A seemingly rare sight, rain fell across parts of the city yesterday around noon. Rainfall totals were generally light, with many people across South-Central Texas missing rain altogether. The airport observed 0.15 inches of rain, whereas Stinson Field on the south side only observed a trace. This brings the current total observed precipitation for the year up to 6.72 inches.
The “heaviest” hit areas were generally confined to the coastal regions of South Texas as a larger cluster of storms produced strong winds and rainfall totals in excess of a couple inches. Check the slideshow on the left-hand side of this page for Doppler radar estimates of how much rain fell yesterday.
The good news, in any case, is that the combination of clouds and light rain kept temperatures below 100º for the first time in 10 days. The high at the San Antonio International Airport was only 93º, which is a great improvement in comparison to the last several days.
That break, however, will be quite short lived. High pressure is building back into the region, bringing in dry air to the mid and upper levels of the atmosphere, ending any chance for rain. This will also result in temperatures exceeding 100º once again for the next several days.
High temperatures this afternoon should top out at around 103º.
This weekend, temperatures will soar to the hottest levels recorded in years. If the current projected high for Saturday of 105º verifies, it would be the hottest reading at the San Antonio International Airport since September 25, 2005. However, if temperatures exceed 105º, it would be the hottest reading since the airport reached the all-time record high of 111º back on September 5, 2000. Given the slight increase in ground moisture and humidity from the brief rainfall yesterday, the current forecast will keep projected highs lower than the all-time record highs. That said, daily record highs will very likely be broken today, tomorrow, Sunday, and Monday.
A Heat Advisory is in effect for almost all of South-Central Texas, with the exception of the Hill Country, until 7 PM Sunday. This replaces the previous heat advisory that was in effect only for counties along the I-35 corridor.
The heat should continue through at least the first half of next week. By Thursday, computer models hint that the upper level ridge will break down over South-Central Texas. This will allow for moisture to flow in from the Gulf of Mexico and bring at least the opportunity for some scattered showers and thunderstorms. It is possible this pattern of slightly cooler temperatures and increased rain chances could last at least a few days.
The latest Drought Monitor came out yesterday. Now 100% of the state of Texas is experiencing at least some form of drought, and 99.01% of the state is dealing with a severe or worse drought. San Antonio, along with 77.80% of the state, is listed under the worst drought category on the Drought Monitor – an Exceptional Drought.
For an increased perspective, the area in the highest level of drought covers in Texas alone, it would cover more than 100% of every other state in the US with the exception of Alaska. And just for fun, if the area of Exceptional Drought were to be superimposed over Alaska, it would cover 31.5% of the state!
Another indicator of how severe the current drought over the state is the Long Term Palmer Drought Severity Index (PDI). According to the latest PDI, San Antonio would need over 15 inches of rain to reverse the effects of the drought.
How accurate is this measurement? Fairly. The PDI matches well with our current annual deficit of 13.61 inches. Since the drought began in middle of September of 2010, it is quite conceivable that the city needs at least an additional 15 inches to balance things out.
Area reservoirs have suffered significantly during the drought and continue to drop from last week. Every local reservoir has lost water since the last check a week ago. The steepest drops occurred at Lake Buchannon (1.37 ft), Lake Travis (1.26 ft), and Medina Lake (1.10 ft). Coincidentally, these reservoirs are also at the lowest capacity out of all area lakes with Lake Buchannon at 48.68% full, Lake Travis at 42.01% full, and Medina Lake at 34.19% full.
A graphic showing most of the local reservoirs and their current levels is also available in the slideshow located at the top left region of this page.
Tracking the Tropics
Hurricane Irene remains an incredibly large storm as she approaches the east coast of the US. As of the 8 AM EDT update from the National Hurricane Center (NHC), Irene has weakened into a strong category 2 hurricane with maximum sustained winds of 110 mph. Her intensity is expected to fluctuate between category 2 and major category 3 strength between now and her landfall overnight tonight.
The current projected path remains generally unchanged from yesterday. Irene is expected to make landfall late tonight east of Wilmington, North Carolina as a strong category 2 to lower-end category 3 hurricane. From there, Irene is expected to ride up along the entire east coast, before making another landfall somewhere near New Jersey or Long Island, New York. The angle of approach between these areas will be so tight that any wobble could result in a landfall of several hundred miles from any projected point. However, impacts are not expected to change much over these areas.
A Hurricane Warning in the United States are now in effect from Little River Inlet, North Carolina to Sandy Hook, New Jersey. This includes the Pamlico, Albemarle, Currituck Sounds, Delaware Bay, and Chesapeake Bay south of Smith Point. A Hurricane Warning means that the first occurrence of tropical storm force winds are expected within the next 36 hours, with winds expected to reach hurricane strength.
A Hurricane Watch is in effect from Sandy Hook, New Jersey to the mouth of the Merrimack River in Massachusetts This includes New York City, Long Island, the Long Island Sound, Block Island, Boston, Martha’s Vineyard, and Nantucket. A Hurricane Watch means that the first winds of tropical storm strength are possible within 48 hours, with an eventual increase of winds to hurricane strength.
Tropical Storm Warnings are in effect from Edisto Beach, South Carolina to the Little River Inlet in North Carolina, and from Chesapeake Bay at Smith Point northward to the Tidal Potomac. A Tropical Storm Warning means that the first occurrence of tropical storm force winds are expected within the next 36 hours.
Given the current track, this storm is especially dangerous for the coastal regions of the East Coast. Irene is an incredibly large storm and will produce high storm surge that will lead to very significant flooding. In addition to the storm surge, rainfall totals are expected to be over a foot near the core of the storm. This foot will fall over already supersaturated soils, leading to severe flooding over many of the major cities across the Mid Atlantic and New England.
Locations under evacuation orders will most likely be to areas where the strongest storm surge and flooding are expected. Anyone residing in evacuation zones are strongly urged to leave, as the conditions in these regions will be potentially life-threatening.
Tropical storm to Hurricane Force winds will be possible from eastern North Carolina to Virginia, to Washington, D.C., to Philadelphia, New York City, Boston, and points north in New England. This will result in widespread tree and power-line damage. Power outages could potentially affect several million people this weekend. Winds are not expected to be strong enough to cause widespread severe structural damage across the Mid Atlantic and New England, but will be high enough to cause some roof and window damage.
This is a serious storm that will impact up to 50 million people. Those in the path of this storm should prepare immediately by stocking up on nonperishable foods, batteries, flashlights, first-aid kits, battery operated radios, and all necessary papers. The biggest threat to most people besides flooding will be power outages. Given the potential widespread nature of these power outages, it is possible electricity may not return for several days.
Elsewhere in the Altantic, Tropical Depression 10 continues to struggle over the open waters of the central Atlantic. This storm is expected to gradually strengthen into a Tropical Storm later today. If this storm does become named, it will become Jose. In any case, Tropical Depression 10 poses no threat to land.
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