At least three large fires (Juliet, Marek and Sesnon) continue to burn in Southern California. This morning, the three fires could actually be seen on the Infrared satellite imagery (see photo below).

Infrared satellite works by reading the infrared radiation emitted from earth. Normally we look at cloud top temperatures using this imagery, however since skies were clear this morning over the southwest US, the surface temperatures were being picked up by the satellite. Since the ground around the fires was cooler and the fire/smoke is very hot, it shows up on the imagery as black areas.

Smoke from fires currently burning in California, and being driven by Santa Ana Winds, can be seen on visible satellite. Below is an image taken at 2:30pm, showing the large area of smoke being pushed off to the WSW over the Pacific Ocean.

As stated, in our last post “Cold Front Moves Through - Cool Weather!”, a trough of low pressure and associated cold front have brought a very dry and cold air mass into the area. This mornings low temperature at our location was 43.6ºF, which is lowest temperature we have ever recorded for the month of October, since our records began in 2001.

Numerous location across the high country of Arizona set new record lows for the day (October 12th). These records include:

City / New Record / Old Record in Date
Bagdad / 35 / 40 in 1969
Cottonwood / 35 / 35 in 1986 (tied)
Grand Canyon S. Rim / 18 / 21 in 1969
Prescott / 23 / 24 in 1946
Winslow / 21 / 25 in 1969

This cool air mass should continue over the area through Monday, with high pressure then building back into the area for the rest of the week, resulting in warmer temperatures.

Over the past several days, a strong trough of low pressure has been digging down into the western United States, resulting in windy and cooler weather across the area. Today, October 11th, a cold front, associated with this strong low pressure system, moved through the area, leaving in its wake very dry and cold air. While this cold front moved through our area on the dry side, just to our east, in southern Gila, Graham and Cochise County, strong to severe thunderstorms (even some supercells) where able to form within the area of very strong dynamics ahead of this system, coupled with moisture streaming into the area from Hurricane Norbert to our south.

The loop above/right is the surface analyses for the day, showing the cold front moving through the state. Looking at the graphs/tabular data, the front likely moved through our area around 8:00am this morning. Below is the tabular data (7:30am to 8:30am) and the graphs (temperature/dew point/wind direction) which shows the passage of the cold front.

Time / Temp / Dew Pt. / Hum / Wind Dir
7:30am / 72.3 / 49 / 44 / 138º
7:45am / 73.3 / 50 / 43 / 185º
8:00am / 72.7 / 42 / 33 / 228º
8:15am / 72.0 / 48 / 31 / 265º
8:30am / 69.4 / 38 / 30 / 285º

This area of low pressure will continue to bring cool air into the region throughout the next couple days, resulting in below normal temperatures. This system will likely shift off to the east by Monday/Tuesday as high pressure builds back into the area resulting in a warming trend.

Enjoy the cooler weather!

The 2008 Monsoon Season has come to an end as of September 30th, as a result of the newly created finite start and end dates. The season started back on June 15th.

During the 2008 Monsoon Season, our location received 4.48in. of rainfall, with the peak rain rate being 5.24in/hr, occurring on August 20th. The peak wind gust also occurred on August 20th, and was from the north at 44mph.

A complete summary of the 2008 Monsoon Season will be made available this weekend, which will include a complete suite of statistics, radar archives, photos, etc..