####018004463#### FNUS21 KWNS 021624 FWDDY1 Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Fri Apr 02 2021 Valid 021700Z - 031200Z The main change this morning was to expand the elevated risk area across the Plains to better capture recent observed trends. Surface observations across western IA and southern MN show 15-25 mph winds with humidity values already falling into the 30s and upper 20s, much lower than anticipated by most guidance. With only marginal moisture influx into the region this afternoon, humidity values should continue to fall into the 20-30% range. Diurnal mixing and the slow eastward progression of the surface low/trough across the Dakotas will help maintain breezy conditions through the day. Dry fine fuels across this region and reports of recent fire activity further support the expansion. A few locations may experience periodic critical conditions, but the coverage and duration of these conditions is too uncertain to warrant a critical risk area. Further to the west, similar trends are noted across western NE where morning RH values are lower than anticipated by guidance. Although winds may diminish through the day, recent RH trends suggest that the duration of elevated conditions may persist longer than previously thought, warranting the expansion of the elevated risk into western NE. All other regions appear to be on track as outlined in the previous discussion below. ...Dry Thunderstorms... A few dry thunderstorms are possible throughout the day across central AZ and into western NM. A few lightning strikes have already been noted across this region associated with an upper-level disturbance. Both observed and forecast soundings show PWAT values between 0.4-0.5 inches, suggesting little precipitation and dry lightning is possible with any storm. However, below average ERC values across the region indicate that fuels are not overly receptive, precluding the need for a risk area. ..Moore.. 04/02/2021 .PREV DISCUSSION... /ISSUED 0158 AM CDT Fri Apr 02 2021/ ...Synopsis... Upper-level ridging will continue to develop across the West and central U.S. today. The strongest flow aloft will be displaced to the north along the and near the Canadian border. With the building upper-level ridge, a surface high pressure system will maintain its strength as it moves through the Midwest and into the Mid-South. To the north, a strong shortwave trough will help to deepen a surface low in the Canadian Prairies. These two surface features will promote elevated fire weather conditions across portions of the Plains and western Florida. ...Northern Plains.. 15-20 mph winds with 10-25% RH during the afternoon will be possible from northern Montana into the Dakotas behind a weak surface front/pressure trough. Fine fuels continue to dry out in this region and will support fire spread. Winds aloft will be greater in this region compared to points southward; however, a weaker surface pressure gradient will tend to limit the potential critical fire weather in most locations. Some areas of the High Plains will see similar conditions, but the duration of these conditions is in doubt given the weaker winds aloft. ...Southern/Central Plains... Between the surface trough and the surface high pressure, a zone of enhance winds in the lowest 2-3 km will develop from the Texas Panhandle into the Mid-Missouri Valley. Winds of 15-25 mph appear possible in this region. Guidance differs on how low RH will fall, especially with eastern extent. In similar situations with a frontal boundary nearby with surface trajectories generally remaining continental, the drier guidance tends to perform better. With that in mind, the elevated area has been expanded north and east. Even though some areas could see higher RH values in the afternoon, the strength of the winds and dry fuel conditions will support elevated risk. ...Western Florida Coast... Post-frontal wind will remain strong into the afternoon with the surface high maintaining its strength. 10-20 mph winds will overlap RH potentially as low as 25-30% in areas near the western coast. ERCs in this location are nearing the 90th percentile and will support an elevated fire weather risk. ...Please see www.spc.noaa.gov/fire for graphic product... $$