textproduct: NWS Phoenix

UPDATE

Updated Aviation Discussion.

KEY MESSAGES

- Strong high pressure over the region will continue to result in dry conditions and well above normal temperatures, leading to daily record warmth, through the rest of the weekend.

- Cooler temperatures, although remaining above normal, along with continued dry conditions can be expected next week.

SHORT TERM /TODAY AND SUNDAY/

Latest objective analysis shows the ridge of high pressure centered near the central Baja Peninsula with 500 mb heights across the region ranging between 584-586dm. 850 mb temperatures continue to hover near 20C, which is near record maximum for this time of the year. As a result, afternoon high temperatures will once again be anomalously warm with readings topping out low to mid 90s across most of the lower desert communities, with even some upper 90s across the western deserts, especially between Yuma and El Centro. In fact, there is even a 50/50 shot that El Centro may actually hit 100 degrees later this afternoon. Either way, record highs are most certainty going to be tied/broken across all three of major climate sites (Phoenix, Yuma, and El Centro). There is even a high probability (>70% chance) that Phoenix may set the all-time high temperature record for February. By Sunday, the ridge will be on a slight weakening trend as a upper trough approaches the northern California coast. However, despite the slight lowering of heights aloft, low-level thermal profiles will remain nearly unchanged and thus surface temperatures will once reach the low to mid 90s with daily record highs once again likely to be broken. With afternoon high temperatures in the 90s, and especially occurring this early in the year when the body has yet to fully acclimate to the heat, it is very important to perform the necessary heat precautions if planning outdoor activities during an extended period of time during the warmest portion of the day.

LONG TERM /MONDAY THROUGH FRIDAY/

The Pacific weather system is forecast to quickly weaken as it moves across the northern half of California early Monday and through the Great Basin later Monday and Monday night. The path of the system will mostly be outside of our region, but it will be close enough to totally displace the ridge well to our southeast. Monday looks to be a fairly breezy day with gusts commonly reaching 20-25 mph during the afternoon hours. Lowering heights early next week will help to bring temperatures back down into the upper 80s for most of the lower deserts on Monday and likely into the low to mid 80s starting Tuesday.

The weather pattern for the rest of next week looks to stay fairly progressive with a quick moving weak shortwave ridge on Wednesday followed by more persistent troughing setting up late next week. Dry conditions should however continue to prevail through the rest of the workweek as any system that may affect our region will be fairly moisture starved. Guidance is attempting to suggest an upper low will develop somewhere within or just to the west of our region by next weekend. This system could eventually bring some precipitation chances for some areas next weekend, but uncertainty on its strength, track, and moisture availability remains very high.

AVIATION

Updated at 0510Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT; Southeast California/Southwest Arizona including KIPL and KBLH: No aviation weather concerns will exist during the TAF period under FEW to BKN high cirrus decks. Winds will follow a persistent diurnal trend with speeds generally AOB 10 kts at all terminals. Periods of variability to nearly calm conditions are anticipated, particularly during the morning and typical diurnal transitions. A few gusts to 15-20 kts cannot be ruled out Sunday evening into the overnight hours at KIPL.

FIRE WEATHER

Warm and dry weather will continue through the middle of next week as well-above normal temperatures cool slightly as the weather pattern begins to shift. Minimum afternoon humidity levels will fall into the teens across the lower elevations with some areas nearing single digits Sunday and Monday. Humidity levels will only be somewhat higher in foothills and mountains. This will follow mostly fair to good overnight recovery of 30-60% though some areas of poor recovery under 20% will exist early next week. Wind speeds will largely remain under 15 mph with modest afternoon upslope gusts 20-25 mph becoming common. The strongest gusts would be expected Monday and Thursday afternoon. Overall conditions will be favorable for early spring prescribed burning operations.

CLIMATE

Daily High Temperature Records:

Phoenix Yuma El Centro --------- --------- --------- 2/28 89 (1986) 97 (1986) 92 (1986) 3/1 89 (2016) 93 (1986) 91 (2016) 3/2 90 (2016) 94 (1910) 92 (2016)

PSR WATCHES/WARNINGS/ADVISORIES

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