Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
276 FXUS65 KTWC 112055 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 155 PM MST Sat May 11 2024 .SYNOPSIS...Warm, dry, and breezy conditions continue through the weekend. Daily high temperatures will be near normal through the weekend, then several degrees above normal next week. && .DISCUSSION...Satellite imagery shows an upper level low over northern Arizona that has brought in the continuous westerly flow across Southeast Arizona over the last several days. Luckily, the low will be moving out of our hair very soon. But first, it will bring gusty to breezy conditions rest of this afternoon and keeping temperatures around the 80s to lower 90s. Near similar conditions expected tomorrow as the low moves to our east, but the winds will be more on the gusty side with pockets of locally breezy. Temperatures for the start of the week will be a near to slightly above seasonal normal. The typical afternoon gusty winds returns due to the differential heating of the May sun. By Wednesday, a small upper level low, along with a larger trough draped along the Great Basin, will be moving through the region to keep temperatures in check and bringing low chances (~20%) for showers and thunderstorms for the White Mountains. Looking ahead in the last half of the week, ensemble model consensus is not there yet on the type of pattern; ridge building or troughiness. Let`s start with the troughiness camp solution, ~53% of the ensemble members lean on a troughy pattern along our western edge which can be resulted from the upper level low moving across the region in the middle this week. The low would amplified the trough along the Great Basin and thus make it stick around longer to bring some breeziness and temperatures in the lower 90s. There is still variations in type of solution on how breezy or even with the temperatures. In the other camp, ~47% of members show a ridge building with different model interpretations on how much building and where the ridge will be place. That ridge will boost temperatures to the upper 90s and possibly in the 100 degree territory. (For reference, last year Tucson hit 100F on April 30th and 30-year normal is May 18th). 21% of members within the ridge building camp lean on the stronger ridge which could result more for chances to hit the 100 degree mark. The GEFs is the main hitter in that camp, but the chances for Tucson hitting and exceeding 100 degrees on Saturday is 10% and Sunday 25%. Still, looking at both camps, the 25th-75th percentiles is 91F-98F for Saturday and 93F-100F for Sunday. That is a some spread in the temperature solutions from all of the ensembles! Therefore, there is lower confidence on the ridge building solution and a lean of more confidence towards on some variation of a troughiness pattern. && .AVIATION...Valid through 13/00Z. Skies SKC through the valid forecast period. SFC winds generally westerly to northwesterly at 12-18 kts with gusts 25-30 kts through 12/03Z and again after 12/18Z through the end of the period. During the nighttime hours, SFC winds less than 10 kts and following typical diurnal trends.Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Afternoon temperatures near to slightly above normal will persist into next week. Min RH values will remain in the single digits in the valleys, with values generally in the teens for the mountains. Expect breezy west to northwest winds 15-20 mph this afternoon with gusts to 25-30 mph. These winds combined with already low relative humidity in place may result in brief near critical fire weather conditions. Otherwise, typical afternoon breeziness will persist into next week each afternoon due to daytime heating with winds becoming light and variable overnight. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson