Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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625 FXUS63 KFGF 100429 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1129 PM CDT Sun Jun 9 2024 .KEY MESSAGES... - Showers and scattered thunderstorms are expected late Monday afternoon through Monday night. The main threat will be lightning. - There is a low chance for severe thunderstorms Wednesday afternoon and evening. && UPDATE Issued at 1001 PM CDT Sun Jun 9 2024 Forecast remains on track after the last update, with decreasing winds and the stratus layer almost completely eroded (still a narrow sliver). Additional minor adjustments were made to near term trends. UPDATE Issued at 632 PM CDT Sun Jun 9 2024 Low stratus is finally eroding in northwest MN, and adjustments were made to reflect current coverage/timing of eventual clearing. Winds have been much stronger within the valley aided by northerly flow maximizing momentum transfer. Decoupling should start within the next few hours and we should see winds quick drop, eventually becoming light/variable/calm with surfaced high centered over our region tonight. && .DISCUSSION... Issued at 332 PM CDT Sun Jun 9 2024 ...Synopsis... An active pattern continues into next week as several troughs traverse the region. Shortwave troughing and ridging oscillate through the area, with H5 heights increasing this evening as an upper low moves slowly eastward. Moisture is expected to increase along a narrow ridge axis tonight into Monday morning, with a shortwave expected to push across the area during the evening hours and overnight into Tuesday morning. Showers and mainly embedded thunderstorms are possible with this system, with perhaps an isolated stronger storm capable of small hail and gusty winds. The best chance for strong storms Monday evening will be west of the Red River, mainly the Devils Lake area. Showers and thunderstorms are expected to move east of the area by midday Tuesday, with another H5 shortwave ridge building in during the late evening and overnight hours. ...Potentially Strong Storms Wednesday... Severe Potential for Wednesday afternoon into the late evening. The synoptic pattern has a 700mb low pressure system sitting over the great lakes area a transient ridge over us and another 700mb low pressure system follow closely behind in Saskatchewan. The severe potential will be tied to how amplified this ridge becomes over us to advect enough warm air and moisture into the area. If the second system speeds up and flatten the ridge the risk for severe storms decreases. The NBM depicts an 80 percent chance for the maximum temperature to be greater than or equal to 80 south of Grand Forks. Global ensembles (GEFS, ECMWF, GEPS) depict a 50 percent probability for CAPE to exceed 1000 j/kg south of Grand forks. Looking at deterministic model skew T`s they currently show the potential for severe storms between 18z and 03z. However, there is disagreement between models on the storm mode which would alter the types of hazards that could be present during this event. Some of the models support tornadoes, however, there is much stronger support for clusters or discrete storm mode. Another disagreement between models and model runs. The mid level lapse rate will bounce between 7 and 8.0 degrees with a PWAT between 0.6 and 1.4 inches. These inconsistent runs lowers confidence for the development of severe storms on Wednesday. Thursday morning, a second low pressure system makes its way through our area to continue our chances for rain. Friday and Saturday looks to be our needed break from the rain as a broader ridge moves over our area. The later half of the week will be monitored closely to determine the severe storm potential risk and any possible threats. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1129 PM CDT Sun Jun 9 2024 VFR conditions and light winds (5kt or less) are expected to prevail through the early morning hours, with surface high pressure in place. THere is a low chance for ground fog development early Monday morning, but guidance is not resolving this at this time and coverage would be limited if it develops. Winds shift to the southeast and increase 7-14 kt Monday with the highest winds/gusts in eastern ND towards KDVL. Rain showers overspread eastern ND Monday evening, with scattered thunderstorm (coverage 30% too low for TAF inclusion). This activity arrives in NW after midnight. MVFR ceilings are shown to overspread KDVL after 03Z and this may approach KGFK towards the end of the TAF period (show to hold west for now). && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...DJR DISCUSSION...Lynch AVIATION...DJR