Updated 915am CT – Monday / 27 March 2017
.. Unseasonably Warm Temperatures to Start the Week ..
.. Stormy Weather Due with Thunderstorms Mid Week and Again by the Weekend ..
On this Monday… a surface low pressure area is over northern Arkansas with a warm front extending eastward along the Arkansas/Missouri border eastward to along the Tennessee/Kentucky border. A weakening cold front extends southwestward from the surface low into north central Texas into the western Hill Country then into southwest Texas. As a result of this surface weather pattern, our surface winds across south central Texas are light southerly.
In the upper levels of the atmosphere, a trough of low pressure extends from western Iowa south southeastward into the lower Mississippi valley with another to the west stretching southward from Oregon and Washington into southern California and Nevada. As a result of this upper air weather pattern, the 30,000 foot winds over south central Texas are northwesterly at 50 to 60 mph.
Overnight, we saw a few east southeastward moving rain showers and thunderstorms in our northern areas as the upper level low pressure trough.. to our east.. passed by west to east over the area. For most folks, it was a non-event; however, some hail up to 1″ in diameter fell, according to the public, around the Jarrell area (in northern Williamson County) around 1240am CDT this morning.
In the wake of the upper level trough, the weakening surface cold front, to our northwest, will move a bit more to the southeast before washing out and pulling up stationary somewhere close to the Austin area by later today into this evening before shifting back northward as a warm front in advance of the next upper level low pressure area, out west, approaching the area. At this point, I expect us to stay southeast of the frontal boundary and for skies to partially clear with a warmer southwesterly surface wind to develop over the area this afternoon with unseasonably warm levels with some highs near 90 degrees. If the front ends up moving further southeast than expected, then we will see a wind shift and temperatures cooling a little. It’s clearly going to be “touch and go” regarding the forward progress of the front and my forecast confidence today is lower than I would normally have in a first period forecast (today). While we could see an isolated thunderstorm develop along the front this afternoon, I just really think the likelihood of that happening at any given location over our area is too slim to mention in the forecast.
It looks quiet across the area tonight into tomorrow with just some late night and early morning low cloudiness developing as the earlier mentioned front retreats northward quickly as a warm front.
By tomorrow afternoon into tomorrow night, our atmosphere will grow quickly more unstable as the leading edge effects of the upper level trough, to our west, moves eastward out of the Rockies into the southern plains. We’ll see isolated to widely scattered rain showers and thunderstorms as early as midday tomorrow to our west and then more area wide tomorrow night through most of the day Wednesday. In addition to a threat of heavier rains, 1 to 2 inches in some areas, there will be a associated threat of dangerous lightning as well as severe weather including larger hail and damaging thunderstorm winds. As the system passes late Wednesday into Wednesday evening, a weak cold front will move eastward through the area with rain chances decreasing rather rapidly with skies clearing as drier air moves in from the west.
It looks like plenty of sunshine with above average daytime high temperatures for both Thursday and Friday. The front, that passes southeast of the area Wednesday afternoon, will retreat back northward as a warm front by Friday into Friday night with low level moisture increasing once again.
The next upper level low pressure storm system and associated cold front will result in increasing moisture and atmospheric instability and lift by Friday night into Saturday with increased clouds and renewed and increasing rain and thunderstorm chances Saturday into Saturday night and into Sunday morning. Again, I see the chance of periods of heavier rain along with an associated lightning risk and the possibility of severe thunderstorms possibly accompanied by larger hail and damaging straight line thunderstorm winds. Guidance suggests that the system will linger across the area on Sunday and moving east of the area, with decreased rain chances, by Monday.
Have a good Monday….
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel
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Updated 845am CT.. Monday / 27 March 2017
TODAY…. Some morning low clouds.. otherwise becoming mostly sunny and unseasonably warm. High 89. South southwesterly wind 5 to 10 mph.
TONIGHT…. Mostly clear early.. low clouds developing after 10pm. Low 66. Southeasterly wind 4 to 8 mph.
TUESDAY…. Some morning low clouds.. otherwise partly to mostly cloudy with widely scattered rain showers and thunderstorms with an attendant lightning risk by afternoon. A 20% chance of rain at any given location; rainfall, where it occurs, will average 1/4 inch. High 86. South southeasterly wind 8 to 15 mph.
TUESDAY NIGHT…. Mostly cloudy with rain shower and thunderstorm chances.. with an attendant lightning risk.. increasing especially after midnight. A 30% chance of rain early then increasing to 50% at any given location after midnight; where it occurs, rainfall will average 1/4 inch. Low 66. South southeasterly wind 8 to 15 mph.
WEDNESDAY…. Cloudy with rain showers and thunderstorms likely with an attendant lightning risk before 3pm. Periods of heavier rain are possible along with the possibility of severe thunderstorms accompanied by larger hail and damaging straight line thunderstorm winds. An 80% chance of rain at any given location; rainfall, where it occurs, will average 1/2 to 1 1/2 inches. Decreasing clouds becoming partly cloudy and less humid after 3pm. High 82. South southeasterly wind 5 to 12 mph becoming west southwesterly by mid afternoon.
WEDNESDAY NIGHT…. Partly cloudy and a little cooler. Low 60. West southwesterly winds 4 to 8 mph.
THURSDAY…. Mostly sunny. High 81. Northwesterly wind 5 to 10 mph.
THURSDAY NIGHT…. Mostly clear. Low 57. Light northwesterly wind becoming light and variable after midnight.
FRIDAY…. Mostly sunny and unseasonably warm. High 87. Southerly wind 5 to 12 mph.
FRIDAY NIGHT…. Mostly clear early with low clouds developing after midnight. Low 64. South southeasterly wind 5 to 10 mph.
SATURDAY…. Mostly cloudy with scattered rain showers and thunderstorms developing, with an attendant light risk, by midday and continuing through the afternoon. A 30% chance of rain by midday increasing to 50% by late afternoon; rainfall, where it occurs, will average 1/4 inch. High 81. Southerly wind increasing to 8 to 15 mph.
SATURDAY NIGHT…. Mostly cloudy with scattered rain showers and thunderstorms with an attendant light risk. A 50% chance of rain; rainfall, where it occurs, will average 1/2 inch. Low 64. Southerly wind 8 to 15 mph.
SUNDAY…. Mostly cloudy with scattered rain showers and thunderstorms with an attendant light risk continuing. A 50% chance of rain; rainfall, where it occurs, will average an additional 1/4 inch. High 79. Southerly wind 5 to 12 mph.
NATIONAL WEATHER SERVICE / 8 TO 14 DAY OUTLOOK
Valid Monday / 03 April 2017 through Sunday / 09 April 2017…
Temperature… Above Average
Precipitation… Near to Slightly Below Average
AUSTIN SUNSET/SUNRISE TIMES…..
Sunrise this morning (27 Mar)……………………………………………. 7:26 am
Sunset this evening (27 Mar)……………………………………………… 7:47 pm
Sunrise tomorrow (28 Mar)………………………………………………… 7:25 am
Sunset tomorrow (28 Mar)…………………………………………………. 7:48 pm