Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Flagstaff Arizona
300 am MST Thursday Aug 28 2014
Synopsis...the low pressure system that brought rain to the region
over the past few days has moved east into Colorado this morning.
Drier northwesterly flow moving in behind the low will bring a sharp
end to precipitation chances through the first half of next week.
Long range models are showing weak signs of some moisture returning
across southeastern Arizona from next Wednesday Onward.
Discussion...the low pressure system that brought showers and
thunderstorms to northern Arizona over the past few days has moved
east into Colorado. A dry and subsident northwesterly flow has moved
in along with a high pressure ridge over Southern California and
Nevada. As a result...expect drier humidity levels...warmer days and
cooler nights with no chances for rain through the first half of next
By next Wednesday...long range models show a deep baroclinic trough
moving in across the western states. Colder air moving in with this
trough will cause upper level heights to fall across the west and
the subtropical ridge to retreat eastward. This pattern shift may open
the door for southerly flow to bring up another round of tropical
moisture from Wednesday Onward. Chances for thunderstorms will be
highest within the deeper moisture currently forecast for
southeastern Arizona with chances for storms as far north as the
White Mountains region.
Aviation...for the 12z package...expect VFR conditions for the next
24 hours. After a clear start...expect sky clear-scattered SC/cumulus with bases from
8-10kft above ground level...mainly over the mountains sky clear again after 02z Friday. Aviation
discussion not updated for amendments.
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