104 
fxus65 kpsr 200321 
afdpsr 


Area forecast discussion 
National Weather Service Phoenix Arizona 
145 PM MST Friday Mar 19 2010 


Synopsis... 
a fast moving cold front moved through southeast California and 
Arizona today...leaving clear skies and breezy conditions over the 
region. Temperatures will begin to warm again above normal starting 
Sunday and Monday before dropping again as another low pressure 
system skirts eastern Arizona on Wednesday. 


&& 


Discussion... 
low pressure trough and cold front quickly swept through southeast 
California and Arizona today. Only a few weak showers made it to the 
ground with most of the precipitation remaining aloft. There were a few 
brief lightning strikes and one or two stray reports of blowing dust 
when the front went through. Out west winds picked up to the 20-35 
miles per hour level along the lower Colorado River valley...just barely at or 
near Wind Advisory levels. These winds are already beginning to 
weaken...and so have elected to kill the Wind Advisory which was 
scheduled to run until 5 PM MST/PDT. 


The low is now located along the border between southern Arizona and 
Sonora Mexico and if forecast to merge in with the larger storm 
system setting up across West Texas. GFS and European model (ecmwf) are in agreement 
over the next few days...with a ridge setting up over the region for 
the weekend. By Monday the next storm system...this one coming off 
the Pacific across Southern California...will begin to move into our 
County Warning Area. Not much precipitation is indicated with this system and is forecast 
to merge in with a Rocky Mountain low pressure system dropping down 
across the Great Basin on Tuesday. This second system will skirt the 
northeastern quadrant of Arizona. At this time not much weather is expected 
from either of these two lows. Main impact may be some enhanced 
gradient wind Tuesday and especially Wednesday. Given that...have 
cut back the probability of precipitation for that system. Not anticipating any hazardous 
weather anymore for the next seven days...and so decided to 
terminate the severe weather potential statement at the same time as the Wind Advisory was cancelled. 


Temperatures should remain a little above normal for the next few 
days before falling back to the 70s when the Wednesday system passes 
by. Little or no rain is expected for most of the region for the 
seven days with only a slight chance for Wednesday across higher 
terrain north and east of Phoenix. 


&& 


Aviation... 
kipl...kblh...and surrounding airfields... 
the cold front is already well through southeast California and 
gusty winds are still ongoing. I expect the winds to stay up until 
00-03z at which point the gustiness should go away. Generally light 
winds around 12z at ipl but a strong 10-15kt northerly wind is 
possible at blh all night through the end of the taf period. 
Otherwise VFR conditions with clear skies and no visibility restrictions. 


Kphx...kiwa...and surrounding airfields... 
cold front is through the area. Showers are over and I expect mostly 
clear skies from 21z through the end of the taf period. Winds will 
pick up a bit this afternoon but should weaken a bit and the 
gustiness should diminish after 00-03z. Winds will become 
northwesterly tonight...then northeasterly after 08z as high 
pressure builds in from the north. 


Aviation discussion not updated for amended tafs. 


&& 


Fire weather... 
Sunday through Thursday... 
lighter winds and a warming trend are anticipated Sunday into 
Monday...before another low pressure system tracks across the region 
Tuesday into Wednesday providing the area with cooler maximum 
temperatures and a slight chance of precipitation. High pressure 
returns Thursday...along with warmer and drier conditions. 


&& 


Psr watches/warnings/advisories... 


Arizona...none. 


California...none. 


&& 


$$ 


National Weather Service Phoenix is on the internet at 


Weather.Gov/Phoenix 


Discussion...waters 
aviation...leins 
fire weather...leins