[AZ-Observing] A Chimichanga Storm event forecasted for Thursday

For those of you who missed the forecast this morning, a chimichanga storm
event is forecasted for Phoenix this Thursday. :-)

Below from:  http://www.wrh.noaa.gov/cgi-bin/Phoenix/redirect.pl?pil=phxafdpsr

        -Paul


FXUS65 KPSR 290941
AFDPSR
AZZ020>028-CAZ030>033-291745-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION 
NATIONAL WEATHER SERVICE PHOENIX ARIZONA
245 AM MST SUN JUN 29 2003

.SYNOPSIS...
A STRONG HIGH PRESSURE SYSTEM WILL CONTINUE BUILD ACROSS THE 
SOUTHWESTERN UNITED STATES INTO NEXT WEEK...RESULTING IN WELL ABOVE 
NORMAL TEMPERATURES. THE CENTER OF THE HIGH PRESSURE SYSTEM WILL 
MOVE INTO WESTERN NEW MEXICO BY TUESDAY...ALLOWING FOR AN INCREASE 
IN MOISTURE OVER THE EASTERN ARIZONA MOUNTAINS. THIS WILL RESULT IN 
A SLIGHT CHANCE FOR AFTERNOON OR EARLY EVENING THUNDERSTORMS...OVER 
THE HIGHER MOUNTAINS OF SOUTH CENTRAL ARIZONA TUESDAY THROUGH THE 
FOURTH OF JULY. 

.DISCUSSION...
THERE WILL BE ALOT GOING ON WITH THE UPPER TROPOSPHERIC FLOW THE 
NEXT SEVERAL DAYS...CULMINATING IN A PATTERN THURSDAY SIMILAR TO 
JULY 7TH 1999. MORE ABOUT THIS LATER.

ISOLATED CONVECTION SATURDAY AFTERNOON WAS LIMITED TO THE EAST 
CENTRAL AND SOUTHEAST AZ MOUNTAINS. MOISTURE FROM THIS CONVECTION 
WAS MID LEVEL...AND JUDGING FROM THE TUCSON SOUNDING...700 MB 
DEWPOINTS NEAR MINUS 4 C IS ALL THATS NEEDED FOR MINIMAL CONVECTIVE 
AVAILABLE POTENTIAL ENERGY. UNFORTUNATELY A STRONG 500/300 MB RIDGE 
WILL BUILD INTO AZ TODAY (STABLE PATTERN)...WITH A LITTLE MORE 
DRYING NORTHWEST WINDS AT 850/700 MB. THEREFORE CLEAR SKIES WILL 
RULE OUR FORECAST AREA TODAY AND MONDAY.  YESTERDAY THE 300/250 MB 
FLOWS WERE SLIGHTLY DIFLUENT AND SUPPORTIVE OF CONVECTION ALONG THE 
EASTERN BORDER.

THE PATTERN IS A CHANGING. BY MONDAY THE 500 MB HIGH CENTER MIGRATES 
TOWARD THE 4 CORNERS WHERE IT STAYS THROUGH JULY 4TH.  THIS IS A 
GOOD POSITION FOR MID LEVEL MOISTURE TO RETURN TO SOUTHEAST AZ FROM 
NEW MEXICO MONDAY THROUGH FRIDAY.

AT THE SAME TIME...THE 300/250 MB HIGH CENTERS START MIGRATE FROM 
JUST OFF THE NORTHERN BAJA COAST TODAY...TO NORTH CENTRAL NEW MEXICO 
WEDNESDAY.  AS A RESULT...THESE FLOWS BECOME DIFLUENT ACROSS 
SOUTHWEST NEW MEXICO/FAR SOUTHEAST AZ/AND ADJACENT OLD MEXICO FOR A 
LARGE CONVECTIVE OUTBREAK WED. NORTH AND WEST MOVING CONVECTIVE 
OUTFLOWS COULD PROVIDE SOME MOISTURE TO SOUTH CENTRAL AZ BY THU 
...WHEN 300/250 MB FLOWS BECOME HIGHLY DIFLUENT...AND REMINISCENT OF 
JULY 7TH 1999.  WE LIKE TO CALL JULY 7TH 99 THE CHIMICHANGA STORM 
EVENT IN PHOENIX. THIS IS BECAUSE THE PRESIDENT WAS IN TOWN EATING A 
CHIMICHANGA AT A LOCAL MEXICAN RESTAURANT WHEN IT HIT (SEVERE 
THUNDERSTORMS WITH BLINDING DUST...FLOODING...AND WIND DAMAGE). OF 
COURSE THAT DAY THE MONSOON MOISTURE BOUNDARY WAS NEARBY.

ALTHOUGH THE UPPER AIR PATTERN THURSDAY WILL BE SIMILAR...SOUTH 
CENTRAL AZ WILL LACK ABUNDANT MONSOON MOISTURE.  HOWEVER...IF ENOUGH 
MID LEVEL MOISTURE IS AVAILABLE (AND LIKELY)...WE COULD SEE STRONG 
DOWNBURSTS IN PORTIONS OF SOUTHEAST AZ WITH MASSIVE NORTHWEST MOVING 
DUST STORMS AND 40 TO 50 MPH OUTFLOWS TOWARD PHOENIX BY THURSDAY 
EVENING. WE WILL WATCH THIS EVOLVING UPPER AIR PATTERN CLOSELY FOR 
ANY CHANGES IN THE RIGHT DIRECTION. WE MAY KNOW AS EARLY AS SUNDAY 
NIGHT.

OTHERWISE...THICKNESS AND 700 MB TEMPERATURES REMAIN CONSTANT UNDER 
HIGH PRESSURE THROUGH THURSDAY...RESULTING IN LITTLE TEMPERATURE 
CHANGE TODAY AND NEXT WEEK. 

WE WILL CONTINUE TO MENTION THE SLIGHT CHANCE AFTERNOON/EVENING 
THUNDERSTORMS IN OUR MOUNTAINOUS ZONE 24 TUESDAY...ALTHOUGH THE BEST 
POTENTIAL MIGHT BE WEDNESDAY AND ESPECIALLY THURSDAY.  VASQUEZ 

.PSR...HEAT ADVISORY AZ ZONES 22...23...27...AND 28 FOR TODAY.

$$
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