Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
139 FXUS65 KTWC 272103 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 203 PM MST Thu Jun 27 2024 .SYNOPSIS...Southeast Arizona will continue to see enough moisture for a daily chance of thunderstorms. Storm chances increase over the weekend and early next week. Some storms will generate strong winds and locally heavy rainfall. && .DISCUSSION...Latest (2030Z) radar scans show thunderstorms developing south of Coronado National Monument with another storm struggling to form near Green Valley. CAPE values are up in the 1500-2000j/kg across the region. The higher values are along the international border to the southeastern Cochise County, along with better environment for thunderstorms. 12Z HREF paintball plots highlights the international border this afternoon and into the early evening. The biggest threats is gusty erratic winds and locally intense rainfall. The PWATs are 1.56 inches from this morning and will stay elevated through the rest of the weekend. Tomorrow, HREF 3 hour probability matched mean shows a signal for more substantial rainfall south of Nogales which could result in a rise in the Santa Cruz River and Nogales Wash. Something to keep an eye on tomorrow afternoon. This weekend, the high pressure center will push off to the east and be a better position to bring in southerly moisture flow. Thunderstorm chances increases along with coverage starting Saturday. Sunday appears to be the one of the more active days due to weak disturbance moving around the high pressure center. Next week, the high pressure will sit more to our east and thus opening the moisture flow gate a little more. PWATs will be increasing close to the 1.7-2 inch mark across most of Southeast Arizona. The ensemble models show a signal for above normal rain amounts by starting as early as Tuesday through at least Thursday. One way to look at it, 33% of the 100 member ensemble show a wetter solution with 24 hour rain totals 0.75 inches to some locally areas close to 1.50 inches. The other two thirds show rainfall amounts a little less than that but is worth to keep an eye out over the next several days. At the moment, there is low confidence since it is close to a week out but there is increase risk for flooding impacts especially with the 4th of July events coming up. && .AVIATION...Valid through 29/00Z. FEW-SCT 5-10 kft and SCT-BKN 20-25 kft AGL thru the forecast period. Isolated -TSRA thru 28/03Z with brief MFR conditions possible near storms, mainly along the international border and in the White Mountains. SFC winds generally 10 kts with the occasional gust up to 20 kts in the afternoons, except for gusty outflow winds from storms. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Relatively deep moisture will stick around through the forecast period. This will give isolated thunderstorms and showers today and tomorrow, mainly south and east of Tucson. Moisture will increase more through the weekend and into the new week to bring higher chances and coverage for thunderstorms and showers each day. Strong erratic gusty winds of 40 mph or higher can be expected with any storm development, along with locally brief heavy rainfall. Outside of thunderstorm winds, 20-foot winds will generally be 15 mph or less each afternoon with the occasional gust of 20 mph. Min RHs will generally be around 20% in the valleys and 30s in the mountains with good overnight recoveries. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ KJS Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson