I suspect all but Rip Van Winkle have noticed we’ve been in a more active pattern with more frequent rounds of convection crossing parts of the region. There is more to come into at least this weekend, with less clarity showing for next week. The nature of the convective beast is uneven coverage, uncertain intensity, and different timing and pathways between the number of high resolution models in play. Global models have improved resolution from a few years back, but they are not a substitute for the high-res mesoscale/close-in models when you get closer to each event. Later this week, the moisture surging into SE TX and SW LA from a vigorous tropical disturbance (as of Monday evening) in the NW Gulf will curl around the warm SE ridge and move toward the Ohio Valley. Current indications point to this main surge staying south of our region, after producing potentially serious flooding in parts of the western Gulf states and Miss Valley. We can be grateful for that trajectory. In the mean over the next couple of weeks, the 500mb flow will be more zonal than not. Short waves embedded in that flow will be difficult to discern more than a few days in advance. There are signs that this week and coming weekend will be wetter than at least the first half of next week. There are no signs of any unusual cooling, but heights may lower over the Great Lakes for a few days early next week, bringing some cooling. Average high as of June 15 is 75 and the average low is 57. Lake Erie has slipped to 59, which is -2. June temps thus far are not far from average.
As for ENSO, el nino continues to be at moderate intensity currently. Key region 3.4 has a positive anomaly of 1.3 degrees having slipped to 1.2 degrees the previous week. More models are now pointing toward a potential Strong el nino, with 90% confidence of el nino continuing through the rest of the year, and 85% confidence it will continue through next winter. Duration is less uncertain than intensity, even with more models leaning toward moderate to strong, and more toward strong than in at any time in this recent cycle. In general, the amplitude/strength of el nino is expected to increase by mid and late summer from where it is now. A strong el nino is often associated with warmer than average temperatures across the northern tier of the lower 48. Precipitation is less certain. Some of memories of the destructive Pacific storms focus on the el ninos of 82-83 in CA, and again in 97-98. That part of the country desperately needs rain. The destructive aspects of a strong el nino are far from a given, as no 2 el ninos are the same…and no 2 Strong el ninos are the same. So, a moderate to strong el nino increases probabilities for a wetter and perhaps stormier winter in CA & the SW, but does not make such a pattern inevitable. An el nino as strong as the extremely anomalous 97-98 event would increase those odds. At this point, only one outlier model out of many is showing such an extreme solution.
What I can say at this early point is that if el nino remains at its current intensity or strengthens further (as is favored in many models), the probability of having extreme cold winters in our part of the country as per the last 2 winters goes down sharply. Snowfall projections are more difficult, and a warmer winter than the last 2, if realized, does not guarantee a big snow drought here or along the NE coast.
Finally, the el nino of moderate or greater intensity lessens the likelihood of a busy Atlantic hurricane season, while it increases activity in the eastern and central Pacific. As I pointed out in an earlier thread, however, killer Hurricane Andrew occurred during a vigorous el nino.