textproduct: NWS Phoenix

UPDATE

Updated 12Z Aviation Discussion.

KEY MESSAGES

- Breezy to locally windy conditions for the foothill and higher terrain areas of the Desert Southwest will continue today.

- Dry conditions will prevail as temperatures rise toward well above normal levels by the middle of the week.

SHORT TERM /Today through Tuesday/

A rex block pattern has set up over Western CONUS with the center of the low currently positioned over southern Baja Peninsula. The center of the low will remain to the south of our region during its track but this pattern has been responsible for the gusty conditions seen in many areas of the eastern portions of the CWA. Gusty condition with speeds between 25-30 mph to higher speeds possible in the higher terrain areas will be common today in the late morning to early afternoon hours. However, due to the limited scope of advisory level winds, no wind products will be issued. After a stretch of near to below normal temperatures, temperatures will be climbing back to above normal as H5 heights will be between 576-580 mb, near climatological max for this time of year. This will drive temperatures for the start of the upcoming workweek as lower desert highs rebound into the upper 60s and lower 70s.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

Ensemble members are in good agreement that the rex blocking pattern will hold through at least the beginning of the workweek before the low finally starts to break down by Wednesday, with what little is left being absorbed into a large troughing feature over Eastern CONUS. During this time period the high pressure will strengthen with temperatures gradually warming throughout the work week. The warmest temperatures of the week are forecasted for the end of the workweek, coinciding with when the high is forecasted to be near climatological max. By Wednesday, high temperatures will warm into the mid to upper 70s to near 80 degrees across the lower deserts and in the mid 60s to low 70s across the higher terrain. Temperatures in this range will be 7-10 degrees above normal for the middle of January. By the weekend, the high pressure over the region will retrograde slightly into the NW coast line, however ridging will still be present but this will allow temperatures to cool a few degrees across the CWA. Dry conditions will also continue through the weekend.

AVIATION

Updated at 1120Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT: E'rly winds will prevail through Monday under FEW to SCT cirrus clouds. Winds this morning and overnight tonight will remain elevated, sustained up to 5-10 kts, across parts of Phoenix, with lighter winds in sheltered locations like KSDL. Marginal LLWS impacts are through early this morning, with shear magnitudes around 20-30 kts. E'rly wind gusts up to 15-25 kts will develop later this morning beginning around 17Z and then gradually subside through the afternoon.

Southeast California/Southwest Arizona including KIPL and KBLH: No major weather issues will exist through this TAF period. Confidence is very good that a northerly wind component will be preferred at KBLH through the TAF period, while KIPL sees westerly winds during the overnight hours and northerly during the day. FEW to SCT cirrus will pass over the area through Monday.

FIRE WEATHER

Temperatures will be near to slightly above normal today and will gradually warm through the workweek. Temperatures will go well above normal by the middle of this coming week. MinRH values of 15-30% and overnight recoveries of 40-70% will continue through this coming week. Breezy to locally windy conditions will continue today. The highest gusts will be across the eastern districts, especially ridgetops, where gusts in excess of 40 mph are likely through the early afternoon. Wind speeds will return to more seasonable levels this evening and continue into next week. Winds will maintain a northeasterly to easterly prevailing direction today and possibly into early next week.

PSR WATCHES/WARNINGS/ADVISORIES

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