Climatology 101: 1st April with above average rain since 2005

Apr 2016

11 years.

That’s a long April streak of normal to below normal rainfall in Tucson. Alas, we’re no longer streaking. A trio of storm systems dumped 0.71″ rain last month at Tucson International Airport. We were guaranteed the 16th wettest April on record as early as the 12th of last month.

Also noteworthy is the 95° day registered on April 21st. Climatology says Tucson’s first 95° typically arrives around May 2nd, but that date’s been closer to April 22nd since 2000.

Below is the complete April climate recap compiled by the good folks at NWS Tucson

April started off like March ended, cooler than normal. Then strong high pressure built over the desert southwest which resulted in well above normal high temperatures on the 4th (91°), 5th (89°) and 6th (94°).
Low pressure off the northern Baja California coast on the 7th spread moisture across the state with showers and a few thunderstorms occuring across the area late on the 7th into the 8th. This storm was the first in three Pacific storms that brought the most active precipitation weather pattern to the area since January. Rainfall amounts across the area with this first system were mostly below a half an inch with localized totals near three-quarters of an inch across the southeast sections of the metro area..
The second storm system, which was the coldest of the three systems, brought valley rain and scattered thunderstorms to the area on the 10th. Since this system was colder, daytime temperatures were mostly in the 60s to lower 70s. A thunderstorm produced a wind gust of 48 mph at the airport. Rainfall amounts were mostly below three-quarters of an inch with localized amounts over 1″ near Sabino Canyon. The airport recorded just under a half an inch (0.45″) on the 10th which not only set a daily record (old record 0.16″ in 1968) but ranks as the 20th wettest April day on record.
The last in this series of storm systems brought very light showers to the area on the 12th with rainfall amounts mostly less than a tenth of an inch.
After a rapid warmup into the upper 80s to near 90° on the 14th, a weak storm system passing by north of the area brought gusty winds and cooler temperatures on 15th through the 17th.
Daytime temperatures warmed into the 90s on the 20th and 21st under strong high pressure aloft. The first 95° high of 2016 occurred on the 21st at 2:56 pm. The historical average 1st 95° date is May 2nd, but since 2000 the average date is April 22nd.
The last week of the month was cooler than normal as several weather systems affecting the area. These systems brought very light showers and gusty winds to the area on the 27th, 28th & 30th.
Temperature extremes for the month ranged from a high of 95° on the 21st to a low of 44° on the 1st. The average temperature for the month of 68.6° is 1.6° above normal and ranks as the 23rd warmest April on record (tied with 1993 & 1994).
April 2016 daily high temperature departure from normal April 2016 daily low temperature departure from normal
Click on image above for larger view
Rainfall amounts across the metro area for the month, using several sources like rainlog.org, the Pima County Regional Flood Control District gages and CoCoRaHS, varied widely and ranged from 0.20″ to 1.50″ with locally higher amounts. Most of the 1″+ total was in an area extending from from mid-town to Sabino Canyon. The International airport, which is the official recording location for Tucson, recorded 0.71″ which is 0.40″ above normal and ranks as the 16th wettest April on record.
April 2016 stats
Month
Normal
Departure
Average high temperature
82.9°
82.1°
+ 0.8°
Average low temperature
54.3°
52.0°
+ 2.3°
Average temperature
68.6°
67.0°
+ 1.6°
Rainfall
0.71″
0.31″
+ 0.40″

Spring 2016 (so far)
Two-thirds of Spring 2016 is in the books and its been another warm one for Tucson. The average temperature so far of 66.8° ranks as the 4th warmest on record (tied with 2011 & 2014). Rainfall across the metro area generally ranged from 0.25″ to 1.50″ with localized totals up to 2.50″. Officially, the airport has recorded 0.82″ which ranks as the 53rd wettest March/April period on record.
Spring 2016 stats (March-April)
Year
Normal
Departure
Average high temperature
81.6°
78.1°
+ 3.5°
Average low temperature
52.0°
49.1°
+ 2.9°
Average temperature
66.8°
63.6°
+ 3.2°
Rainfall
0.82″
1.04″
– 0.22″
Warmest March/April period on record – 69.4° in 1989
Driest March/April period on record – Trace in 1895
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