Re: December 2018: Compact Potent Storm/High Winds Late Week
Posted: Tue Dec 11, 2018 10:23 pm
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Maybe North and NW of us - College Station to conroe - but I'll be mighty surprised if it reaches the galveston bay area.KHOU BLake wrote: ↑Tue Dec 11, 2018 4:56 pm Anybody else paying attention to Friday morning? The GFS has been very persistent in a deep, cold upper-level low passing through north central Texas. I know the profiles are marginal here but I’m beginning to think that snowflakes, maybe a light snow shower may be possible around the region very early Friday, maybe a dusting on the grass in north Texas.
The low just has a “look” about it that seems funny to me. I’m not exactly sure how this compares to the mid November snow event here because I don’t remember what the soundings looked like but with notable dry air we could get enough wet-bulbling, especially closer to the low where lift will be strongest to squeeze out some wintry precipitation. I’ll be watching the NAM and HRRR closely as they were the first and to my knowledge the only models that picked up on the mod november event.
What kind of travel impacts could this have Friday? My daughter is traveling from Austin to C.S. Friday.don wrote: ↑Wed Dec 12, 2018 6:41 am Several of the global and mesoscale models trended further south overnight with the cold core low. Most of them now bring the system over southeast Texas with wrap around moisture. The system being so potent could have more dynamic cooling than what the models show, a fly in the ointment is surface temps but if we can get some wet bulbing that could help. While I wouldn't feel confident putting snow in the forecast, I wouldn't rule it out either as these types of systems can have surprises.
Another highly dynamic storm system heading for the area.
Brief heavy rainfall and very strong winds likely.
Active weather event likely late tonight-Friday with multiple impacts across the state. Surface low pressure will rapidly develop today in response to the approach of a strong upper/mid level low out of the NW US. Southerly flow overnight has already begun to return moisture to the region and expect this increase in moisture to continue today. Lift will gradually increase today into tonight and a weak cool front/dryline feature will move across the area early Thursday morning (100am-800am). This feature will likely produce a line of thunderstorms with brief heavy rainfall of 1-2 inches likely. Fast movement of the line should preclude any significant flooding concerns, but some ponding on roadways will be possible during the morning commute on Thursday. Expected rainfall should not have any significant changes to ongoing river flooding over the area given the expected low totals and fairly small spatial coverage of this event. May see a brief rise on the West Fork of the San Jacinto River given the flashly nature of Spring and Cypress Creek drainage.
Approach of the strong upper level system on Thursday will help to rapidly deepen the surface low over TX and greatly tighten the pressure gradient. A powerful low level jet will develop on the backside of the surface low pressure system over eastern TX allowing very strong NW winds to spread out of WC TX into much of the state during the afternoon hours. Sustained winds of 25-35mph are likely with frequent gust to 40-45mph especially west of a line from College Station to Bay City and then along the coast. Solid gale conditions are expected across the coastal waters and area near the coastal bend could see storm force conditions with frequent gusts over 50kts over those waters. Winds will howl Thursday night with the pressure gradient remaining tight before starting to weaken by Friday afternoon. Sporadic power outages can be expected with these kind of winds along with disruptions to aviation travel at the various airports.
Thursday night/Friday morning:
Dynamic core of the upper level low will move just north of SE TX will additional lift being generated. Air mass looks to be fairly dry in the low levels as strong NW winds scour out the moisture. Strong cold air advection will drive temperatures into the 40’s by Friday morning with wind chills well into the 30’s with the strong winds. A mixture of light snow/rain will be moving from C TX toward SE TX Friday morning in association with the cold core upper level low. Think most of this precipitation will weaken and fall apart before arriving into SE TX, but cannot rule out some flurries or sleet north of a Columbus to Hempstead to Livingston line Friday morning. With surface temperatures remaining well above freezing…anything that falls will result in NO impacts.
Marine:
Extremely hazardous marine conditions will be developing on Thursday and lasting in Friday. Gale watch is up for all waters including Matagorda and Galveston Bays and expecting sustained winds of 30-35kts with frequent gusts of 40-45kts over the upper TX coastal waters and even the inland bays. Winds may be a bit higher toward Matagorda Bay and offshore the coastal bend with gust over 50kts. Seas will builds 12-14 feet quickly offshore Thursday night and 6-7 feet in the inland bays. Visibility will reduce offshore in blowing sea spray. Small craft should remain in port Thursday into Friday. Winds will gradually weaken on Friday as the pressure gradient slackens.
Strong offshore flow will drive water level below normal and a Low Water Advisory will be in place Thursday night and Friday as winds push water out of the inland bays. Looking at tides falling 2-3 feet below normal in the Ship Channel and NW sections of Galveston and Matagorda Bays which will produce hazardous marine travel for vessels and increase the risks for groundings.
There will be no impacts across SE Texas. Even Austin should be good.snowman65 wrote: ↑Wed Dec 12, 2018 6:49 amWhat kind of travel impacts could this have Friday? My daughter is traveling from Austin to C.S. Friday.don wrote: ↑Wed Dec 12, 2018 6:41 am Several of the global and mesoscale models trended further south overnight with the cold core low. Most of them now bring the system over southeast Texas with wrap around moisture. The system being so potent could have more dynamic cooling than what the models show, a fly in the ointment is surface temps but if we can get some wet bulbing that could help. While I wouldn't feel confident putting snow in the forecast, I wouldn't rule it out either as these types of systems can have surprises.
FV3 GFS has chilly air and the indices point toward a below normal time period. The old GFS can’t make up its mind between chilly or seasonal.
You’ll be wrong. There’s nothing that suggests that in the long range pattern or weeklies.