Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/01/20

Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
921 PM CST Sat Feb 29 2020 .UPDATE... Issued at 921 PM CST Sat Feb 29 2020 Update for new 03Z Aviation Discussion below. && .SHORT TERM...(This evening through Sunday night) Issued at 322 PM CST Sat Feb 29 2020 Mostly sunny skies this afternoon is expected to transition to more clouds and fog this evening and overnight, with southerly flow remaining in place. Warm air advection will support warmer temperatures for tonight and Sunday. Generally dry conditions will remain over the area through Sunday morning, thanks to a large upper-level ridge that will gradually translate over the region. A fairly strong low-level thermal inversion is expected to develop, per the latest NAM, GFS, and RAP soundings, which should support the return of mostly cloudy skies tonight. Measurable precipitation is not expected as the moisture under the inversion remains quite shallow, but there may be some flurries tonight, mainly along the Borderland due to some saturation within the dendritic growth zone aloft. With a layer of above freezing air in place, it seems unlikely for any ice crystals to reach the surface, but still maintained just a chance of flurries across our north, particularly if there could be enough wet-bulb cooling. The bigger impacts will likely be for the potential for low stratus clouds and/or fog that may develop under this inversion. The latest high-resolution models are progging the most likely area for fog to be near the Brainerd Lakes region once again, with low stratus clouds expanding across the east. Tonight`s lows will warm to the lower 20s north to the middle 20s south. As we go into Sunday, a compact mid-level shortwave will eject out of the Canadian Prairies and skim across our northern areas. The bulk of the isentropic ascent will remain north of the region, but this shortwave could bring a wintry mix of light snow and drizzle/freezing drizzle as deeper saturation moves into the region. QPF appears to be lacking, so not thinking there will be much, if any, accumulations of snow or icing. Another big note for Sunday will be on the warming temperatures, with daytime highs in the lower to middle 40s. Sunday looks to be fairly breezy, particularly in the afternoon, with gusts in the 20 to 30 mph range over northeast Minnesota. Winds will turn more west to northwesterly during the day Sunday, which will help usher in some colder air. There will be some small chances of a wintry mix lingering through Sunday night, but little impact is expected. Sunday night lows will fall back into the middle teens north to the upper teens and lower 20s south. .LONG TERM...(Monday through Saturday) Issued at 322 PM CST Sat Feb 29 2020 A series of shortwaves move through the area in the long term, and while some of them have the potential to bring accumulating precipitation to the area, they are mostly on the weak side and probably will not have much impact on the region. The first shortwave to move through the area on Tuesday will keep mainly north of the area, with the surface low center tracking from southern Manitoba east across Ontario Monday night and Tuesday. This will bring cloudy skies and some small precipitation chances across the area Monday night and Tuesday, but the precipitation amounts will remain on the light side. It will also keep us on the mild side of this system and expect highs on Tuesday in the mid 30s to around 40. Small precipitation chances linger on Wednesday with a baroclinic zone and warm air advection aloft, even with a weak ridge axis at the surface. Have kept temps on the mild side as well, with highs in the mid 30s to low 40s. Wednesday night and Thursday is our next chance for precipitation as another shortwave moves from Manitoba east-southeast across Ontario. Some of the models are putting this on a slightly more southerly track, and the upper level feature is a little deeper aloft. These differences may bring some better precipitation chances into the area, and have some higher pops in the forecast relative to Tuesday. This may change however, and do not have a lot of confidence in it. Again, temperatures remain mild with Thursday highs in the mid 30s to low 40s. A surface ridge axis and broad weak ridging aloft should bring a dry and mild day on Friday and Saturday, with mild temperatures continuing. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 921 PM CST Sat Feb 29 2020 Updated terminal forecasts to remove low stratus overnight and Sunday morning. Additional model data has come in a bit drier, especially the RAP forecasts. The cirrus overhead should provide enough insulation to prevent fog development at most locations. There may be some MVFR/IFR visibilities at times overnight and have added a few TEMPOs to account for it. Will continue to monitor the forecast, and while it`s unlikely we`ll need to reintroduce the stratus, the chance is certainly non-zero. Remainder of the forecast is on track. Confidence in flight categories and timing is medium. && .PRELIMINARY POINT TEMPS/POPS... DLH 25 43 19 32 / 10 10 0 0 INL 21 42 13 30 / 10 20 20 0 BRD 25 42 17 31 / 10 0 0 0 HYR 26 46 21 35 / 10 10 0 0 ASX 27 45 24 35 / 10 10 0 0 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...None. && $$ UPDATE...Huyck SHORT TERM...JTS LONG TERM...LE AVIATION...Huyck