329 FXUS63 KMPX 261719 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 1219 PM CDT Sun May 26 2019 .SHORT TERM...(Today through Monday) Issued at 428 AM CDT Sun May 26 2019 Main concern in the short term is the threat for heavy rain Monday morning. Today will be one of the nicest days of the year. High pressure will be overhead which will result in light winds and not much more than some fair weather cu. Low to mid 70s for highs look like a good bet area wide. Tonight, a short wave will eject out of Colorado, heading for southern MN Monday morning. A strong LLJ will develop once again in response to the height falls. In addition, strong differential divergence develops over the area by Monday morning as we get into a favorable coupled jet structure. Pwats will increase to near 1.5", which is a little over 2 standard deviations above normal. In addition MUCAPE values of the airmass that will be running up over the warm front in Iowa will be between 2k and 3k j/kg, so many of the ingredients for a heavy rain event are in place for Monday morning. ECMWF and HREF probability matched QPF guidance show a widespread 2-3 inches of rain occurring south of a Canby, New Prague, to Red Wing line and most of that falls between 12z and 18z on Monday. Current QPF is close to the model consensus/WPC guidance, but would not be surprised to see the area of heaviest precip shift south some toward the better instability. WPC excessive rain outlook shows a slight risk for flash flooding where we have the heaviest rain, which looks reasonable. Will be initiating a SitRep for this event this morning along with playing up the heavy rain threat a bit more in the HWO. For Memorial Day, it looks like another crummy day, no other way to really dance around that one. We look to have a deformation shield of precipitation setting up across most of our area during the day on Monday, with temperatures in the afternoon holding steady in the 50s with a steady light rain falling. So get out there and enjoy the weather today. .LONG TERM...(Monday night through Saturday) Issued at 428 AM CDT Sun May 26 2019 Active weather continues into midweek, but signs are pointing towards a pattern change towards the end of the week which looks to bring a change to zonal flow aloft and relatively drier weather. The bulk of the precipitation on Memorial day should be east of the area by evening, with a relative lull shaping up Monday night into Tuesday morning as a brief period of shortwave ridging builds behind the departing wave. Can't rule out some scattered light showers during this period but any precipitation would be light. A second bout of widespread precipitation is then expected to develop Tuesday afternoon into Wednesday morning as the upper level low passes overhead. Most guidance keeps the surface boundary and threat for severe thunderstorms well to our south Tuesday afternoon, but there's enough uncertainty in the warm sector nosing into far- southern Minnesota to warrant a slight risk on the SPC Day 3 Outlook. Heavy rain again looks to be the main threat with plenty of overrunning ascent on the north side of the front leading to widespread showers and thunderstorms. PW values Tuesday night into Wednesday morning again surge to above the 90th percentile with additional rainfall amounts of around an inch looking possible across southern Minnesota. This will only exacerbate any impacts we see from Monday's rainfall. Rain will taper off during the day on Wednesday as the low departs to the east, with the flow aloft becoming more zonal as the stout ridge over the southeastern US begins to flatten. Even with the weak flow aloft we could still see a few precip chances, mainly Friday into saturday, but overall precip amounts with these look light. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) Issued at 1215 PM CDT Sun May 26 2019 No aviation concerns through this evening as VFR conditions prevail and winds will slowly become east. Between 03-06z, convection will likely begin to develop in southwest Minnesota and spread across southern Minnesota, and into western Wisconsin between 06-18z Monday. The worst conditions will be in far southern Minnesota where confidence is high that TSRA and MVFR/IFR cigs develop toward 12z. Lower confidence on how far the MVFR cigs develop between 12-18z in central Minnesota. Heavy rainfall is likely in the southern quarter of Minnesota late tonight with vsbys likely IFR at times. Gusty east/east-northeast winds will develop late tonight, and become more northeast late Monday morning. KMSP... Confidence is low on timing of SHRA development between 06-12z, but nearly 100% chance of SHRA will occur between 12-18z with locally heavy rainfall and MVFR/IFR cigs at times. Thunder chances remain questionable but I can't rule out VCTS between 12-18z. East to northeast winds will develop and become gusty toward 15z. /OUTLOOK FOR KMSP/ Tue...MVFR. Chc IFR. -SHRA/-TSRA likely. Wind ENE 10-15kts. Wed...MVFR. Chc -SHRA in mrng. Wind NE 5-15 kts bcmg NW. Thu...VFR. Wind W/WNW 5-10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...MPG LONG TERM...ETA AVIATION...JLT