181 
fxus65 ktwc 161529 
afdtwc 


Area forecast discussion 
National Weather Service Tucson Arizona 
830 am MST Tuesday Mar 16 2010 


Synopsis...high pressure will continue to build along the Colorado 
River through Thursday...which will allow temperatures to climb 
above average and cause our breeziness from today to diminish. A 
storm system entering the Pacific northwest will dive southeast into 
the Southern Plains by Friday. This will sweep another...mostly 
dry...cold front across Southeast Arizona...and with it will come 
some breeziness and temperatures closer to normal. 


&& 


Discussion...forecast in excellent shape this morning. Nice ducting 
inversion and modest pressure gradient is yielding typical gap winds 
this morning...with some areas in central Tucson gusting close to 30 
miles per hour and morning lows in the 50s...with other parts of the metropolitan dead 
calm with morning lows in the lower 40s. These winds typically peak 
around 18z and then drop a bit during the afternoon...but with 
20-25kt NE winds all the way up to the lowering subsidence 
inversion...they may stay up for much of the day. One thing this 
will do...especially since we do not have a particularly cold 
airmass advecting in from the east...is it will give US a downslope 
assist on highs. It may also give US another night of widely varying 
lows tonight as dewpoints continue to slip. We will evaluate that in 
the afternoon package. 


&& 


Aviation...main aviation issue this morning are gap winds through 
our east-west aligned valleys. This is mainly affecting ktus...but winds 
at both kols and kdug will be gusty at times later this morning. 
Expect generally east-southeast winds of 12-22kt with gusts up to 30kts. 
Aviation discussion not updated for taf amendments. 


&& 


Fire weather...no fire weather concerns expected with fire danger 
remaining low. Gusty east winds today will diminish by Thursday...with 
another bout of breeziness expected on Friday. 


&& 


Climate...as stronger high pressure builds over the area next 
couple of days...Tucson might hit 80 degrees for the first time in 
2010 on Wednesday or Thursday. The historical average 1st date is 
February 12th. You can find a special webpage for this on our 
website at http://weather.Gov/Tucson 


&& 


Hydrology...there are no flood concerns at this time...but a 
combination of warm temperatures and breeziness has ripened our 
mountain snowpack again...which will lead to increasing snowmelt 
runoff out of many of the mountains over the next 2 to 3 days. This 
is more of an issue for hikers near streams since despite these warm 
temperatures...the melting will be slow enough to keep all streams 
well within their banks. Will issue an revise highlighting this later 
this morning. 


&& 


Twc watches/warnings/advisories...none. 


$$ 


Pytlak 


Weather.Gov/Tucson