Winter Outlook Update 09-10

Remember I am not a meteorologist or an expert, but instead someone interested in the weather and this el nino.

As we descend into Fall there are still several conflicting factors. Right nwo we have a west based moderate El Nino it may go back to neutral or east or even basin wide. The strength part appears to be even more confusing. Somewhere in the 1.2-1.7C range for the peak ONI is what I am expecting. As continued warming although it slowed down in July and August continues. Also the PDO appears to be near neutral. A +1.2 or +1.3C compared to a +1.7 or +1.8C or even higher can mean way different results.

My Thoughts

• A Moderate El Nino that is west based or a Low End Strong EL Nino that is west based or neutral/basin wide. Thinking (+1.25to +1.7C)
  
• Average Siberia and Eurasia Snowfall started out very unfavorable but turned favorable.
  
• A West Based El Nino should keep the Pacific Jet in check and not allow it to ruin the systems, which could allow for a West Ridge and East Trough setup at times, although at other times especially if it gets in the strong range Pacific and Subtropical air could flood the nation and make the pattern unfavorable for most everyone.
  
• Low Sunspots may lower the chances for extended winter long warmth
• Some brief and intense Arctic Outbreaks are still possible although the el nino may lessen their duration and extent. Could be a big Arctic Outbreak possible in Late Jan/Feb period due to El Nino Climatology and a favorable Pacific Pattern if a -NAO can develop.
  
• An active Subtropical Jet running across South Texas though the Gulf Coast and occasional phasing with the northern polar stream will be the main weather makers.
• The NAO is hard to predict over 2 weeks in advance but I think it should be mostly neutral with positive periods and negative periods

My Month Overlook

December: Many El Nino years and many analogs are warmer than average on December. It isn't as easy as El Nino= Warm December. Factors like the NAO and PNA are at play with this one. This is the month the subtropical jet starts to crank, but the first part of this month after the cold snaps of October and maybe late November to will first moderate. This may be a boring weather month until after the 20th. Around Christmas and New Years Eve time-frame things could get interesting with a possible cold snap and an active subtropical jet. We can always hope for a white Christmas and New Years. The Pacfic Pattern may also be unfavorable allowing for some blowtorch into the pattern if a -NAO can occur it may negate some of the warmth.

January: This is where things get interesting. The Subtropical Jet will continue to crank out the December Cold could setup in Canada than move on though into the area. There will also probably be a few days of 60's and maybe even 70's ahead of big storms that could pay visit this month. Overall especially if the nao goes negative it can possibly get down right cold at times. Wouldn't be surprised to see a few winter events, and maybe a severe wx event from West KY and across the Southeast and East Coast this month as this could be an unsettled month.

February: This appears to probably be the coldest times for West KY and the East Coast the Pacfic and Subtropical Jets may moderate the month towards the end. The Potential for the NAO to go negative and also a favorable track across the East Coast could result in the funnest times for the winter. Also many analogs and el ninos like this support a cold February.

Overall- I feel the winter potential is low esp. in the first half of December, but depending on timing either after the Winter Solstice or sometime in Early to Mid Jan the pattern should favor more of a winter pattern the Pacific may be a little more favorable and Arctic invasions should occur at times. The El Nino will be an issue and I don't think it will weaken though the year except for maybe a slight weakening maybe in Jan and Feb that may allow for a stronger north stream. The Pacfic pattern may be horrible in Dec but gets slightly better into Jan and Feb.

If the El Nino stays West Based and in the ONI Peak +1.2-+1.5 range we will have better potential for a good winter

If it goes east based or basin wide and gets above +1.6ONI I think a lot of people will be disappointed in this winter and most of West Kentucky will be lucky to get to average in snowfall. Because the Subtropical Jet will dominate the pattern and severely limit the chance for arctic cold snaps.