Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
059 FXUS65 KTWC 222038 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 138 PM MST Sat Jun 22 2024 .SYNOPSIS... Ample moisture will bring daily chances for thunderstorms to the area through next week. Some thunderstorms will generate strong outflow winds with locally heavy rain possible. This will also knock several degrees off of the heat. Temperatures may climb up a bit middle of next week as high pressure builds overhead. && .DISCUSSION... Anomalously moist precipitable water values (for this time of year) were observed over southeastern Arizona on this morning`s upper air observation. While morning cloud cover prevented developing instability in western Pima and much of Graham and Greenlee Counties, adequate insolation over eastern Pima, Santa Cruz, and Cochise Counties has allowed for convective development this afternoon. Mid-level lapse rates are fairly weak with the near tropical atmospheric column, which should hamper today`s severe convection potential as thunderstorm updrafts should struggle to push through the mid-levels. That said, with precipitable water clearing 1.5 inches periods of heavy rainfall rates are likely under any thunderstorms this afternoon and evening, and weak mean winds may lead to an isolated flooding potential as storms will be slow to move. Tomorrow, a bit of drying may lower convective chances in eastern Cochise and Graham counties as the moisture axis nudges west. Steeper mid-level lapse rates should intersect with the moisture axis from the Santa Cruz area through central to eastern Pima counties tomorrow afternoon, which may be the window for a few strong to potentially severe thunderstorms. 12Z HREF updraft helicity and max wind speed probabilities highlight this area as well. Uncertainty remain at this point however with questions about how models handle how current convection`s impact on the atmosphere for tomorrow. Looking at next week, atmospheric moisture should generally remain in place as the upper high nudges slightly westward over our area during the early portion of next week. Warmer mid-level temperatures associated with this high may tamper the thunderstorm severity threat at times, however ample moisture and surface heating should allow for chances each day. && .AVIATION... Scattered TSRA with BKN ceilings around 6k feet KOLS-KTUS through 23/03Z. Possibly very isolated TSRA elsewhere this afternoon. Briefly heavy rainfalls may significantly reduce visibilities at times. East to southeast winds 10-15 kts. Stronger and erratic outflows possible with any thunderstorms. Activity diminishes after 23/03Z with just isolated -SHRA possible overnight. && .FIRE WEATHER... A strong increase in moisture will bring better relative humidity values along with a chance of thunderstorms into next week. Some storms will generate strong and erratic outflow winds. Moisture is expected to be deep enough for some storms to generate locally heavy rain. Temperatures may heat back up by mid week as high pressure builds nearly overhead, however we should keep some storm chances around. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Public...Edwards Aviation...Edwards Fire Weather....Edwards Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson