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
820 FXUS63 KMPX 152312 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 612 PM CDT Sun Sep 15 2024 .KEY MESSAGES... - Highs in the mid-upper 80s to continue through Wednesday. - A more active pattern is expected for the second half of next week into next weekend with the best chances for rain right now coming Thursday/Thursday night and Friday night into Saturday. - Heavy rain is currently the greatest potential hazard, though a severe potential is slowly starting to emerge for the two active periods as well. && .DISCUSSION... Issued at 308 PM CDT Sun Sep 15 2024 We`re back to the unseasonably mild and mostly quiet weather today as a blocking high over the Great Lakes continues to shunt any significant forcing west and north of the upper MS Valley. However, continued south winds have slowly pushed dewpoints back up into the mid/upper 60s, which has pushed mlCAPE back up to near 2000 j/kg. However, the last two MPX soundings showed a stout warm nose in place just below h7 and that cap is still in place, so we`re not anticipating any convective initiation. The atmosphere has been giving it a valiant effort southwest of Redwood Falls, where some differential heating along the Buffalo Ridge has resulted some brief successes at deep convection, but none of this activity has survived once it leaves this source of differential heating. For the rest of tonight, the shower potential is expected to remain north of the area, so we have maintained a dry forecast. We`re not seeing the forcing to support all the QPF that the 15.12 GFS spits out over the MPX area tonight. For Monday through Wednesday, it`s more of the same, with the active storm track remaining west and north of the MPX area as ridging to our east continues to force rainfall around us. To go along with the dry weather, it`s three more days of summer, with highs continuing to run around 10-20 degrees above normal as they comfortably rise into the 80s with dewpoints remaining in the 60s. Change finally starts to happen mid-week as the h5 ridge to our east begins to break down. This will finally allow a cold front to enter the region on Thursday, which is when our first widespread rain chances of the month finally arrive. For our first chance of rain, a surface low will be tracking east across southern Canada, with a cold front coming across the Dakotas during the day on Thursday. Storms should fire along this front and work east across the MPX area Thursday night. Where storms initiate during the afternoon, there should be sufficient moisture, instability, and shear to at least support a small threat for severe weather, nothing significant, but something we`ll have to watch over the coming days. We`re trending toward a drier scenario on Friday as a weak high pressure moves in behind the Thursday night front. As this high is moving in, a wave will be coming out of the 4-corners region, heading for the upper MS Valley next weekend. There`s still quite a bit of spread with exactly where this feature and its associated surface low will track, but a threat for heavy rain and possibly some severe weather will follow it depending on where it tracks. The one trend seen over the last 24 hours with the models is a shift to the east in where these two rounds rain fall, with the 2-4+ inch rain swaths yesterday placed across the eastern Dakotas into western MN now shifted east to be centered over MN. There`s still lots of time for details to change, but it looks like normal precip for the month of September will be within reach for MSP, despite only getting 0.02" of rain in what is supposed to be the wetter half of the month. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 610 PM CDT Sun Sep 15 2024 VFR conditions with southerly winds through the period. KMSP...No additional concerns. /OUTLOOK FOR KMSP/ TUE...VFR. Wind SE 10-15kts. WED...VFR, chc MVFR/-TSRA late. Wind SE 10-15kts. THU...VFR, chc MVFR/-SHRA. Wind SE 5-10kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...MPG AVIATION...Dye