Austin/San Antonio, Texas

New SHORT TERM, LONG TERM, AVIATION

• Warm and humid through Monday with low clouds and at least some patchy fog each morning
• Cold front passage overnight Monday night into Tuesday morning with a line of rain and storms; a few strong to severe storms are possible
• A drier airmass arrives mid to late next week behind front with cooler mornings and mild, but pleasant afternoons.

Winds entering this morning are to remain of light to calm levels across the region. These light winds along with the warm and muggy airmass, in addition to lingering saturated soils from the recent rains, will help result in development and expansion of the low clouds and areas of fog. The fog could become locally dense in spots. The most favored regions for fog on the latest short term guidance is across the valleys of the Hill Country and points east and northeast of the I-35 corridor from Georgetown through Austin southward to near New Braunfels and Schertz. The low clouds may remain stubborn into midday before scattering out during the afternoon. We`ll also see an increase in high clouds arriving from the west during the day and this would likely result in continued mostly cloudy skies across the region. I`ll slightly lower high temperatures today from the NBM towards the latest short term guidance, especially in the Hill Country, as a result of the cloud cover.

Tonight through Monday will see the short lived mid-level ridging, which is atop of the region today, slide east in response to the upper level storm system moving across the Intermountain West. The low-level flow across our area turns more southerly and intensifies beginning overnight with the nocturnal jet, and continues into Monday. This should be able to help limit fog development entering Monday morning but there could be patchy fog in protected valley locations and where winds are lightest. With a stiffer breeze, the clouds should be able to mix/scatter out easier and quicker into Monday afternoon. Monday afternoon looks to be the warmest with slightly greater sunshine.

The parent storm system across the Intermountain West is then forecast to advance into the Central Plains from Monday night into Tuesday. This will sweep a cold front across the region overnight through Tuesday morning and should exit the Coastal Plain counties sometime early afternoon. A line of showers and storms (could be broken) will be expected along the front. There should be sufficient deep layer shear around 30 to 40 kt range and enough instability despite the time of day, between 500 and 1000 J/kt to support the possibility for a few isolated strong to severe storms within that line. The primary severe hazard would be damaging winds but some large hail may be possible as well. A level 1 of 5 risk for severe weather is highlighted for areas along and north/west of the I-35 corridor in the outlook ending at 12Z Tuesday. I would not be surprised if SPC does expand this risk to include areas farther to the east in the next update for the outlook that ends at 12Z on Wednesday. The rain chances will quickly end behind the front as a northwesterly flow establishes and ushers in drier air across the region. Wind speeds increase but not like some of our stronger fronts in the cool season.

The drier airmass results in cooler mornings during mid to late in the week where the Hill Country dips into the 40s while elsewhere areas generally fall into the low to mid 50s. Afternoons are to remain mild but low humidity should keep the weather pleasant with mostly sunny skies and no rain. The weather becomes more unclear heading through next weekend with differences within the medium range guidance on the location and progression of various upper level features. The latest NBM continues to have low (10-20%) rain chances entering into the picture as of now with some low-level moisture.

All terminals are starting off VFR. MVFR/IFR ceilings and visibilities will develop around 09Z or 10Z. VFR conditions will return by around noon. There is some guidance keeping VFR conditions through the night, but chances seem better for deteriorating conditions.

Austin Camp Mabry              84  67  87  68 /   0   0   0  70
Austin Bergstrom Intl Airport  84  66  86  68 /   0   0   0  60
New Braunfels Muni Airport     84  67  86  68 /   0   0   0  40
Burnet Muni Airport            81  65  83  65 /   0   0   0  80
Del Rio Intl Airport           80  68  85  66 /  10   0   0  50
Georgetown Muni Airport        84  66  84  66 /   0   0   0  80
Hondo Muni Airport             82  67  85  68 /   0   0   0  50
San Marcos Muni Airport        84  66  86  68 /   0   0   0  50
La Grange - Fayette Regional   87  68  87  69 /   0   0   0  30
San Antonio Intl Airport       82  68  85  69 /   0   0   0  40
Stinson Muni Airport           85  68  85  70 /   0   0   0  40

None.