Area Forecast Discussion
Issued by NWS Aberdeen, SD
Issued by NWS Aberdeen, SD
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
49
50
768 FXUS63 KABR 092323 AAA AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 523 PM CST Sat Nov 9 2024 .KEY MESSAGES... - The main focus for accumulating rain will be over north central South Dakota through this afternoon. Rain and drizzle chances will diminish to less than a 40 percent chance after 10 pm. - Fog is expected this evening and overnight behind the rain and drizzle. There is a 40-60% chance of visibility around 1 mile or less over the Prairie Coteau of eastern SD. - Temperatures will be around 10-15 degrees above normal through Saturday, excluding Monday when temperatures will be near normal. - There is around a 25% chance for light rain Tuesday night. && .UPDATE... Issued at 521 PM CST Sat Nov 9 2024 The forecast remains on track this evening. Rain and drizzle will gradually come to an end toward Sunday morning. && .SHORT TERM /THIS EVENING THROUGH SUNDAY NIGHT/... Issued at 231 PM CST Sat Nov 9 2024 Thick clouds remain in place across the entire forecast area, rotating around the surface low centered near LBF/NE at 20Z. Light rain and drizzle has given way to fog at PIR with visibility down to around 2 miles. This trend will be common as the main area of rain over Corson/Dewey/Walworth/Campbell and western McPherson pivots northeast and out of the forecast area. We will continue to monitor the trends for fog as increased low level moisture and light winds increase the potential for visibility to fall to around 1 mile or less. While there`s only around a 20 percent chance of visibility falling below 1 mile west of the James River (other than small pockets here and there), the potential increases to 40-60 percent on the eastern slopes and just east of the Prairie Coteau of eastern SD. Our chances for measurable precipitation drop to less than 30 percent after 06Z as the surface low exits far southeastern SD and moves into southern MN/northern IA. Expect dry weather Sunday through Sunday night. Given the recent light rain and relative humidity remaining at or above 45 percent, fire weather concerns will be limited. Most locations will stay above 60 percent for relative humidity Sunday afternoon. The main questions for Sunday will be temperatures, which could be higher if thicker clouds exit eastern SD sooner. Temperatures Sunday will be around 15 degree above normal, ranging from near 60 degrees over central South Dakota to the low 50s across eastern South Dakota and west central Minnesota. Look for increasing clouds Sunday night as a shortwave nears on the northwesterly flow at 500mb. && .LONG TERM /MONDAY THROUGH SATURDAY/... Issued at 231 PM CST Sat Nov 9 2024 Monday morning we will have a weak shortwave departing the region, with a 1022-1024mb high pressure high following close behind. 850mb temperatures are already at their lowest at 12Z Monday, with a gradient across the state from central SD at about +4C to the northeast/western MN at around -2C. Thus, Monday is expected to be the coolest of the upcoming days. As that high pressure moves east and an upper level trough develops across the intermountain west, lee side low pressure develops over northeastern Montana leading to a tightening gradient across the Dakotas/Nebraska. The ~16mb gradient across the state (west to east) will result in increasing winds out of the south southeast, with 1/2km winds in the GFS topping around 40-45kts. NBM probabilities of sustained winds of 30mph and gusts in excess of 45mph (advisory criteria) are between 20-50% and 15-30% respectively which is on par for most set-ups of this nature. A cold front comes through Tuesday afternoon through early Wednesday with limited POPs as the parent shortwave lifts across the area and strengthens over the Western Lakes region. The cold airmass on the backside of the system will have a stark contrast to the warm airmass that precedes it, but overall not a lot of cold air behind the system as the source region is the Pacific Northwest. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 521 PM CST Sat Nov 9 2024 Terminals KABR,KATY,KPIR,KMBG A mix of MVFR and IFR cigs will persist through Sunday morning. As the low pressure system exits, cigs and vsby will improve leaving VFR conditions by afternoon. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Wise SHORT TERM...KF LONG TERM...Connelly AVIATION...Wise