836 FXUS65 KBYZ 030342 AFDBYZ Area Forecast Discussion...Updated National Weather Service Billings MT 842 PM MST Wed Jan 2 2019 .UPDATE... No update needed to forecast this evening. Main concern was winds in the western areas. Wind speeds have been increasing this evening at KLVM, while the other areas had gusts into the 40s to around 50. None of the sites have hit Advisory/Warning criteria yet. The pressure gradient was a tight 25 mb between KLWT and KIDA and looked N-S which was favorable for strong winds in the gap areas. The gradient will remain the same strength through the night, and would expect occasional Advisory wind gusts due to this strength and orientation. Local studies showed decent probabilities of Big Timber hitting 58 mph overnight and Harlowton's sounding showed 55 kt below 700 mb overnight. With a warm airmass over the area, Harlowton has a chance of mixing down some stronger winds. Thus the Advisories and High Wind Warnings were in good shape. Temperatures should remain steady or rise overnight under the warm airmass and cirrus. Arthur && .SHORT TERM...valid for Thu and Fri... Couple of changes to wind highlights with this package. We extended the High Wind Warning for Southern Wheatland to 11 AM Friday morning, and also added Judith Gap as strong winds are probably occurring further north of Harlowton even though we lack data from there. This also lines up better with our WFO Great Falls wind highlights to our north. High winds have been consistent at Big Timber all day with gusts to around 60 mph common, while gusts at Livingston and Nye have been 40 to 50 mph. The pressure gradient orientation will continue to favor Big Timber into the evening. However, models suggest the orientation will turn a bit overnight to better favor Livingston and Nye later tonight into Thursday. The windy pattern will persist through Thursday night and into Friday morning before the pressure gradient lets up. In the meantime, the westerly flow will inhibit precipitation. High temperatures will generally be in the 30s to mid 40s the next couple of days. We are experiencing a modest Big Horn Basin drainage effect in the Billings area today (Billings 26 while Roundup 39 and Columbus 36 at 1 pm today), and we see no reason not to see somewhat of an influence again tomorrow. So we will keep Billings forecast highs a little below model guidance. BT .LONG TERM...valid for Sat...Sun...Mon...Tue...Wed... The long term continues to look fairly quiet with mainly dry conditions prevailing. Windy periods look to plague the western foothills as well with tight pressure gradients at the surface. A disturbance moving in from the west looks to bring snow chances to the southwest mountains Sunday through Monday, before ridging builds back over the region Tuesday and Wednesday. High temperatures are forecast to range from the 30s to 40s most days, with low temperatures in the teens and 20s most nights/mornings. STP && .AVIATION... VFR flight conditions with scattered to broken high clouds will prevail through Thursday. Strong SW-W winds will continue along the western foothills, with gusts of 50+ knots at KLVM and 35-50 knots at K6S0 and K3HT. Gusts of 25-35 knots will spread as far east as KBIL. Localized shallow drifting of snow is possible on some runways. JKL && .PRELIMINARY POINT TEMP/POPS... Thu Fri Sat Sun Mon Tue Wed ----------------------------------------------------------- BIL 021/037 029/043 026/039 023/040 024/039 026/043 029/042 00/N 00/N 00/B 10/B 11/B 11/B 01/B LVM 027/041 028/045 028/044 027/041 026/041 030/046 031/045 00/N 00/N 01/N 11/N 21/N 11/N 11/N HDN 020/043 023/045 020/040 018/041 020/041 022/043 024/043 00/B 00/B 00/B 00/B 11/B 11/B 01/B MLS 025/043 028/044 023/039 020/038 021/038 021/040 023/041 00/B 00/B 00/B 00/B 11/B 00/B 01/B 4BQ 022/040 024/042 022/038 020/037 020/037 020/039 024/040 00/B 00/B 00/B 00/B 11/B 01/B 00/B BHK 025/044 027/045 023/040 020/036 020/039 019/040 022/041 00/U 00/B 00/B 00/B 11/B 01/B 00/B SHR 019/043 022/048 021/042 020/044 019/042 020/046 024/046 00/B 00/B 00/B 00/B 11/B 10/B 00/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...High Wind Warning in effect until noon MST Friday FOR ZONES 28-41-63. Wind Advisory in effect until noon MST Friday FOR ZONES 65-66. WY...None. && $$ weather.gov/billings