Here comes our first round of Winter

TUCSON – While Winter is officially three weeks away, Mother Nature is sending a Winter-like blast of rain, snow and cold air to southern Arizona. 

A cold front will sweep through the State late tonight and into Friday morning bringing plenty of changes. Valley rain and mountain snow begins around 1 am and should finish up by midday Friday. 

Rainfall amounts will be light – generally around 0.25″ or less in most spots while above 7000′ the precipitation will be in the form of snow. 

While October was a wet month for Tucson, no rain has been picked up during the month of November. 

Much cooler air will filter in for Friday and the weekend with highs only in the upper 50s to lower 60s. Rain is in the forecast for Sunday as well. 

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Who’s ready for a blast of cold air?

TUCSON –  With only a few days remaining in November, it seems likely that the month will go into the record books as slightly cooler than average.

October was also cooler than average. The last time Tucson strung together consecutive months with below average temperatures was November 2015 – January 2016. It’s a tight race but with a big pattern change arriving the last day of the month, odds favor another below average.

High pressure will result in mostly sunny and warm conditions Wednesday as highs warm well above average into the mid 70s. Thursday begins warm but then we track a cold front barreling down from the north. This front will pick up our winds and give us the best rain chance we’ve seen in almost a month. Most of our forecast tools indicate light rain – up to a 1/4″ with 1-3″ of snow for Mt. Lemmon. 

Rain is likely early Friday morning and highs will top off only into the low 60s. This cooler air mass will stick around through the entire weekend and another shot of light rain is possible through Monday. Sunday through Tuesday look very cold as temperatures struggle to get out of the mid-to-upper 50s. 

Snow levels will come crashing to 4500′ early Sunday morning, and some of the higher towns in the region could pick up a dusting of snow. 

The Climate Prediction Center keeps well below average temperatures around for much of next week as well. 

So giddy up Rudolph, it’s beginning to look – and feel – a lot like Christmas. 

The October chill continues

TUCSON – Today marked the 12th consecutive day the City of Tucson has seen below average temperatures. Out of the 17 days so far this month, 14 have been below average.

If you compare the first 17 days of October this year to last year, well there is simply no comparison. This year’s average October temperature is more than 10 degrees cooler.

We’re off to the coldest start to October since 1982 – when through the first 17 days the average temperature was 67.4 degrees.

Many years we talk about the latest 100 degree day occurring in October: well forget about that. The highest temperature we’ve recorded this month has been a “cool” 89 degrees.

Don’t look now but warmer weather is in the forecast, but even highs on the warmest days look to only be a degree or two above average.

With two weeks still remaining of the month, it would take a major heat wave to put the entire month of October above average…and that isn’t in the forecast. This means October 2018 will be the first below average month we’ve seen since September of 2016.

What month is it? More cold, rain and snow is here.

TUCSON – Rain overspread much of metro Tucson – AGAIN – tonight and more rain is in the forecast tonight through Tuesday. And oh, don’t look now, but more rain is possible this weekend and even into next week if we can tap into Tropical Storm Tara.

Okay back to the big chill: the first 15 days of October have been colder than the first 15 days of November last year. (How is that even possible?)

So halfway through the month, we now rank as the 19th coldest October since records have been kept (1894). What’s more staggering is if you take out most of the colder October’s which occurred at the beginning of the 20th century, this October ranks as the 4th coldest since 1959! Only the first 15 days of October in 1966, 1970, and 1982 were colder!

 

And by the way, it’s currently snowing on top of Mt. Graham. See the image below.

A What Kind of Cloud?

A big shout out to Amie Montes who captured an interesting cloud photo taken today near Willcox.

Here is the photo, and at first glance it certainly looks like it could be a funnel cloud.

Beaver Tail Cloud

What do you see?

Okay here’s the scoop. Without seeing video we don’t know if the cloud is rotating.

Looking back at our Doppler radar from earlier today, there was no indication of rotation in any of our afternoon storms.

So the question is, what kind of cloud is this? The answer: a Beaver Tail Cloud.

Beaver Tail Clouds form in the boundaries between a thunderstorm’s updraft and downdraft.

In the storms downdraft, the heavier rain-cooled air descends and spreads out laterally.

At the same time, warm, moist air is being lifted.

As this warmer air becomes saturated it undergoes condensation and becomes visible in the shape of the ‘Beaver Tail’.

According to the American Meteorological Society, ‘the Beaver Tail shows that a supercell thunderstorm is getting its act together’

The Beaver Tail Cloud can become a much larger Shelf Cloud if there is enough low-level moisture.

Monsoon Madness ‘A Tale of Two Cities’

Have you been a bit disappointed lately with the lack of rain in midtown Tucson?

Would you belive me if I told you that this monsoon has been epic so far? Well it has, and I’ve got the proof.

As of today, Tucson (at the airport where records are kept) is way above average for July rain. Monsoon City Column

In fact we are at double in the rain department.

 

 

 

 

Monsoon City Column 2And if this wasn’t enough to wash away any doubt – check out the July rain in Douglas:

Nearly 700% of average for July.

So despite what you may consider a slow start to the monsoon, we are actually faring quite well.

 

 

 

I expect a bit of a downturn in rain chances from Friday through the weekend, but some signs are indicating another uptick as we head into the middle of next week.

Hopefully the daily round of storms works its way a bit farther to the north.

Matt’s Monsoon Update

Here’s my Monday monsoon update.

We’re off to a good start this year when it comes to our monsoon rain. Nearly 1″ of rain fell at TIA on Friday, and way more out toward Vail.

We have two positive factors for the potential of heavy rain this week and one potentially negative.

I’ll address the ‘good’ first, good  if you were hoping for rain.temp1

1) Tropical Storm Erick

A very favorable factor is on our side if you like rain. Tropical Storm Erick is churning to the West off  Baja  in Mexico. Often times we get what’s called a ‘gulf surge’ from tropical storms – even when they’re well to our south. Essentially, mid level moisture travels up the Sea of Cortez and helps us in the rain category. We still need a ‘trigger” or a mechanism to lift this tropical moisture to create rain. Enter factor #2.

2) A disturbance moving from East to West.

Remember the definition of monsoon? A seasonal shift of the wind. While most of the year we look to the West for our weather, disturbances this time of year come from the East and can help lift our moist air to create the rain. A disturbance is moving our way and should help lift our moist air for good rain chances. In the following picture you can see an area of lower pressure to our Southeast- this would be our trigger. wave

The Bad

I’ve seen this too many times during the summer months. Often times despite a ‘trigger’ and good moisture, we do NOT get good rain in the Desert. This can be a function of too much of a good thing.

Ample storms may fire-up, many miles away from Tucson, but they can weaken sending us only clouds. If we are left with leftover clouds, we do not get warm enough at the surface to destabilize the atmosphere for convection (aka storms).

So as of now, I think the two ‘good’ factors outweigh the one ‘bad’ one and parts of Southern Arizona get abundant rain this week. But keep in mind, as contrary as it may sound, waking up with sunshine is a good thing if you are hoping for rain!