It has been well over two weeks since any sort of significant rainfall has fallen across Green Country. While we expect the landscape to change to some shade of tan or brown this time of year, we still usually see a little liquid nourishment from the skies. It is no surprise that our drought has worsened across the state – in a fairly big way.
The latest Drought Monitor shows a 20% jump in extreme drought, the second-worst category in the index. What little relief we had earlier in the fall has now been all but abolished from the map. Only the far northeastern corner of the state has been spared anything worse than a "moderate" drought. Still, the worst of the drought is relegated to northern and western Oklahoma where some places haven't seen a tenth of an inch of rain in over 2 months on any given day.
The other bit of bad news is that a drought is hard to bust this time of year. We are entering the driest time of the year, climatologically speaking. Rainfall tends to be lower partly because we are cooler and cool air can't hold as much moisture as warm air. The good news about the winter is that we don't lose as much moisture to evaporation – drying out the ground further.
That being said, the Climate Prediction Center is somewhat optimistic for at least eastern Oklahoma to receive near or above-normal precipitation over the course of meteorological winter (December, January and February). The short-term pattern does not lend much help to our drought relief though. With a fairly zonal jet stream pattern, we are in waiting mode for a significant storm system to bring the trigger for significant rainfall. As of now, only one decent shot of rain lies ahead in the next week. It may just enough to keep the drought from worsening further for a week's time period.
The fact of the matter is, drought begets drought. Take a look at this drought timeline over the past 12 years or so. One thing you'll notice is that periods of drought often last for a year or longer. This may seem obvious, but the worse the drought is, the more rain is needed to break it. More drought relief usually requires a longer period of wetter-than-normal weather. Clearly, the last two years have been the worst in recent memory. While we almost staggered out of it last winter, it will likely be a longer haul before we found ourselves completely drought-free once again. Historic droughts for our state like that in the 1930s and 1950s last for years, if not the entire decade. Hopefully this won't be one of those instances, but we can't be sure it isn't.
For now, we'll continue to deal with our 10"+ and growing rainfall deficit. Longer-term models do hint at significant pattern changes that would line us up to have more frequent bouts of precipitation. Once we get past this next warm and dry stretch of weather, lasting through a portion of next week, our prospects for water will hopefully look better. The drought won't likely be resolved fully in the next month or even season, but hopefully we'll start back on the road to improvement soon.