1TEXAS A&M FOREST SERVICE

August 24th-August 27th, 2020

Predictive Services Department

Texas Fire Potential Update

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Fire Potential Notes

• Underlying risk for initial attack fires will be linked to where fuel is dry (ERC >75th %). Moderate potential for significant fires will continue where critically dry fuel (ERC > 90th %) is present.

• Uncertainty remains on the tracks of both Tropical Storms Marco and Laura. Widespread rainfall and increased wind speeds will likely be confined to East Texas closer to the Louisiana Border.

• Moderate drying potential is likely for the Western half of the state with forecast warm and mostly dry conditions. Temperatures are forecast to increase to near 100° F along and west of I-35 by Friday.

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Reported fire activity has remained steady over the past 7 days. Several large fires were reported north of Amarillo and southwest of Odessa. Underlying dryness from the absence of monsoonal moisture has produced an environment conducive for fire occurrence in these areas, which is unusual for August.

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8889 Fire (Ward County)8/23/20

Photos submitted by Joe Pasqua

The 1,300 acre fire in Ward County occurred Sunday near Monahans Sandhills State Park. Weather conditions from the Winkler County Airport Sunday at 1700 were: Temperature 99°F, Relative Humidity 21%, Winds SSE 12-15 mph, Gusts 20-23mph. ERC values at Winker Co. Airport are at the 90th percentile.

The combination of above normal grass loading, critically dry fuel, very sandy soils, and brief elevated fire weather produced this large initial attack fire.

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7 Day Observed Rainfall

7 Day Radar Estimated Rainfall

Most rainfall over the past week occurred last Friday night and Saturday, with the greatest coverage and amounts along the I-35 corridor near Austin.

Rainfall amounts near 1 inch have provided short term improvement in dead fuel moisture and some green up in shorter grasses. Additional rainfall will be needed to keep dead fuel moisture elevated and promote increased herbaceous greenness.

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30 Day Percent of Normal Rainfall

August 23rd

Underlying risk for fire occurrence remains where rainfall deficits are less than 25% normal over the past 30 days. Improvement has been observed near the Austin area after this weekend’s rainfall with some rainfall surpluses now present.

An expanding area of rainfall deficits less than 5% is emerging in the Trans Pecos and Southern Plains

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This weekend’s rainfall produced a significant increase in 100-hr fuel moisture around the Capital Region.

Timber and brush litter remains dry and receptive to burning where 100-hr fuel moisture is below the 10th percentile, including the timber dominant fuel beds of East Texas. Improvement in 100-hr fuel moisture this week will be dependent on the eventual track and rainfall footprint of Tropical Storms Marco and Laura.

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Monday rainfall forecast

A few isolated thunderstorms are possible west of San Antonio in the Hill Country Monday afternoon. The area of potential storms is captured on both the forecast surface and rainfall maps. Dry surface fuel ispresent and receptive to lightning ignitions if these storms occur.

Monday Evening Forecast Surface Map

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Underlying risk for initial attack fires will be linked to where fuel is dry (ERC >75th %). Moderate potential for significant fires will continue where critically dry fuel (ERC > 90th %) is present. There is a signal for increased difficulty of control Monday in parts of East and Central Texas where Burning Index is forecast above the 75th percentile.

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Monday forecast fire weather

ForecastWind 6 PM

ForecastMinimum RH

East to southeasterly winds under 10 mph are forecast for most of the state Monday, except for the Trans Pecos and High Plains where winds will be near 15 mph. The warmest and driest conditions will remain across the western third of the state. Relative humidity values in East and Central Texas may approach 30% Monday afternoon.

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Tuesday into Wednesday

Tropical storm Marco is forecast to make landfall near New Orleans Monday afternoon. Marco will likely weaken to a tropical depression as the system moves west, increasing gulf surface moisture into Texas. Current forecast rainfall from Marco is generally under 1 inch for most of East Texas. Please stay up to date with current tropical activity from the National Hurricane Center https://www.nhc.noaa.gov/.

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Tuesday and Wednesday forecast weather

ForecastWind 6 PM

ForecastMinimum RH

The most noticeable difference on Tuesday and Wednesday will be in the increasing surface moisture and relative humidity values east of I-35. Warm and dry conditions are forecast to remain for the Western half of the state.

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Thursday

There remains a lot of uncertainty with the eventual track and strength of Tropical Storm Laura and much can change between the forecast landfall on Thursday.

Slight variations in the track to the west or east can have a big impact on the potential rainfall from Laura.Elevated fire weather conditions have been observed in the past over Texas on the left (west side) of

tropical systems moving north out of the Gulf of Mexico.

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Forecast Temperature Trend

Monday Forecast High Temperatures

Thursday Forecast High Temperatures

Forecast high temperatures Tuesday through Thursday for the eastern half of the state will be dependent on cloud cover and rainfall that may occur from both Marco and Laura.

The western third of the state will have moderate drying potential this week due to forecast warm and dry conditions. Temperatures are forecast to increase back to near 100°F close to the I-35 corridor Thursday and Friday.

15https://ticc.tamu.edu/Documents/PredictiveServices/Fuels/TXERCmap.htm

ERC Seasonal Trends

PSA Observed

High Plains Above Normal

Southern Plains >90th percentile

Trans Pecos Above Normal

Western Hill Country

90th Percentile

Rolling Plains Above Normal

Eastern Hill Country

90th Percentile

Cross Timbers 90th Percentile

Central Texas Above Normal

North Texas Above Normal

Western Pineywoods

Near Normal

Northeast Texas Near Normal

Southeast Texas Above Normal

South Texas Below Normal

Gulf Coast Below Normal

ERC values remain near the 90th percentile in several PSAs. Drying potential will be moderate in the western third of the state this week. Increasing gulf surface moisture, cloud cover, and chances for rainfall will keep drying potential low in East Texas.