{"id":5090,"date":"2026-09-03T17:55:17","date_gmt":"2026-09-03T17:55:17","guid":{"rendered":"https:\/\/discussions.weather.arizona.edu\/?p=5090"},"modified":"2026-09-03T17:56:41","modified_gmt":"2026-09-03T17:56:41","slug":"september-3rd-2026-scattered-afternoon-and-evening-thunderstorms-today-across-southern-arizona-strongest-near-the-international-border-precipitation-shifts-east-tomorrow-and-will-li","status":"publish","type":"post","link":"https:\/\/discussions.weather.arizona.edu\/?p=5090","title":{"rendered":"September 3rd, 2026: Scattered afternoon and evening thunderstorms today across\u00a0southern Arizona,\u00a0strongest\u00a0near the international border. Precipitation shifts east tomorrow and will likely miss\u00a0Tucson."},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Summary<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Two tropical moisture streams from the Gulf of California\/Hurricane Marie and Hurricane Karina are influencing the region as they merge over New Mexico. Moisture transport from these hurricanes is modest and may be the main source of error in recent forecasts. Satellite and surface observations show dry air moving into western Arizona, similar to a dry line in West Texas, while mid-level warming is capping most storm development. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Today, only strong surface-based updrafts are likely to produce isolated, non-severe storms with localized heavy rain, mainly over higher terrain. Tomorrow, storm activity is expected in southeastern Arizona and New Mexico, with precipitation shifting eastward. Light rain is possible in western Arizona by Saturday from flow associated with the dissipation of Marie off the West Coast. Overall storm chances are decreasing early next week, though another tropical system could increase rainfall chances next weekend.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Yesterday&#8217;s Weather<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The visible satellite overlaid with lightning animation shows that warm air at 500 mb suppressed most storms. The 12Z HRRR-UA WRF forecast sounding for Nogales yesterday afternoon showed more Convective Available Potential Energy (CAPE) than the rest of the region, and thunderstorms formed in southeast Pima and Santa Cruz counties. A rain gauge near Green Valley reported 1.3&#8243;\u00a0of rain, but most of the rainfall was less than a third of an inch. Although the clouds in the mountains\u00a0in the rest of the region did not have much vertical extent (probably topping out at less than 20,000 feet, 6km), some did produce light precipitation.<\/p>\n\n\n\n<figure class=\"wp-block-video aligncenter\"><video height=\"808\" style=\"aspect-ratio: 1238 \/ 808;\" width=\"1238\" autoplay controls loop muted src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/20260903-1616-26.8505814.mp4\" playsinline><\/video><figcaption class=\"wp-element-caption\">GOES-19 visible satellite imagery overlaid with GLM lightning from September 2nd from 12:30 pm to 8 pm, College of DuPage.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Overnight, as forecast, showers moved into southern Arizona, Cochise and Santa Cruz counties,\u00a0from a dying Mesoscale Convective System (MCS) in Mexico. The showers\u00a0dissipated before 3:00 am. Other light showers developed in eastern Pima and southern Pinal counties, as shown in the radar animation, and had much less precipitation than forecast. One reason may be that Hurricane Marie is supplying much less moisture than forecast.\u00a0Also, the showers formed on the west side of the Tucson Mountains, not in the Tucson\u00a0metro.\u00a0<\/p>\n\n\n\n<figure class=\"wp-block-video aligncenter\"><video height=\"822\" style=\"aspect-ratio: 1690 \/ 822;\" width=\"1690\" autoplay controls loop muted src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/20260903-1619-22.2982361.mp4\" playsinline><\/video><figcaption class=\"wp-element-caption\">HRRR-UA WRF 12Z simulated radar reflectivity forecast (left) and corresponding observed radar reflectivity from MRMS (right) for September 1st.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The HRRR-UA WRF 12Z 24-hour accumulated precipitation forecast (left) and corresponding observed precipitation from MRMS (right) are shown below.\u00a0Typically, the forecast gets the location of the precipitation right, but in this case it overestimated the rainfall, especially south of the border.\u00a0<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"334\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-8-1024x334.png\" alt=\"\" class=\"wp-image-5094\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-8-1024x334.png 1024w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-8-300x98.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-8-768x251.png 768w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-8-1536x501.png 1536w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-8.png 1735w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">HRRR-UA WRF 12Z 24-hour accumulated precipitation forecast (left) and corresponding observed precipitation from MRMS (right) for September 2nd.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">The 24-hour rainfall totals for eastern Pima County\u00a0are shown below.\u00a0<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"985\" height=\"796\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-10.png\" alt=\"\" class=\"wp-image-5096\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-10.png 985w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-10-300x242.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-10-768x621.png 768w\" sizes=\"auto, (max-width: 985px) 100vw, 985px\" \/><figcaption class=\"wp-element-caption\">24-hour precipitation totals from Pima County Regional Flood Control District gauges, <a href=\"https:\/\/alertmap.rfcd.pima.gov\/gmap\/gmap.html\">Alert Map<\/a>.<\/figcaption><\/figure>\n<\/div>\n\n\n<h2 class=\"wp-block-heading\">Analysis<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">None of the\u00a0three hurricanes in the central and eastern Tropical Pacific are expected to significantly\u00a0affect Arizona.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"620\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-9-1024x620.png\" alt=\"\" class=\"wp-image-5095\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-9-1024x620.png 1024w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-9-300x182.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-9-768x465.png 768w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-9.png 1032w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">National Hurricane Center <a href=\"https:\/\/www.nhc.noaa.gov\/\">outlook<\/a> for the Pacific basin<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Several flows of tropical moisture are entering the region. One\u00a0flows from the southern Gulf of California northward into New Mexico (green arrow), and another comes from Hurricane Karina across northern Baja, combining with the first flow in central New Mexico\u00a0(red arrow).\u00a0The red arrow represents a mid- to upper-level moisture flow and contains little precipitable water. The other\u00a0arrows (black)\u00a0are related to the jet stream and circulation around the polar low off the California coast.\u00a0A\u00a0Tropical Upper Tropospheric Trough (TUTT)\u00a0has moved further south into Mexico.\u00a0<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"568\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-093454-1024x568.png\" alt=\"\" class=\"wp-image-5097\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-093454-1024x568.png 1024w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-093454-300x167.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-093454-768x426.png 768w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-093454.png 1207w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">GOES-19 upper-level water vapor image September 3rd at 8 am, College of DuPage.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">The\u00a08 am visible satellite image\u00a0shows debris clouds\u00a0that moved into Mexico overnight. A few light showers remain in Graham County.\u00a0<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"680\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-11-1024x680.png\" alt=\"\" class=\"wp-image-5098\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-11-1024x680.png 1024w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-11-300x199.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-11-768x510.png 768w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-11.png 1222w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">GOES-19 visible satellite imagery from September 3rd at 8 am, College of DuPage.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Surface dewpoint temperatures in western Arizona have decreased sharply as dry air moves in from the Pacific Ocean. It&#8217;s reminiscent of a West Texas dry line.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"540\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-094408-1024x540.png\" alt=\"\" class=\"wp-image-5100\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-094408-1024x540.png 1024w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-094408-300x158.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-094408-768x405.png 768w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-094408.png 1512w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Surface weather station observations for Arizona and New Mexico at 7:00 am, <a href=\"https:\/\/www.weather.gov\/wrh\/hazards?&amp;zoom=8&amp;scroll_zoom=false&amp;center=32.656025851099066,-110.76888628244107&amp;boundaries=false,true,false,false,false,false,false,false,false,false,false&amp;tab=observation&amp;hazard=true&amp;hazard_type=all&amp;hazard_opacity=80&amp;obs=true&amp;obs_type=weather&amp;elements=temp,wind,gust&amp;temp_filter=-80,130&amp;gust_filter=0,150&amp;rh_filter=0,100&amp;elev_filter=-300,14000&amp;precip_filter=0.01,30&amp;obs_popup=false&amp;obs_density=60&amp;obs_provider=ALL\">NWS<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">The HRRR-UA WRF 12Z initialization (left) and observed (right) sounding for Phoenix at 5 am are below.\u00a0Both\u00a0the initialization and observed sounding capture the warming between 500 and 600 mb, which will cap the boundary layer.\u00a0Any cumulus clouds below the cap will be unable to produce precipitation, as there&#8217;s not enough vertical extent for droplet formation. <\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"583\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-094033-1024x583.png\" alt=\"\" class=\"wp-image-5099\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-094033-1024x583.png 1024w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-094033-300x171.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-094033-768x437.png 768w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-094033.png 1392w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">HRRR-UA WRF 12Z (left) initialization and observed sounding (right) at Phoenix for 5 am this morning.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Like the water vapor satellite imagery, two jet streams are apparent\u00a0at 250 mb. The\u00a0one to the north (out of frame) is the polar jet stream\u00a0and extends from northern California east to central Wyoming. The jet to the south\u00a0(black arrow) is the reemergence of the subtropical jet and extends from northern Baja to southern Nebraska. The high-pressure ridge is in north-central Mexico, centered\u00a0west of Laredo, and the other is west of the Baja Peninsula spur.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"860\" height=\"856\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095100.png\" alt=\"\" class=\"wp-image-5101\" style=\"aspect-ratio:1.0046645431502725;width:592px;height:auto\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095100.png 860w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095100-300x300.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095100-150x150.png 150w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095100-768x764.png 768w\" sizes=\"auto, (max-width: 860px) 100vw, 860px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">The polar jet is well to the north, and what&#8217;s left of the monsoon ridge is east of El Paso\u00a0at 500mb. Warm air aloft is being pulled into Arizona.\u00a0<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"847\" height=\"851\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095251.png\" alt=\"\" class=\"wp-image-5102\" style=\"aspect-ratio:0.9952999627555135;width:588px;height:auto\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095251.png 847w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095251-300x300.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095251-150x150.png 150w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095251-768x772.png 768w\" sizes=\"auto, (max-width: 847px) 100vw, 847px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">At\u00a0700mb,\u00a0moisture\u00a0in Arizona is rotating northward between the monsoon high\u00a0located\u00a0over Big Bend,\u00a0Texas, and a trough off the West Coast. The moisture is mostly trapped under a mid-level cap from the international border northward,\u00a0and we will need to reach convective temperatures for storms to start from the surface.\u00a0<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"865\" height=\"852\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095443.png\" alt=\"\" class=\"wp-image-5104\" style=\"aspect-ratio:1.0152488420312147;width:620px;height:auto\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095443.png 865w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095443-300x295.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-095443-768x756.png 768w\" sizes=\"auto, (max-width: 865px) 100vw, 865px\" \/><\/figure>\n<\/div>\n\n\n<h2 class=\"wp-block-heading\">Today<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The Tucson and Phoenix soundings are similar, and there is enough Convective Available Potential Energy (CAPE) to get past the mid-level warming for storms this afternoon. Only the strongest surface-based updrafts will be able to break the cap, most likely over higher terrain.\u00a0The storms that can use the CAPE will be non-severe and will produce only localized areas of heavy rain near the storm cores.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"568\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-100148-1024x568.png\" alt=\"\" class=\"wp-image-5105\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-100148-1024x568.png 1024w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-100148-300x167.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-100148-768x426.png 768w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/Screenshot-2026-09-03-100148.png 1423w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">HRRR-UA WRF 12Z forecast soundings for Phoenix (left) and Tucson at 3 pm (right).<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">The radar\u00a0reflectivity forecast shows the storms in Arizona east of the dry line, extending west into New Mexico. Storms will be more numerous\u00a0in Cochise\u00a0County and strongest\u00a0in Santa Cruz and central Pima counties.\u00a0Storms may form overnight in Pinal and far southeast Maricopa counties, then move up to northwest New Mexico, as shown below.\u00a0<\/p>\n\n\n\n<figure class=\"wp-block-video aligncenter\"><video height=\"754\" style=\"aspect-ratio: 1134 \/ 754;\" width=\"1134\" autoplay controls loop muted src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/20260903-1717-20.8630253.mp4\" playsinline><\/video><figcaption class=\"wp-element-caption\">HRRR-UA WRF simulated radar reflectivity 12Z forecast from 1 pm to 6 am tomorrow.<\/figcaption><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Tomorrow<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The focus of the activity shifts east into eastern Pinal\u00a0and Pima counties as the West Coast trough and the dry line move further east.\u00a0Storms in New Mexico will be more numerous\u00a0in the northern part of the state.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"678\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-12-1024x678.png\" alt=\"\" class=\"wp-image-5109\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-12-1024x678.png 1024w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-12-300x199.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-12-768x508.png 768w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-12.png 1136w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">HRRR-UA WRF simulated radar reflectivity 12Z forecast for tomorrow at 5 pm.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">The\u00a0forecast\u00a024-hour total accumulated precipitation (left) and 48-hour (right) show\u00a0most precipitation falls today in central and southern Arizona;\u00a0 the\u00a0two-day precipitation in New Mexico is about the same each day.\u00a0<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"334\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-13-1024x334.png\" alt=\"\" class=\"wp-image-5110\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-13-1024x334.png 1024w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-13-300x98.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-13-768x251.png 768w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-13-1536x502.png 1536w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-13.png 1736w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">HRRR-UA WRF 12Z total precipitation forecast 24-hour accumulation (left) and 48-hour (right).<\/figcaption><\/figure>\n<\/div>\n\n\n<h2 class=\"wp-block-heading\">Outlook<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">On Saturday, scattered showers and thunderstorms are expected over eastern Arizona and New Mexico, in about the same locations as Friday, over the mountains. In western Arizona, mid-level moisture from Hurricane Maria is pulled into the state by the subtropical jet stream. Most of the rain will be light.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"673\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-15-1024x673.png\" alt=\"\" class=\"wp-image-5112\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-15-1024x673.png 1024w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-15-300x197.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-15-768x505.png 768w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-15.png 1137w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">HRRR-UA WRF simulated radar reflectivity 12Z forecast for Saturday at 3 pm.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">The long-range global model\u00a0ensemble\u00a0shows a marked decrease in storms Sunday through Thursday. Another tropical system may increase rain chances next weekend.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"822\" src=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-14-1024x822.png\" alt=\"\" class=\"wp-image-5111\" srcset=\"https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-14-1024x822.png 1024w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-14-300x241.png 300w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-14-768x617.png 768w, https:\/\/discussions.weather.arizona.edu\/wp-content\/uploads\/2026\/09\/image-14.png 1077w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Global Ensemble Forecast System (GEFS) ensemble forecasts of 2-meter temperature (top) and 3-hour accumulated precipitation (bottom), NCAR.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Discussion written by Pat Holbrook and Patrick Bunn<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Summary Two tropical moisture streams from the Gulf of California\/Hurricane Marie and Hurricane Karina are influencing the region as they merge over New Mexico. Moisture transport from these hurricanes is modest and may be the main source of error in recent forecasts. Satellite and surface observations show dry air moving into western Arizona, similar to &hellip;<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[8],"class_list":["post-5090","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-8"],"_links":{"self":[{"href":"https:\/\/discussions.weather.arizona.edu\/index.php?rest_route=\/wp\/v2\/posts\/5090","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/discussions.weather.arizona.edu\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/discussions.weather.arizona.edu\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/discussions.weather.arizona.edu\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/discussions.weather.arizona.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5090"}],"version-history":[{"count":8,"href":"https:\/\/discussions.weather.arizona.edu\/index.php?rest_route=\/wp\/v2\/posts\/5090\/revisions"}],"predecessor-version":[{"id":5116,"href":"https:\/\/discussions.weather.arizona.edu\/index.php?rest_route=\/wp\/v2\/posts\/5090\/revisions\/5116"}],"wp:attachment":[{"href":"https:\/\/discussions.weather.arizona.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5090"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/discussions.weather.arizona.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5090"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/discussions.weather.arizona.edu\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5090"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}