![National Oceanic and Atmospheric Administration](/build/images/header/noaa.d87e0251.png)
![National Weather Service](/build/images/header/nws.4e6585d8.png)
![United States Department of Commerce](/build/images/header/doc.b38ba91a.png)
Flash Flood Guidance
Issued by NWS
Issued by NWS
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
926 AWUS01 KWNH 110756 FFGMPD OKZ000-111355- Mesoscale Precipitation Discussion 0859 NWS Weather Prediction Center College Park MD 356 AM EDT Sun Aug 11 2024 Areas affected...Oklahoma Concerning...Heavy rainfall...Flash flooding possible Valid 110755Z - 111355Z SUMMARY...Showers and thunderstorms will be increasing in coverage going through the early to mid-morning hours. Some isolated to widely scattered instances of flash flooding will be possible where any backbuilding and training of cells occur. DISCUSSION...The latest GOES-E IR satellite imagery in conjunction with dual-pol radar shows showers and thunderstorms developing and expanding in coverage across areas of central and western OK. The convection which is elevated north of a quasi-stationary front near the Red River is being facilitated by the strengthening and gradual veering of a southerly low-level jet out ahead of low-amplitude shortwave energy ejecting across the central Rockies and out into the High Plains. MUCAPE values across the region are locally as high as 1000 to 1500 J/kg with the strongest nose of the low-level jet focused across the TX Panhandle where VWP data shows southerly 850 mb flow of 40+ kts. This energy though will continue to shift east across western and central OK over the next several hours going through 12Z (7AM CDT) and should promote an additional uptick in the coverage and local organization of heavier showers and thunderstorms. PWs across the region are forecast to increase early this morning to locally near 2 inches over central OK with the aid of the strengthening moisture transport into the region, and this coupled with the instability and relatively strong shear overhead should favor some rainfall rates of 1.5 to 2 inches/hour with the stronger and more organized cells. As the warm air advection regime strengthens and the low-level jet veers and becomes a bit better aligned with the deeper layer steering flow this morning, there will be some growing concerns for backbuilding and training convective cells. The 00Z HREF guidance suggests the greatest potential for this will be over central OK and especially toward the 12Z (7AM CDT) time frame and beyond. Some localized rainfall amounts by mid-morning may reach 3 to 5 inches which is consistent with the consensus of the HREF solutions. The antecedent conditions are very dry across western and central OK, and so these rains will initially be going into moistening the soil conditions, but with locally persistent heavy rainfall rates over time, eventually there may be some isolated to widely scattered instances of flash flooding. The urban corridors will be most susceptible to these potential impacts which will include the Oklahoma City metropolitan area. Orrison ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...OUN...TSA... ATTN...RFC...ABRFC...NWC... LAT...LON 36809742 36609606 36199511 35589472 34939524 34579645 34749848 35279960 35999990 36459965 36729889