Wednesday, July 8, 2015

July Update: Flooding, Heat, Dust, you name it!

Forecast Discussion:
Good Wednesday evening everybody. Saturated ground, added cloud cover, and a real lack of any significant, stubborn upper level high pressure systems has given us a fairly mild summer across the area so far. We can thank El NiƱo for all of that. The highest temperature we have seen this year here in Austin is 95°F. A stubborn early July stationary cold front that has been parked to our northwest for the past several days now in association with a stagnant upper level trough, or dip, in jet stream winds across the western plains has brought several rounds of flooding showers and thunderstorms to portions of the Texas Big Country, north and northwestern portions of central Texas as well as southern and central Oklahoma. Abilene received a record-shattering 8.26 inches of rain yesterday which led to flash flooding across a large portion of the Big Country/West Texas. Areas north of the Hill Country have received a widespread 2-10 inches over the past week. That is great news for Lake Buchanan, because a good majority of that runoff will find its way into Lake Buchanan. The LCRA (Lower Colorado River Authority) is estimating Lake Buchanan to rise as much as 5-6 feet over the coming days. Lake Buchanan is still only considered to be around 52% full.

Rainfall Accumulation Map (South Central U.S. past week)


In addition to creating those flooding rains across portions of the state, lower pressure associated with the frontal boundary/upper level trough to our north and higher pressure parked off to our east has really made a good chunk of Texas a wind tunnel over the past several days. Those gusty and persistent southerly winds are more reminiscent of the spring months. As that trough of lower pressure and the stationary cool front retreat north and out of the state and higher pressure begins to take charge of our weather pattern from the east, I’m expecting winds to really begin to lighten up across the area, however, they will maintain direction out of the south making sure to keep that sticky Gulf air in place. As high pressure moves overhead this weekend into early next week, our highs will accordingly climb across the area from the upper 80s and lower 90s into the lower to middle 90s across the area…a few locations may even challenge the upper 90s early next week, however, that should be the exception and not the majority. Regardless of what the actual air temperature is, the combination of Gulf of Mexico moisture and heat will promote heat indices above 100°F across the region. Looking ahead into the middle/end of next week (which may I remind you is similar to an eternity in weather forecasting) is hinting at some rainfall chances returning to the area as models are painting an upper level trough of low pressure approaching the state from the east and northeast. With all of this mentioned, look for a warming trend over the coming days as we settle into what is typically a drier time of year for us here in central Texas. The nice thing is, I’m keeping triple digit temperatures out of the forecast for now; the ground is just still too saturated to get that kind of heat.

GFS Forecast Model showing ridge of high pressure over Texas this weekend:



Heat Safety Tips: HEAT is the #1 weather-related killer


Saharan Dust:
Let me add one more thing to the pot, African Dust…it has been with us on and off for the past several weeks now and really looks to continue to be with us (on and on and off basis) over the next couple of weeks…thankfully it doesn’t have much of an impact on most folks, however, younger children, the elderly, and those sensitive to dusts/allergens need to limit their time outdoors on particularly dusty/hazy days. This is a great source to get the very latest air quality forecasts for the state of Texas. Click HERE to be redirected to that website (it will open in a new tab). A lot of people don’t believe that dust can travel so far, however, it can and it does…for more information on how it does so make sure to check out an older blog post I wrote on African Dust and how it affects us here in Texas, by clicking HERE.

Hazy Austin Skyline
Photo by Ralph Barrera/Austin American-Statesman