<message to="mfannin2@nwws-oi.weather.gov/jaxl#8395e566314fd33c6b1bc05106c66b56" type="groupchat" from="nwws@conference.nwws-oi.weather.gov/nwws-oi"><body>KPSR issues Area Forecast Discussion (AFD) valid 2024-05-10T17:29:00Z</body><html xmlns="http://jabber.org/protocol/xhtml-im"><body xmlns="http://www.w3.org/1999/xhtml">KPSR issues Area Forecast Discussion (AFD) valid 2024-05-10T17:29:00Z</body></html><x xmlns="nwws-oi" cccc="KPSR" ttaaii="FXUS65" issue="2024-05-10T17:29:00Z" awipsid="AFDPSR" id="6107.8549"><![CDATA[

274

FXUS65 KPSR 101729

AFDPSR



Area Forecast Discussion

National Weather Service Phoenix AZ

1029 AM MST Fri May 10 2024



.UPDATE...

Updated Aviation



&&



.SYNOPSIS...

A warming temperature trend going through the weekend will result in 

above normal temperatures and increasing chances of triple digit 

highs across the lower deserts going into next week. Otherwise, dry 

conditions will persist, with afternoon breeziness continuing to 

cause areas of elevated fire weather conditions over the next 

several days.



&&



.DISCUSSION...

Early morning satellite depicts few to scattered high clouds spread 

out across southern Arizona, while water vapor imagery shows a 

persistent east to west oriented longwave trough entrenched across 

western CONUS. This trough has been responsible for keeping 

temperatures at or below normal over the last several days. However, 

this trough is expected to weaken over the next few days, as 

anomalously strong ridging that is currently over the Pacific 

Northwest impinges on this trough. However, negative or neutral 

height anomalies will continue to persist over the next several 

days, so while a warming trend will occur, it will mute the absolute 

maximums of this warming trend to the low 100s at most through early 

next week.



Ensembles have hedged towards stronger negative height anomalies to 

persist across the region through the middle of next week, resulting 

in lower probabilities of 100 degree highs for the Phoenix area to 

generally a 30-50% range through most of next week. Generally 

speaking, the warmest day based on the deterministic NBM forecast 

will be Sunday (Monday) for the western (eastern) districts as the 

trough weakens during this period before reestablishing its position 

as the aforementioned ridging flattens out early next week. Winds 

will continue to be breezy during the afternoon hours as westerly 

flow persists through this period, resulting in areas of elevated 

fire weather conditions when combined with the very dry conditions 

(minimum RH's in the 10-15% range), mainly in higher terrain areas 

where the gustiness will generally be stronger.



Looking towards late next week, ensembles continue to show 

potentially more robust ridging building into the Desert Southwest 

going into next weekend. However, ensembles show considerable spread 

in regards to a troughing feature that may dig southward across 

Alberta and Saskatchewan, which could dampen the strength of this 

ridge. Thus, temperature trends are a bit more uncertain, as chances 

for highs exceeding 100 degrees seem higher, but should the more 

robust troughing occur, high temperatures staying below 100 degrees 

would be a near certainty.



&&



.AVIATION...Updated at 1728Z.



South-Central Arizona including KPHX, KIWA, KSDL, and KDVT; and

Southeast California/Southwest Arizona including KIPL and KBLH: 



Winds will follow their typical diurnal patterns and be very

similar to what they have been over the past couple of days.

However, wind gusts this afternoon will be less with gusts only up

around 15 kt. periods of variable winds will also be common, 

especially during times of wind shifts and the late night/early 

morning hours. Skies will remain mostly clear with a FEW passing

cirrus cloud decks at times.



&&



.FIRE WEATHER...

Temperatures are expected to warm over the next several days, with 

chances for highs reaching 100 degrees increasing above 50%, at 

least for the western districts, by late this weekend. Temperatures 

are expected to remain above normal going through early next week. 

MinRHs will be in the 5-10% across the lower deserts and in the 10-

15% range across the higher terrain through this weekend. Overnight 

recovery will be poor in the 20-40% through tonight, before improved 

recoveries in the 30-60% range heading into early next week. Typical 

springtime breeziness continues through the weekend with afternoon 

and early evening wind gusts of 20-25 mph. These breezy conditions 

combined with dry fine fuels, and low RHs will likely create some 

elevated fire weather conditions. Dry conditions persist into next 

week.



&&



.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...None.

CA...None.

&&



$$



DISCUSSION...Young

AVIATION...Berislavich/18

FIRE WEATHER...Young/Berislavich

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