WACO, Texas (KWTX) - Although our next cold front, arriving Wednesday, could drop a bit of rain, the weather it leaves in it’s wake will cause the wildland and grass fire danger to increase in parts of Central Texas Wednesday.

Thanks to a passing front, there's a higher-than-normal risk of wildfires and grassfires today... — Thanks to a passing front, there's a higher-than-normal risk of wildfires and grassfires today west of I-35. A red flag warning is in place through 8 PM Wednesday for the elevated wildfire danger.(KWTX, NWS)

A red flag warning is in effect for Coryell, Lampasas, Mills, San Saba, Hamilton, and Bosque Counties from 12 PM through 8 PM. A red flag warning is issued when critical fire danger weather conditions are expected.

It’s HIGHLY discouraged for anyone to do outdoor burning Wednesday midday and afternoon despite a lack of burn bans in place. The only county with a burn ban in our area is San Saba County.

All wildfire ingredients will be in place

Whenever we talk about wildland fires and grass fires, we’re really talking about a combination of a few different ingredients coming together (much like with severe storms, winter storms, etc.). Wildfires need warm temperatures, dry ground, low humidity, and strong winds to grow and thrive and all four of those requirements will be around behind Wednesday’s front.

Wednesday’s cold front likely kicks up scattered showers and even a few storms during the morning, but the approaching front will clear skies and end the rain west of I-35 by 9 AM and potentially even earlier.

Wednesday's south winds in the morning will quickly turn westerly after a cold front swings... — Wednesday's south winds in the morning will quickly turn westerly after a cold front swings through area by mid-morning. Winds may gust as high as 30 MPH west of Highway 281 where the wild fire danger is highest.(KWTX, NWS)

Wednesday’s front has it’s origins in the Pacific Ocean, as opposed to in Canada, so the airmass immediately following the front is more desert-like than “tundra-like”. The front’s strong westerly winds, gusting between 20 and 30 MPH, acts to pull dry air from West Texas in. Dry air heats and cools more quickly than humid air, so the return of morning sunshine and west winds means temperatures should quickly rebound from the upper 50s and 60s into at least the mid-70s by the afternoon.

The dry air from West Texas will also cause relative humidity values to tank. We’ll start out the morning ahead of the front with relative humidity values greater than 90%, but the extremely dry air in combination with the warming temperatures will send afternoon relative humidity values to near 10%. A relative humidity of around 10% with high temperatures in the mid-70s roughly translates to a dew point in the teens.

Relative humidity, a measure of how much moisture is near the surface, will be into the 10%... — Relative humidity, a measure of how much moisture is near the surface, will be into the 10% range late Wednesday aiding in the wildfire danger.(KWTX)

The wildfire ingredient we all know about is the overall lack of precipitation Central Texas has been seeing for over a year now. Cities and towns near and east of I-35 have been faring a bit better in the rainfall department, but cities and towns west of I-35 and especially west of Highway 281 have been rain-starved. The latest drought monitor, updated January 12th, shows all locations under the Fire Weather Watch with between moderate drought to extreme drought conditions. Even if morning rain falls, the exceptionally dry air and rainfall totals below a tenth-inch will not make much of any impact on the dry ground.

Northerly winds and cooler temperatures arriving Wednesday night will bring the fire weather danger to a close for the foreseeable future. We’ll need a lot more rain over the coming months otherwise we’ll be talking about an elevated fire danger risk with some frequency as we head into spring and eventually summer.

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