By Gary McManus, Oklahoma Climatological Survey:
We had drought advance in part of the state and retreat in others, but all in all, pretty much the same numbers. Seinfeld called it “Even Steven.” I like to say that’s just our naturally varying weather. Farmers call it something I probably shouldn’t say on here. This week’s U.S. Drought Monitor map tells the story of the changes in impacts following the rain over last weekend.
We had severe (D2) drought extend farther to the southwest into Grady County and also up through Tulsa County in the northeast. There is still a very small area of moderate (D1) drought up in the far northeastern corner of the state as well. We also saw that exceptional (D4) drought expand in the Panhandle to cover all of Beaver County now. So the percentage of exceptional remained virtually unchanged at 32%, while the D3 dropped by about 4%. The area of the state covered by severe-exceptional (D2-D4) remained just a tad under 100%.
If things don’t change in a hurry, November is on its way to a dismal finish.
Through the 15th, the state has had an average of 0.54 inches of rain, nearly an inch below normal. It’s normally one of our drier months anyway, regardless of deficits.
The next five days are mostly dry, although there is expected to be a little bit of rain with a storm system early next week. The amounts at this time are expected to be pretty light, however.
At this time, the remainder of November looks fairly warm and dry with increased odds of warmer and drier than normal weather forecast by the NWS’ Climate Prediction Center (CPC). The worrisome part there is that drier than normal this time of the year is really dry.
Now we can go out further and check the December and Seasonal outlooks from the CPC. First off for December, they see nothing from any large-scale climate factors (e.g., El Nino, La Nina, etc.) influencing our weather patterns, so they gave us the old “Equal Chances,” meaning equal chances of above-, below- or near-normal temperatures and precipitation. We do see the odds of warmer than normal weather starting to creep up from the south, however.
That type of pattern correlates with the negative phase of the Pacific Decadal Oscillation (PDO), another of those far-flung oceanic influences, or what is known in climate circles as a “teleconnection.”
The new winter outlook (Dec-Feb) brings those chances for above normal temperatures into the state, but also slightly increased odds of above normal precipitation into the eastern quarter of Oklahoma.
These forecasts are mostly a combination of long-range model output and the composites of what has occurred in the past with a negative PDO and the lack of La Nina or El Nino (otherwise known as “ENSO-Neutral”). For Oklahoma, it generally means dry weather, although the signal is not overwhelming.
Given all of that, the new U.S. Seasonal Drought Outlook from the CPC still has little in the way of encouragement for Oklahoma with drought persisting or intensifying over the next few months.
I’ll just give my own two cents on these forecasts. Yes, it does look dry as we go forward, but winter is normally a dry time in Oklahoma anyway. We will most likely still be in drought as we come out of the winter into spring. That’s when the rains will need to kick in and not give summer a headstart like we’ve seen the last two years. And as we’ve talked about before, the wildcard with our temperatures is the Arctic Oscillation, which has played havoc with those huge masses of cold air over the last few winters. Should it go back to being primarily negative like it was in 2009-10 and 2010-11, expect more frequent bouts with frigid air. If it stays positive like last year, we might be in for another mild winter. Unfortunately, the AO is impossible to predict more than a couple of weeks out. It looks to remain positive for the next couple of weeks after a negative October.