A winter weather and wind advisory is in effect for portions of the North Country today. A wintry mix of precipitation will change to all rain by 10 AM this morning. Gusty winds will develop this morning and continue at times into this afternoon and evening. Isolated power outages and locally slick travel expected. Read More >
Subject: NAM3 EXPERIMENTAL Froude Number for the Northern_Greens Model run: BTV_GRID_D2D_NAM3_20250403_0000 Using the MB925 to MB850 layer. Assumes Northern_Greens are orthogonal to 290 degree winds. 925-850 mb Layer Average Wind/RH. Avg QPF over the Northern_Greens. Date Time Wind RH% 700 850T QPF Day mm/dd hhZ Frd# DDFF (%) RH% (C) (in) === ===== === ==== ==== === === === ==== Thu 04/03 00Z 0.26 1720 71 96 -4 0.00 Thu 04/03 01Z 0.29 1624 92 98 -3 0.02 Thu 04/03 02Z 0.33 1630 93 99 -2 0.09 Thu 04/03 03Z 0.34 1732 94 98 -3 0.09 Thu 04/03 04Z 0.35 1737 94 99 -3 0.09 Thu 04/03 05Z 0.29 1739 94 99 -3 0.04 Thu 04/03 06Z 0.23 1841 95 99 -2 0.05 Thu 04/03 07Z 0.18 1845 96 96 0 0.06 Thu 04/03 08Z 0.11 1946 96 96 2 0.09 Thu 04/03 09Z 0.06 1943 96 98 4 0.20 Thu 04/03 12Z 0.13 2047 97 92 7 0.11 Thu 04/03 13Z 0.13 2047 97 93 8 0.04 Thu 04/03 15Z 0.30 2245 92 87 11 0.21 Thu 04/03 16Z 0.39 2248 84 89 12 0.18 Thu 04/03 18Z 0.67 2443 96 46 9 0.10 Thu 04/03 19Z 0.73 2437 98 24 8 0.01 Thu 04/03 20Z 0.91 2436 97 20 7 0.00 Thu 04/03 21Z 1.14 2535 97 28 6 0.03 Thu 04/03 22Z 1.30 2536 85 23 6 0.01 Thu 04/03 23Z 2.09 2539 70 11 6 0.02 Fri 04/04 00Z 3.11 2543 69 1 5 0.02 Fri 04/04 01Z 3.04 2643 82 1 3 0.02 Fri 04/04 02Z 2.54 2640 92 3 2 0.01 Fri 04/04 03Z 1.86 2736 95 6 1 0.00 Fri 04/04 04Z 1.60 2835 90 8 0 0.00 Fri 04/04 05Z 1.72 2836 83 11 -1 0.00 Fri 04/04 06Z 1.27 2933 84 14 -2 0.01 Fri 04/04 07Z 1.12 2931 88 17 -3 0.02 Fri 04/04 08Z 0.93 2929 89 18 -3 0.02 Fri 04/04 09Z 0.82 2930 88 15 -3 0.01 Fri 04/04 10Z 0.74 2930 86 8 -3 0.00 Fri 04/04 11Z 0.65 2929 84 1 -2 0.00 Fri 04/04 12Z 0.61 2930 81 2 -1 0.01 Fri 04/04 13Z 0.60 3031 78 1 -1 0.01 Fri 04/04 14Z 0.56 3030 73 1 -1 0.01 Fri 04/04 15Z 0.52 3029 68 1 0 0.01 Fri 04/04 16Z 0.49 3028 65 1 0 0.01 Fri 04/04 17Z 0.49 3128 64 1 0 0.01 Fri 04/04 18Z 0.51 3128 66 1 0 0.01 Fri 04/04 19Z 0.53 3128 65 1 0 0.01 Fri 04/04 20Z 0.53 3128 63 1 0 0.00 Fri 04/04 21Z 0.50 3228 62 1 0 0.00 Fri 04/04 22Z 0.43 3227 61 2 0 0.00 Fri 04/04 23Z 0.36 3326 61 4 1 0.00 Sat 04/05 00Z 0.28 3424 58 6 2 0.00 Sat 04/05 01Z 0.22 3422 57 7 2 0.00 Sat 04/05 02Z 0.17 3520 54 7 3 0.00 Sat 04/05 03Z 0.10 0018 49 5 3 0.00 Sat 04/05 04Z 0.02 0114 43 7 4 0.00 Sat 04/05 05Z 0.02 0112 41 7 4 0.00 Sat 04/05 06Z 0.03 0307 41 7 4 0.00 Sat 04/05 07Z 0.07 0606 35 6 4 0.00 Sat 04/05 08Z 0.11 0906 29 5 5 0.00 Sat 04/05 09Z 0.13 1207 26 6 5 0.00 Sat 04/05 10Z 0.14 1410 27 13 4 0.00 Sat 04/05 11Z 0.14 1614 30 36 4 0.00 Run total areal avg QPF for the Northern_Greens is: 1.63 inches. Froude Number (Frd#): Frd# < 0.5 Flow is subcritical and blocked. Upslope clouds/precip backed farther upwind of and up to mtn crest. W Upslope snow favors eastern Champlain Valley, BTV, and Western slopes. Gap winds possible. Frd# 0.5-1 Flow is subcritical/slow moving/blocked. Upslope clouds/precip falls immediately upwind of mtn crest. W Upslope snow favors western slopes to the Green Mt. spine including: Montgomery,Underhill,Jericho,Bolton,Richmond,Huntington,Lincoln. Gap winds possible. Frd# 1-2 Flow is critical. With strong winds, Mountain waves/downslope winds possible. Precip falls close to mountain ridge crests and on lee side. W Upslope snow favors Green Mt Spine,Jay,Stowe,Waterbury,NE Kingdom. Froude > 2 Flow is supercritical/unblocked(rapid flow). Air flows freely over terrain. Persistent upslope snow not favored. Scattered snow showers and flurries. Relative Humidity (RH): 925-850 mb RH > 90% needed for upslope precipitation. with 700mb RH > 70% favors upslope snow. with 700mb RH > 90% greater amounts of W upslope snow possible. 850mb Temperature (T degC) Westerly Upslope Snow Ratios: (Avg=28:1) T > -11 10-15:1 T -11 to -15 25-35:1 T < -15 15-20:1