Wednesday, October 26, 2016

November 2015 was nice!

As we were finishing up one of the warmest Octobers on record, my attention turned to November 2016 and what sort of stuff we could expect!

The normal range for temps in November is 58ºF for the average high and 34ºF for the low. When you think about it, that's not a very bad range. Shown above, is a graph of the temps I recorded for my Davis weather station in Forsyth Missouri in 2015. That year the averages were 63ºF and 41ºF! Quite a departure from the normal with some folks saying global warming and such things as that.

The month was also wetter than normal with a recorded rainfall amount of 6.84 inches versus a normal average of 4.9 inches. So, we had us a pretty durn nice month all told!

Another indicator of what is trending is the Arctic Oscillation index or AO. In simple terms, it indicates the degree to which Arctic air penetrates into middle latitudes which is defined by surface atmospheric pressure patterns. When the AO index is positive, surface pressure is low in the polar region. This helps the middle latitude jet stream to blow strongly and consistently from west to east, thus keeping cold Arctic air locked in the polar region. And that's normally a good thing. When the AO index is negative, there tends to be high pressure in the polar region, weaker zonal winds, and greater movement of frigid polar air into middle latitudes. Here's a look at the current graphic:

 Note that the 'trend' line is heading into the negative. That by itself doesn't mean a lot. However, the ENSO or El Niño Southern Oscillation is also trending toward a neutral phase which could bear some watching as it is slightly re-enforcing the trending pattern for a colder than normal winter to come!

Sunday, October 16, 2016

My winter 2016-2017 forecast for Missouri!


Taney County MO – After promulgating for some time, and after looking at some of the very recent changes in global weather data, I'll admit to some confusion. In just the past month or so, the tropical Pacific has changed gears, and now expert forecasters think there’s a 70% chance that La Niña conditions will develop this fall. However, any La Niña that develops is likely to be weak, and forecasters aren’t quite as confident that La Niña conditions will persist long enough to be considered a full-blown episode, giving it a 55% chance through the winter. So... what's that mean exactly for people living in southwest Missouri?

As is often the case in a strong La Niña setup, we would be looking at warmer than normal conditions, at least through the month of December, at which point some more 'interesting' weather may develop at the start of 2017 in the form of sporadic icing types of events! However, this time around we could likely see a weak or barely there La Niña that could even move in the opposite direction towards an equally weak El Niño setup. Blah and balderdash!

Below, the latest graphical summaries for the period Oct thru Dec:

For now, the weather watchers will be eyeing the tropical Pacific closely over the month of October, to see if the 'suggestions' of La Niña that showed up in the second half of September is really here to stay. The current computer model forecasts are predicting a few more three-month-average periods of around half a degree (C) below average in the Niño3.4 region—right at the La Niña threshold. Remembering that a weak La Niña likely means lower confidence impacts on U.S. weather and climate during the winter compared to a stronger event probability. If that sounds a bit wishy washy, so be it!

Friday, October 14, 2016

Taney County MO work week #3!

It would seem that summer just won't go quietly into the night... and that's a good thing! So, it shouldn't be a surprise to see a warming trend occurring Saturday on into Monday, as an upper level ridge builds over the region. High fives all around! But, you can expect some light drizzle on Saturday morning under the low level clouds that will be over the area but otherwise dry conditions will dominate. Highs on Saturday will likely top out in the upper 70's to the low 80's with highs in the lower to middle 80's occurring Sunday. (Got my grill ready)!

The warmest day of the week will occur on Monday as highs in the middle 80's to upper 80's occur. Some record highs may be approached across some of the area on both Sunday and Monday. Breezy southwesterly winds will occur on each afternoon from Saturday through Monday, as wind gusts nearing 30 mph are expected across southeastern KS and western MO.

By mid week, a pesky upper level trough will push across the western United States from Tuesday on into mid week. This front and upper level trough will also bring chances for showers and storms to the area Tuesday night into the middle of next week.

A much cooler air mass will spread into the region behind the front and trough Thursday and Friday. Highs on Thursday will be in the upper 50's to lower 60's with highs in the mid to upper 50's expected Friday. Southerly winds will start to return next weekend with highs in the 60's expected on Saturday and highs in the 70's on Sunday.

Sunday, October 9, 2016

Taney County October work week #2!

A slight warming trend will continue Monday, with temperatures warming well into the mid to upper 70's. Monday looks to be somewhat breezy, as the surface pressure gradient tightens between high
pressure on the east coast and a developing surface trough over the High Plains.

Temperatures (and to a lesser degree, dew points) will increase further on Tuesday as a frontal boundary begins to move south toward the region. Thunderstorms look to develop to the northwest of the area Tuesday night, with a decent chance for precipitation on Wednesday as a cold front moves through.

That front looks to make it down to roughly I-40 before stalling Thursday, and lifting back north into the area on Friday. After a brief period of cooler and dry weather Thursday, this will bring a renewed chance for showers and thunderstorms to end the workweek.

For now, the tail end of the forecast looks quite warm, with upper level ridging holding strong over the southern CONUS, and the main storm track remaining across the northern Plains and Great Lakes.

Monday, October 3, 2016

Hurricane Matthew to slam Haiti!

WIND: Hurricane conditions are expected to reach Jamaica and Haiti tonight, and eastern Cuba Tuesday. Tropical storm conditions are expected to first reach Jamaica and Haiti later today and eastern Cuba tonight, making outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. Tropical storm conditions are expected along the
southern coast of the Dominican Republic within the warning area beginning today. Tropical storm conditions are expected to reach the southeastern Bahamas early Tuesday with hurricane conditions expected by late Tuesday.

Hurricane conditions are possible in the hurricane watch areas by Tuesday night with tropical storm conditions possible on Tuesday. Tropical storm conditions are also possible in the tropical storm watch area in the Dominican Republic by late today.

RAINFALL: Matthew is expected to produce total rain accumulations of 15 to 25 inches across southern Haiti and the southwestern portion of the Dominican Republic, with possible isolated amounts of 40 inches. Across eastern Cuba and western Haiti, total rain accumulations of 8 to 12 inches are expected with possible isolated maximum amounts of 20 inches. Across eastern Jamaica, total rainfall of 5 to 10 inches is expected, with isolated maximum amounts of 15 inches possible. This rainfall will likely produce life-threatening flash floods and mudslides.

Taney County work week 1 for October

Temps this week will generally be warmer than last week. A strong southerly flow will increase through the mid week ahead of our next system. Temperatures early on should be a few degrees
above average for both daytime highs and overnight lows.

An upper level trough or front will begin to move eastward with time across the western states and into the plains by Wednesday. This trough is forecast to slow as it nears our area, which should position our region under a southwesterly flow aloft from Wednesday through perhaps Friday. A series of impulses are forecast to develop and ride northeastward within this flow. A cold frontal boundary is also forecast to push eastward toward our area by midweek, however, this front stalls within the SW to NE flow regime. With each impulse there will be a wave of showers and T`storms develop and move through the region. The better rain chances will reside across southeast Kansas and southwest Missouri.

As for strong storm potential, there may be a low chance of a stronger storm or two west of the interstate 49 corridor early Wednesday, however, timing doesn't support anything more than a marginal threat. On Wednesday, the atmosphere looks rather capped with height rises behind the earlier shortwave. The better shot at storms will likely occur north of our area in closer proximity to the surface frontal boundary.

Finally, a strong shortwave is expected to push the cold front through the region late Friday. The orientation and evolution of the trough is still in question with some differences among the global computer runs with the ECMWF being a bit flatter, which causes a slower progression with the front.