Subj : HVYSNOW: Probabilistic Heavy Snow And Icing Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Feb 08 2024 20:06:58 FOUS11 KWBC 082006 QPFHSD Probabilistic Heavy Snow and Icing Discussion NWS Weather Prediction Center College Park MD 306 PM EST Thu Feb 08 2024 Valid 00Z Fri Feb 09 2024 - 00Z Mon Feb 12 2024 ....The West... Days 1-2... A small/compact upper low near the Four Corners this evening will move eastward out of CO to the central Plains by Friday midday, north of the strong subtropical jet (~170kts) from the Baja to the Mid-South. Modest upper divergence will support some broad lift over the Four Corners, but snowfall will be primarily driven by decent height falls and lower level convergence as the surface cold front meets the terrain, especially into the San Juan Mountains. There, WPC probabilities for another 6 inches of snow are >50% above about 7000ft. Broader area of light to modest snow is forecast into northern/central AZ (Mogollon Rim to the White Mountains) as well as into northern NM (Sangre de Cristos) tied to the progression of the front tonight. To the north, the next and likely last in a long series of shortwaves (with origins in the North Pacific/Gulf of Alaska) will dive south-southeastward through interior WA/OR into the Great Basin tomorrow afternoon and into AZ by Saturday midday, spanning the D1-2 period. For areas along and west of the Rockies, this incoming system will help spread modest amounts of snow over much of the West into the Southwest as a weakening northern stream jet noses into NV. Upslope on generally NW flow will favor the Cascades into the Blue Mountains, but also northern ID into western MT on some easterly flow as surface high pressure slips southeastward along and east of the Divide. Into the Southwest, strongest height falls should move into central AZ which will try to balance the relatively lower than normal moisture in the column to yield some modest snow totals for the mountains. Snow levels around 5000ft will drop as the cold upper trough moves through, bringing some additional light amounts to the valley floors north of the Mogollon Rim. Highest WPC probabilities for at least 8 inches of snow D1-2 lie over the Wasatch and into the Mogollon Rim, nearest the track of the mid-level trough, and into the San Juan Mountains in SW CO on favorable W to SW flow as the trough starts to turn eastward. ....Central and Southern Rockies into the Plains... Days 2-3... The previously-noted shortwave diving into the Southwest on Saturday will continue to amplify the flow, with a positively-tilted upper trough moving from the Four Corners across the southern Rockies, before a closed low forms over the High Plains on Sunday. Snow is expected to initially develop along a low-to-mid level front extending from central Colorado to southeastern Wyoming and the Nebraska Panhandle early Saturday. It will then gradually shift east with the front into eastern Colorado later in the day. While light to moderate snow is expected to continue across this region into Saturday night, the focus for heavy snow will begin to shift south into the southern Rockies and High Plains. Upslope flow and a developing deformation band will contribute to heavy snow extending east from the Sangre de Cristo Mountains eastward, potentially impacting portions of southwestern Kansas, the Texas and Oklahoma Panhandles, and central Oklahoma. For the 48 hour period ending 00Z Monday, WPC probabilities indicate accumulations of 4 inches or more are likely along the I-25 corridor from Cheyenne to Denver, with some moderate probabilities (greater than 40 percent) for accumulations of 8 inches or more along this corridor. Farther to the south the highest probabilities (greater than 90 percent) for accumulations of 4 inches or more extend from the Sangre de Cristo Mountains to the Raton Mesa, with moderate probabilities for accumulations of 8 inches more there as well. Moderate probabilities for accumulations of 4 inches or more extend as far east as central Oklahoma. Fracasso/Pereira $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .