Area Forecast Discussion
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
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941 FXUS63 KBIS 060251 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 951 PM CDT Sun May 5 2024 .KEY MESSAGES... - Southeast winds gusting to 50 mph continue over western and south central North Dakota into late tonight. Thereafter, focus for higher winds Monday shifts east including all of central North Dakota including the James River Valley. - Widespread showers and isolated to scattered thunderstorms are expected late tonight through Tuesday, especially in far western North Dakota. - There is a conditional risk of strong thunderstorms Monday afternoon, mainly across southern parts of the state. - Focus for stronger winds shifts to southwest North Dakota for Tuesday, after winds shift westerly. && .UPDATE... Issued at 950 PM CDT Sun May 5 2024 The forecast for tonight remains on track. Showers and thunderstorms continue to lift north/northeast across the high plains on eastern Wyoming and Montana. Will see some of this activity nearing the MT/ND border area later this evening, with CAMs and NBM still suggesting another area of showers and perhaps a few thunderstorms developing across South Dakota and lifting north into western and south central ND overnight. Models still in great agreement with the formation of a 40-50 knot low level jet, along with lead embedded impulses ejecting north out of an upper low across the Central Rockies, both of which would support this development. Opted to keep the wind advisory as is with this product issuance, despite winds tapering off some this evening, as the increasing LLJ coupled with shower activity may mix down some of these stronger winds tonight. UPDATE Issued at 658 PM CDT Sun May 5 2024 Southeast winds remain strong west and south central, with gusts ranging from 40 to 50 mph. Thus, the wind advisory remains valid and no changes to headlines with this product issuance. Mainly a BKN-OVC upper level cloud deck over west and central ND early this evening. Will see increasing mid level clouds followed by ceilings lowering as precipitation starts to develop into the local area later this evening and especially overnight. Right now all activity is well to our west and southwest, which should change as the upper low moves over the Central Rockies and lead impulses start to life north across the plains as we progress through the night. && .DISCUSSION... Issued at 221 PM CDT Sun May 5 2024 Current surface analysis places low over the Northern and Central Rockies, with broad high over the Midwest. This is resulting in a tight pressure gradient through the Central into the Northern Plains. Upper level analysis places ridging over the Northern Plains ahead of low that is now pushing through Great Basin. Over our neck of the woods, gusty southeast winds continue in the tight pressure gradient, especially over western into south central North Dakota. Strongest winds now focused over southwest North Dakota where some gusts around 50 mph have been noted. For tonight, upper low passes over the Rockies with surface low pushing to the lee side of the Rockies into the plains of Montana/Eastern Wyoming. In the meantime, a low level jet will also be intensifying. Gusty southeast winds therefore will continue through the evening into the overnight given the gradient and possible enhancement from the jet, but will start to ease up over western North Dakota after midnight, while continuing over portions of central North Dakota. In the meantime, rain shower chances will gradually be on the increase with the upper low continuing its approach. On Monday, upper low becomes influenced by a low to the northwest and becomes negatively tilted as it works into the Northern Plains, but still remains closed. Chances for showers/storms will continue to spread across the area, with the highest chances remaining to the west. There remains some concern for severe potential over southern portions of the area, with the potential remaining rather consistent per multiple runs of the CSU machine learning probabilities. Forcing will be ample giving the lifting boundary, and 0-6KM deep layer shear will be more than ample at ~40-60kts, just instability remains in question. The next issue is winds, with the focus for gusty southeast winds shifting more into central/eastern North Dakota with the surface low lifting into the far western Dakotas/eastern Montana. Pressure gradient remains rather tight, so expect another round of gusts to 50 mph. As we get into the overnight into Tuesday, low lifts northeast well into the Northern Plains and loiters over the region. Still some question on the exact implications of the dry slot and how far west it will go. Speaking of Tuesday, northwest winds become a possible concern over the southwest, but again the intensity of the winds depend on how far north the surface low lifts. Precipitation chances remain through Wednesday and possibly into Thursday pending the departure of the low from the region. Seasonably mild temperatures expected. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 658 PM CDT Sun May 5 2024 Gusty southeast winds are expected to continue over most locations through the 00Z forecast period. VFR conditions will prevail until late tonight as periods of rain start to move into the area from west to east. Ceilings will drop to MVFR to IFR levels Monday morning and through the day. && .BIS WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 4 AM CDT /3 AM MDT/ Monday for NDZ001-002- 009-010-017-018-031>033-040-041-043-044. Wind Advisory from 6 AM Monday to midnight CDT Monday night for NDZ003>005-011>013-022-023-025-037-048-051. Wind Advisory until midnight CDT /11 PM MDT/ Monday night for NDZ019>021-034>036-042-045>047-050. && $$ UPDATE...NH DISCUSSION...JJS AVIATION...NH