
A Wind Advisory is in effect for majority of the region from 8AM to 8PM Tomorrow for southerly winds gusts between 45 and 55 MPH. There will be two rounds of gusty winds with the first tomorrow morning for most of the area and the second mainly over northern New York. The strongest winds will be between 9AM and 1PM in the CPV, western facing slopes of the higher terrain and the St. Lawrence Valley Read More >
Subject: NAM3 EXPERIMENTAL Froude Number for the Central_Greens
Model run: BTV_GRID_D2D_NAM3_20260618_0000
Using the MB925 to MB850 layer.
Assumes Central_Greens are orthogonal to 260 degree winds.
925-850 mb Layer Average Wind/RH. Avg QPF over the Central_Greens.
Date Time Wind RH% 700 850T QPF
Day mm/dd hhZ Frd# DDFF (%) RH% (C) (in)
=== ===== === ==== ==== === === === ====
Thu 06/18 00Z 0.46 2012 68 93 11 0.00
Thu 06/18 01Z 0.53 1914 71 97 11 0.00
Thu 06/18 02Z 0.54 2017 83 93 11 0.04
Thu 06/18 03Z 0.63 2120 80 89 11 0.05
Thu 06/18 04Z 0.65 2122 82 92 11 0.00
Thu 06/18 05Z 0.52 2021 85 89 11 0.00
Thu 06/18 06Z 0.40 2020 89 82 11 0.02
Thu 06/18 07Z 0.33 2020 89 76 12 0.00
Thu 06/18 08Z 0.44 2023 92 95 11 0.03
Thu 06/18 09Z 0.41 2021 95 96 11 0.19
Thu 06/18 10Z 0.39 2022 96 93 11 0.19
Thu 06/18 11Z 0.26 1923 92 86 12 0.05
Thu 06/18 12Z 0.33 1928 90 95 12 0.02
Thu 06/18 13Z 0.33 1935 92 97 12 0.05
Thu 06/18 14Z 0.41 1937 92 91 12 0.04
Thu 06/18 15Z 0.41 1937 92 83 12 0.02
Thu 06/18 16Z 0.47 1939 97 84 12 0.08
Thu 06/18 17Z 0.22 1833 94 54 14 0.06
Thu 06/18 18Z 0.40 1931 94 55 14 0.01
Thu 06/18 19Z 0.62 1928 95 75 13 0.01
Thu 06/18 20Z 0.82 2026 94 46 14 0.01
Thu 06/18 21Z 0.90 2324 95 76 13 0.13
Thu 06/18 22Z 1.00 2525 87 49 13 0.15
Thu 06/18 23Z 1.21 2524 94 62 12 0.00
Fri 06/19 00Z 1.51 2427 90 46 12 0.01
Fri 06/19 01Z 2.06 2531 87 69 11 0.01
Fri 06/19 02Z 1.66 2532 93 47 10 0.02
Fri 06/19 03Z 1.45 2531 93 56 9 0.01
Fri 06/19 04Z 1.20 2531 94 72 9 0.01
Fri 06/19 05Z 1.12 2630 96 75 9 0.03
Fri 06/19 06Z 1.09 2631 96 67 8 0.01
Fri 06/19 07Z 0.99 2631 95 70 8 0.01
Fri 06/19 08Z 0.91 2630 96 72 9 0.01
Fri 06/19 09Z 0.89 2730 96 71 8 0.01
Fri 06/19 10Z 0.84 2729 96 69 8 0.01
Fri 06/19 11Z 0.80 2728 96 70 8 0.01
Fri 06/19 12Z 0.80 2728 96 68 8 0.01
Fri 06/19 13Z 0.81 2727 92 65 8 0.01
Fri 06/19 14Z 0.87 2726 89 61 9 0.00
Fri 06/19 15Z 1.21 2625 91 63 9 0.00
Fri 06/19 16Z 4.59 2623 91 61 9 0.00
Fri 06/19 17Z 11.03 2621 87 61 9 0.00
Fri 06/19 18Z 10.22 2521 87 59 10 0.00
Fri 06/19 19Z 11.62 2621 83 55 10 0.00
Fri 06/19 20Z 12.77 2621 83 57 10 0.00
Fri 06/19 21Z 11.63 2521 81 43 10 0.00
Fri 06/19 22Z 8.76 2523 79 35 10 0.00
Fri 06/19 23Z 4.32 2525 73 41 10 0.00
Sat 06/20 00Z 2.45 2528 73 36 10 0.00
Sat 06/20 01Z 2.24 2531 80 41 9 0.00
Sat 06/20 02Z 1.74 2632 87 49 9 0.01
Sat 06/20 03Z 1.28 2831 90 58 8 0.04
Sat 06/20 04Z 1.01 2829 90 63 8 0.03
Sat 06/20 05Z 0.95 2828 93 71 7 0.02
Sat 06/20 06Z 0.96 2728 95 84 7 0.02
Sat 06/20 07Z 0.95 2728 95 85 7 0.03
Sat 06/20 08Z 0.94 2729 95 84 7 0.01
Sat 06/20 09Z 0.97 2731 95 86 7 0.02
Sat 06/20 10Z 1.01 2733 97 91 7 0.05
Sat 06/20 11Z 1.04 2832 97 90 6 0.04
Run total areal avg QPF for the Central_Greens is: 1.59 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