation is a cycle that fluctuates much more often and can play the biggest role in the weather pattern that we experience during the winter.   THE ONI increased dramatically during October and is nearing EL Nino Level that the Climate Prediction Center if forecasting. 

2014-15 (DJF) Winter Outlook from Climate Prediction Center



That leads me to the official forecast from the NWS.  The map above to the left is the temperature forecast and shows that there is a decent chance that we will experience another winter of below normal temperatures.  The map to the right indicates that we will experience a wetter winter than last year with a slightly above normal chance for above normal precipitation.

My Outlook based on Current AMO, PDO and ONI (Updated November 20, 2014):

My outlook seen below is now similar to the outlook from the CPC.  Based on current AMO, PDO, and ONI readings, it appears that this winter COULD be similar to the winters of 1997-98, 1987-88, and 1957-58.   Before I give you more detail on what could be on the way for December, January, and February temperatures, check out what the oceans indicated would be likely for November.  The large map below shows that those 3 Novembers saw temperatures that were a significant 3 to 4 degrees below normal on average for the month.  So far this month we are running more than 8 degrees below normal.  It will probably fall closer to the 3-4 degrees since warmer temperatures are on the way in the next week.

NovemberTemps

December Outlook:

Now based on data from the Decembers of 1997, 1987 and 1957, I can give you details on what could be on the way for December 2014.   The first map below at left shows that IF this December repeats what was experienced in the past, we should expect above normal precipitation with the heaviest rainfall over Southwest Arkansas.  Six to 6.5 inches could be possible there with lighter amounts over NW LA and NE TX.  Normal Rainfal for the month of December is anywhere from 4.5 to 5".

The map in the middle indicates that low temperatures for December will average out to be 38 to 40 degrees over the southern third of the area from Center to Natchitoches.  Average lows will be 37 to 39 degrees across the E TX and NW LA from Marshall to Shreveport to Minden.  Average lows for the month will be 33 to 35 degrees for NE TX, SW AR and SE OK from Atlanta to Texarkana to Hope to De Queen to Broken Bow.

The map at right below indicates average high temperatures for the month of December.  They look to be 60-62 for the southern part of the area from Center to Many to Natchitoches.  Average highs should be 58 to 60 over E TX and NW LA from Marshall to Shreveport to Minden.  The northern part of the area including Mt. Pleasant, Texarkana, Magnolia, Hope, De Queen and Broken Bow should expect highs from 51-55 degrees.

Snow:  no snowfall was recorded in any of the Decembers in question so December snow looks unlikely.






Update for January 2015:

Data from the Januarys of 1997, 1987 and 1957 shows that we should expect to see above normal rainfall for January 2015.  The first map below at left shows that IF this January repeats what was experienced in the past, we should expect above normal precipitation with the heaviest rainfall over Northwest Louisiana.  Five and a half to six inches could be possible there. The lightest amounts will be over SE OK where 3.5 to 4" should be expected.  January normal for Shreveport is 4.20".  Shreveport could receive anywhere from 4.5 to 5".  Texarkana's normal rainfall is 3.4" while 4.25 to 4.5" looks possible this January

The map in the middle indicates that low temperatures for January will average out to be 35 to 37 degrees over the southern third of the area from Center to Natchitoches.  Average lows will be 34 to 36 degrees across the E TX and NW LA from Marshall to Shreveport to Minden.  Average lows for the month will be 29 to 32 degrees for NE TX, SW AR and SE OK from Atlanta to Texarkana to Hope to De Queen to Broken Bow.  The average January low for Shreveport is 36.  It' 33 degrees in Texarkana.  So it looks like lows will be just a little below normal for January.

The map at right below indicates average high temperatures for the month of January.  They look to be 57-59 for the southern part of the area from Center to Many to Natchitoches.  Average highs should be 55 to 57 over E TX and NW LA from Marshall to Shreveport to Minden.  The northern part of the area including Mt. Pleasant, Texarkana, Magnolia, Hope, De Queen and Broken Bow should expect highs from 50-53 degrees.  The average January high in Shreveport is 57 degrees.  The average high in Texarkana is 54 degrees.  So it looks like temperatures should average out to be pretty close to normal.  That doesn't mean that we won't have any big cold outbreaks, it does mean that if we do, they should be countered with periods of warm weather too.

Snow:  It appears that IF we are going to see any more snow this winter, it will be during the month of January.  Records indicate that 2 out of the 3 Januarys in question were snow free across the entire area.  We did have a significant  winter storm in 1998 that left 1" of snow in Shrevoport, 4" in Texarkana and 8.5" in De Queen.  This means doesn't mean I can guarantee snow this January.  It just means that the chance is higher than normal.

Update for February 2015:

Data from the Februarys of 1997, 1987 and 1957 shows that we should expect to see above normal rainfall for February 2015.  The first map below at left shows that IF this February repeats what was experienced in the past, we should expect below normal rainfall area wide with the heaviest amounts over the SE third of the region.    The February normal for Shreveport is 4.75".  Shreveport could receive anywhere from 4 to 4.5".  Texarkana's normal rainfall is about 4" while 3 to 3.5" looks possible in Texarkana this February.

The map in the middle indicates that low temperatures for February will average out to be 37 to 39 degrees over the southern third of the area from Center to Natchitoches.  Average lows will be 35 to 38 degrees across the E TX and NW LA from Marshall to Shreveport to Minden.  Average lows for the month will be 32 to 34 degrees for NE TX, SW AR and SE OK from Atlanta to Texarkana to Hope to De Queen to Broken Bow.  The average February low for Shreveport is 40.  37 degrees is teh average February low in Texarkana.  So it looks like lows will be just a little below normal for February.

The map at right below indicates average high temperatures for the month of February.  They look to be 59-61 for the southern part of the area from Center to Many to Natchitoches.  Average highs should be 58 to 60 over E TX and NW LA from Marshall to Shreveport to Minden.  The northern part of the area including Mt. Pleasant, Texarkana, Magnolia, Hope, De Queen and Broken Bow should expect highs from 53-56 degrees.  The average February high in Shreveport is 62 degrees.  The average high in Texarkana is 58 degrees.  So it looks like high temperatures should average out to be slightly below normal for the month of February.

Snow:  No snow was reported any of the 3 Februarys in question.

Another update may be posted if ocean conditions change...stay tuned!

--Todd Warren