Area Forecast Discussion
Issued by NWS Flagstaff, AZ
Issued by NWS Flagstaff, AZ
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435 FXUS65 KFGZ 152203 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 303 PM MST Wed May 15 2024 .SYNOPSIS...Scattered showers and thunderstorms will continue throughout the day with isolated showers and storms continuing overnight. Rain and thunderstorm chances remain Thursday for portions of northern and northeast Arizona. A brief ridge Friday through the weekend over the region will result in warmer and drier conditions. Unsettled weather returns next week. && .DISCUSSION...The closed low along with a longwave trough to the northeast are working in conjunction to bring showers and thunderstorms to a good portion of northern Arizona. Mostly light westerly winds are being impacted significantly by the erratic gusts from the scattered storms. A few of the stronger storms have produced wind gusts of 40 to 50 mph as outflow boundaries propagate in various directions. Be aware, thunderstorms do not have to be directly overhead to bring hazardous winds and/or lightning. These gust fronts continue to trigger additional activity, tapping into the 250-500 J/kg of CAPE across the area. Most of the gauges where precipitation has fallen thus far have recorded only a few hundredths of an inch. However, heavier showers are impacting localized areas along the Mogollon Rim, Coconino Plateau, and Black Mesa with radar indicated QPE of 0.5" to 1.25". Additional isolated strong storms and rainfall will be continue to be possible, especially over high terrain. Tonight through Thursday...The scattered showers and storms will continue through the afternoon and evening hours before shifting eastward as the low to our south tracks eastward. More isolated to widely scattered showers and convection will linger overnight, primarily be relegated to Navajo County and Apache County. While the dynamics will not be nearly as conducive for precipitation Thursday, the ECMWF and GFS show a small shortwave ripple through eastern Arizona. This wrinkle in the atmosphere along with left over moisture will allow for a slight chance of rain. The best chances will be along the Arizona/New Mexico border and White Mountains (20-35%) that will extend along the Mogollon Rim as far west as the Flagstaff area (10-15%). Much of western Arizona is expected to remain dry tomorrow with diminishing cloud cover. Once again, widespread heavy rainfall is not forecast with precipitation amounts of less than 0.1" likely. Friday through Sunday...By Friday, an upper-level ridge will begin to form across the Southwest U.S., leading to a warming and drying trend that will extend through the weekend. Afternoon highs will be roughly 5 degrees above average each day. Winds do strengthen out of the southwest, becoming breezy each afternoon as a longwave trough to our north pushes against the ridge, tightening pressure gradients. Overall, winds are forecast to remain below advisory levels with gusts of 25 to 35 mph expected. Monday through Wednesday...More unsettled conditions are expected as models show a trough pushing into the region to start next week. There is low confidence that this system will have the moisture required to bring precipitation to Arizona. Anticipate another increase in the already breezy west-southwest winds along with temperatures cooling to near to just below seasonal norms. These winds along with drier conditions will push us towards near critical fire weather conditions once again. However, the rainfall we are currently experiencing should help somewhat in this regard. More updates to follow. && .AVIATION...Wednesday 15/18Z through Thursday 16/18Z....Mainly VFR expected. Brief periods of MVFR or lower conditions in SHRA/TSRA. Southwest to west 10-20 kts becoming light and variable after 02Z. Gusty, outflow winds around 30-40 kts possible. OUTLOOK...Thursday 16/18Z through Saturday 18/18Z...Mainly VFR conditions expected. Mainly west winds 10-20 kts each afternoon. && .FIRE WEATHER...Tonight through Friday...Scattered showers and thunderstorms will continue through tonight, becoming more isolated on Thursday. Southwest to west winds at 5-15 mph through this evening, becoming west to northwest on Thursday. Erratic outflow winds up to 40 mph possible due to storms. Dry conditions return on Friday. South to west winds 10-20 mph with afternoon RH values between 10-20%. Saturday through Monday...Warmer and drier weather conditions are expected through the weekend. Southwest to west winds 15-25 mph gusting 30-35 mph, increasing to 35-40 mph on Monday. Afternoon RH values will range between 5-15%, increasing to 10-20% on Monday. && .FGZ WATCHES/WARNINGS/ADVISORIES...None. && $$ PUBLIC...Mazon AVIATION...Meola FIRE WEATHER...Meola For Northern Arizona weather information visit weather.gov/flagstaff