Area Forecast Discussion
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
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754 FXUS63 KBIS 272344 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 644 PM CDT Mon May 27 2024 .KEY MESSAGES... - Isolated to scattered showers and thunderstorms expected through this evening. Severe weather is not anticipated, although a few storms may produce small hail and gusty winds. - Patchy fog is possible tonight, with overnight lows in the upper 30s to mid 40s. - Mainly dry conditions with near to slightly below average temperatures expected for Tuesday. - Windy and warmer conditions on Wednesday. Isolated strong to severe storms are possible across the west later in the day Wednesday through Wednesday night. - Through the end of the workweek, chances for showers and thunderstorms return with temperatures remaining near to slightly above average. && .UPDATE... Issued at 644 PM CDT Mon May 27 2024 Widely scattered showers and thunderstorms continue across southern and western portions of the forecast area, in an environment with 15 to 20 knots of bulk shear and less than 1000 J/kg of bouyancy, per RAP-based mesoanalysis. Additional showers are moving into northern North Dakota from across the International Border, but no lightning is expected with this activity. Freshened up POPs and used coverage wording through the evening, but otherwise going forecast looks good. && .DISCUSSION... Issued at 345 PM CDT Mon May 27 2024 A weak boundary followed by a mid level shortwave will continue to bring isolated showers and thunderstorms through this evening. MUCAPE of near 1000 J/KG and effective shear of around 30 knots could bring some small hail. CAPE profiles overall look skinny, thus hail is expected to be generally less than an inch in diameter, although cannot rule out an isolated stronger pulse like storm producing hail to around an inch in diameter. DCAPE today is fairly low, although some inverted V soundings are present. An isolated gusty wind 50 to 60 MPH could be possible with the stronger storms today, although small hail will likely be the main threat with any thunderstorms. Behind this wave tonight will be a surface high moving in. This will lessen the winds and bring clearing skies. Overnight low temperatures are expected to be in the upper 30s to mid 40s. Some areas across the north central could get close to patchy frost, although the temperatures are overall expected to remain above frost criteria tonight. These light winds and cooling temps could bring about patchy to areas of fog. For now patchy fog has been placed in the forecast for much of the area and will have to be monitored for tonight into Tuesday morning. Surface high moves eastward Tuesday while an upper level ridge buildings overhead. The result will be mainly clear skies and light winds. Areas in the west closer to the building ridge will be warmer and in the 70s, while eastern areas look to remain below normal and in the 60s. An increasing pressure gradient could then bring some breezy winds to the west Tuesday night. Dry conditions look to remain, while overnight lows remain in the 40s. Developing low on Wednesday will bring a breezy to windy southerly flow. This will also help warm temperatures back into the 70s for most areas. SPC continues a marginal risk for severe weather Wednesday through Wednesday night. This still all depends on timing of the surface low development and then passage of a cold front. It is interesting to note that high amounts of instability are starting to be forecast. The ECMWF EFI even bringing elevated numbers for areas in this marginal risk. There does still appear to be a lack of shear with most models putting 0 to 6 km in the 30 to 40 knot range. EFI CAPE/Shear values are also quite low. Given the modest cape and shear, a wind and hail threat will be the biggest concerns. Some convective parameters hint that a nonzero tornado threat is possible in the southwest. Hodographs do show some turn in the atmosphere present, although the best veering is more in the 0 to 3 KM layer. 0 to 1 km shear is also elevated. STP values may peak around 1, yet are mostly below 1. So overall Confidence in an isolated tornado threat is still low, especially given the overall lack of shear. The associated cold front then moves through Wednesday night into Thursday. Perhaps along this front a line of strong to severe storms could be found with a wind and hail threat also possible. Wind especially may be of concern with increasing 0 to 3 KM shear and elevated amounts of DCAPE. Depending on timing of this front the stronger storm threat could push eastward quickly through the day Thursday. Behind this front looks to be slightly cooler temperatures and some breezy westerly winds. Friday through the weekend a broad trough to almost zonal flow pattern could then setup. This may help keep temperatures near to slightly above average. The unsettled nature of this pattern has also allowed for at least slight PoPs each day from the NBM. Those could increase if more well defined waves move through this pattern. Something to monitor going forward. CSU-MLP currently not showing much for chances of severe weather with this feature. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 644 PM CDT Mon May 27 2024 VFR conditions overall expected through the TAF period. Widely scattered showers and thunderstorms continue across western and southern North Dakota this evening, as well as some showers across the north. This activity is expected to diminish through the night tonight. Although predictability in impacting any one terminal is low, any heavier showers or thunderstorms could produce MVFR conditions. Patchy fog is possible tonight but confidence was too low to include at any terminal with this update. Tuesday will feature mostly clear skies and light north to northeast winds, becoming southeasterly towards the end of the TAF period. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Jones DISCUSSION...Anglin AVIATION...Jones