upcoming cold spell? (Phoenix, Mesa: how much, air quality, health)

[KatrynS]

Ok, looks like I'll get into town just in time for it to get cold and rainy. What should I expect next week? Just quick showers or actually lots of cloudy weather? I can see the forecast synopsis, but that doesn't tell me if it's likely to really impact our plans beyond no outdoor pools. Experience or predictions?

Thanks!

[observer53]

You know as much as we do, probably. No two storms are exactly alike. So, parts of town will get more, or more constant, rain than others. Be careful driving in the rain, slow down, keep more distance between cars, etc.

[Ponderosa]

This one looks from the computer models like a VERY wet one the likes of which we haven't seen in quite a while. Flow/flooding of washes is very possible and I would not be surprised to see releases into the normally dry Salt River (though that would take a while to reach the PHX area). 5-10! inches of rain is not something our watersheds see much. It often is not nearly as bad down in the deserts as they say it will be. Sometimes these things just fizzle too. Overall, though, it's going to seem more like Oregon than Arizona though as the polar jet takes a dip our way.

By the way, for all who scoffed at El Nino and doubted (I am one), this pattern is textbook El Nino.

[Phxguy]

DayForecastDescriptionPrecip chanceToday

Jan 16
Details
Mostly Cloudy Hi: 69° Lo: 46°
Day: Mostly Cloudy. High 69F. Winds E at 3 mph. Air Quality: Good, UV Index: 3
0%Night: Partly Cloudy. Low 46F. Winds E at 5 mph.
0%Tomorrow

Jan 17
Details
Mostly Cloudy Hi: 69° Lo: 47°
Day: Mostly Cloudy. High 69F. Winds W at 7 mph. Air Quality: Good, UV Index: 3
0%Night: Showers. Low 47F. Winds E at 7 mph.
40%Monday

Jan 18Showers Hi: 64° Lo: 50°
Showers. High 64F. Winds SE at 14 mph. Air Quality: NA, UV Index: 1
60%Tuesday

Jan 19T-storms Hi: 64° Lo: 49°
T-storms. High 64F and low 49F. Winds SE at 6 mph. Air Quality: NA, UV Index: 1
40%Wednesday

Jan 20Showers Hi: 65° Lo: 48°
Showers. High 65F and low 48F. Winds SW at 8 mph. Air Quality: NA, UV Index: NA
40%Thursday

Jan 21Showers Hi: 66° Lo: 49°
Showers. High 66F and low 49F. Winds S at 16 mph. Air Quality: NA, UV Index: NA
40%Friday

Jan 22Showers Hi: 64° Lo: 39°
Showers. High 64F and low 39F. Winds S at 9 mph. Air Quality: NA, UV Index: NA
40%Saturday

Jan 23Showers Hi: 45° Lo: 32°
Showers. High 45F and low 32F. Winds NW at 6 mph. Air Quality: NA, UV Index: NA
40%Sunday

Jan 24Partly Cloudy Hi: 46° Lo: 34°
Partly Cloudy. High 46F and low 34F. Light winds. Air Quality: NA, UV Index: NA
0%Monday

Jan 25Mostly Cloudy Hi: 49° Lo: 37°
Mostly Cloudy. High 49F and low 37F. Light winds. Air Quality: NA, UV Index: NA
0%
Here's our forecast. Usually when they predict rain storms in Phoenix during this time of year they are almost always right( For once). And these storms are great because they seem to become stantionary over us and drop significate amounts of rain.

[Ritchie_az]

"By the way, for all who scoffed at El Nino and doubted (I am one), this pattern is textbook El Nino."

I certainly didn't scoff. I said (in a Monsoon thread) that the Old Farmer's Almanac was predicting a wet winter/spring. You get wet winters (and dry summers) in El Nino years, and you get dry winters (and wet summers) in La Nina years. It's cyclical.

[Ponderosa]

Originally Posted by Ritchie_az

"By the way, for all who scoffed at El Nino and doubted (I am one), this pattern is textbook El Nino."

I certainly didn't scoff. I said (in a Monsoon thread) that the Old Farmer's Almanac was predicting a wet winter/spring. You get wet winters (and dry summers) in El Nino years, and you get dry winters (and wet summers) in La Nina years. It's cyclical.

The correlation in our region is pretty poor, actually. You got lucky . And the winter is not over yet. This is but one week. If the pattern goes back to the decidely un-El Nino one we have been having, then what?

[Ritchie_az]

"The correlation in our region is pretty poor, actually. You got lucky . If one predicts just wet or dry, they are going to be right 1/2 of the time."

I'm not going to go back and look at precipitation data over the last 100 years, but I beleive the wet-winter/dry-summer in El Nino and dry-winter/wet-summer in La Nina is a lot more than 50% true. It may not be 100% true, but it's a lot more than 50%.

[KatrynS]

El nino or not, the NWS forecast is so grim I think I'll postpone my trip a few weeks. If I wanted cold, windy and wet I'd visit my family in Seattle!

Thanks to folks for pointing out how bad this series of storms could be.

[LocoAZnative]

I'll believe when I see it The when the predict a ton of rain you get nada. Then when they predict nothing it pours. So it will probably be uneventful

[Valley Native]

Originally Posted by Ponderosa

This one looks from the computer models like a VERY wet one the likes of which we haven't seen in quite a while. Flow/flooding of washes is very possible and I would not be surprised to see releases into the normally dry Salt River (though that would take a while to reach the PHX area). 5-10! inches of rain is not something our watersheds see much. It often is not nearly as bad down in the deserts as they say it will be. Sometimes these things just fizzle too. Overall, though, it's going to seem more like Oregon than Arizona though as the polar jet takes a dip our way.

I'd love to see a healthy helping of much needed moisture, but I think the predictions of five to ten inches of rain are exaggerated. Of course, rainfall totals of those substantial amounts have occurred here on occasion ... but in most cases, the totals end up being less than what was originally in the forecast. We shall see what happens this coming week.

Originally Posted by Ponderosa

By the way, for all who scoffed at El Nino and doubted (I am one), this pattern is textbook El Nino.

I was a scoffer as well ... and still am a doubter. If this El Niño is truly as strong as what they predicted last year, we would have seen substantially more moisture as early as November or December. However, both November & December ended much drier than normal. We still have the rest of January, as well as February, March, and April to really see how much of an effect El Niño will have on our weather. A couple of major storms do not automatically make a wet winter!

Originally Posted by Ritchie_az

I'm not going to go back and look at precipitation data over the last 100 years, but I beleive the wet-winter/dry-summer in El Nino and dry-winter/wet-summer in La Nina is a lot more than 50% true. It may not be 100% true, but it's a lot more than 50%.

I have looked at precipitation trends over the past 100+ years, and you're generally correct that El Niño brings us wetter winters & drier summers. However, you might recall that they were predicting a wet El Niño pattern as recently as three years ago (the 2006-2007 winter) ... but that actually turned out to be drier than normal. As I've said before: I'll believe it when I see it. After our dry November, December, and first half of January, I'm not convinced yet!