Severe Weather Alerts

Your Weather

To update your location please enter your ZIP code, city, state, airport code or country in the field below. Weather by E-mail: Forecast storm alerts. Weather E-Mail Alert Sign Up »

Next 12 Hours

Forecast data from the National Digital Forecast Database.

5 Day Forecast

• Wednesday
• 
• High: 90 °
• Low: 72 °
• Chance of T-Storms

• Thursday
• 
• High: 90 °
• Low: 72 °
• Chance of Rain

• Friday
• 
• High: 88 °
• Low: 68 °
• Partly Cloudy

• Saturday
• 
• High: 90 °
• Low: 68 °
• Partly Cloudy

• Sunday
• 
• High: 90 °
• Low: 66 °
• Partly Cloudy

Area forecast discussion 
National Weather Service Houston/Galveston Texas 
918 PM CDT Tuesday may 21 2013 


Discussion... 
monitoring showers and thunderstorms...some strong/severe...across the 
northern portions of our area this evening under a very good looking 
diffluent flow aloft. Greatest risk continues to be large hail and strong 
damaging winds with this activity...and a Severe Thunderstorm Watch 
remains in effect until 1 am CDT. Isolated tornadoes will continue to 
be possible with the stronger storms. In addition to the severe...radar 
estimates indicate that some 2 to 4 inches of rain has already fallen 
across portions of Madison and Brazos counties. Additional activity 
off to the west and southwest of this area has the potential to produce 
more heavy rains across this area which could lead to some flooding. 
42 
&& 


Previous discussion... /issued 710 PM CDT Tuesday may 21 2013/ 


Update... 
Severe Thunderstorm Watch is in effect for our far northern and 
northeastern zones through 1 am CDT. 


00z aviation discussion below. 


Aviation... 
broken line of thunderstorms on our north(west)ern doorstep...timed 
to impact kcll within the next hour...kuts by 01-02z. Many short 
range hi rez models (that initiated well)...slowly take a more 
ragged...or more diffuse...line to the coast through midnight. 
Handled points from Conroe southward with a thunderstorms in the vicinity...will tempo as 
needed during this 00-03z watch and wait period. Activity should 
come to a close shortly past midnight...maybe closer to 09z near 
the coast...with VFR for the middle-late period. Background wind field 
will primarily be southeast at under 10 kts...early easterly flow 
at coast to turn more southerly past 19z with the inland movement 
of the late morning sea breeze boundary. 31 


Previous discussion... /issued 354 PM CDT Tuesday may 21 2013/ 


Discussion... 
a strong upper level trough moving across the Southern Plains was 
combining with a cold front to generate thunderstorms across North 
Texas this afternoon. A fairly large cap was inhibiting any 
convection over the hgx County Warning Area through 330 PM. 
However...do expect the cap to erode during the latter part of the 
afternoon especially over the northern half of the area. The high 
res models were pushing the line of thunderstorms into the far 
northern set of counties between 5 and 7 PM...and then into the 
central set of counties between 7 PM and midnight. The model 
forecast soundings and a special 18z sounding taken near cll all 
forecast the cape to be around 2800 to 3000 and a downdraft cape 
around 1450. Feel that the main severe threat will be winds. There 
is a lessor threat for large hail and cannot rule out an isoalted 
tornado due to helicity values of about 150. Agree with the 
moderate risk generally along and north of a line from near Kurten 
in northern Brazos County to Madisonville to Lovelady to 
Centralia. A slight risk was mainly north of a line from Eagle 
Lake to Houston to Liberty. The main time frame will likely be 
during the evening between 6 PM and midnight. 


The models bring another shortwave trough across the area on 
Wednesday. Combining this fact with a seabreeze and the onshore 
flow means rain chances should linger through the day on 
Wednesday. An upper level ridge will then build over southeast Texas through 
the weekend. The European model (ecmwf) and GFS differ on the strength of the ridge 
but the main effect will be a drying trend with high temperatures 
reaching to near 90 or into the lower 90s. Both models then 
develop a northwesterly flow Monday through Wednesday. 40 


Marine... 
a moderate to occasionally strong onshore winds will persist through 
this evening in response to the approaching upper level disturbance/ 
storms associated with it. Will let the scec expire as scheduled. As 
high pressure builds into the area the gradient is expected to relax 
and winds should begin to diminish overnight into Wednesday. However this 
onshore pattern is expected to continue through the rest of the week 
and into the weekend (and mayhap the rest of the summer). 41 


&& 


Preliminary point temps/pops... 
College Station (cll) 73 91 72 91 71 / 60 20 10 10 10 
Houston (iah) 73 90 72 90 72 / 50 30 10 20 10 
Galveston (gls) 75 84 75 81 74 / 40 30 10 20 10 


&& 


Hgx watches/warnings/advisories... 
Texas...none. 
GM...none. 
&& 


$$ 


Discussion...42 
aviation/marine...31