Monday, April 22, 2013

COOL DOWN on the way!

Happy Earth Day!

Keep this in mind: "We treat this world of ours as though we have a spare in the trunk"




I hope you all had a fantastic weekend. Click HERE for a neat write up on Earth Day by CNN.

TUESDAY COLD FRONT & RAIN CHANCES:

Just finished scanning all of the latest computer models and they are all singing a similar tune. The latest run of the NAM Model shows Tuesday's cold front arriving between 1-3 p.m. Tuesday afternoon. Ahead of the front temperatures will climb well into the 70s area wide with a few locations, especially south and east of Austin, nearing 80°F. Warm, humid southerly flow will persist Tuesday morning allowing for widespread low clouds and patchy areas of drizzle.

Cold Front at 3 p.m. (Knocking on the door step here in Austin) Check out the temperature contrast on either side of the front! Temps will be in the 90s across deep south Texas with temps in the 70s and 80s here in central Texas. Temps will be in the 30s, 40s, and 50s across the rest of Texas!




As the much cooler air mass behind the front interacts with the warm, moist air over central Texas, there is a 30% chance for a few showers or thunderstorms to accompany the front as it arrives, however, the rain chances are not all that impressive. There actually looks to be a better chance for some rain showers behind the front. Temperatures will plummet into the 50s and 60s behind the front Tuesday afternoon on breezy northerly winds. Lows fall into the 40s area wide Tuesday night/Wednesday morning with a northerly breeze helping to make it feel even colder.

Temps on Wednesday will struggle to get out of the 50s as cool northerly breezes persist and widespread cloud cover will keep temperatures from warming. A few locations may climb into the lower 60s by late afternoon. Light rain showers possible through the day from time to time. 

FORECAST CLOUD COVER: 90-100% cloud cover on Wednesday 





Thursday, April 11, 2013

Heat & Humidity Returning Soon

Good afternoon everybody. It is an absolutely beautiful day across the state of Texas. We are currently in the 60s here in Austin under a picture-perfect blue sky. Very dry air moving over the area in the mid and upper levels of the atmosphere and a ridge of high pressure are responsible for the crystal-clear skies.

Large Mid-Latitude Cyclone (Upper Level Low Pressure System) that brought us the cold blast and the showers yesterday is now affecting the deep south and the eastern United States. A strong/severe line of storms is marching across the southeastern United States as I'm writing this with Tornado Watches in effect for much of Alabama and northwestern Georgia (including the Atlanta Metro Area until 11 p.m. EST)...as the significantly colder and drier air behind the front clashes with the warm, humid air ahead of it, thunderstorms have exploded. A large tornado dropped out of the sky near Macon, Mississippi earlier today. Check it out HERE

This is a look at the large storm system using Water Vapor Satellite Imagery; I've labeled some of the key features. The large red "L" represents the position of the upper level low pressure (remember, low pressure spins counter-clockwise) in the northern hemisphere:


After a brief, but potent, cool down yesterday, Mother Nature is going to be cranking up the heat and humidity as we head into the weekend and into next week.

Friday's Forecast: Chilly start in the 40s will give way to a mostly sunny & pleasant afternoon with highs in the upper 70s to near 80°F; Wind: SE 5-10 mph

Saturday's Forecast: Cool start in the 40s and 50s will give way to a mainly sunny, warm, and breezy afternoon with highs in the lower to middle 80s; Wind: SE 10-20 mph

Sunday's Forecast: Mostly cloudy and cool start to the day in the upper 50s will give way to a partly sunny and warm afternoon with a high in the middle to upper 80s; Wind: SE 5-15 mph

Monday's Forecast: Mostly cloudy and mild start in the 60s will give way to a partly sunny, warm, and humid afternoon with highs in the upper 80s to near 90°F; Wind: S 5-15 mph (AM DRIZZLE POSSIBLE)

Tuesday's Forecast: Mostly cloudy and mild start in the 60s to near 70°F will give way to a partly sunny, hot, and humid afternoon with a high near 90°F; Wind: S 5-15 mph (AM DRIZZLE POSSIBLE)

Wednesday's Forecast: Mostly cloudy and muggy start in the 60s and 70s will give way to a partly sunny, warm, and humid afternoon with a high near 90°F; Dry line will push into the western Hill Country where temps may climb well into the 90s thanks to the drier air; a strong front will push through late Wednesday Evening with a 30% chance for a strong/severe thunderstorm as instability levels look to be quite high. Unfortunately, rainfall will be very spotty and light in nature. (AM DRIZZLE POSSIBLE)

Thursday's Forecast: Mostly sunny, WINDY, and cooler with highs in the lower 70s behind an early morning cold front; Wind: N 15-25 mph

*Persistent southerly winds starting from tomorrow and lasting through Wednesday will help to pull smoke from agricultural fires burning and pollution from Mexico, therefore, expect hazy conditions to return by as soon as Sunday and persist through Wednesday until our next front arrives*

SLIGHT CHANCE FOR STRONG/SEVERE STORMS LATE AFTERNOON/EVENING ON WEDNESDAY: Dry line will push into the western Hill Country ahead of a strong front that will be pushing through the Panhandle...there is a slight chance for a storm or two to pop along that boundary late Wednesday afternoon and late Wednesday evening as a front pushes into the area. The atmosphere will be capped over the area, however, if there is enough lift present (rising motion in the atmosphere), the cap may be able to break, therefore, a strong/severe storm cannot be ruled out. Here's how the weather map should look Wednesday afternoon. Better chance for more organized thunderstorm activity will be across Oklahoma and north Texas. 


SEVEN DAY FORECAST:




Monday, April 8, 2013

Severe Storms Possible Tuesday Night!

Hello everybody. Hope you all had a fantastic and relaxing weekend. As of writing this blog we are currently sitting at 73°F in Austin with a breezy southerly wind gusting to 22 mph. It is definitely muggy out there thanks to those persistent southerly winds off of the Gulf. Temperatures have climbed well into the 80s across south and west Texas this afternoon; however, the clouds over the I-35 corridor are helping to keep temperatures much cooler than they could have been. We can thank a strong cap, or lid, on our atmosphere starting at about 5,000 feet aloft…the cap is a layer of warm, dry air that is blown over the area off of the deserts and plateaus of northern Mexico. This warm, dry air aloft has set up an inversion over the area where temperatures are actually rising with height, whereas typically it is the opposite way around. I know this by looking at something meteorologists call a Skew-T plot. Imagine the Skew-T Plot as a slice into the atmosphere; it shows us how temperature, moisture, and wind change with elevation. According to the latest plot it will take a surface temperature of 96°F to produce enough rising air to break the cap.

If you want to learn more about the CAP click HERE

Here’s the latest Skew-T Plot out of Del Rio, TX:


 The Storm Prediction Center out of Norman, Oklahoma has placed a large part of the southern and central plains under a SLIGHT RISK category for severe weather on Tuesday/Tuesday Night. Severe storms are likely to develop in the areas shaded in yellow and produce large hail, damaging winds, and tornadoes.


For us here in central Texas, Tuesday will start off overcast, mild, muggy, and breezy with areas of drizzle possible. Temperatures will be in the 60s area wide. By afternoon, the west Texas Dry Line (Boundary separating dry desert air to the west of it from warm, humid air to the east of it) will approach the western Hill Country, clouds look to erode earlier and more efficiently on Tuesday thanks to warm southwesterly winds at the surface and aloft. Afternoon highs will climb well into the 80s across the area. A strong cap will be in place over the area tomorrow, which will inhibit thunderstorm development, however, if a developing storm is able to break the cap, it would turn severe quickly with very large hail and damaging winds because the amount of instability in our atmosphere will be extremely high tomorrow as indicated by the forecast CAPE values well above 2,000 for all of central Texas.

Forecast CAPE Values for 6 p.m. Tuesday Evening: VERY HIGH


The most likely place for storms to develop during the afternoon tomorrow is well west of the Interstate 35 corridor near the dry line. By tomorrow night, a dry line/cold front combination will approach the area from the north and west. Ahead of those boundaries the warm, muggy air over central Texas will be forced to rise and condense into towering cumulus clouds. Those clouds will eventually grow to become a line of strong to severe storms which will extend from Oklahoma all the way south into central Texas late tomorrow night. The line of storms will form west of central Texas and march east during the overnight hours towards and eventually through the I-35 corridor. The main threats from the storms that develop will be very large hail, high winds, and isolated tornadoes. The best chance for large hail looks to be west of Austin across the Hill Country, however, some medium to large sized hail along with gusty outflow winds are definitely a possibility here in Austin during the early morning hours of Wednesday. The front will push through all of central Texas by midday Wednesday with gusty and chilly northerly winds moving in behind it. Highs will only make the 50s and 60s across the area on Wednesday with temps falling into the 40s Wednesday night.

Forecast Temperatures for 3 p.m. Tuesday: How's that for a temperature difference! South Texas will climb well into the 90s to lower 100s tomorrow!


The Storm Prediction Center's SREF Model is forecasting a 70% chance for showers and storms up and down the I-35 corridor early Wednesday morning; This same model is predicting a 30-40% chance for storms that develop in central Texas to become severe tomorrow night and early Wednesday morning.



The latest High Resolution Model out of Texas Tech University shows a skinny, but strong line of storms pushing through much of north and central Texas early Wednesday morning. In this type of situation, the main threats from the storms will be small to medium sized hail and gusty winds.




Latest high resolution rainfall accumulation models are showing generally less than a half of an inch of rain for most of the area, however, isolated spots may receive as much as an inch of rainfall.



Thursday, April 4, 2013

Severe Weather Threat Next Tuesday!

Hello everybody! The weekend is almost here and it looks like we are going to have great weather if you don't mind the wind.

Tonight's Forecast: Mostly clear and chilly with lows in the 40s area wide; NE winds 5-10 mph.

Friday's Forecast: Mostly sunny and BEAUTIFUL with a high in the middle 70s; calm wind becoming SSE at 5-10 mph in the afternoon. Temps fall into the 50s by Saturday morning.

Saturday's Forecast: Partly cloudy, warm, and gusty with a high near or just above 80°F...winds will be out of the south at 10-15 mph gusting 25-30 mph at times. Temps fall into the 50s to near 60°F by Sunday morning.

Sunday's Forecast: Partly to mostly cloudy, warm, and gusty with a high near 82°F...winds will be out of the south at 10-15 mph gusting to 25 mph at times. Temps fall into the 60s by Monday morning.

Monday's Forecast: AM clouds and drizzle will give way to a partly sunny and warm afternoon with highs in the lower to middle 80s; wind will be breezy out of the south at 10-20 mph. Temps fall into the 60s to near 70°F by Tuesday morning. Severe storms will blossom north and west of central Texas in northwest Texas and Oklahoma.

Tuesday: AM clouds and drizzle will give way to a partly sunny, warm, and humid afternoon with highs soaring well into the middle 80s...there is a good chance for STRONG or SEVERE thunderstorms late in the afternoon (west of Austin) and in the evening/late night hours (along and east of 35)...storms that develop will be capable of producing very large hail, destructive winds, torrential downpours, and plenty of cloud to ground lightning. An isolated tornado cannot be ruled out.

TUESDAY'S SEVERE WEATHER SET-UP

The Jet Stream (river of fast-moving air that moves storm systems) will take a big dip south into northern Mexico. That big dip in the jet stream is known as a trough of low pressure...think of a trough as an elongated area of low atmospheric pressure. Remember, low pressure provides lift (rising motion in the atmosphere). Lift is what generates showers and storms as moisture is lifted from the surface to higher altitudes aloft it condenses into clouds to produce showers and thunderstorms. Lift from the trough, a strong dry line, and an approaching cold front will all work together to allow for a good chance of showers and storms across the area Tuesday afternoon through early Wednesday morning.

With this said, the air over north central and south central Texas will be very unstable, meaning that air forced upward from the surface will move very quickly in turn allowing for explosive storm development. There will be plenty of cold air sitting above the area with warm air below at the surface (where we are).

CAPE (Convective Available Potential Energy) is a measure of the amount of instability in the atmosphere. The GFS Model is forecasting CAPE values to be well above 2 to 3,000 across central Texas which tells me that storms that develop are likely to quickly turn severe with large hail and destructive winds.

FORECASTED CAPE VALUES:


Here's a look at what winds will be doing at around 18,000 above us next Tuesday:


Storms will initially fire along the dry line west of central Texas mid afternoon and into the evening hours. Those individual storms that develop will merge into a line of storms and push east towards the Austin area by Tuesday evening.

DRY LINE:


The only thing that may hinder thunderstorm development would be a strong CAP, or LID on the atmosphere around 5-8,000 feet over central Texas. The CAP is basically a layer or hot, dry air blown on top of central Texas off of the high plateaus and deserts of northern Mexico...to learn more about the cap and how it works to inhibit thunderstorm development check my blog post on it at this link:

http://michaelsweatherblog.blogspot.com/2013/03/the-cap.html

Cooler and drier air will push into the region behind the storms for Wednesday and Thursday of next week! Another 0.25 inches to 1 inch of rainfall is possible with this next round of storms.

If you have a Twitter Account make sure to follow me at this link:
 https://twitter.com/WeatherMinute

If you have a Facebook make sure to LIKE my page, Michael's Weather Center
http://www.facebook.com/michaelswxcenter









Wednesday, April 3, 2013

4-2-13 Hill Country Hail Storm

While the storms that blew through central Texas yesterday and today have been mostly beneficial in nature, they did produce quite a bit of severe weather across portions of the area. Severe weather reports mainly came in the form of large hail, flooding, and gusty winds. 

Llano/Burnet County Hail Storm:


  • Around 12:30 p.m. CST I watched a thunderstorm suddenly pop over central Llano County. Just after 1:00 p.m. CST the storm had really strengthened producing radar indicated hail of up to 1.50 inches in diameter (The storm was located just southeast of the town of Llano, with its eyes set on Kingsland, Highland Haven, Granite Shoals, and eventually Marble Falls)
  • At 1:24 p.m. CST things really started to get ugly...radar was now estimating hail of 3.42 inches in diameter falling in between Kingsland and Llano. 
  • At 2:39 p.m. CST the severe storm was closing in on Kingsland with hail estimated by radar to be as large as 2.45 inches in diameter!

  • Just before 2:00 p.m. CST the storm really intensified as it pushed just east of the Kingsland area and right over Highland Haven...radar was now estimating hail of 4.25 inches in diameter...radar was indicating a 100% chance of hail in between Highland Haven and Marble Falls.
  • At 2:12 p.m. CST the super cell thunderstorm was crossing Highway 281 and the city of Marble Falls where it dumped plenty of hail between golf ball to baseball in size.
  • At 2:39 p.m. CST the hail core was pushing through extreme southeastern Burnet County getting ready to cross into far western Travis County where it would later lose the hail and go on to produce torrential downpours and gusty winds across the Austin Metro Area.

The Storm (at its peak) was towering some 50,000 feet into the atmosphere!




Here is how the storm looked on radar!




Marble Falls Hail Storm (4-2-13) posted by Darrell Fishbeck
https://www.youtube.com/watch?v=ZGzJ5lPQYDE

Hail Reports submitted to the National Weather Service:



Monday, April 1, 2013

Storms are on the way!!!

Good evening everybody. It has been a partly cloudy, warm, and humid day with highs in the 80s area wide. Temps climbed well into the middle 80s here in the Austin Metro Area. The airport officially topped out at 85°F this afternoon. Storms have fired up across the mountains of northern Mexico this afternoon as well as the Texas Panhandle where a strong tornado touched down southeast of Silverton, TX...no reports of damage or injuries as it touched down in a mainly rural location. 

Storms from Space

Northern Mexico:




Texas Panhandle: (Storms formed along the dry line and a stationary frontal boundary draped across the Panhandle...storms also produced extreme amounts of hail as well as hail well over the size of golf balls in spots




Hail Photo from Panhandle:



Tornado SE of Silverton: Photo captured by David Drummond




Tonight's forecast: Increasing clouds, mild and humid with lows only dropping into the 60s...there is a slight chance for a shower or weak thundershower overnight.

As a low pressure system and its attendant strong cold front push across the state of Texas tomorrow (Tuesday) from west to east, warm and moist atmosphere ahead of the two will allow for strong to severe thunderstorms to develop across west Texas late Tuesday afternoon/evening. Those storms in west Texas will form into a complex of storms that will push through central Texas late Tuesday/early Wednesday. Computer models are suggesting a widespread 0.5-1.5 inches of rainfall is possible. 

The Storm Prediction Center out of Norman, Oklahoma has placed areas along and west of the I-35 corridor under the SLIGHT RISK category for severe weather tomorrow. Honestly, the worst of the weather should stay well to the west of the Austin Area, however, we should not let our guard down for some strong gusty winds and some large hail. The complex of storms looks to push through the Austin Metro Area after midnight and persist through the overnight hours before settling down early Wednesday morning. 



The storms will be pushed east with a cold front, therefore, much cooler on Wednesday behind the front with highs in the 50s and 60s expected under a mainly cloudy sky. 

Let's break down the forecasted radar hour by hour: Austin represented by the ORANGE CIRCLE

5 p.m. Tuesday afternoon (Strong storms possible across SE Texas, however, the thing to watch is the storms developing across west Texas...those storms will likely go severe with hail and high winds):




9 p.m. Tuesday evening (Strong to severe storms organizing into a complex north and west of central Texas...circled in red):



12 a.m. Wednesday morning: Strong line of storms pushing through the Hill Country with strong wind, heavy rain, lightning, and possible small to medium sized hail



4 a.m. Wednesday morning: Leading edge of storms has pushed well east of the I-35 corridor with residual shower and thunderstorm activity continuing across the Hill Country and the I-35 corridor



Temperatures across the state at 6 p.m. Tuesday evening (you can clearly see the location of the front with the stark difference in color and temperature between the Panhandle in the 30s and 40s with central and south Texas in the 80s and 90s!



High Resolution GFS Model is forecasting a widespread 1-1.5 inches of rainfall to accumulate across central Texas between now and late Wednesday...several inches possible between Austin and Dallas (southwest of Dallas/Fort Worth) where up to 4 inches of rainfall is possible according to this model run:



Cooler air will filter into the region behind the storms on Wednesday with highs in the 60s for Wednesday and Thursday...cool mornings in the 40s and 50s through Friday night before temps rebound into the 80s for the weekend and into next week.