Texas Fire Potential Update September 27Th – October 3Rd 2021 Predictive Services Department

TEXAS FIRE POTENTIAL UPDATE SEPTEMBER 27TH – OCTOBER 3RD 2021 PREDICTIVE SERVICES DEPARTMENT

Link to Fire Danger Products Fire Potential Notes

 Monday’s fire environment will support moderate initial attack potential across the Rolling Plains, Cross Timbers, and East Texas. By Tuesday, the fire environment will change as increased low level surface moisture and opportunities for rainfall improve dead fuel moistures and decrease fire potential to low. This moist fire environment and low fire potential will persist through Sunday.

 The accelerated drying and increased fire activity observed last week will end as gulf surface moisture streams inland. Two separate upper level storm systems will interact with the gulf surface moisture, providing several opportunities for rainfall for most of the state this week. Dead fuel moisture will improve, reducing the coverage of dry and critically dry fuel beds.

 Forecasted rainfall through Sunday should help alleviate some of the current rainfall deficits and underlying dryness that is observed across much of the state. Herbaceous fuel that is drought cured may exhibit minimal green up and growth this late in the growing season. 7-Day Fire Activity

The volume of reported initial attack fire activity over the past 7-days increased surrounding the pre and post frontal winds of last Tuesday and Wednesday’s cold front. A very dry air mass behind the front accelerated the drying of surface fuel late in the week providing receptive fuel beds for wildfire ignitions.

This week will be much different. By Tuesday, the fire environment will begin to moisten substantially resulting in low fire potential through the first weekend in October. Dry brush/timber litter fuel combined with increased fire weather will support moderate initial attack potential across the Rolling Plains, Cross Timbers, and East Texas on Monday.

4 Southerly winds on Monday will increase low level surface moisture from the Gulf of Mexico and result in higher relative humidity values. Moisture return will be slower further north away from the Gulf.

Forecast 4 PM Wind Forecast Min RH Monday Monday 5 A pattern change will be underway this week as two separate upper level storm systems interact with Gulf surface moisture to produce periods of rain and thunderstorms for much of the state. Forecast rainfall amounts for the northern half of the state may change depending on the evolution of the second upper level storm system Friday into Saturday.

Monday through Friday Rainfall Forecast

6 Rainfall deficits should improve nearly statewide based off this week’s forecasted rainfall. Remaining dryness will be evaluated next week once the rainfall has occurred.

7 30-Day 60-Day Percent of Normal Rainfall Percent of Normal Rainfall Temperatures will trend down this week as cloud cover and rainfall chances increase. Cooler temperatures combined with forecast rainfall will keep drying potential low.

Tuesday Forecast Thursday Forecast High Temperatures High Temperatures

8 Accelerated drying observed last week has resulted in 5 PSAs energy release component values reaching or exceeding the 90th percentile. A reverse is expected this week as the fire environment becomes moist. Most PSA ERC values will likely be at or below normal by the weekend.

PSA Observed High Plains Above Normal Southern Plains Above Normal Trans Pecos Above Normal

Western Hill Country Above Normal Rolling Plains >90th Percentile Eastern Hill Country 90th Percentile Cross Timbers Above Normal Central Texas 90th Percentile North Texas 90th Percentile Western Pineywoods 90th Percentile Northeast Texas Above Normal Southeast Texas Above Normal South Texas Above Normal Gulf Coast Near Normal

9 Link to ERC Seasonal Graphs The Rolling Plains ERC should begin trending down as gulf surface moisture works inland. Drying in the Central Texas PSA has peaked as increasing surface moisture over the weekend has resulted in a slight decline. Forecasted rainfall should produce a significant decline in ERC values in all PSAs.

10 Monday’s forecast fuel dryness map indicates that dead fuel is already gaining moisture from the increasing low level surface moisture. Dry to critically dry fuel beds will be replaced with normal to above normal fuel moisture by the weekend due to the forecasted periods of rain.

11 By the weekend, a cold front is forecast to stall over the state. There is forecast uncertainty on the progression of this frontal boundary and where the focus of rainfall will occur. The rest of the state will continue to observe a cool and moist fire environment.

Saturday through Sunday Rainfall Forecast Saturday Morning Forecast Surface Map

12 The fire environment for Saturday and Sunday will remain moist resulting in low initial attack fire potential.

Forecast 1 PM Wind Forecast Min RH Sunday Sunday 13 There is an unknown on how drought cured grasses will react in terms to green-up this late in the growing season. Less daylight and cooler temperatures may result in some green up in short grass loadings. Normal to above normal grass loading is less likely to see green up in the entire grass profile.

Briscoe County east of Silverton Burnet County Photo submitted by Steven Moore, Sept. 21st Photo submitted by Will Hood, Sept. 26th