Area Forecast Discussion
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
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197 FXUS63 KBIS 010905 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 405 AM CDT Wed May 1 2024 .KEY MESSAGES... - Widespread rain showers will continue moving across central and eastern North Dakota through tonight. - Daily chances (low to medium) for rain (and maybe an isolated thunderstorm or two) through the rest of the week, with temperatures slightly below normal. - Breezy to Windy across the forecast area on Friday. && .DISCUSSION... Issued at 405 AM CDT Wed May 1 2024 Today, the region remains under the influence of a fast approaching upper level low moving into the southern Canadian Prairies out of the Pacific Northwest. An associated surface low center continues to be parked over southern Saskatchewan, and is responsible for the light showers and low stratus that continues to pivot northward out of the area at this time. The upper level low will stall out over the southern Canadian Prairies late today, and allow a shortwave trough to push another round of rain showers and low stratus into the southwest later this morning. Lows this morning are in the upper 20s west to upper 30s east. Highs today are expected to be a little warmer as a weak ridge is pushed ahead of the shortwave trough, from the lower 50s west to the lower 60s east. Rain showers will slowly expand to the northeast through the day today as the surface low in southern Saskatchewan dips into northern Montana and begins to mature, with the highest chances (40 to 80 percent) presently expected across the south central. Modest instability over the southwest and portions of the south central will allow for an isolated thunderstorm or two to potentially develop this afternoon and again on Thursday (10 to 20 percent chance), though these are not expected to become severe at this time. The surface low will then become mature as it pushes across the International Border late Wednesday and through the day Thursday, with rain chances becoming widespread (60 to 80 percent) across the forecast area as the showers again begin to pivot northward throughout the day. Rain totals for this whole period will vary across western and central North Dakota. The west will only see limited chances for showers, mainly on Thursday, and thus has the lowest expected totals from the trace (southwest) to a quarter of an inch (northwest) range. With more consistent showers expected in central North Dakota along with some enhanced rainfall rates where isolated thunderstorms do develop, rainfall totals here are favored (50 to 60 percent) to exceed one half inch by late Thursday, with the ensemble hinting that some locations could even exceed one inch overall (20 percent chance). Behind this system on Friday, some light wrap around showers could persist across the forecast area while modest CAA promotes breezy to windy conditions. Temperatures through Friday are expected to be below normals, with highs in the 50s and lows in the lower 30s to mid 40s. Upper level ridging will begin to intrude into the west late Thursday and into early Saturday, allowing conditions to dry out and begin to warm up into the upper 60s and 70s by Sunday afternoon. Another upper level low will move over the Pacific Coast on Saturday before supplanting the ridge late Sunday into Monday, again establishing an active pattern for the early portions of next week. CSU Machine Learning has begun to paint the southern portions of the state with severe weather potential Monday and Tuesday. Uncertainly remains with regards to this system as the ensemble remains discordant at this time, with the deciding factor appearing to a minority cluster (~15% membership) resolving on the sufficient instability for initiation. In any scenario, this pattern again bring widespread chances for showers across western and Central North Dakota through early next week. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 405 AM CDT Wed May 1 2024 A broad area of light rain showers and low stratus pivoting around a surface low center in the southern Canadian Prairies continues to exit the forecast area to the northeast. At the start of the 06Z TAF period, only the southeastern terminal of KJMS continues to observe MVFR to LIFR ceilings, and will soon join all other terminals at VFR conditions through the late afternoon. Another round of light showers and MVFR ceilings will begin to push into the southwest just before noon today before spreading to the southern terminals of KDIK and KBIS by the end of the TAF period, then to all other sites through early Thursday morning. Modest winds in KJMS will diminish by the early morning, with winds remaining generally light through the end of the TAF period. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Adam AVIATION...Adam