Weather for Primary Trick-Or-Treat Time Still Questionable...

A cold front will move across the region this afternoon and evening, causing shower and thunderstorm activity both along it and well behind it. Ahead of the front this morning into the midday hours, areas of drizzle and/or light rain can be expected, along with some scattered showers. As the front approaches later this afternoon, we expect showers and thunderstorms to develop and/or increase across the local area by around 4-5pm and continue into the mid-evening hours before decreasing between 8pm and 10pm. Scattered showers and isolated thunderstorms will then be possible into the pre-dawn hours of Thursday morning, but will be less numerous compared to the late afternoon and evening hours today.

Locally heavy downpours of rain and lightning can be expected at times with any thunderstorms especially later this afternoon into this evening. A few strong thunderstorms are also possible, which could produce strong, gusty winds and/or spotty hail in some parts of the area. At this time the most likely time period for any stronger activity locally appears to be from around or shortly after 4-5pm through about 8pm.

Please also note that strong to severe thunderstorm activity is likely to be even more numerous to the immediate East of the local area this evening.

Regarding the threat of locally heavy downpours across the local area, please keep in mind that ground conditions remain very damp to wet from recent rainfall. Any concentrated areas of locally heavy downpours could result in minor flooding of low lying and poor drainage areas at times from late this afternoon into this evening.

We will continue monitoring the situation and issue updates as conditions warrant.

Weather May Provide More Tricks than Treats for Halloween...

A cold front will move across the region on Wednesday afternoon, causing shower and thunderstorm activity both along it and well behind it into Wednesday evening. At this time we expect showers and thunderstorms to be most numerous across the local area from around/shortly after 4-5pm through about 10pm on Wednesday, and then decrease in coverage from after 10pm Wednesday on into the pre-dawn hours of Thursday morning.

Locally heavy downpours of rain and lightning can be expected at times with any thunderstorms. A few strong thunderstorms are also possible, which could produce strong, gusty winds and/or spotty hail in some parts of the area. At this time the most likely time period for any stronger activity locally appears to be from around or shortly after 4-5pm through about 8-9pm.

Please also note that strong to severe thunderstorm activity is likely to be even more numerous to the immediate East and Northeast of the local area on Wednesday afternoon and evening.

Regarding the threat of locally heavy downpours across the local area, please keep in mind that ground conditions remain very damp to wet from recent rainfall. Any concentrated areas of locally heavy downpours could result in minor flooding of low lying and poor drainage areas at times from late Wednesday afternoon into Wednesday evening.

We will continue monitoring the situation and issue updates as conditions warrant.

Rain To Increase Throughout the Day Today - Possible Issues This Afternoon into Tonight...

Periods of drizzle and light rain will continue across the area this morning. Most of this precipitation will be very light to light in intensity. Rain is expected to increase in coverage and intensity during the afternoon hours today and continue into early this evening before ending from West to East across the area by 8-9pm. Moderate to locally heavy downpours of rain are possible at times with some of the activity during the afternoon and/or early evening hours today. An isolated thunderstorm also cannot be ruled out during the afternoon or early evening hours.

Average additional rainfall of 1.0-1.5 inches can be expected across most of the area through 8-9pm today, with locally higher amounts possible in some spots.

Due to saturated ground conditions and continued higher than normal stream levels across much of the area, ponding of water and/or minor flooding is possible at times mainly this afternoon and/or evening in low lying areas such as low water crossings, etc. in some parts of the area. Areas that are most susceptible include locations that received heavier rainfall earlier this week, as well as areas where any moderate to heavier showers may recur at times during the afternoon and/or early evening hours today.

The Colorado and San Gabriel rivers and tributaries will need to be monitored for possible rises mainly this afternoon into tonight due to rainfall that occurs upstream during the day today. 

As we work through the day today, we'll be able to identify any concentrated areas of enhanced rainfall (if any) on the upstream portions of these rivers which should make it easier to anticipate where rises may occur later on.

Please remember that larger rivers will continue rising well after the upstream rains end, as runoff flows downstream. Hence the reason we mention that these streams will need to be monitored into the nighttime hours tonight.

We will continue to monitor the situation and issue updates as conditions warrant.

Drizzle/Light Rain Today, More Measurable Rain Tonight/Tomorrow...

Drizzle and light rain will continue this morning and then decrease for a time this afternoon and evening. Rain will increase again late this evening and/or tonight and continue into the daytime hours on Wednesday.

Moderate to briefly heavy downpours of rain are possible at times with some of the activity during the day on Wednesday. Due to saturated ground conditions and high stream levels, ponding of water and/or minor flooding is possible in low lying areas at times on Wednesday in some parts of the area, especially during or shortly after any periods of moderate to heavier downpours.

Most locations have received around 0.5 inch of rain so far (from yesterday afternoon through 6am today). On average, additional rainfall of 1.5-2.5 inches can be expected through 6pm Wednesday, with locally higher amounts possible in some spots. The majority of the additional rainfall will occur from later tonight into the day on Wednesday. This will bring total rainfall for the event (Monday thru Wednesday) into the 2-3 inch range on average across the area.

Present indications suggest the rain will end from West to East across the area around 6pm on Wednesday.

We will continue monitoring the situation and issue updates as conditions warrant.

Rain will increase this evening, continue at times through late Wednesday afternoon...

...Overview...
Periods of rain and possibly an occasional isolated isolated thunderstorms will increase across the area from now into this evening and then continue at times through late Wednesday afternoon or early Wednesday evening. Locally heavy downpours of rain are possible at times with some of this activity in at least some parts of the area, especially during the daytime hours on Wednesday. Any concentrated areas of heavier rain could lead to mostly minor flooding of low lying and poor drainage areas such as low water crossings at times in at least some parts of the local area, especially on Wednesday.


...Forecast Rainfall Amounts...
Average total rainfall of 2-3 inches can be expected at most locations during the period, with locally higher amounts possible in some spots. Present indications suggest the rainfall is likely to be most widespread and/or possibly heavy at times locally from mid-morning (i.e., near 9am) on Wednesday through about Sunset on Wednesday. The period of time with expected heavier downpours at times will likely include the afternoon rush transportation period on Wednesday based on present indications.


...Potential Flooding Risks...
Due to saturated ground conditions and continued moderate to high river and stream levels across the region, conditions will need to be monitored closely for potential low land flooding at times, especially on Wednesday. If such flooding were to occur locally, it would most likely consist of periods of high water in the typical low lying and flood prone areas such as low water crossings and similar areas, and again, this would most likely be of concern during the day on Wednesday, and perhaps into Wednesday evening, per present indications.


...A Note on the Uncertainties with this Forecast...
While computer forecast model guidance has come into better agreement today vs. yesterday, there is still a somewhat higher than normal amount of uncertainty associated with the forecast, particularly with regard to the most likely rainfall amounts across the area through the period. Another update may be required later this evening or tomorrow morning to make a final adjustment to forecast rainfall amounts particularly for the Wednesday daytime period.



We will continue monitoring the situation and issue updates as conditions warrant.

Update on Heavy Rain Potential This Week...

...Overview...
Periods of rain and isolated thunderstorms will increase across the area again at times from Monday afternoon or evening through late Wednesday evening. Locally heavy downpours of rain are possible at times with some of this activity in at least some parts of the area, which could lead to mostly minor flooding of low lying and poor drainage areas such as low water crossings at times in at least some parts of the local area.


...Forecast Rainfall Amounts...
Average total rainfall is expected to range from near 1 inch in extreme Northern parts of the area (northern Williamson County) to around 3 inches in Southern parts of the area (southern Hays County).  

Locally higher amounts possible in some spots (especially in Southern parts of the metro area). Present indications suggest the rainfall is likely to be most widespread and possibly heavy at times locally from near dawn Wednesday through about Sunset on Wednesday. This will potentially include both the morning and afternoon rush transportation periods based on present indications.

Please note that present indications suggest that even heavier rain will occur on a more widespread basis not far to the South of the local area on Tuesday and Wednesday, generally toward I-10 and South from there, including the San Antonio metro area.


...Potential Flooding Risks...
Due to saturated ground conditions and continued moderate to high river and stream levels across the region, conditions will need to be monitored closely for potential flooding at times, especially on Wednesday. 

If flooding were to occur locally, it would most likely consist of periods of high water in the typical low lying and flood prone areas such as low water crossings and similar areas, and again, this would most likely be a concern on Wednesday per present indications.

As noted in the section above, present indications suggest that even heavier rain will occur on a more widespread basis not far to the South of the local area on Tuesday and Wednesday, generally toward I-10 and South from there, including the San Antonio metro area. An even higher risk of flooding is likely in this region during the period.


...A Note on the Uncertainties with this Forecast...
Please note, there is a higher than normal spread among computer forecast models regarding the most likely rainfall scenario for the local area in this situation. This is likely due to the complex nature of the situation, with a weather disturbance moving in from the West and moisture from two tropical systems in the Pacific possibly being pulled Northeast into the local area from Tuesday into Wednesday. 

There is no question that rainfall will occur area-wide especially on Tuesday and Wednesday ("high" confidence) but due to the above mentioned uncertainties and complexity of the situation, the confidence on the forecast rainfall amounts is only "moderate" at this time. If any changes were to be made, it would most likely be to raise rainfall forecast amounts for a good portion of the local area, not lower them, for the Tuesday-Wednesday period. This should become more clear during the day on Monday.

We will continue monitoring the situation and issue updates as conditions warrant.

More Locally Heavy Rainfall Possible at Times Monday thru Thursday...

Periods of rain and scattered thunderstorms will increase across the area again at times from early Monday morning through late Thursday evening. Locally heavy downpours of rain are possible at times with some of this activity in at least some parts of the area.

Total rainfall is expected to average from around 1.0 inch in the Northern parts of the metro (northern Williamson County) to around 3.0-3.5 inches in Southern parts of the metro (southern Hays County).  Locally higher amounts are possible in some spots.

Due to saturated ground conditions and continued moderate to high stream levels across the region, conditions will need to be monitored closely for potential flooding at times during the above referenced time period.

We will continue monitoring the situation and issue updates as conditions warrant.

More Rain On the Way, but Should be Mostly Light In Intensity into Saturday...

At this time yesterday it appeared that locally heavy rainfall would redevelop to our West today, over the Hill Country, and that some area creeks, streams and rivers that haven't already flooded could see rises as a result of those heavy rains to the West.

Fortunately, the rain that did form over the Hill Country today was not heavy, and the rainfall across our area has been mostly light to occasionally moderate in intensity, as expected.

Therefore...we are no longer as concerned about potential new rises on area creeks and streams (again, referring to the ones that haven't already flooded from this event).

We will still see areas of drizzle and light rain, as well as scattered light to moderate showers at times this evening into tonight and the first half of Saturday, but this activity will continue to be mostly light in intensity across the local area overall.

Please keep in mind that many local creeks, streams and low water crossings are still experiencing higher than normal water levels, and in some cases, fast moving water as well (though not at flood stage, other than the Colorado River obviously).  As a result, we recommend that caution be used and recreational type activities be avoided this weekend on or near area creeks, streams and rivers due to the higher than normal and faster than normal conditions which could prove quite hazardous regardless of any potential flooding situation.  Several area parks are closed due to high water anyway, which is a wise move for the above mentioned reasons.

Meanwhile, the Colorado River at Lake Travis will continue in major flood through the weekend and is likely to reach 705-706 feet on Saturday.  This area should continue to be avoided as many secondary roadways (even those other than low water crossings) will remain under water and very dangerous.  

We will continue monitoring the situation and issue updates as conditions warrant.

Major Cold Blast Still on Tap for Tonight into Mid-Week...

A very strong cold front will blast into the region tonight and into the pre-dawn hours of Monday, bringing a variety of significant weather impacts to the area through Tuesday.

...Wind Impacts...
North winds will increase to 20-25 mph sustained with frequent gusts of 30-35 mph starting between Midnight tonight and 2am Monday and will continue into late Monday evening. During this same time period, some gusts of 35-40 mph are also possible at times, especially from 5am to 1pm on Monday.

...Temperature Impacts...
Temperatures will fall from a pre-dawn high in the lower to mid 70s, into the 50s during the morning and perhaps the upper 40s by Monday afternoon. Wind chill or "feels like" temperatures will mainly be in the 40s during the morning on Monday and may reach the upper 30s during the afternoon hours on Monday. For Tuesday, temperatures will range from the lower to middle 40s in the morning to the upper 40s to lower 50s during the afternoon, with wind chills mainly in the 40s throughout the day. Readings should moderate into the upper 50s by Wednesday afternoon.

...Rainfall and Thunderstorm Impacts...
Showers and thunderstorms are likely along/ahead of the cold front from near Midnight into the early pre-dawn hours of Monday, some with locally heavy downpours of rain in some parts of the area. An isolated stronger thunderstorm between Midnight tonight and 3am Monday may also produce strong, gusty winds, fueled in part by the strength of the winds associated with the cold front itself. Behind the front, a raw, cold light rain and periodic moderate showers will occur at times area-wide on Monday and Tuesday. Activity will likely become more scattered in nature on Wednesday.

Average total rainfall of 1-2 inches is likely for most of the local area from tonight through Tuesday evening. Locally higher amounts are possible in some spots. While there could be some localized concerns with regard to ponding of water, "street flooding" or other minor issues in a few of the low lying/poor drainage areas at times, this does not appear to be the type of event where significant flooding is likely area-wide.

We will continue monitoring the situation and issue updates as conditions warrant.

First Strong Cold Front of the Season to Arrive on Monday...

The strongest cold front so far this fall season will move into the region on Sunday night/pre-dawn Monday, resulting in strong and gusty winds and much cooler temperatures area-wide on Monday.

Northerly wind will increase to 20-25 mph sustained with frequent gusts to 35 mph from just before dawn on Monday through late Monday evening. Several peak wind gusts of 35-40 mph are also expected, mainly between 9am and 6pm on Monday.

The combination of the strong, gusty winds along with temperatures falling into the 50s throughout the day will produce wind chill or "feels like" temperatures in the 40s by Monday afternoon and evening.

The wind should gradually start to subside toward Midnight late on Monday evening/Monday night, lowering mainly into the 15-25 mph range by that time.

We will continue monitoring the situation and issue updates as conditions warrant.