Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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260 FXUS63 KFGF 220925 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 425 AM CDT Sun Sep 22 2024 .KEY MESSAGES... - There is potential for localized frost in portions of west- central Minnesota Sunday night into Monday morning. && .DISCUSSION... Issued at 425 AM CDT Sun Sep 22 2024 ...Synopsis... A cooler continental airmass migrates near the Canadian Border filtering in cooler dry air as the Northern Plains sits in northwest flow. We transition to a more westerly flow increasing the amount of dry over the Northern Plains. A shortwave will bring us some breezy conditions but the dry air at the lower levels will likely continue our dry pattern. Following the shortwave a ridge pattern sets up and temperatures look to rise slightly above normal. Sunday Night: A dry airmass will filter in from Northern Canada and move near the Northern Plains. While some of the cooler dry air will filter over the Northern Plains, 850mb temperatures look to remain near 9 degrees celsius at the coldest over the Northern Plains. 925 temperatures also look to be around 10 degrees at the coldest as well. Surface Dewpoints look to drop into the low 40`s/upper 30`s for the majority of the forecast area. 00Z run of the HREF does depict a 30-40% probability of reaching 36 degrees by 5am Monday morning South of I-94. With cloud cover moving in from the Northwest this would be the most likely area to have temperatures develop frost if it stays cool enough to due so. To add to the uncertainty most of the models dont have us reaching the 36 degree threshold most likely due to the warmer 850/925 temps and encroaching cloud cover. So I did not go with a Frost advisory for tonight as conditions look to remain too warm for frost production. Monday and Tuesday: Monday, we will stay dry with westerly flow aloft filtering dry air. Monday evening into Tuesday, a weak shortwave migrates through the region. Some of the deterministic models show precipitation moving into over area. However, Model soundings show a dry layer extending up to 700mb. With this much dry air the most likely scenario will be some cloudy skies and windy conditions developing but any precipitation may evaporate long before it hits the ground. Wednesday through Friday: Riding pattern sets in to bring increasing temperatures following Tuesday`s shortwave. The ridge will likely advect some moisture into atmosphere to raise the humidity into the 40`s and 50`s but doesnt look like any chances of rain for the rest of the week with that area of high pressure sitting over us. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1128 PM CDT Sat Sep 21 2024 VFR conditions should prevail through the TAF period. Clearing skies/light winds raises the potential for patchy fog early in the TAF period, but the amount of dry air immediately off the surface (and no guidance highlighting development) lowers confidence in impacts/coverage. Surface gradient remains weak through the day Sunday. Prevailing winds should increase with mixing in the west- northwest direction (6-10kt) for most locations and there is a low chance for 5000 FT AGL CU redeveloping in northeast ND during the afternoon (ceiling development unlikely at the CU). && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ DISCUSSION...MM AVIATION...DJR