With a cold/dry air mass over the region, coupled with clear skies and light winds, another round of freezing to near freezing temperatures occurred across the valley this morning. The map to the right shows temperatures across the state recorded at 8:00am this morning (current valley, state and west US maps can be viewed by clicking HERE). As can be seen, the lowest temperature on the maps is a very cold –14ºF at the Grand Canyon. The low temperature at our location was 31.9ºF, occurring at 7:34am, which is actually the lowest temperature recorded so far this year.

With continued clear skies and light winds expected tonight into early tomorrow morning, temperatures are likely to once again be right around the freezing mark tomorrow morning. Be sure to protect any sensitive plants and take action to protect your outdoor pets.

A storm system may spread clouds over the region Monday morning into the middle of next week that will result in low temperatures rising above the freezing mark for almost locations across the valley. This system may also bring the area a chance of rain for the first part of next week, but that will be discussed in more detail later.

The storm system which moved through the region on December 22nd, brought with it cold air that has resulted in below normal high and low temperatures for this time of year over the past couple days. With clear and calm conditions tonight and Saturday night, temperatures will fall to near or slightly below the freezing mark during the early morning hours Christmas Day and Saturday morning. Be sure to protect frost sensitive plants and animals from the cold conditions.

Frost is possible on roof tops overnight; however, do not worry, as it will not pose a threat to Santa in either landing or taking off as he should have made his deliveries before the frost develops.

Merry Christmas!

Track Santa on his journey across the world using NORAD’s sophisticated tracking system!

To track Santa LIVE (starts Christmas Eve), click on the link below:
http://www.noradsanta.org/

Weather Bus.com wishes everyone a very Merry Christmas and a Happy New Year!!

A Public Information statement released by the National Weather Service in Tucson indicates that five car accidents, resulting in 2 fatalities occurred today (Saturday, Nov 28th) on I-10, two miles southeast of Picacho.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
414 PM MST SAT NOV 28 2009

*** 2 FATAL, 1 INJ *** TOTAL OF 5 ACCIDENTS REPORTED ON INTERSTATE 10 NEAR MILE MARKER 214 DUE TO LIMITED VISIBILITY IN BLOWING DUST. ONE ACCIDENT RESULTED IN 2 CONFIRMED FATALITIES AND 1 SERIOUS INJURY.

If you are caught in a dust storm the National Weather Service recommends the following:

If dense dust is observed blowing across or approaching a roadway, pull your vehicle off the pavement as far as possible, stop, turn off lights, set the emergency brake, take your foot off of the brake pedal to be sure the tail lights are not illuminated. In the past, motorists driving in dust storms have pulled off the roadway, leaving lights on. Vehicles approaching from the rear and using the advance car’s lights as a guide have inadvertently left the roadway and in some instances collided with the parked vehicle. Make sure all of your lights are off when you park off the roadway. Don’t enter the dust storm area if you can avoid it.

If you can’t pull off the roadway, proceed at a speed suitable for visibility, turn on lights and sound horn occasionally. Use the painted center line to help guide you. Look for a safe place to pull off the roadway. Never stop on the traveled portion of the roadway.

A news story, from a media outlet in Tucson, regarding these accidents can be viewed by clicking the link below:
http://www.kvoa.com/news/dps-investigating-five-separate-collisions-along-i-10/

For a more complete list of weather hazardous, click on the link below:
http://www.wrh.noaa.gov/psr/general/safety/index.php

A cold front moved through the valley this afternoon, resulting in much cooler temperatures and breezy conditions. Several areas of showers and thunderstorms also developed behind the front as a result of cold air aloft and other forcing mechanisms rotating around the low (currently centered in southern CA – image to the left).

The low pressure system will move into northern Mexico tonight into tomorrow morning (image to the left). As the low brushes the state to the south-southwest additional dynamics may move through the valley resulting in another chance of rain tonight into tomorrow afternoon. By tomorrow evening into Monday the low will move to the southeast of Arizona, resulting in clearing skies from west to east.

With cold air moving into the region with this low pressure system, temperatures Sunday and Monday will be in the mid 60’s, which is a couple degrees lower than average for this time of year.