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Monsoon Watch

Posted: Tue Jun 15, 2004 3:51 pm
by Aslkahuna
Today marks the start of the official NWS "monsoon season" in Arizona (a rather redundant term) which runs trough 30 September. We now start the watch for the onset of the monsoon. This year's monsoon is especially important because of NAME (Experimento de Monzón de América del Norte/North American Monsoon Experiment) which is an International multi Agency project intended to improve the understanding of the dyanmics and morphology of severe monsoon convective events as well as the ability of the operational models to forecast accurately the morphology of the monsoon (a capability that does not exist right now). Since my son, who starts Grad School in August is a forecaster's assistant for NAME there's a personal interest as well.

We will monitor the progress towards onset and report on significant monsoon events in this thread during coming months. For now, the operational models do not indicate any start to the monsoon during the remainder of this month though as everyone in AZ knows, the onset can often be sudden and violent and frequently with little warning from the model guidance.

Steve
8-)

Posted: Tue Jun 22, 2004 7:14 pm
by SEAZSky
Steve -

(And others here)

See my post of today, "Arizona Monsoon Preview"......

For those of you who don't live in Arizona, this is a great
interactive media presentation that I save on my computer. And is a "refresher" for us here in monsoon
country. Here is the web site I referenced:

http://www.azstarnet.com/monsoon/

Stan

Posted: Tue Jun 22, 2004 7:37 pm
by Stephanie
I hope that it is fruitful for all of you out there!

Posted: Wed Jun 23, 2004 3:25 am
by weatherlover427
Local NWS mentions a slight instrusion of SE flow and thus monsoon'type moisture the next couple of days here as well; then a return to drier flow after that.

However; if the GFS if ever to be believed at the 10-14 day range (we can all dream about that :P ) then if it holds true the monsoon **could** make it very close to southern California.

Posted: Wed Jun 23, 2004 7:17 am
by azsnowman
Stephanie wrote:I hope that it is fruitful for all of you out there!


Me TOO! Had a *little* shower yesterday, .12"....it's a START!

Dennis 8-)

Posted: Wed Jun 23, 2004 9:30 am
by weathergalnal
Well with my history of bad luck, I can almost guarantee ya'll that you will get rain for the weekend of the 4th. I live in Alabama but grew up in Phoenix (Glendale 2b exact). I'm headed out there to visit some friends for the holiday weekend. One of whom I haven't seen in 15 years!!! I know ya'll need the rain but let's try to keep it dry at least until the weekend is over! Please! :wink:

Not Looking Good

Posted: Fri Jun 25, 2004 7:26 pm
by Aslkahuna
for a monsoon start anytime soon-in fact, my outlook for 3-7 July could very easily bust as it could be later than that-in fact model guidance would suggest that we could be pushing for the latest start ever.

Steve

Posted: Fri Jun 25, 2004 7:49 pm
by vbhoutex
Steve, does this also mean there is a good possibility that you won't get the needed amounts of rain from the season since it could be the latest start ever? I know you have years of catch up to dent the drought, but I am talking short term here.

Posted: Fri Jun 25, 2004 7:50 pm
by weatherlover427
We know better than to believe the long range GFS. ;) Come on now.

Posted: Sat Jun 26, 2004 7:20 am
by azsnowman
WELL Steve, you hit the NAIL on the head....check out this article from todays Az. Republic :cry: :cry: :cry: :cry: the news just KEEPS getting worse!

http://www.azcentral.com

Monsoon forecast: Late start, more rain
Judy Nichols
The Arizona Republic
Jun. 26, 2004 12:00 AM


Despite the recent dust storm and damp breezes, Arizona's monsoon season is nowhere on the horizon.

Forecasters predict a later arrival this year than the average July 7 start, but also expect more rain than usual.



Special Report
• Monsoon »


And although the moisture will help suppress forest fires, experts say, it will have little effect on the region's worsening drought, the state's shrinking reservoirs or the long-term health of the forests.

Although people often mistake isolated storms for the monsoon, especially at this time of year, the weather phenomenon is technically a seasonal reversal in wind patterns that brings moist air and thunderstorms.

"We perceive a little increase in humidity and thunderstorms lurking on the (Mogollon) Rim as the monsoons," said Andrew Ellis, climatologist for Arizona. "But from an atmospheric standpoint, it doesn't yet look anything like a monsoon."

In fact, this weekend will be drier again, as warm air moves in from California.

Ellis, who predicts monsoon activity for Salt River Project, forecasts a weak or late start to this year's monsoon season but higher-than-average amounts of rainfall.

He believes the season will bring about 150 percent of the normal monsoon rainfall, or about 4 inches, most of it in the last week of July through the first week of September.

The summer monsoon that visits the Southwest is called the North American Monsoon, and it turns the region's westerly winds (those from the west) in a more southerly direction.


From ocean and gulfs
That atmospheric change draws moisture from the Pacific Ocean, the Gulf of California and the Gulf of Mexico, pulling the rain across central Mexico and into Arizona, New Mexico, southern parts of Colorado and southeastern Utah.

Thunderstorms develop as the damp air is pushed upward by the mountains and heated by the sun.

Much of the rain falls in central Mexico, but Phoenix receives an average of 2.65 inches, about a third of its yearly rainfall.

Rainfall is greater in the mountains, where Greer averages more than 11 inches, and least along the Colorado River Valley, where Yuma averages 1.21 inches.

Most places don't mark a specific start to the monsoon season, taking the stance that the phenomenon has arrived when it starts raining.

But Phoenix and Tucson mark its beginning when the dew point is 55 degrees or higher in Phoenix, 54 degrees or higher for Tucson, for three consecutive days.

At a dew point of 55 degrees, enough moisture is in the atmosphere that if it all precipitated out, it would create 1 inch of rain.

"There isn't anything special about that," Ellis said. "But 55 is a nice number, an inch of rainfall is a nice number, and 55 degrees for a dew point is about the amount needed to kick off thunderstorms here in Phoenix.

"So that's been the standard here for years and years."


Reservoirs and trees
This year's expected higher-than-average rainfall will have only minimal effect on the state's drought-starved reservoirs, Ellis said.

"The reservoirs respond much more to winter precipitation than summer," Ellis said. "Because it's the warm season, a lot of the rain evaporates or is used by plants that are now active."

Water resource managers are focused on winter predictions, he said.

"They realize the monsoon season is not a savior," he said.

Unfortunately, the prediction is for above-normal temperatures for the winter, which usually means dry conditions, more winter irrigation in Phoenix and rapid snow melt, all of which means less water to store.

And one season of rain will not significantly help the region's drought-stressed trees, said Chuck Maxwell, leader of the predictive services group for the Southwest Coordination Center, a group of fire-managing agencies headquartered in Albuquerque.

Thunderstorms tend to run off, while slow snowmelt seeps in.

"For long-term growth, it's entirely critical for the snowpack to be near average and to melt off in average time," Maxwell said.

"That has not occurred in large scale in the last five years."

Maxwell said the West has thousands of acres of dead trees from drought or beetle infestation because they are stressed from lack of water.

"From what I've seen, the deforestation, trees turning red, it's pretty dry," he said. "It's about as dry as ever in people's memories."


Fire season
Maxwell is eagerly awaiting the start of the monsoon but said he doesn't see it coming in the next couple of weeks.

"The start of the monsoon is the beginning of the end of the fire season," he said.

"The start is critical. If they wait another month, we will begin to compete with the rest of the West for firefighting resources."

So far, cooler weather, sparse lightning, more coordination in forest closures and better awareness among campers has kept the number of fire starts down, Maxwell said.

Jim Payne, regional spokesman for the U.S. Forest Service, said recent spectacular fires, media coverage and a public safety campaign have combined to create more awareness and reduce human-caused fires.

"People are taking their camp stove instead of building a fire, and they're having a good time," he said.

To check forest restrictions, go to http://www.fs.fed.us/r3/fire or call toll-free 1-877-864-6985.

Posted: Sat Jun 26, 2004 10:27 am
by Stephanie
Well, I hope that they are right about more rain though.

Late Starts

Posted: Sat Jun 26, 2004 3:04 pm
by Aslkahuna
and early starts for that matter, usually have no bearing upon the effectiveness of the monsoon. The latest modern start (since 1949) was in 1987 (July 25th) and the months of August and September were wetter than usual-same for 1995 and 1997 which also saw late starts. In 2001, we had a normal start and a pitiful monsoon. As far as using the GFS for the extended, I know it's crap and in reality no model works well for forecasting either the onset or the progress of the monsoon (one of the goals of NAME is to develop such a model) but it's the only one that goes out far enough to give us an idea of what the computers are thinking until we get close enough to the start to be able to use the short range models-have to have something to look at besides Tea Leaves and Chicken Gizzards :D

Steve
8-)

Re: Late Starts

Posted: Sat Jun 26, 2004 5:35 pm
by Stephanie
Aslkahuna wrote:-have to have something to look at besides Tea Leaves and Chicken Gizzards :D

Steve
8-)


:lol:

Posted: Sun Jun 27, 2004 5:37 pm
by SEAZSky
But -

Look at this good article in today's Arizona Daily
Star - by the interviewing reporter at NWS-Tucson:

http://www.dailystar.com/dailystar/printDS/27747.php

Stan - near Tucson, AZ ........waiting.....

Well, I Have

Posted: Sun Jun 27, 2004 7:53 pm
by Aslkahuna
a copy of the table that TUS posted on their website showing start dates
and total rainfall for the 'soon but haven't gotten around to comparing them to my records but a preliminary glance shows that the June 24th date doesn't hold up well. Two of the driest monsoons ever-1989 and 2001 both started well after June 24th.

Steve
8-)

Posted: Fri Jul 02, 2004 2:30 pm
by Aslkahuna
I have revised my outlook for the monsoon and posted the revision on my homepage. Basically I have declared my onset period outlook a bust as there's no way the 'soon will start by July 7th and have scaled down my rainfall expectations. I now believe that the monsoon will start during the 15-20 July timeframe though confidence is not high-in fact, I would not be surprised if the monsoon didn't start at all in July. This Summer is fast becoming a loser.

Steve

Posted: Fri Jul 02, 2004 10:23 pm
by azsnowman
Indeed it is Steve.....AH WELL, the way the FIRES are burning up here, it won't matter in a few days, there won't be anything LEFT to water!!!

Dennis

Posted: Sat Jul 03, 2004 6:17 pm
by Aslkahuna
I have posted a Monsoon Climatology page on my homepage which can be accessed from the main Climatology page there. It compares the monsoon averages and actuals for Tucson and my records for the period of 1987 through 2003 which is the POR for my records.

Steve
8-)

Posted: Sat Jul 03, 2004 6:43 pm
by cycloneye
Steve I am curious as you live at that part of the US and may know some past history about the monsoons.My question is Is there haved been a year or years that the monsoon never showed up?

Posted: Sat Jul 03, 2004 11:15 pm
by Aslkahuna
There has never been a year when the monsoon failed to show (the latest start since 1949 was July 25th in 1987) however, there have been years when it was extremely pathetic-to the point that it didn't make any difference if it had shown or not. The monsoon is a seasonal reversal of windflow, pressure and mass transfer patterns and being such it doesn't have to be a wet one.

Steve