ticka1
09-12-2007, 07:21 AM
Flash Flood Threat increasing across SE TX today through Saturday.
Discussion:
Low pressure over the NW Gulf of Mexico will move very slowly WNW toward Matagorda Bay over the next 48 hours while deep tropical moisture on the east side of this low sweeps into SE TX. Rain shield is already well defined this morning along the coast and spreading inland. Appears the center of the low is located about 85-90 miles SSE of Palacios on HGX radar and is moving toward the WNW at around 8mph. Given the closeness to land no significant development of this system is expected…however excessive rainfall will be a very real threat. Even if a tropical depression develops the main threat will continue to be excessive rainfall.
Expect rain shield and moisture to overspread the region from SE to NW this afternoon and tonight with the onset of potential nocturnal core rainfall event after midnight tonight. Low position places area E of a Matagorda Bay to BCS line to be most favored for excessive rainfall. Low then stalls and drifts across the area through Saturday with PWS of 2.3-2.5 inches in place flooding rains are likely.
Rainfall Amounts:
Given tropical air mass and threat for training within feeder bands 3 hours totals of 4-6 inches will be possible through late Friday. Widespread amounts of 2-5 inches with isolated amounts of 5-10 inches will be possible. HPC progs blast the area tonight with a widespread 4.0 inch bullseye centered on Galveston Bay. Given the moist profile excessive short term rainfall rates of 2.5-4.5 inches per hour could be had across the area.
Appears the best threat for concentrated flooding rains will be on Thursday as area comes under good influence of upper air divergence with a trough to the W of SE TX and surface/mid level low drifts just to out W and SW. Would not rule out a few extreme totals of 15+ inches with this system due to its slow motion and threat to stall out over the area through the weekend.
A Flash Flood Watch will likely be issued later today for portions of SE TX.
Discussion:
Low pressure over the NW Gulf of Mexico will move very slowly WNW toward Matagorda Bay over the next 48 hours while deep tropical moisture on the east side of this low sweeps into SE TX. Rain shield is already well defined this morning along the coast and spreading inland. Appears the center of the low is located about 85-90 miles SSE of Palacios on HGX radar and is moving toward the WNW at around 8mph. Given the closeness to land no significant development of this system is expected…however excessive rainfall will be a very real threat. Even if a tropical depression develops the main threat will continue to be excessive rainfall.
Expect rain shield and moisture to overspread the region from SE to NW this afternoon and tonight with the onset of potential nocturnal core rainfall event after midnight tonight. Low position places area E of a Matagorda Bay to BCS line to be most favored for excessive rainfall. Low then stalls and drifts across the area through Saturday with PWS of 2.3-2.5 inches in place flooding rains are likely.
Rainfall Amounts:
Given tropical air mass and threat for training within feeder bands 3 hours totals of 4-6 inches will be possible through late Friday. Widespread amounts of 2-5 inches with isolated amounts of 5-10 inches will be possible. HPC progs blast the area tonight with a widespread 4.0 inch bullseye centered on Galveston Bay. Given the moist profile excessive short term rainfall rates of 2.5-4.5 inches per hour could be had across the area.
Appears the best threat for concentrated flooding rains will be on Thursday as area comes under good influence of upper air divergence with a trough to the W of SE TX and surface/mid level low drifts just to out W and SW. Would not rule out a few extreme totals of 15+ inches with this system due to its slow motion and threat to stall out over the area through the weekend.
A Flash Flood Watch will likely be issued later today for portions of SE TX.