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Area forecast discussion 
National Weather Service Tucson Arizona
320 am MST Wednesday Oct 7 2015 upper level low pressure system will move slowly
southeast across the area today. State through Wednesday. This will
result in continued chances for showers and thunderstorms with the
main coverage from Tucson east and northeastward today. In addition
expect cooler daytime temperatures. The second half of the week
will see a warming trend...but still a few showers mainly near
eastern mountains and the international border as the low hangs
around over northwest Mexico.


Discussion...our low is right over eastern Maricopa and northern
Pinal County this morning...drifting slowly on a track that will
take the center into Cochise County later this afternoon. For this
morning we have an interesting area immediately south and
southeast of the low through Pinal and eastern Pima County. About
500-700 j/kg surface computed cape coming together with a secondary
area of 850-500hpa bulk shear between 20 and 35 kts for early
morning showers and thunderstorms. Slower storm motion than
yesterday this close to the low so heavier rainfall amounts possible
from individual storms...however we will be less prone to training

As the low shifts slowly through...the cool pool will help keep
things unstable even as we lose shear magnitude during the day. The
most active eastern area of the low will put Cochise and Graham
counties under the gun for the strongest storms today.

With features below 40n now taking control...Thursday will see the
low sagging into northwest Mexico as the ridge builds near the West
Coast. Weaker wrap-around activity for areas mainly east of Tucson
and near the international border Thursday.

The low will then retrograde under the influence of the
ridge...ultimately on a trip back to a position near the Pacific
Baja California coast over the weekend. It will tend to fill and weaken
somewhat as it does so and current model resolutions may not be
showing enough weakening over time. Regardless...this same low will
probably show back up in our weather again around the middle of next


Aviation...valid through 08/12z.
Expect isolated to scattered rain showers with a few embedded thunderstorms and rain this
morning along with scattered to broken clouds with bases
generally 4-9 kft above ground level. Localized areas of valley fog possible
dependent on partial intermittent clearing...although confidence is
too low to include mention in tafs at this time. Scattered rain showers/thunderstorms and rain
will redevelop today with greatest coverage expected north and east
of a kgxf-ktus-kols line. Surface winds generally less than 12 kts
outside of thunderstorms and rain influences. Aviation discussion not updated for taf


Fire area of low pressure will be hanging around the
SW US much of the coming week. The best chance for showers and
thunderstorms in Southeast Arizona will continue through today but cooler
temperatures and unsettled weather will persist through the weekend.
As the low moves southward...a strong east wind will develop over Southeast
Arizona Friday. Otherwise...20 foot winds will be fairly light
outside of thunderstorms.


Twc watches/warnings/advisories...none.




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