Area Forecast Discussion
Issued by NWS Twin Cities, MN
Issued by NWS Twin Cities, MN
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024 FXUS63 KMPX 221158 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 658 AM CDT Wed May 22 2024 .KEY MESSAGES... - Active pattern remains bringing additional chances for rain Thursday night into Friday and Memorial Day. - Mild temperatures expected through the holiday weekend. && .DISCUSSION... Issued at 302 AM CDT Wed May 22 2024 Light, stratiform rain associated with the deformation band on the west side of the surface low continues over our WI counties early this morning. This activity is slowly moving east and should clear the MPX CWA prior to sunrise, though some mist may still occur (like what is currently being observed at our office). Nearly the entire CWA received at least 0.5" of rain over the last 24 hours with the big "winner" being a corridor from the Twin Cities metro into northwest WI. Here, amounts range from 1.5" to around 2.5". It`s kinda nice to hear the soil squish beneath your feet again. Westerly winds will be breezy this morning but gradually slow as Wednesday progresses with the surface low moving away. A few afternoon showers are possible underneath the cyclonic flow aloft, mainly north of I- 94. Otherwise, the rest of area will see a relatively nice day with partly sunny skies and highs upper 60s to lower 70s. Our winds will flip to southerly ahead of the next incoming shortwave Thursday, warming us completely into the 70s during the afternoon. We will be dry to start the day, but PoPs increase in western MN heading into the evening hours as forecast models develop showers and thunderstorms in the eastern Dakotas and track them eastward. If thunderstorms can arrive in western MN early enough in the evening so surface parcels are still able to be lifted, a small severe risk would also exist. The primary threat appears to be damaging winds, as the cold front would be catching the convection and thus favoring line segments. Forecast models do develop additional precip along the cold front as it travels east across the CWA overnight Thursday into Friday afternoon. Categorical PoPs along the entire cold highlight the confidence in guidance of an extended line of precipitation with this system. So expect wet weather for at least the first half of Friday. Once the front passes through, we should dry out and see a brief cool down with the change of air mass following the front. Lows Friday night look a little chilly with temperatures currently forecast in the low to mid 40s. Temperature-wise, the holiday weekend looks mild with temperatures hanging near or just below normal. A welcome change from the abnormal warmth we`ve experienced the last few Memorial Day weekends. Guidance does give us a chance for rain later Sunday into Monday as models favor a system developing over the Central Plains and tracking northeast into the Lower Great Lakes. If this comes to fruition, MN/WI would be affected by northern fringes of the precip shield associated with the deformation band and precip shield north of the warm front. However, considerable model spread still exists on exact low track and how far north the precipitation extends. Thus, only have PoPs in the 30s at this time. Afterwards, the weather appears to become quieter as long-range ensembles favor upper-level ridging building over the western CONUS and slowly pushing east during the middle to latter half of next week. This could also signal a return to warmer than normal temperatures as we approach June. && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 634 AM CDT Wed May 22 2024 Low stratus shield over eastern MN into western WI continues to erode to the east, allowing all sites to be VFR by late morning. All sites are expected to remain as VFR through the duration, but there is a small chance (20-30 percent) of showers generally in the 17z-22z timeframe which could briefly produce MVFR conditions east of AXN-RWF. Chances are too low to include at this point but multiple short-term models do show the possibility. Will monitor how the models evolve this possibility, along with radar trends, and introduce -SHRA where necessary. Breezy westerly winds will persist through the daylight hours today, around 15G25kts, then diminish to under 10kts after sunset and back to SW. KMSP...Small chance of MVFR-worthy -SHRA this afternoon, mainly in the 17z-21z window. Not looking for any persistent showers nor anything heavy, but intermittent showers could briefly drop visibility to 5sm. No other concerns. /OUTLOOK FOR KMSP/ THU...VFR. Wind W 10 kts. FRI...VFR/MVFR with -SHRA/TSRA likely. Wind SE 10-15 kts. SAT...VFR. Wind SE 05-10 kts. && .HYDROLOGY... Issued at 321 PM CDT Mon May 20 2024 Given the setup for widespread heavy rainfall, were certain to see most rivers in the area end their recent recession and begin rising once again. Extended probabilistic guidance (HEFS) shows the potential for decent rises on area rivers should rainfall exceed 2.5 inches or so over large areas, something that is in the realm of possibility. The upper Minnesota and tributaries, as well as the Crow river basin, are probably the most susceptible to seeing rises to near or above flood stage by later in the week should this occur. Urban/small stream/overland flooding is also possible during and shortly after some of the heavier downpours Tuesday and Tuesday night. A reminder: The NWS hydrology/river forecast webpage (AHPS) at water.weather.gov is going to be discontinued next week (May 28th). The new site (NWPS, the National Water Prediction Service) is located at water.noaa.gov now is the time to replace bookmarks and familiarize yourself with how the new site looks and feels. Resources for learning more are available at the bottom of this page: https:/www.weather.gov/owp/operations && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...CTG AVIATION...JPC HYDROLOGY...CCS