Area Forecast Discussion
Issued by NWS Phoenix, AZ

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS65 KPSR 221005 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 305 AM MST Wed Nov 22 2017 .SYNOPSIS...
-- Changed Discussion --
Dry weather and unseasonably warm temperatures will persist through the weekend with near record highs each day. High pressure will weaken early next week bringing cooler, although still above average temperatures.
-- End Changed Discussion --
&& .DISCUSSION...
-- Changed Discussion --
The unseasonably strong high pressure ridge has now moved over much of Arizona and southern California with the 594dm 500mb height center just off the coast of Baja. This positively tilted ridge will remain nearly stationary through Friday, but begin to get flattened by Thursday night into Friday. Area 00z raobs showed record or near record 500mb heights and these heights should persist for another couple days. Today will be the first really widespread warm day as warm air continues to advect northward. 850mb temps reach near 20C today or around 99% of climo, and inch up another degree on Thursday which would be in record territory for the date. Highs today should increase to between 84-88 across the deserts and stick around these readings through Saturday. Thursday still looks like it should be the warmest day, likely breaking daily records. Some high clouds moving into northern and central Arizona later Thursday may impact temperatures somewhat, so temperatures may have to be adjusted down a degree or two in subsequent forecasts. A fast moving shortwave trough moving well to the north Thursday night into Friday will knock down the ridge slightly, but little change in sensible weather is expected. Once the trough moves into the Plains States early Saturday, the ridge will rebuild slightly while also pulling in drier air aloft from the southwest. This will lead to clearing skies late Friday, lasting through much of the weekend. The near record temperatures should last through the weekend with highs holding fairly steady in the middle 80s and lows mostly in the 50s. Some relief from the unseasonably warm temperatures is likely to move in early next week as a stronger upper level trough moves southward into the Great Basin on Monday. This should drop highs into the upper 70s and lower 80s while bringing increased clouds. Good model agreement shows the trough tracking southeastward through the Four Corners area Monday night into Tuesday with a weak cold front moving through the Desert Southwest Monday afternoon and evening. This will bring breezy and cooler conditions next Tuesday as highs drop into the middle to upper 70s, but these readings are still a good 5-10 degrees above normals. Heights aloft seem to trend lower into late week, likely bringing even cooler conditions. Many areas should see overnight lows dip into the 40s again starting late next week. No significant moisture is seen moving into the Desert Southwest through next week, so the dry streak will continue.
-- End Changed Discussion --
&& .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: A weak backdoor cold front moving into south-central Arizona will result in a more substantial easterly component than typical. This could result in a period of stronger/gusty easterly winds after sunrise as mixing occurs, but gusts should remain at or below 20 kt. Confidence is low that winds will shift out of the west during the afternoon, and if they do, it`ll likely be brief. For now, kept this mention out of the TAF as sustained easterly winds are expected to persist, but will weaken throughout the day. High clouds should begin to recede by late morning. Southeast California/Southwest Arizona including KIPL and KBLH: Clearing skies with very light winds, following typical diurnal tendencies will prevail for the next 24 hours. No other aviation concerns. Aviation Discussion not updated for amended TAFs. && .FIRE WEATHER... Thursday through Monday: Strong high pressure aloft will persist across the lower deserts for the rest of the week and likely into early next week as well. This will keep high temperatures well above seasonal normals with the warmer deserts into the mid to upper 80s most every day this week. Sunny to mostly sunny days are on tap through Saturday, with some increase in mid and high clouds expected Sunday into Monday. Expect relatively dry conditions as well with minimum RH values each day running from the teens to around 20 percent. Winds each day will be on the light side, favoring typical diurnal tendencies especially across the south-central deserts. && .CLIMATE...
-- Changed Discussion --
Record highs for selected dates this week: Date Phoenix Yuma ---- ------- ---- Nov 22 89 in 1950 91 in 1950 Nov 23 87 in 1950 87 in 1950 Nov 24 88 in 1950 89 in 1950 Nov 25 88 in 1950 90 in 1950 Nov 26 88 in 1950 87 in 1950 The Phoenix record high for any Thanksgiving is 87 on Nov 23 1950 and Nov 27 2014. The Yuma record high for any Thanksgiving is 87 on Nov 23 1950. Most days of 80+ during November in Phoenix: 24 in 1949. Most days of 80+ during November in Yuma: 24 in 1954, 1950, and 1949. Latest 90+ day in Phoenix: Nov 15 (1999) Latest 90+ day in Yuma: Nov 25 (1950)
-- End Changed Discussion --
&& .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook, Twitter, and at weather.gov/phoenix DISCUSSION...Kuhlman AVIATION...Rogers/Wilson FIRE WEATHER...CB CLIMATE...MO/Iniguez

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.