Friday Weather Discussion Clark Evans 27 March 2015
MJO Phase Diagram Peak amplitude on record (1974-present):
MJO & Tropical Wave Evolution
OLR: MJO and Anomaly
850/200 hPa u: MJO and Anomaly 850 hPa at left, 200 hPa at right.
850 hPa u: Full, Anomaly Full field at left, anomaly (from climo) field at right.
Equatorial Pacific Ocean State
ENSO Forecasts “…the dynamical models are anticipating a moderately strong event to develop in the Northern Hemisphere’s late spring and summer. They are notoriously bad for seeing through the spring predictability barrier, though, so it should be noted that the statistical models are more conservative, predicting a neutral-to- weak El Niño event.” IRI March 2015 Climate Briefing,
April-May-June 2015 Forecasts
Winter In Review
Dec 2014 – Feb 2015 Temperature
Dec 2013 – Feb 2014 Temperature
Dec 2014 – Feb 2015 Temperature
Dec 2014 – Feb 2015 Temperature
Dec 2014 – Feb 2015 Precipitation
Dec 2014 – Mar 2015 Precipitation
Dec 2014 – Mar 2015 Snowfall
Drought Monitor
500 hPa Height, Anomaly Derived from NCEP-NCAR Reanalysis, 1 December 2014 – 23 March
850 hPa Temperature, Anomaly Derived from NCEP-NCAR Reanalysis, 1 December 2014 – 23 March
Five Periods of Interest 5-27 December (warm) 29 December – 14 January (cold) January (warm) 1 February – 6 March (cold) 8-20 March (warm)
A Mild December
A Mild December Derived from NCEP-NCAR Reanalysis, 5-27 December
A Chilly New Year
A Chilly New Year Derived from NCEP-NCAR Reanalysis, 29 December 2014 – 14 January
Warmer and Dry in Late January
Warmer and Dry in Late January Derived from NCEP-NCAR Reanalysis, January
A Persistent Mid-Winter’s Chill
A Persistent Mid-Winter’s Chill Derived from NCEP-NCAR Reanalysis, 1 February to 6 March
Spring into March
Spring into March Derived from NCEP-NCAR Reanalysis, 8-20 March
Possible Pattern Influences
Possible Pattern Influences
Possible Pattern Influences SLP’ - SLP’ + SLP’ -
Possible Pattern Influences SLP’ - SLP’ + SLP’ -
Possible Pattern Influences +NAO very similar to +AO during boreal winter +PNA in winter: below- (above-) normal heights in C. Pacific (western N. America).
Possible Pattern Influences
Some Scientific Questions Why does the spring predictability barrier for ENSO exist, and will the current El Niño intensify or not? Why has anomalous cold occurred over North America and nowhere else in the last two winters? Why did the mid-latitude pattern evolve as it did on sub-seasonal scales? Can we even identify why? What caused the MJO to achieve such a high amplitude this March, and what does it mean?