textproduct: NWS Phoenix

UPDATE

Updated 06Z Aviation Discussion.

KEY MESSAGES

- Above normal temperatures with afternoon highs in the nineties will be common through much of the upcoming week as high pressure prevails over the area.

- A weak weather system will traverse the region Monday, providing slightly cooler temperatures and chances for scattered showers and isolated thunderstorms with activity mainly confined to the Arizona high terrain.

- Another stronger weather system is likely to affect the region late this week into next weekend, leading to breezy conditions and cooling temperatures as well as the potential for increasing rain chances across portions of the area.

SHORT TERM /Today through Tuesday/

Objective analysis shows ridging encompassing across much of the western CONUS with 500 mb height fields today expected to peak around 580 dam. Under abundant sunshine, afternoon high temperatures across the lower deserts will top out in the low to mid 90s. Overall, tranquil weather is expected for this Easter Sunday. Heading into tonight and Monday morning, another easterly wind surge similar to was observed this morning is expected with peak gusts ranging between 25-35 mph across the higher terrain areas east of Phoenix and between 15-25 mph across the lower elevations.

A weak mid-level disturbance will move through the region during the day on Monday, and with moisture levels increasing somewhat from the easterly wind surge, this will be sufficient to generate scattered showers and isolated thunderstorms across portions of the AZ High Country during the afternoon hours. Across the lower deserts, there will be too much dry air in place in the low-levels to impede any convective activity from materializing. As this disturbance moves across, there will be an abundance mid to upper- level clouds that could result in some occasional virga across the lower deserts. The abundance of clouds will cause afternoon highs to cool by 5-7 degrees from the high temperatures today, particularly across south-central AZ, as readings will top out in the upper 80s to around 90 degrees. Across the western deserts, temperatures will still manage to reach the low 90s as there will be a bit more sunshine. Heading into Tuesday, as the disturbance moves east of the area and drier air filters back into the region causing clear skies, temperatures will rebound back into the mid 90s across the lower deserts.

LONG TERM /Wednesday through Saturday/

Upper level ridging will continue to prevail through Thursday with afternoon highs in the lower deserts generally staying in the low to mid 90s. By Friday models are pointing towards a stronger upper-level low progressing into our region from the eastern Pacific. Unfortunately, at this time a lot of uncertainly can be seen on cluster analysis in the exact timing and potency of this system. However, even with the uncertainty, temperatures will most likely begin to trend back to near normal by Saturday, with afternoon highs in the mid 80s. Continued monitoring of this upcoming system will be needed, especially for increasing moisture and rain chances.

AVIATION

Updated at 0553Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT: Lingering gusty conditions will be the main aviation concern through the TAF period. Gusts are expected to be between 15-20 kts tonight lasting into the early morning hours, while sustained speeds will generally staying aoa 10kts. Easterly winds are expected to dominate, with potential for SSW winds by tomorrow afternoon, before going back easterly tomorrow evening. Virga and any light showers may create sudden wind shifts between 17-23Z Monday. The gusty winds will be capable of producing more lofted dust Monday, resulting in poor slantwise visibility at times, particularly around sunset/sunrise. SCT-BKN mid to high level clouds are expected through Monday evening then quickly moving out of the area to mostly FEW near the end of the TAF period.

Southeast California/Southwest Arizona including KIPL and KBLH:

No major aviation concerns through the TAF period. Winds will continue to primarily stay westerly flow with periods of VRB, mostly at KBLH. Wind speeds at KIPL will be slightly elevated hovering around 10kts, while a bit more relaxed at KBLH with speeds aob 08kts. SCT- BKN CIGs will remain through most of the period, before quickly filtering out by tomorrow evening into the over night hours.

FIRE WEATHER

Generally dry weather and above normal temperatures will persist during the upcoming work week. Afternoon MinRHs today will bottom near 10% across the lower elevations and near 20% across the far eastern districts before peaking on Monday to around 10-20% across the lower elevations and 25-40% across the far eastern districts. Lower humidity values return during the middle portion of the week. The increase in moisture will result in some shower and thunderstorm activity, mainly confined to northern and far eastern AZ on Monday. Another round of elevated easterly winds is expected Monday morning, particularly across the higher terrain areas of south-central AZ where peak gusts upwards of 25-35 mph are possible. Lighter winds expected during the middle portion of the week before increasing once again by the end of the week with the approach of another weather system.

PSR WATCHES/WARNINGS/ADVISORIES

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