Area Forecast Discussion
Issued by NWS Twin Cities, MN
Issued by NWS Twin Cities, MN
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316 FXUS63 KMPX 132013 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 313 PM CDT Mon May 13 2024 .KEY MESSAGES... - Smoke should push south through tonight, improving air quality. - A good chance of showers and thunderstorms Wednesday, especially Wednesday afternoon thru Wednesday night. The threat for severe weather and flooding is low. && .DISCUSSION... Issued at 312 PM CDT Mon May 13 2024 Smoke continues to plague us as the mid-to-upper level flow has been favorable for transporting wildfire smoke from the active fires in British Columbia. The Air Quality Alert has been extended until 11 PM tonight before CAMs finally show the majority of the smoke pushing south of MN. Skies will remain mostly clear of clouds through Tuesday afternoon with tonight`s lows dropping into the 40s while Tuesday`s highs will again be similar to today`s. However, cloud cover will slowly build from west to east Tuesday evening through Wednesday morning. These clouds will be followed by a shortwave trough which will move over the Rockies Tuesday night and slowly approach MN/WI Wednesday evening. Isolated showers should travel into western MN during Wednesday morning and continue moving eastward throughout the day, with coverage and intensity likely growing throughout Wednesday afternoon as daytime heating occurs. Isolated thunderstorms are also possible in the afternoon and evening, evidence by a couple hundred J/kg of MUCAPE in forecast soundings. However, the still meager CAPE and lack of organization of this wave does not give much hope for severe weather. Temperatures will trend upwards for the final days of this week. Currently, we have highs well into the 70s for the entire CWA for Friday while Saturday most of southern MN will have a good shot at lower 80s. These warmer temperatures will occur due to an 850 hPa thermal ridge building north into the Northern High Plains ahead of an incoming upper-level jet from the Pacific Northwest. However, large disparities exist between model guidance on how this jetstreak is handled as it approaches the Northern Plains. The GFS and GEFS are able to dig a shortwave as it crosses the Rockies, potentially leading to a more well-developed surface low in the Northern Plains Saturday. The ECMWF, EPS, and (to an extent) GEM keep the flow more zonal through the first half of the weekend, leading to better chances of a more light, disorganized precipitation. After Saturday, model disagreement really grows as the jetstreak settles briefly over the Northern CONUS early next week. Subtle disturbances within the flow will affect MN/WI but timing and eventual precipitation placement is greatly uncertain. The NBM has basically smeared 20-30% PoPs across the region Saturday through the end of the period due to the said uncertainty. As we get closer to the weekend, details should begin to iron themselves out but we`ll have to wait for now. If you are wanting a return of more active weather, long-range ensembles once again favor a trough forming over the western CONUS during the last week or so of May. This signals greater potential for synoptic cyclones to be ejecting somewhere east of the Rockies into the Plains, though, details of such features this far in advance are fruitless to be covered at this time. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1232 PM CDT Mon May 13 2024 VFR conditions throughout. Visibility from the wildfire smoke has increased, and should remain above 6 miles throughout the TAF period. North winds should become northeast and eventually southeast for Tuesday morning. No precipitation is expected. KMSP...No weather-related aviation concerns expected with VFR conditions throughout. Visibility from the wildfire smoke has increased, and should remain above 6 miles throughout the TAF period. North winds should become northeast and eventually southeast for Tuesday morning. No precipitation is expected. /OUTLOOK FOR KMSP/ WED...VFR/MVFR, chc PM -SHRA. Wind SE 10-15 kts. THU...VFR/MVFR, chc -SHRA. Wind NW 10-15 kts. FRI...VFR. Wind SSW 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...Borghoff/CTG AVIATION...JRB