548  
FXUS64 KHGX 250837  
AFDHGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX  
337 AM CDT WED APR 25 2018  
   
DISCUSSION
 
 
A WEAK COLD FRONT IS EXPECTED TODAY, AND WILL CARRY ALONG WITH IT  
SOME SHOWERS. WE COULD ALSO MANAGE SOME ISOLATED THUNDERSTORMS,  
BUT STORM POTENTIAL APPEARS FAIRLY LIMITED AS IT LOOKS LIKE THE  
BEST POTENTIAL FOR PRECIPITATION WILL COME BEHIND THE FRONT. ONCE  
THE FRONT IS THROUGH, EXPECT FAIR WEATHER THROUGH AT LEAST THE  
WEEKEND. EARLY NEXT WEEK, A SERIES OF WEAK DISTURBANCES WILL SPUR  
A CHANCE FOR SHOWERS OR EVEN THUNDERSTORMS, BUT THE INGREDIENTS  
WILL HAVE TO COME TOGETHER JUST RIGHT.  
   
NEAR TERM [THROUGH TODAY]
 
 
A COMPACT, BUT FAIRLY POTENT VORT MAX IN NORTH/NORTHWEST TEXAS  
HAS SPARKED SHOWERS AND STORMS WELL UPSTREAM THIS EVENING. THOUGH  
THE ACTIVITY HAS BEEN ON A TRAJECTORY THAT COULD IMPACT AT LEAST  
NORTHERN PARTS OF OUR AREA, THE ACTIVITY HAS THUS FAR FALLEN OFF  
RAPIDLY AS IT OUTRUNS ITS UPPER SUPPORT, AND EVEN MORE UNDERNEATH  
THAT FEATURE THERE LOOKS TO BE A SLOW DOWNWARD TREND. BECAUSE OF  
THIS, KEEP THE OFFICIAL FORECAST DRY TODAY. HOWEVER, RATHER THAN  
ZERO OUT POPS AS THE VORT MAX MOVES OVER OUR AREA, DO LEAVE 10ISH  
PERCENT. DAY SHIFT WILL HAVE TO KEEP AN EYE ON THIS FEATURE AND  
SEE IF WE SEE ANY RENEWAL OF ACTIVITY UNDERNEATH THE UPPER FEATURE  
THROUGH THE DAY. ALSO, SOME GUIDANCE HAS HINTED AT A PRE-FRONTAL  
TROUGH DEVELOPING AND COULD PROVIDE A BIT OF A FOCUS FOR ANY  
AFTERNOON WARM SECTOR DEVELOPMENT. HOPING THAT HOLDING TO DRY  
WORKS OUT, BUT I CAN AT LEAST SEE A POTENTIAL FAILURE POINT IN THE  
FORECAST HERE.  
 
BEYOND THE RAIN POTENTIAL TODAY, ALSO LOOKING AT SOME PATCHY FOG  
CROPPING UP IN THE SOUTHWEST AROUND MATAGORDA BAY, WHERE MOISTURE  
RETURN LOOKS STRONGEST UNDERNEATH A MORE POTENT THAN EXPECTED LOW  
LEVEL JET. EXPECTING FOG WHILE WINDS ARE CALM, BUT IF THE STRONGER  
WINDS WORK DOWN TO THE SURFACE, COULD SEE THAT FOG LIFT TO LOW  
STRATUS. LOCALIZED SPOTS MAY BRIEFLY BE FAIRLY DENSE, BUT THINK  
 
OTHERWISE, LOOK FOR SEASONABLE LOWS, RISING TO HIGHS NEAR OR A  
LITTLE ABOVE NORMAL. DO PAINT A NARROW CORRIDOR OF TEMPS  
AROUND/JUST ABOVE 85 NEAR THE COAST IN A PRE- FRONTAL TEMPERATURE  
BUMP THIS AFTERNOON THAT GUIDANCE SO FREQUENTLY SEEMS TO NOT QUITE  
GRASP.  
 
   
SHORT TERM [TONIGHT THROUGH FRIDAY]
 
 
COLD FRONT THAT'S BEEN ADVERTISED FOR SOME TIME IS FINALLY POISED  
TO CROSS. IF WINDS HAVEN'T ALREADY TURNED TO WESTERLY OR  
NORTHWESTERLY WITH A PRE-FRONTAL TROUGH, WINDS WILL CHANGE THIS  
EVENING. FOCUS MY POPS ON TONIGHT, AS IT APPEARS THAT WE MAY SEE A  
BETTER CHANCE FOR ELEVATED PRECIP ONCE THE SURFACE FRONT HAS  
ALREADY PASSED. DO NOTE THE DEVELOPMENT OF A SMALL UPPER JET  
STREAK WITH US IN THE RIGHT ENTRANCE REGION, WHICH WOULD HELP  
SUPPORT VERTICAL MOTION. FORECAST SOUNDINGS STILL DON'T GET TOO  
CRAZY WITH THE MUCAPE, SO THINK THUNDER POTENTIAL WILL BE FAIRLY  
LIMITED, WITH ISOLATED STORMS. ALMOST ALL THE GUIDANCE HAS JUMPED  
ON THE BANDWAGON ON HAVING A BROKEN LINE OF SHOWERS/STORMS  
TONIGHT, AND NOT CONFIDENT THAT EVERYONE WILL GET WET TONIGHT.  
BECAUSE OF THIS, I FADED POPS FROM THE GUIDANCE SLIGHTLY. ONCE  
THERE'S GREATER CONFIDENCE IN HOW PRECISELY THINGS SET UP, SOME  
MORE SPECIFICITY MAY BE POSSIBLE. BUT FOR NOW...FELT MORE  
COMFORTABLE WITH DESCRIBING THE POTENTIAL AS "CHANCE" RATHER THAN  
"LIKELY" RAIN.  
 
RAIN SHOULD WRAP UP BY MORNING, AND THE REST OF THE SHORT TERM  
WILL BE THE UPPER TROUGH BEGINNING TO EXIT THE AREA, WITH RIDGING  
FROM THE MIDLEVELS ON DOWN GETTING SET UPSTREAM. HIGHS THURSDAY  
WILL BE HACKED BACK INTO THE 70S, AND SHOULD REPEAT FOR MOST ON  
FRIDAY, ALTHOUGH SOME MAY MANAGE TO REACH 80 DEGREES AS HEIGHTS  
WILL BE A TOUCH HIGHER.  
 
   
LONG TERM [FRIDAY NIGHT THROUGH WEDNESDAY]
 
 
RIDGING MENTIONED AT THE CLOSE OF THE SHORT TERM WILL COME TO  
DOMINATE MOST OF THE WEEKEND, ALLOW HIGHS IN THE 80S TO CREEP BACK  
INTO THE PICTURE A LITTLE MORE EACH DAY. LOWS FRIDAY  
NIGHT/SATURDAY MORNING MAY STILL BE A LITTLE CHILLY, BUT AS THE  
SURFACE HIGH DRIFTS INTO THE DEEP SOUTH AND WINDS HERE TURN BACK  
TO ONSHORE LATE SATURDAY, THOSE LOW TEMPERATURES SHOULD BEGIN TO  
MOVE BACK UPWARDS NEXT WEEK ALONG WITH A GRADUAL INCREASE IN  
HUMIDITY. THE HIGHER TEMPERATURE FLOORS SHOULD HELP AFTERNOON  
HIGHS CONTINUE TO REACH THE 80S EACH DAY, BUT THE MIDLEVEL RIDGE  
FROM THE WEEKEND QUICKLY SHOVES OFF, LEAVING US OPEN TO A SERIES  
OF MODEST SHORTWAVE TROUGHS IN THE FIRST HALF OF THE WEEK. PAIR  
THAT WITH ONSHORE FLOW AND DEEPENING AVAILABLE MOISTURE, AND IT  
SEEMS REASONABLE TO BRING AT LEAST SOME LOW POPS BACK INTO THE  
PICTURE EACH DAY NEXT WEEK. EACH DAY IS A LITTLE BIT HIGHER THAN  
THE LAST, BUT DON'T WANT TO GET CARRIED AWAY HERE AS THINGS WILL  
BE VERY DEPENDENT ON SHORTWAVE TIMING, AND I HAVE LITTLE  
CONFIDENCE IN BEING ABLE TO NAIL THAT THIS FAR OUT.  
 

 
   
AVIATION [06Z TAF ISSUANCE]
 
 
CHALLENGING FORECAST UNFOLDING FOR THE 06Z TAFS WHERE MODEL  
GUIDANCE HAS STRUGGLED TO CAPTURE THE DEVELOPMENT OF A 25-30 KNOW  
LOW LEVEL JET THAT HAS DEVELOPED ACROSS THE REGION. SURFACE  
ANALYSIS SHOWS THE SEA BREEZE HAS LIFTED NEAR TO JUST NORTH OF  
IAH WITH A WEAK ENOUGH SURFACE PRESSURE GRADIENT IN THE VICINITY  
OF THIS FEATURE TO PRODUCE CALM TO NEARLY CALM WINDS AT THE  
TERMINALS NEAR AND NORTH OF INTERSTATE 10. THIS, COUPLED WITH AN  
EXPECTED DECREASING TREND IN SURFACE WINDS AT THE TERMINALS SOUTH  
OF THERE, HAS RESULTED IN THE ADDITION OF LLWS IN THE TAF AS A  
RESULT THROUGH 08Z AND WILL MONITOR TRENDS FOR UPDATES. THE VEERED  
NATURE OF THE JET RAISES CONCERNS THAT MVFR CEILINGS THAT DEVELOP  
NEAR MATAGORDA BAY OVERNIGHT PER LATEST TRENDS IN THE HRRR MAY  
ADVECT NEAR THE TERMINALS. NOT CONFIDENT AT ALL IN THIS SOLUTION  
BUT HAVE ADDED A FEW020 GROUP TO HIGHLIGHT POTENTIAL FOR IAH, HOU,  
SGR, LBX, AND GLS. ELEVATED LOW LEVEL WINDS MAY DELAY OR INHIBIT  
FOG DEVELOPMENT TONIGHT, BUT BRIEF MVFR VISIBILITY DROPS MAY BE  
POSSIBLE AT CXO AND LBX. REGIONAL RADAR MOSAIC SHOWS OUTFLOW  
ASSOCIATED WITH STORMS OVER WEST CENTRAL TEXAS MAY SERVE AS A  
FOCUS FOR AN ISOLATED SHOWER OR TWO EARLY THIS MORNING AND  
POTENTIALLY A BRIEF NORTHERLY WIND SHIFT AT CLL BUT HAVE NOT  
INCLUDED ANY MENTION OF THIS IN THE 06Z TAF DUE TO LOW CONFIDENCE.  
 
EXPECT VFR CONDITIONS TO PREVAIL AT ALL TERMINALS AFTER 16Z WITH  
WINDS BECOMING SOUTH TO SOUTHWEST AROUND 5-8 KNOTS AHEAD OF AN  
APPROACHING COLD FRONT. WILL HAVE TO KEEP AN EYE ON THE REMNANT  
OUTFLOW BOUNDARY DURING THE MORNING HOURS FOR ADDITIONAL SHRA  
DEVELOPMENT NEAR CLL, BUT EXPECT THE TAF SITES TO REMAIN DRY UNTIL  
AFTER FROPA WEDNESDAY AFTERNOON AND EVENING. NORTHERLY WINDS NEAR  
10 KNOTS WILL BECOME ESTABLISHED BEHIND THE FRONT WITH A BRIEF  
WINDOW FOR A FEW ELEVATED SHRA POSSIBLE WEDNESDAY EVENING BEFORE  
DRIER AIR MOVES IN WEDNESDAY NIGHT.  
 
HUFFMAN  
 

 
   
MARINE
 
 
LIGHT WINDS AND LOW SEAS SHOULD PERSIST UNTIL A WEAK  
COLD FRONT AND ASSOCIATED SHOWERS MOVE THROUGH THE  
AREA TONIGHT. OFFSHORE WINDS BEHIND THE FRONT MIGHT  
REACH CAUTION LEVELS FOR A SHORT PERIOD THURSDAY  
MORNING. THE OFFSHORE FLOW WILL PERSIST THROUGH THE  
END OF THE WEEK AS ANOTHER COLD FRONT MOVES THROUGH  
THE AREA ON FRIDAY. ONSHORE WINDS THAT ARE EXPECTED  
TO RETURN LATE SATURDAY OR SATURDAY NIGHT SHOULD  
PERSIST THROUGH AT LEAST THE FIRST HALF OF NEXT WEEK.  
AT THIS TIME, IT LOOKS LIKE CAUTION AND/OR ADVISORY  
FLAGS MIGHT BE NEEDED BEGINNING LATE MONDAY OR MONDAY  
NIGHT FOR THE INCREASING WINDS AND BUILDING SEAS. 42  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
COLLEGE STATION (CLL) 82 51 76 53 77 / 10 40 0 0 0  
HOUSTON (IAH) 85 58 78 55 78 / 0 50 0 0 0  
GALVESTON (GLS) 78 63 75 62 75 / 0 50 0 0 0  
 

 
   
HGX WATCHES/WARNINGS/ADVISORIES
 
 
TX...NONE.  
GM...NONE.  
 

 
 

 
 
NEAR TERM...LUCHS  
SHORT TERM...LUCHS  
LONG TERM...LUCHS  
AVIATION...HUFFMAN  
MARINE...42  
 
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