![National Oceanic and Atmospheric Administration](/build/images/header/noaa.d87e0251.png)
![National Weather Service](/build/images/header/nws.4e6585d8.png)
![United States Department of Commerce](/build/images/header/doc.b38ba91a.png)
Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
921 FXUS65 KTWC 052112 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 212 PM MST Fri Jul 5 2024 .SYNOPSIS...Excessive heat with temperatures expected to approach record levels in some locations. With high pressure building in from the northwest, daytime temperatures will be trending hotter into next week. Shower and thunderstorm chances will mainly be confined south and east of Tucson into early next week as drier air overspreads much of Arizona from the north. && .DISCUSSION...Our main story is going to turn to the heat over the next several days with strong high pressure driving near record heat as the monsoon temporarily dips into lower grade activity. Overall another down day with thunderstorm coverage. Moisture at the surface continues to ebb and flow as we see periodic relatively shallow input from the south. Precipitable water values are trending down, now below 1 inch in Graham, Greenlee and Pinal counties, up to 1.2 inches near the border and 1.5 inches south of the border. Isolated initiation mainly near the mountains in the early afternoon, with a few wandering into valleys south of Tucson. A good day for isolated pulse severe. They shouldn`t last much past sunset. Overall that will be the trend over the next several days, however don`t expect our corner of the state to scour all of the moisture out. Some days will be busier than others, but in general not much activity expected north of Tucson. As high pressure builds in from the northwest and we see lower levels of moisture, heights and thicknesses will support near record heat for areas from Tucson into the lower deserts. Right now we just have an excessive heat warning through Tuesday for all but Santa Cruz and Cochise counties. Ultimately it may even be extended another day or two if we don`t see much moisture return by mid week. Ensemble means continue to suggest the high center will eventually reconsolidate into a more favorable position by the middle of next week and into the following weekend. Keeping an eye on the tropics as TS Aletta off the southwest Mexican coast has been quick to hit a rough patch as expected and has been downgraded to a depression. No real impact expected for our area. Height anomalies suggest a strong easterly wave across central Mexico exiting into the Pacific later next week. That, along with a more favorable synoptic pattern should get deeper moisture back into at least our corner of the state. && .AVIATION...Valid through 07/00Z. SCT-BKN clouds at 7k-10k ft AGL and ISOLD-SCT TSRA/SHRA mainly south and east of KTUS. MVFR conditions near TSRA, with mountain obscurations and gusts to 40+ kts. Aft 06/03Z, gradual clearing with ISOLD -TSRA returning after 06/20Z. Other than TSRA outflows, SFC wind less than 12 kts favoring a WLY/NWLY direction during the afternoon/early evening hours and variable in direction at other times. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...There will be the daily chance for isolated to scattered showers and thunderstorms mainly from Tucson south and east into early next week. High pressure aloft will build to our northwest through the weekend into early next week, which will result in hot conditions. With the hotter temperatures and some of the deeper moisture getting pushed to the south and east of the region, min RH values will lower into the 10-18% range across the lower elevations and 15-30% in the higher elevations into the middle of next week. Hot high temperature are expected through early next week, with highs 109-114 degrees from Tucson westward and up to 110 in the Gila River Valley. Excessive Heat will be an issue during this time frame. Outside of any thunderstorm outflow winds, 20-foot winds will generally be 15 mph or less each afternoon with occasional gusts to 20-25 mph through the weekend. Early next week there will be the potential for more elevated wind speeds in the 15- 20 mph range, especially east of Tucson. && .TWC WATCHES/WARNINGS/ADVISORIES... Excessive Heat Warning until 8 PM MST Monday for AZZ501-502- 504>506-509. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson