SPC Day 2 Fire Weather Outlook

By Newsroom America Feeds at 17 Mar 2018

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0143 PM CDT Sat Mar 17 2018 Valid 181200Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS... The previous forecast is generally on track. Some adjustments to the critical and elevated areas have been made based on latest model guidance. Mainly, the western edge of the elevated and critical have been expanded to the west and north with some minor adjustments on the eastern edge. Some uncertainty on the eastern extent of fire weather potential continues due to differences in forecast position of surface low and dryline. Regardless, a corridor of higher-end critical fire weather conditions are expected from east-central NM into the TX Panhandle and TX South Plains vicinity. Models have generally been over-forecasting dewpoints/RH conditions, but did not feel confident enough to undercut guidance enough to issue an extremely critical area for this region. This is due to aforementioned differences in surface features and the affect this has on projected westward extent of better moisture return ahead of the surface low. That being said, ERC values across much of the region are approaching the 90th percentile and a large area of severe to exceptional drought is ongoing. These fuel conditions combined with expected meteorological conditions will support extreme fire behavior given ignition. Overnight, westerly winds will remain strong and RH recovery will be poor (20-30 percent), posing challenges for any ongoing fires. ..Leitman.. 03/17/2018 .PREV DISCUSSION... /ISSUED 0158 AM CDT Sat Mar 17 2018/ ...Synopsis... A shortwave trough will move eastward from the Southwest to the southern High Plains through Sunday evening, with a belt of enhanced (70-90+ kt) mid-level flow overspreading eastern NM into west TX and the TX/OK Panhandles by Sunday afternoon. Large-scale lift preceding this shortwave trough will promote the deepening of a surface low over southeastern CO Sunday afternoon. A Pacific cold front associated with the shortwave trough will sweep eastward across the southern High Plains on Day 2/Sunday, likely reaching into southeastern KS and far western OK into western north TX around Sunday evening. ...Portions of the Southern/Central High Plains... As the surface pressure gradient strengthens and enhanced mid-level winds reach the surface with mixing of the boundary layer, strong/gusty southwesterly to westerly winds of 20-35 mph will develop on Day 2/Sunday across parts of the southern/central High Plains. RH values should fall into the 10-15% range across much of this region due to downslope warming/drying processes even though temperatures will be reduced behind the cold front passage. Critical conditions appear most likely from eastern NM into west TX, much of the TX/OK Panhandles, far southeastern CO, and extreme southwestern KS. Elevated conditions should occur across a broader portion of the southern/central High Plains, with low-level moisture return across much of OK and central TX generally limiting the eastward extent of substantial fire-weather concerns. Some uncertainty remains concerning how far east elevated/critical conditions will develop on Day 2/Sunday across southwestern KS and the eastern TX/OK Panhandles. This uncertainty stems mainly from differing forecast positions of the cold front by late Sunday afternoon/early evening. Have not made substantial changes to the elevated and critical delineations across these areas for now, but adjustments will likely be needed as models hopefully come into better agreement on the cold front location in later forecast cycles. ...Please see www.spc.noaa.gov/fire for graphic product... Read more



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