textproduct: NWS Phoenix

KEY MESSAGES

- Well above normal temperatures and dry weather will prevail across the entire region all week.

- Record setting highs and warm lows will be possible across the lower deserts today, including Phoenix.

SHORT TERM /TODAY THROUGH WEDNESDAY/

Large scale ridging will overall remain dominant across the Southwestern U.S. this week, but a shallow weak shortwave trough will push through the Desert Southwest today. This disturbance will only bring some higher level clouds for the first part of today followed by a 2-3 degree dip in temperatures into mid week. Highs today are likely to top the daily record of 79 degrees in Phoenix with widespread readings in the upper 70s to lower 80s across the lower deserts. Once H5 heights settle down closer to 580dm Tuesday into early Wednesday, afternoon highs will generally fall short of 80 degrees but still remain at least 10 degrees above normal.

LONG TERM /THURSDAY THROUGH SUNDAY/

The eastern Pacific ridge off the coast of southern California and northern Mexico is forecast to strengthen again over the next couple of days as it gradually shifts eastward toward our region. By Thursday into Friday, a weather system should be exiting the Northern Rockies into the Northern and Central Plains allowing the ridge to our west to move more into our region. As a result, ensemble mean H5 heights are shown to increase again closer to 585dm by Thursday or well into the 90th percentile of climatology. This should push our temperatures upward again with some lower 80s likely possible on Friday. Models do still keep the center of the ridge off the Baja coast Friday into next weekend, but the ridge will still remain dominant over the Desert Southwest through at least the coming weekend providing continued dry and tranquil weather conditions. This may eventually come to an end later next week as guidance still supports a trough setting up off the West Coast by Christmas.

AVIATION

Updated at 0845Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT; and Southeast California/Southwest Arizona including KIPL and KBLH:

No aviation weather concerns will exist through the TAF period. Winds will be light (aob 10 kts) and should remain predominantly easterly at the Phoenix Metro terminals this morning followed by a NNW-NW direction later in the afternoon into early evening. At the SE California TAF sites, winds will be mostly out of the N-NW at KBLH and the current W'rly flow at KIPL will also go N-NW'rly by late morning. FEW-SCT high clouds early this morning will transition to clear skies by the afternoon.

FIRE WEATHER

Persistent high pressure across the region will result in warm and dry conditions all week. Highs in the upper 70s to the lower 80s will be common across the lower deserts, or 10 to 15 degrees above daily normals. Winds will overall be light and mostly following familiar diurnal trends. MinRHs will range from 15-25% while overnight recoveries will generally be between 40-70%.

CLIMATE

Daily Record Highs

Phoenix ------- 12/15 79 (1969)

PSR WATCHES/WARNINGS/ADVISORIES

AZ...None. CA...None.