Despite a widespread coverage of clouds, today's temperature warmed into the 50s and 60s across the region. The arctic air mass that arrived Sunday is modifying and shifting off to the east. A warming trend will continue Thursday and Friday but cooler air will be arriving this weekend and medium-range forecasts suggest the cooler air will hang around through most of next week. Although don't see any arctic air headed our direction, I can't totally rule another light freeze or two for the Hill Country and parts of Central Texas over the next 10 to 15 days.
A weak wave of low pressure in the upper atmosphere has been moving southeast across Texas this afternoon, causing widespread clouds and a few sprinkles of light rain. This system will exit to the east this evening, allowing a weak cold front to sweep south across the area. Clouds will slowly clear from west to east overnight as the temperature remains somewhat chilly. Low temperatures Thursday morning will generally be in the mid and upper 30s.
Mostly sunny weather and slightly warmer temperatures will develop Thursday through Friday as a weak ridge of high pressure temporarily sets up across Texas. High temperatures Thursday will generally be in the low 60s. There will be a north-northeast wind with speeds of 10-15 mph. Low temperatures Friday morning will be in the upper 30s to low 40s. High temperatures Friday will be around 70-72 degrees.
Forecasters continue to monitor the evolution of a large trough of low pressure that will be moving southeast out of the southern Rockies Saturday into Sunday. Today's forecast data now indicates our region may not see as much rain with this system compared to what was previously forecast. Most forecast solutions now indicate the strong atmospheric dynamics previously forecast won't quite come together as was believed on Tuesday. Today's forecast data indicates there will be a fairly widespread coverage of rain showers and scattered thunderstorms developing Saturday afternoon, continuing Saturday night into Sunday morning. The chance for rain will end from west to east Sunday afternoon into Sunday night as the upper trough exits to the east. Rainfall over this period is now only forecast to generally average between one quarter and one half inch. The chance for rain will be near 40 to 50 percent Saturday afternoon and Saturday night. It will decrease to 20 percent by Sunday afternoon.
The following National Weather Service graphic shows the amount of rain forecast between Wednesday evening and Monday evening:
A Canadian cold front is forecast to push southeast across the state Saturday afternoon and Saturday evening, bringing in cooler air. Ahead of the cold front, high temperatures Saturday will generally be in the low and middle 60s. Lows Sunday morning will range from the upper 30s across the Hill Country to the upper 40s towards the coast. Sunday's temperature will warm to the upper 50s. Low temperatures Monday morning will be in the low and middle 70s.
Medium-range forecast solutions call for mostly sunny and mild weather conditions to be in place next Monday through Wednesday. Daily high temperatures will generally be in the mid to upper 70s. Low temperatures will be mostly in the upper 40s to low 50s.
The models indicate a chance for rain showers will develop next Thursday as another Canadian cold front moves across the area. As of now, rain amounts are not shaping up to be very heavy. Dry and cooler weather will follow next Friday, continuing into next weekend. High temperatures should lower to the 60s with low temperatures mostly in the 40s.Spectacular Shelf Cloud Spreads over Sydney, Australia:
Earlier today, a thunderstorm moved over Sydney, Australia with an amazing looking shelf cloud on the leading edge of the thunderstorm:
Image credit: Cassie Trotter/Getty Images
A shelf cloud is a wedge-shaped cloud that is attached to the base of a thunderstorm. Cool air sinking down to the ground along the downdraft of the thunderstorm often cuts under warm air that is being drawn into the storm. As the warm air gets lifted, water vapor condenses and creates a cloud that often takes on a horizontal roll. Roll clouds are very similar to shelf clouds, except roll clouds are detached from the parent thunderstorm cloud and aren't always associated with thunderstorms.