textproduct: NWS Phoenix

KEY MESSAGES

- Dry conditions and above normal temperatures will prevail through early next week.

SHORT TERM /Today through Thursday/

An amplifying blocking pattern continues to develop over the Conus with pronounced ridging centered over northern California, and negative height anomalies from the Hudson Bay vortex descending into Great Lakes and Northeast. This is a common and very stable pattern for January which shows no signs of deteriorating over at least the next 7 days. Resounding large scale subsidence will ensure dry conditions with, at most some passing thin cirrus. The expansion and intensification of western ridging over the next 48 hours will allow H5 heights to rise into a 582-585dm range to settle over the forecast area. Narrow ensemble guidance spread yields excellent forecast confidence of temperatures 8F-12F above normal, yet still a few degrees short of record territory.

LONG TERM /Friday through Tuesday/

Ensemble members are in good agreement that some form of the western Conus blocking pattern (whether it be a Rex or omega block) will hold through the weekend and into early next week. During this time frame, strong high pressure will be maintained with temperatures remaining well above normal (6-10 degrees) continuing into early next week. The warmest temperatures are forecasted to be during the end of the workweek, coinciding with the high pressure near its climatological max. Over the weekend, the high pressure across the region is expected to retrograde slightly into the NW coastline or northeast Pacific, however ridging will still be present over our region, with only a few degrees of potential cooling due to the relaxation of H5 heights. With ridging continuing to dominate our region into early next week, dry conditions will also continue.

AVIATION

Updated at 2356Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT; and Southeast California/Southwest Arizona including KIPL and KBLH:

No major weather issues will exist through Wednesday afternoon under mostly clear skies. Current light westerly winds in Phoenix will revert back to easterly by mid to late evening. Easterly winds in Phoenix will then prevail through all Wednesday, with some late-morning and early-afternoon gusts as high as 15-20 kts. A light northerly wind will be preferred across SE California during afternoon daylight hours with a tendency towards a W/SW nocturnal component. Extended periods of nearly calm conditions will be common across the entire region through Wednesday morning.

FIRE WEATHER

Temperatures will warm through the week, going well above normal, and maximizing during the end of the workweek. Slight cooling of a few degrees is expected this weekend, but temperatures will remain above normal. MinRH values of 15-30% and overnight recoveries of 40-70% will continue through the end of the workweek. This weekend minRH will drop to 15-25% with overnight recoveries of 30-60%. Wind speeds return to more seasonable levels today and continue through the weekend. Winds will maintain a northeasterly to easterly prevailing direction this week across the eastern districts and a more northerly component across the western districts.

PSR WATCHES/WARNINGS/ADVISORIES

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