612 FXUS65 KBYZ 211553 AFDBYZ Area Forecast Discussion...Updated National Weather Service Billings MT 953 AM MDT Sun Jul 21 2019 .UPDATE... Precipitation chances will continue to decline over SE Montana through the afternoon. Overnight precipitation amounts were quite hefty in some locations with radar estimating 2 to 4 inches fell from eastern Powder River county across southern Carter county. Additional precipitation totals today should be under a tenth of an inch in any one location. Very pleasant temperatures in the 70s to lower 80s expected today before much warmer air moves in for the work week. Chambers && .SHORT TERM...valid for Tdy and Mon... A short wave trough moving across northern/northeast Montana overnight has induced a very moist airmass northward into the eastern half of the forecast area (mainly east of Yellowstone County). Precipitable water values will jump well above an inch and there is decent warm air advection at 700 mb. So heavy rain is certainly expected with some storms that form and could cause some minor flooding issues such as in rural ditches etc. Shear and helicity are decent as well, so sustained updrafts could support some hail, but widespread severe storms are not expected. Best chance for showers and thunderstorms into the morning targets Broadus to eastward to Ekalaka and surrounding areas. Somewhat cooler and drier air builds in behind the shower and thunderstorms by afternoon. Afternoon temperatures will be very similar to yesterdays with 75 to 85 degrees across the region. Amplified ridge builds into the tonight and Monday boosting temperatures into the upper 80s and lower 90s for all but the far eastern portion of SE Montana. Moisture will still be available under the ridge for scattered afternoon/evening mountain based thunderstorms, but these storms will struggle to push very far off the mountains as dry low level air combines with increasing mid level temperatures to cap convective potential over the plains. BT .LONG TERM...valid for Tue...Wed...Thu...Fri...Sat... The ridge will max out over Montana at the beginning of the long term, with temperatures reaching the mid 90s on Tuesday and Wednesday. On Tuesday, showers and thunderstorms still look to initiate over the mountains and move into the foothills and nearby lower plains in our western districts as they contain ample instability, and will helped be forced by the passing of a shortwave. On Wednesday, an upper low passing over SE Canada looks to flatten the ridge, and with good agreement for weak to moderate instability (CAPE) across the lower plains, areas much of southeast Montana could receive showers and thunderstorm activity. After this decrease in upper level heights during the mid week, much uncertainty exists with respect to the synoptic scale weather pattern, but it looks like fairly zonal flow will persist going into the weekend. However, there is good agreement for conditions to drastically dry up in comparison to the past few weeks, as EC ensemble members show reduced PWAT values much below 1" for the entire area. Temperatures will drop to the 80s after Wednesday. Vertz && .AVIATION... Showers and thunderstorms will continue to move out of Montana through 16 Z. Small hail, heavy rain, and erratic winds are possible with these storms. Otherwise, VFR conditions will prevail. Carrothers && .PRELIMINARY POINT TEMP/POPS... Tdy Mon Tue Wed Thu Fri Sat ------------------------------------------------------- BIL 080 057/089 064/095 066/095 062/088 060/087 062/090 0/U 00/U 01/U 11/B 20/U 00/U 00/U LVM 079 050/088 057/092 059/090 054/086 053/086 054/087 0/U 01/U 23/T 13/T 30/U 11/U 11/U HDN 079 056/089 062/094 065/095 061/087 059/085 059/089 0/B 00/U 01/U 11/B 31/U 10/U 00/U MLS 080 055/085 062/093 066/094 063/086 059/084 059/088 2/T 00/U 00/U 11/B 21/U 00/U 00/U 4BQ 075 053/083 060/090 064/093 062/085 059/083 059/087 2/T 00/U 01/U 11/B 31/U 11/U 00/U BHK 076 052/081 058/087 061/092 062/084 059/082 058/086 2/T 00/U 00/U 11/B 21/U 10/U 00/U SHR 075 052/087 059/092 061/093 058/086 056/084 057/087 1/E 01/U 13/T 22/T 42/T 11/U 11/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings