Area Forecast Discussion
Issued by NWS Twin Cities, MN
Issued by NWS Twin Cities, MN
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
331 FXUS63 KMPX 260602 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 102 AM CDT Sun May 26 2024 .KEY MESSAGES... - Warm front pushes northeastward this afternoon/evening, bringing a chance for showers/storms across western and central Minnesota. - The active pattern continues for Memorial Day weekend, especially tomorrow when widespread rain is likely across southeast MN and western WI. && .UPDATE... Issued at 821 PM CDT Sat May 25 2024 Main change noted with the forecast for tonight through Sunday morning is diminishing chances for rain pretty much area wide. The band of rainfall developing along the warm front from southern SD, northeast through western MN to the south of Duluth is mostly losing its battle with dry air in the MPX area and that trend is expected to continue through the night. For the rain chance moving up out of Iowa late tonight into Sunday morning, this continues to drift southeast in the HRRR, it`s now looking like the precip shield to the northwest of the surface low will only make at about as far northwest as a Blue Earth (city), to Red Wing, and Rice Lake line, so for the Twin Cities, it`s looking increasingly likely that Sunday will be dry. Instead, it`s now looking like Memorial Day itself will bring the best chance for rain area wide. The culprit will be the shortwave currently over southern BC that will slide south of the Canadian trough into MN Monday afternoon, with scattered showers/storms developing, in particular along the I-94 corridor. && .DISCUSSION... Issued at 226 PM CDT Sat May 25 2024 A warm front, stretching from central South Dakota towards southern Minnesota, is slowly pushing its way northeastward this afternoon. A broad area of radar reflectivity returns draped over eastern South Dakota and southwestern Minnesota will follow the warm front as it heads into western and central Minnesota later this afternoon/evening. Given the dry layer of air near the surface, many locations have not been reporting any precip making it to the ground. This is expected to be the case for the majority of south- central and eastern Minnesota as well. We have maintained a narrow line of likely (50-70%) PoPs extending from Lac Qui Parle towards Kanabec counties in Minnesota, where the forcing will be strongest and moisture more abundant. A few pockets of stronger storms are possible, especially further north where we could see up to 50kts of effective bulk shear and 1000 J/kg of SBCAPE. This line will weaken overnight, giving a brief break until showers/storms pick back tomorrow morning. This second round will primarily impact the southeastern corner of Minnesota and western Wisconsin, but it could clip the Twin Cities metro late morning into the afternoon. Areas that see rain tomorrow could receive around 0.25-0.5" with locally higher amounts possible as you head into central Wisconsin. Following the system tomorrow, a pair of shortwaves are still on track to ride along the primary circulation and bring additional chances for rain early next week. QPF remains low, with only up to a couple tenths expected through both disturbances. The latest forecast package favors the first wave to track a little further west than the second, further limiting any notion of this being a period of widespread, soaking rain. While a rumble of thunder will not be out of the question, the potential for anything severe looks to be low for both waves (weak lapse rates and limited 0-3km MUCAPE). The area of broad troughing ultimately slides east as ridging builds in over the central Plains around mid-week. This should result in a small stretch of nice outdoor days, with mostly clear skies and light winds. Temperatures during this time frame will attempt to push into the upper 70s for much of Minnesota and Wisconsin. We could be looking at another active period by the end of the week, with global models hinting at a potentially deep, strengthening trough slicing through the Upper Midwest. Both deterministic and ensemble guidance show a strong moisture plume extending from the Gulf up into parts of northern Manitoba and Ontario. While severity and timing are difficult to lock in this far out, there is certainly potential for another wet and active period heading into the weekend. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1239 AM CDT Sun May 26 2024 BKN-OVC skies will prevail for much of this TAF duration at all sites but precipitation will by-and-large be difficult to come by, owing to sufficiently dry lower levels of the atmosphere, except for potentially SE MN into SW WI (thus MKT and EAU) during the day today. Ceilings will likely drop into MVFR range over eastern MN into western WI late this morning through late this afternoon into early evening. Winds will remain generally benign, speeds 10kts or less, while mainly from the NE. KMSP...The only appreciable window for showers today looks to be late this morning into early this afternoon, and should not be overly impactful (worst-case, dropping to MVFR for both visibility and ceiling, but more likely ceiling). Winds will eventually settle on a southeasterly direction early this morning, then gradually back to NE and N over the next 24-30 hrs, with speeds 10kts or less. /OUTLOOK FOR KMSP/ TUE...VFR. Wind NW 10-15 kts. WED...VFR. Wind variable 5 kts. THU...VFR. Wind SE 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ UPDATE...MPG DISCUSSION...BED AVIATION...JPC