Hurricane Season A Month Away

In my opinion the worst forecast I have ever made was for the 2013 Atlantic Hurricane Season (some of you may debate that).  I looked at the Sea Surface Temperature Anomalies of March and April, the persistent cold of March 2013 and saw similarities to 1954 and 2005.  I tossed out 1993 as an analog which was probably the best match in hindsight.  Here is my post from March 2013.  Lessons were learned on my part namely trust the data and do not rush a forecast just to be first.
NHC 2013 Atlantic Tropical Cyclone Tracks
2013 forecast
20-25 named storms
8-12 hurricanes
4-6 major with 1 cat 5

Actual 2013
13 named storms
2 Hurricanes
0 Major Hurricanes

I am glad the United States was sparred and everyone got a year to relax.  I am also disappointed in myself for ignoring the data I've been collecting since my Sr year at Umass-Lowell.  Instead of going big with a 20-25 year I would have pulled back to 11-15 named storms, 4-8 hurricanes, and 2-4 major.  I still would have been wrong but I would have been closer.  With that said here are my thoughts for 2014

2014 Atlantic Hurricane Season
By most model and observational accounts an El Nino will develop during the summer.  See the model plume graph
Intermational Research Institute/CPC/Columbia U ENSO model plume 
The El Nino threshold is 0.5.  Here is the observational evidence of an oncoming warm event
NOAA/OSPO Sea Surface Temperature Anomaly 5/1/2014
For comparison lets look at this time a year ago, with no El Nino/La Nina coming on
NOAA/OSPO Sea Surface Temperature Anomaly 5/2/2013
Notice the colder blues off of NW South America in 2013.  That shows up welling of nutrient rich water which indicates stronger trade winds.  That does not allow the warm water of the Western Pacific warm pool to slosh east.  In 2014 the trade winds are weaker and the warm water is moving eastward along the equator.  The warm pool south of Alaska in 2013 is also what helped cause the record cold May of 2013 in the Midwest as it helped build a ridge in the Northeast Pacific.  That in turn led to a trough downstream that had an Arctic connection.  

Now that we have solid evidence that a warm event will occur, its time to find similar years.  There was a lot of hysteria over the past few months about a Super El Nino this year.  That of course is possible; never rule anything completely out in meteorology.  However it was questionable to those who study Pacific Ocean dynamics for two main reasons.  First of all El Nino prediction is weakest in late winter/early spring.  The model cannot handle the equinox for some reason and forecasts tend to be wild.  That didn't stop many people from comparing this event to the infamous 1997/98 Super El Nino.  Secondly the Pacific is in an overall cool phase.  Nearly all Super Nino's have occurred during the warm phase.  
El Nino AMO/PDO averages North Atlantic Hurricane Season (personal research)
The Atlantic warm phase is at its weakest point in about 20 years.  It remains to be seen if this is the midpoint of this cycle or if the downward turn has begun.  There was a similar dip in the late 40's before the AMO rebounded for another 15-20 years.  The PDO flipped for good around 2007, but it was cool from 98-02 following the 97/98 Super Nino event.  So my best two matches are 2002 and 2009.

Here is 2002 Sea Surface Anomaly
NOAA/OSPO Sea Surface Temperature Anomaly 5/3/2002 
Here is the 2002 tracks
NHC 2002 Atlantic Tropical Cyclone Tracks
Here is 2009 SSTA
NOAA/OSPO Sea Surface Temperature Anomaly 5/4/2009
And here are the 2009 tropical cyclone tracks
NHC 2009 Atlantic Tropical Cyclone Tracks
2002 at the moment looks like a better blend.  Statistically speaking we should expect 10 TS, 6 H, and 3 MH in 2014 with an ACE of around 100.  Looking closer to 2002

12 TS
4 H
2 MH
65 ACE

and 2009
9 TS
3 H
2 MH
51 ACE

Blending the stats & analogs my forecast is

11-13 TS
3-5 H
2-3 MH
60-80 ACE

It only takes one storm to make a hurricane season memorable.  With the far east Atlantic looking unfavorable for development everyone needs to watch closely for systems developing near the United States.  Don't let 2013 or the oncoming El Nino lull you into a false sense of security.  Irene was a weakening Tropical Storm and I was without power for 4.5 days.  Imagine a Category 2 Hurricane Southern New England?  

Have a good day
Zack Green


Popular posts from this blog

Saturday Weather Thoughts

Winter Storm Stella Set To Deliver Blow To Region

You Didn't Really Think Winter Was Over, Did You?