textproduct: NWS Phoenix

UPDATE

Updated Aviation

KEY MESSAGES

- Cold mornings with seasonal afternoon temperatures are expected through the first half of the week.

- Dry and tranquil weather conditions will prevail through the week with a slow warming trend into the weekend.

SHORT TERM /TODAY THROUGH MONDAY/

The atmosphere has dried considerably over the last 12-24 hours in the wake of the shortwave trough which is now pushing through northern TX. Surface RH values have decreased by up to 20-40% and PWAT values are down to 0.1-0.2" on mesoanalysis. Cooler air has also filtered into the region, with most areas experiencing lows this morning in the 30s to mid 40s. Highs this afternoon will reach the mid to upper 60s across the lower deserts, slightly below normal for late January, with mostly sunny skies. Lighter winds tonight and tomorrow morning, along with mostly clear to partly cloudy skies, will lead to slightly cooler temperatures than this morning. Isolated areas of frost may form Monday morning in parts of Pinal County, where temperatures dip into the low to mid 30s.

Monday will feature some breeziness across southern AZ after sunrise, in response to a strong surface high (1040mb) developing in CO. Easterly wind gusts up to 15-25 mph are expected with gradual relaxing of the winds through the afternoon. After another cold morning, high temperatures will warm a couple degrees, back to around seasonal levels, while under scattered high clouds.

LONG TERM /TUESDAY THROUGH SUNDAY/

Through the rest of the workweek and next weekend, a progressive pattern will take shape with successive ridges and troughs within a subtropical westerly flow. Despite the troughs, prevailing positive 500mb height anomalies are forecast throughout the next week by global ensembles. This will result in at least a slow warming trend through the week, with lower desert high temperatures pushing middle 70s by the middle of the week and upper 70s by next weekend. A trough mid to late week will bring an increase in mid and high clouds and likely virga to the Desert Southwest, but that is about it. Previous model runs had some light precipitation with this trough, but that is all but gone now. Latest NBM has PoPs max out around 5% with this trough. So, expect continued dry conditions, and overall tranquil weather conditions, through the next 7 days at least.

AVIATION

Updated at 0515Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT: No major weather concerns will exist through Monday night under thickening cirrus decks. Confidence is fairly good that easterly winds will prevail throughout the period with only modest probabilities of minor variability around sunset Monday. There may be a few gusts around 15kt late Monday morning, though having minimal impact on operations.

Southeast California/Southwest Arizona including KIPL and KBLH: No weather concerns will exist through Monday night under periods of thick cirrus decks. Winds will generally favor a north component at KBLH and NW at KIPL, however extended periods of nearly calm conditions will be common.

FIRE WEATHER

Dry weather conditions will prevail through at least the next week, with daily MinRH values around 10-25% across all districts. Overnight humidity recoveries will be around 35-55% in most populated and agricultural areas. With the dry conditions, no precipitation is expected. Elevated easterly winds winds are expected the next few mornings across southern AZ districts, with gusts up to 15-25 mph. Otherwise, expect light diurnally driven winds. Temperatures will be near normal the next few days and then warm above normal by the second half of the week into next weekend.

PSR WATCHES/WARNINGS/ADVISORIES

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