MESONET TICKER ... MESONET TICKER ... MESONET TICKER ... MESONET TICKER ... October 19, 2017 October 19, 2017 October 19, 2017 October 19, 2017
La Ni?a on the prowl
http://ticker.mesonet.org/archive/20171019/winter-outlooks.png
The National Weather Service's Climate Prediction Center released their official winter outlook today, and for Oklahoma it appears the odds are increased for a bit warmer weather in general. And the odds are increased for below normal precipitation in the southern half of the state. What's that really mean for things like snowfall, ice storms, thunderstorms and the like? Well, not much, really. Remember, these are odds that favor (or don't favor) certain climate patterns over a 3-month period. Significant individual weather events can occur despite the overriding climate pattern. Think back to February 2011, for instance. During that strong La Nina (one of the strongest on record) that began in the fall of 2010, in the midst of the beginning months of the worst drought the state has seen since the 1950s...we set records for the lowest temperature ever recorded in the state (Nowata Mesonet, -31 degrees), and the highest 24-hour snowfall event in state history (27 inches at Spavinaw).
Now this winter outlook is being influenced by the growing threat of La Nina, the associated sea surface temperature and atmospheric changes in the equatorial pacific that, along with El Nino make up the El Nino/Southern Oscillation. There is a third component when El Nino and La Nina are absent, aptly titled "Neutral Conditions." In the case of La Nina, those waters in the eastern equatorial pacific cool and with the associated atmospheric changes, impact weather around the world. For our little corner of the earth, the tendency is for drier and warmer than normal weather during the cool season (let's say October-ish through April-ish). But especially during the height of the cool season, or winter.
http://ticker.mesonet.org/archive/20171019/la.nina.impacts.png
The concern for La Nina is enough that CPC issued a La Nina watch during September, meaning the conditions are favorable within the next 6 months for La Nina development. In this case, within the next month it would appear. The odds for La Nina development rise to nearly 70% within the December-February time frame.
http://ticker.mesonet.org/archive/20171019/ENSO-probabilistic-forecast.png
Now there are still some mixed signals as to the strength of the La Nina (i.e., the "colder" those waters get, the "stronger" the La Nina), but here is the OFFICIAL word:
?If La Nina conditions develop, we predict it will be weak and potentially short-lived, but it could still shape the character of the upcoming winter,? said Mike Halpert, deputy director of NOAA?s Climate Prediction Center. ?Typical La Nina patterns during winter include above average precipitation and colder than average temperatures along the Northern Tier of the U.S. and below normal precipitation and drier conditions across the South.?
Now back to that "climate vs. weather" theme, please keep in mind that ENSO (El Nino or La Nina...or even Neutral Conditions) is only one factor, but as climate factors go, it's one of the more easily predictable. Other factors that can impact our winter climate and weather include the Arctic Oscillation and the North Atlantic Oscillation, which can influence the number of arctic air masses that penetrate deep into the U.S. and are very difficult to forecast more than a week or two in advance.
CPC also released their November outlooks today, as well as their Seasonal Drought Outlook.
http://ticker.mesonet.org/archive/20171019/november-temp-outlook.gif http://ticker.mesonet.org/archive/20171019/nov-precip-outlook.gif
The November outlooks are just beginning to show the influence of La Nina, with warmer than normal weather favored across the Desert Southwest and Oklahoma, and drier than normal weather across the SW third of the state.
As with most things, including BBQ, questions about the basement in the Alamo, and ENSO influences, Texas tends to be more greatly impacted.
Drought relief is expected across the SE corner of the state.
http://ticker.mesonet.org/archive/20171019/season_drought_outlook.png
Let's bring it back closer to the present. Since I've already bored you to death with talk of winter and all this ENSO stuff, let's look at the next few days. Watch for a continued warm up over the next couple of days, culminating on Saturday with a cold front, a chance of storms...some of which could be severe! Much of the eastern half of the state will be under at least an "enhanced" threat of severe weather.
http://ticker.mesonet.org/archive/20171019/nws-norman-svr.png http://ticker.mesonet.org/archive/20171019/nws-tulsa-svr.png
ALL MODES OF SEVERE WEATHER WILL BE POSSIBLE! The tornado threat doesn't appear to be too great, but hey, this is Oklahoma. That should be an official forecast term.
"But hey, this is Oklahoma!"
The heaviest rains appear to be across the southeast, exactly where they are needed, given the U.S. Drought Monitor report released this morning.
http://ticker.mesonet.org/archive/20171019/5day-rain-forecast.gif http://ticker.mesonet.org/archive/20171019/20171017_OK_trd.png
Looks like that might have to last us for awhile, given the medium-range CPC outlooks, which favor drier and warmer weather.
http://ticker.mesonet.org/archive/20171019/oct26-nov1-temp-outlook.gif http://ticker.mesonet.org/archive/20171019/oct26-nov1-precip-outlook.gif
Okay, given all that, now digested, let me just tell you this.
No, I don't have a clue about how much snow we will get this winter. I know you were still thinking about that. So was I.
Gary McManus State Climatologist Oklahoma Mesonet Oklahoma Climatological Survey (405) 325-2253 gmcmanus@mesonet.org
==================================================
The OCS/Mesonet Ticker
https://ticker.mesonet.org/
To subscribe or unsubscribe from the Ticker
or for questions about the Ticker or its content
Phone or Email the Ticker Manager at OCS
Phone: 405-325-2253 Email: ticker@mesonet.org
---------------------------------------------------
-C- Copyright 2024 Oklahoma Climatological Survey
===================================================
|