Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1140 AM CDT Wed Apr 26 2017 Valid 261700Z - 271200Z ...CRITICAL FIRE WEATHER AREA FOR THE BIG BEND REGION OF TEXAS...EXTENDING ALONG THE RIO GRANDE VALLEY TO PARTS OF DEEP SOUTH TEXAS... The critical area along the middle Rio Grande Valley has been expanded westward into the Big Bend region of TX. 16Z surface observations indicate elevated to borderline critical conditions are already occurring across this area along/ahead of a cold front. RH values will likely fall into the 10-15% range for a few hours this afternoon, and strong/gusty northwesterly winds of 20-25 mph will be common. A southeastward expansion into deep south TX has also been made to the critical delineation based on latest short-term guidance and fuel information. Across this region, sustained winds of 20-25 mph are expected as temperatures warm into the 90s/low 100s and RH values fall below 20%. Although green-up of most fuels has occurred across south TX, lack of recent precipitation has allowed fine fuels to become receptive to large fire starts. Across portions of eastern AZ into southern NM, locally critical fire weather conditions may occur, but only isolated/brief instances of sustained winds above 20 mph preclude a critical area with this update. An elevated area has been introduced across parts of the central FL peninsula per recent surface observations, short-term guidance, and fuel info. Although low-level flow is forecast to remain weak, sustained winds around 10 mph, RH values falling into the 30-40% range, and dry fuels due to persistent drought support the elevated designation. ..Gleason.. 04/26/2017 .PREV DISCUSSION... /ISSUED 1230 AM CDT Wed Apr 26 2017/ ...Synopsis... An intense mid/upper level trough over the southern High Plains will eject east across TX today to the mid-MS/lower OH River Valley by early Thursday morning. Strong deep-layer west/northwesterly flow will persist from the southwestern deserts into the southern Plains. While severe storms are expected across parts of the Ozarks and mid-to-lower MS Valley ahead of the trough, elevated to critical fire weather conditions are expected across much of AZ/NM and into parts of western and southern TX. ...Much of AZ/NM into western and southern TX... Widespread elevated to briefly critical conditions are expected across parts of central and eastern AZ into much of NM. RH values will be low, from 10-20 percent and west to northwesterly surface winds will range from 15-20 mph with higher gusts. Concerns of longevity of critical conditions and spotty nature of the strongest wind speeds will preclude upgrades to critical across parts of southeast AZ/southwest NM into parts of east-central NM. Additionally, uncertainty in available fuels exists across eastern NM due to ongoing green-up. Further southeast into western and southern TX, gusty winds will be enhanced as a cold front drops southward across central into southern TX during the afternoon. Northwesterly surface winds of 20-25 mph with higher gusts are expected. As high temperatures warm into the mid 80s to mid 90s, RH values will fall into the 10-15 percent range. Further south into south TX, there are concerns over fuel receptiveness and while gusty winds and low RH conditions will exist, will not upgrade this region given uncertainty in fuel conditions. ...Please see http://ift.tt/2i2um2s for graphic product...Read more
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