Impressive overnight urban flash flood event in the Dallas/Fort Worth area with 9.46 inches of rainfall in 6-hr and 7.8 inches in 3-hr. Significant flash flooding has resulted. A 1-hr storm total of 3.01 inches was recorded at DFW with a storm total of 6.54 inches which wiped out 67% of the sites 2022 rainfall deficit in a few hours. 

Frontal boundary over N TX will slowly move southward today and approach the northern portions of SE TX by mid to late afternoon. Numerous showers and thunderstorms will develop along the boundary along with scattered showers developing northward along the sea breeze and Gulf inflow. High resolution guidance is still struggling with how the convective activity will play out over the next 48 hours.  

Air mass will become extremely moist and unstable with forecasted PWS of 2.2-2.6 inches and when combined with slow moving/stalled boundaries, a series of upper-level disturbances in the NW flow aloft and favorable upper-level flow for cell training, excessive rainfall can result. Will favor areas north of HWY 105 this afternoon for the potential for heavy rainfall then slowly sink southward toward I-10 tonight into early Tuesday. Patterns favor slow storm motions, cell training, and back building of cells to the west and northwest and this all points to heavy rainfall. 

While grounds are dry, the local air mass will be capable for some impressive short duration rainfall amounts of 2-4 inches in an hour. This was clearly seen overnight in N TX and the local air mass will not be much different over SE TX, especially N of I-10. These rainfall rates can lead to rapid flash flooding especially in urban areas. 

Widespread rainfall amounts of 2-4 inches is expected over much of SE TX through mid-week, but isolated higher totals of 6+ inches will be possible, where these higher totals occur, flash flooding will be possible…again the greatest threat at this time looks to be north of I-10. 

Confidence in rainfall is high, confidence in rainfall amounts and location of the heaviest rainfall is low. 

Street flooding will be the primary threat with the heavy rainfall rates, rises on area creeks and bayou will be possible if some of the heavier storm's train or move slowly over any watershed. 

Overall wet pattern will linger into late week, but slightly drier air mass and washing out of the surface front should transition back toward a more “normal” cycle of showers and thunderstorms driven mostly by the sea breeze front.