Phoenix Monsoon

2010 Monsoon Outlook

Monsoon season is scheduled to start June 15, after the definition was redefined to be date-based (June 15) instead of weather based (3+ consecutive days of average dewpoint of 55F or higher). The average start date based on the "old" (or I would prefer "traditional") method was July 7.

Last year's monsoon was just awful, with few storms and even less actual rainfall.

Conversely, El Nino dropped buckets of rain this winter, putting many areas at their annual-average by the end of February.

According to the Climate Prediction Center the Summer months are likely to be above normal in temperature with average precipitation. Last Summer was one of the hotest on record in the Phoenix area, with the average daily temperatures in July and August being almost unbearably hot.

Here's hoping for an early, long, and intese Monsoon Season in the Phoenix Area!

Forecast for this weekend

	Tonight Partly cloudy. Chance of showers and thunderstorms in the evening...then isolated showers and thunderstorms after midnight. Lows 75 to 83. Southwest wind 5 to 15 mph. Chance of rain 30 percent.
	Saturday Considerable cloudiness. Scattered showers and thunderstorms in the morning...then numerous showers and thunderstorms in the afternoon. Much cooler. Highs 88 to 93. South wind 5 to 10 mph. Chance of rain 60 percent. » ZIP Code Detail
	Saturday Night Partly cloudy. Chance of showers and thunderstorms in the evening...then slight chance of showers and thunderstorms after midnight. Lows 73 to 80. Southwest wind 5 to 10 mph in the evening...becoming southeast around 5 mph after midnight. Chance of rain 40 percent.
	Sunday Partly cloudy. Slight chance of showers and thunderstorms in the morning...then chance of showers and thunderstorms in the afternoon. Highs 92 to 97. Northeast wind around 5 mph in the morning...becoming south in the afternoon. Chance of rain 30 percent. » ZIP Code Detail
	Sunday Night Partly cloudy. Chance of showers and thunderstorms in the evening...then slight chance of showers and thunderstorms after midnight. Lows in the mid 70s to lower 80s. Chance of rain 30 percent.
	Monday and Monday Night Partly cloudy. A 10 percent chance of showers and thunderstorms. Lows in the mid 70s to lower 80s. Highs 96 to 101.

Storm

Unable to look at any satellite images (the network here at my office is moving wicked slow) but I'm sitting here at 48th street and Broadway and just heard thunder three different times. Definitely some dark clouds out there but doesn't look like a full fledged storm or anything. Will update later.

Hoping my car gets some of the dirt washed off.

Heat Island

Take a look at this:

Common during the Summer, and much more common over the last 15-20 years, the Heat Island can significantly disrupt developing thunderstorms by creating such strong updrafts that clouds can't move down into the Valley.

This is one of the most frustrating (and common) sat/radar views you will see during the Summer.

Thankfully today it looks like we might be able to overcome the island, as the T-Storms developing to the North and East are looking good.

Update

Storms are continuing to draw down toward the Phoenix area from the North. Looks like we could be in for an exciting night!

NWS:

Scattered showers and thunderstorms will slowly develop over northwest and central Maricopa County...including the greater Phoenix area...and northwest Pinal County through the evening hours. Thunderstorms will be capable of producing moderate to heavy rainfall...as hourly rainfall rates may approach one inch. Brief gusty winds to 45 mph may also accompany these storms.

Monday Activity

So far activity has stayed out of Maricopa county, choosing instead to Pummel Payson, Prescott, et. al.

Sat data indicates that clouds are moving down from the north, likely to hit Fountain Hills and North Scottsdale, possibly working over to Phoenix/Glendale/Peoria, etc.

Keep your eyes on the data. We'll update as things progress.

http://www.wunderground.com/wundermap/?lat=33.48644&lon=-112.06055&zoom=8&typ...

Here are some pics of last night's lightning show, taken from Peoria:

http://www.flickr.com/photos/mcphat/3739963246/sizes/l/

http://www.flickr.com/photos/mcphat/3739953776/sizes/l/

Maps of Phoenix Conditions

A great map of current Phoenix conditions:

http://www.wunderground.com/wundermap/?lat=33.48644&lon=-112.06055&zoom=10&type=ter&units=english&rad=1&rad.num=1&rad.spd=25&rad.opa=70&rad.stm=1&rad.type=N0R&rad.smo=1&rad.mrg=0&wxsn=1&wxsn.mode=tw&svr=0&cams=0&sat=1&sat.num=1&sat.spd=25&sat.opa=85&sat.gtt1=109&sat.gtt2=108&sat.type=IR4&riv=0&mm=0&hur=0&fire=0&tor=0&ndfd=0&pix=0

Storms Rolling into Valley

More storms are rolling into the Valley this evening. Stretching mostly across the southern end of town, lightning, thunder, and very high winds are thrashing Chandler, Southern Phoenix, Goodyear.

Chandler has recorded a 40+ MPH gust so far.

Storms seem to be headed into Tempe and Scottsdale, and perhaps even the NW valley, which is currently only receiving the winds and dust, with a bit of lightning visible off to the south and west.

Duststorm moving into southeast valley

Outflow from a storm to the SE has entered the valley and limited visibility across Tempe Mesa Gilbert Chandler.

Further developments to follow

Casa grande

Storm is about to slam Casa Grande