640 FXUS63 KMPX 221635 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 1135 AM CDT Thu Aug 22 2019 .UPDATED for 18z taf discussion below... && .SHORT TERM...(Today through Friday) Issued at 349 AM CDT Thu Aug 22 2019 Another benign weather day is expected as Canadian high pressure dominates the region. There will be some mid-level/cumulus cloud cover as cyclonic flow lingers, primarily from central MN across west central WI. Temperatures will be akin to early to mid September normals today and Friday, with highs in the mid 70s and lows in the upper 40s to lower 50s. Winds will be light given the presence of surface high pressure. .LONG TERM...(Friday night through Wednesday) Issued at 349 AM CDT Thu Aug 22 2019 Little change was made to the forecast for the long term period as guidance remained consistent with holding off the best chance for widespread of precipitation until Sunday night through Monday. This will be followed by a cold frontal passage and temperatures below normal to finish the month of August. By Friday night, the surface high will be centered over the Northern Great Lakes with the upper level ridge over us. Meanwhile, the western CONUS trough will be in the process of beginning to dig as a strong jet streak pushes ashore across the Pacific Northwest. The trough will continue to dig southeast across the Dakotas Saturday, making slow progress eastward thanks to the stubborn downstream ridge and surface high. Southerly winds will increase Saturday, especially across western MN as the gradient tightens between the departing high and approaching trough. The upper jet will push the shortwave into Minnesota mainly Sunday but there are still some timing uncertainties given model differences at this time. Showers and thunderstorms are likely Sunday night as the wave moves through and ahead of an approaching cold front. CAPE and shear parameters indicate a low severe weather threat, but could foresee a couple isolated strong to severe storms. PWATS increasing to near 2.0" would also suggest potential for heavy rainfall, but the front will be rather progressive, keeping storms moving out ahead of it. One of the other main differences in the model guidance is the handling of the surface reflection of the upper trough, especially given the merger of a pre-existing shortwave initially out ahead of the quicker moving trough with stronger jet support. Regardless of the precise differences, a strengthening surface low will likely drift east across far southern Canada early next week, with a cold front draped south across the Upper Midwest. At this time the front looks to move west to east across MN/WI on Monday. This low will move very slowly across northern Ontario middle of next week as it deepens rapidly at this point. What this means for us is a fairly strong push of below normal temperatures and dew points in from our northwest and given the very slow movement of the system to our north, this cool flow could persist for several days as we finish the month of August. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1145 AM CDT Thu Aug 22 2019 SCT-BKN cumulus over mainly eastern areas this afternoon. Looks to range 4-6K ft. Earlier 6-7K ft deck evaporated during the morning as the upper trough swung southeast. May yet see a few sprinkles in west central WI near KEAU, but still believe sites will remain dry. VFR trend mainly SKC. Generally light N-NE wind this afternoon becoming E-SE later tonight into Friday morning. KMSP...No concerns. /OUTLOOK FOR KMSP/ Fri Night...VFR. Wind SE 5-10 kts. Sat...VFR. Wind SE 10G20 kts. Sun...MVFR/IFR possible. PM -TSRA likely. Wind S 10G20 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...LS LONG TERM...SPD AVIATION...DWE