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FNUS22 KWNS 101904 FWDDY2 Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0204 PM CDT Tue Sep 10 2024 Valid 111200Z - 121200Z ...CRITICAL FIRE WEATHER AREA FOR A LARGE PORTION OF THE GREAT BASIN... Minor modifications to the critical area have been made on account of recent guidance. The remainder of the forecast remains on track. See the previous discussion for greater details. ..Wendt.. 09/10/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Tue Sep 10 2024/ ...Synopsis... The upper trough over the western US will quickly intensify Wednesday, as a shortwave perturbation and mid-level jet streak move onshore over the West Coast. As the trough strengthens, mid-level flow over much of the West will increase. A surface low will deepen over the northern Great Basin, while a cold front moves onshore and also strengthens. To the east, TS Francine will approach the Gulf Coast with offshore winds likely over parts of the mid South. Strong surface winds, low humidity, and thunderstorms over parts of the West and central US will support critical fire-weather concerns Wednesday. ...Great Basin... Ahead of the deepening trough, a potent mid-level jet streak will move over parts of the western Great Basin beginning early Wednesday. A deepening surface low in parts of the eastern Basin will drive 20-25 mph winds over much of NV into western UT. Augmented by downslope flow off the Sierra and the approaching cold front, a brief period of winds of 25-30 mph will be possible along with RH below 15%. Widespread critical fire-weather conditions are likely over parts of the Great Basin. Fire-weather concerns should diminish behind the front as cooler and more quiescent conditions are expected behind the front into early Thursday. ...Lee of the Rockies and High Plains... As the trough approaches, height falls and stronger flow aloft will overspread the Rockies and High Plains. A surface low will deepen first in eastern MT, with a lee trough extending south into the central High Plains. Near the lee trough, strong southerly winds will overlap with areas of low RH and drying fine fuels. Elevated fire weather concerns are expected over parts of the High Plains Wednesday afternoon and evening. ...Mid South... As Francine approaches the Gulf Coast Wednesday and Wednesday night, offshore pressure gradients will increase over parts of the lower MS Valley and Mid South. While humidity values are not expected to be overly low with the tropical air mass approaching, strong gusts are expected to overlap with areas of relatively dry fuels and little recent rainfall. Brief elevated fire-weather conditions are possible before rain chances increase into early Thursday. ...Northwest Thunder... Ahead of the cold front, increasing mid-level moisture and strong lift from the trough will promote scattered thunderstorms Wednesday afternoon. Lightning may interact with areas of somewhat drier fuels over parts of the Northwest and northern Rockies before broader wetting rainfall develops. However, these storms will likely have higher precipitation efficiency with a cooler air mass and more plentiful Pacific moisture in place. This lends significant uncertainty on the threat for any lightning ignitions. ...Please see www.spc.noaa.gov/fire for graphic product... $$