Morning briefing from Jeff: Dynamically strong storm system will move across TX on Friday with heavy rainfall and some severe weather possible. Mid level deck has overspread the region from the southwest this morning ushering in the start of changes in the weather. Surface cold front over the NW Gulf will begin to move northward today while moisture and lift start to increase above the surface cold dome resulting in a weak overrunning pattern mainly across central TX into our western counties today. Light rain, drizzle, and fog will become more widespread tonight as the warm front lifts toward the coast and lift continues to increase as SW flow aloft helps to bring impulses across the area. Still going with a slower warm frontal passage on Thursday as these types of patterns usually like to anchor the front near the coast longer than the models suggest keeping the inland areas in the “soup” for a longer period of time. Air mass will slowly modify with time as temperature slowly warm today-Thursday as the warm front approaches with period of drizzle and light rain Thursday. Thursday night- Friday night: Powerful storm system currently over the Pacific west of N CA will move into the SW US and then across TX late Friday. Strong lift will force surface low pressure development over S TX early Friday which will help push the warm front inland over SE TX Friday morning. Strong lift comes to bear across the region with both good upper level divergence (spreading apart of the high level winds) and low level convergence along the stalling warm front and then approaching cold front. 120kt jet stream carves into the region Friday morning. Surface low looks to track near/over SE TX Friday morning into the early afternoon hours and this will be a very active weather period for the region. Heavy Rainfall: Models prog PWS values to increase to 1.6 inches by Friday morning which is +2 SD above normal for mid December. These high moisture levels combined with impressive lift and a strong warm front surface boundary all point to a heavy rainfall threat along and just north of the warm front position Friday morning. While storm motions will be rapid to the NE and E the potential for cell training for a period of time Friday morning into the early afternoon appears elevated. Global models are suggesting widespread 1-2 inches of rainfall is likely with isolated totals of up to 3 inches possible. Will need to watch the warm front position closely Thursday night into Friday for the best axis setup for heavy rainfall. Severe Threat: Not overly concerned with the severe threat at the moment. Warm front should make it to at least US 59 with a moist and unstable warm sector extending southward into the Gulf of Mexico. Not sure the warm sector air mass will be that “juicy” given the cool shelf waters and time of day (morning) which usually helps to mitigate the severe threat. Wind shear however will be impressive as the surface low approaches from the SW and with backed low level winds near the warm frontal boundary low level shear will be maximized. Think the overall instability will limit the severe threat as we have seen previously this fall with system. With that said, it does not take as much instability this time of year with strong dynamics to produce severe weather. Will redefine this threat tomorrow.
Posted on: Wed, 17 Dec 2014 13:22:42 +0000
Trending Topics
Recently Viewed Topics
© 2015