758
FXUS64 KHGX 151812
AFDHGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1212 PM CST WED JAN 15 2025
..NEW AVIATION
SYNOPSIS
ISSUED AT 433 AM CST WED JAN 15 2025
A COASTAL TROUGH OFF THE LOWER TEXAS COAST IS HELPING FUEL
SPRINKLES TO ISOLATED LIGHT SHOWERS EARLY THIS MORNING. WHILE
THOSE SHOWERS SHOULD BE A BIT MORE SUBSTANTIAL TODAY, THE TROUGH
WILL STAY FAR ENOUGH OFFSHORE THAT WE'LL SEE LITTLE MORE IMPACT
THAN THOSE LIGHT SHOWERS.
THE BIG CONVERSATIONAL PIECE OF THE FORECAST REMAINS NEXT WEEK,
ONCE A BIG ARCTIC AIRMASS PUSHES ITS WAY ACROSS, WELL...MOST OF
THE CONTINENTAL US. THERE'S BEEN LOTS OF CHATTER ABOUT WHAT'S
GOING TO HAPPEN, AND THERE ARE CERTAINLY MULTIPLE POSSIBILITIES ON
THE TABLE, SO HERE ARE THE BIG THINGS TO REMEMBER RIGHT NOW:
- THERE IS VERY HIGH CONFIDENCE (ABOVE 80%) THAT TEMPERATURES WILL
BE BELOW AVERAGE NEXT WEEK, AND PERSIST FOR SEVERAL DAYS FROM
SUNDAY ONWARD.
- CONFIDENCE IS NOT AS HIGH ABOUT HOW INTENSE THE COLD SNAP WILL
BE, AND BECOME LESS CERTAIN CLOSER TO THE GULF COAST. FOR
INSTANCE, THE POTENTIAL FOR NIGHTS WITH A MORE IMPACTFUL HARD
FREEZE IS HIGHEST FOR A NORTHERN LOCATION LIKE CROCKETT (SEEN IN
60-75 PERCENT OF MODEL GUIDANCE). AROUND THE HOUSTON METRO, THAT
POTENTIAL IS LOWER (SEEN IN 20-45 PERCENT OF MODEL GUIDANCE).
CONFIDENCE GOES UP AGAIN RIGHT AT THE COAST, SIMPLY DUE TO THE
LOW POTENTIAL FOR A HARD FREEZE ALL THE WAY TO THE GULF;
GALVESTON SEES A HARD FREEZE IN LESS THAN 5 PERCENT OF THE
GUIDANCE.
- SIMILARLY, NUMEROUS SCENARIOS FOR POTENTIAL WINTRY PRECIPITATION
ARE ON THE TABLE, AS CONFIDENCE IS LOWER IN HOW COLD THE
INCOMING AIR WILL BE, AND IF THAT WILL OVERLAP WITH ENOUGH
MOISTURE AND SUPPORT FOR PRECIPITATION. IN THE MONDAY-WEDNESDAY
TIME FRAME, THERE IS POTENTIAL FOR RAIN, FREEZING RAIN, SLEET,
SNOW, OR A MIX OF ANY AND ALL OF THESE TYPES.
- THE FORECAST SITUATION - ESPECIALLY FOR PRECIPITATION TYPE - IS
HIGHLY FLUID (POSSIBLY *MUCH* MORE FLUID THAN SOME
PRECIPITATION MIGHT BE!). PLEASE KEEP UP WITH THE LATEST
FORECASTS FROM OUR OFFICE AS WE DRAW CLOSER TO THIS UPCOMING
COLD PERIOD.
SHORT TERM
(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 433 AM CST WED JAN 15 2025
THE RADAR IS PRETTY ACTIVE EARLY THIS MORNING, PERHAPS
SURPRISINGLY SO IF YOU GO OUTSIDE AND HAVEN'T EXPERIENCED MORE
ANYTHING MORE THAN A BIT OF A SPRINKLE. THIS IS A PRETTY STRONG
EXAMPLE OF THE COLUMN MOISTENING FROM THE TOP DOWN. WE HAD HIGH
CLOUDS 24 HOURS AGO, PLUS MID-LEVEL CLOUDS TONIGHT, AND APPARENTLY
ENOUGH MOISTURE AND LIFT FOR ELEVATED SHOWERS TO SPROUT ACROSS THE
AREA. HOWEVER, THE LOW LEVELS ARE STILL QUITE DRY, AS PARTS OF THE
AREA STILL HAVE DEWPOINTS BELOW 40 AND RH BELOW 60 PERCENT, WHICH
IS PRETTY LOW FOR THIS AREA AT THIS TIME OF NIGHT.
OF COURSE, THIS MOISTURE IS FILLING IN AT LOWER LEVELS. IAH HAS
BEGUN REPORTING A FEW CLOUDS BELOW 3,000 FEET, DOWN FROM THE
6,000 OR SO FEET THAT MOST LOCATIONS ARE REPORTING THEIR LOWEST
CLOUDS AT. AND AS WE CONTINUE TO BUILD THAT MOISTURE AT LOWER
LEVELS, THE SHOWERS WILL GRADUALLY BECOME A BIT MORE SUBSTANTIAL
TODAY. THEY STILL WON'T BE ANYTHING MORE THAN SOME LIGHT TO
OCCASIONALLY MODERATE SHOWERS, BUT CERTAINLY MORE THAN SPRINKLES.
NOW, WHY IS THAT? WELL, AS WE OFTEN SEE THIS TIME OF YEAR, THE
SURFACE FEATURE DRIVING UNSETTLED WEATHER IS A COASTAL TROUGH
DEVELOPING OFF THE TEXAS COAST, DEVELOPING UNDERNEATH A WEAK UPPER
TROUGH PASSING OVERHEAD. WHEN THESE SITUATIONS CREATE STORMIER
CONDITIONS, IT'S OFTEN BECAUSE THESE TWO FEATURES AT THE SURFACE
AND ALOFT ARE IN A PHASE WHERE THEY BUILD/SUPPORT EACH OTHER, AND
TRACK UP THE TEXAS COASTLINE. WE ARE...GETTING NEITHER OF THOSE
TODAY.
TODAY, THE UPPER TROUGH LOOKS TO SCOOT ITS WAY MORE WEST-TO-EAST
OVER THE OPEN GULF, WITH A WEAKER TROUGH CHASING BEHIND IT, WELL
OFFSHORE AND NOT TRACKING TOWARDS OUR UPPER COAST. THIS LIMITS
ONSHORE FLOW AND THE RETURN OF SIGNIFICANT MOISTURE AND WARMER
AIR. IT ALSO TURNS WINDS AROUND TO BE OFFSHORE MORE QUICKLY,
USHERING DRIER CONTINENTAL AIR SOONER. AND FINALLY, IT KEEPS THE
BEST LIFT WELL AWAY FROM OUR AREA. AND THUS, WE GET ONLY LIGHTER
SHOWERS!
TEMPERATURE-WISE, EXPECT THE LOWS THIS MORNING TO BE AMONG THE
WARMEST OF THE WEEK, THANKS MAINLY TO THE OVERCAST SKY. THE ONLY
NIGHT WITH HIGHER MINIMUM TEMPS SHOULD BE FRIDAY NIGHT (MORE ON
THAT IN THE LONG TERM SECTION). WE GET THE FLIP SIDE OF THAT COIN
DURING THE DAY TODAY, WITH TEMPERATURES ONLY RISING 10ISH DEGREES
(OR FEWER, IN SPOTS!) FOR AFTERNOON HIGHS IN THE LOWER TO MIDDLE
50S. ONCE WINDS TURN OFFSHORE AND SCOUR OUT WHAT MODEST MOISTURE
WE'VE BEEN ABLE TO BUILD, THAT SHOULD ALLOW FOR A CHILLIER NIGHT
TONIGHT, WITH LOWS IN THE UPPER 30S AND LOWER 40S. BUT DESPITE
THAT, I'D EXPECT HIGHS TOMORROW TO ACTUALLY BE A BIT WARMER THANKS
TO SOME MORE SUN, WITH HIGHS AROUND OR A LITTLE ABOVE 60 DEGREES.
CONGRATULATIONS, YOU HAVE READ (OR SKIPPED OVER) SIX PARAGRAPHS
ABOUT THE PART OF THE FORECAST ALMOST NONE OF US CARE ABOUT!
PLEASE PROCEED TO THE LONG TERM SECTION OF THE FORECAST, AKA
"SHOWTIME!"
LONG TERM
(FRIDAY THROUGH TUESDAY)
ISSUED AT 433 AM CST WED JAN 15 2025
HIGH PRESSURE CONTINUES EASTWARD ON FRIDAY, WITH SOUTHEASTERLY FLOW
BRINGING WAA AND MOISTURE ADVECTION. THIS WARMS UP HIGHS INTO THE
60S/LOWER 70S ON FRIDAY WITH TEMPERATURES FOR FRIDAY NIGHT IN THE
40S/50S. RISING MOISTURE WILL INTRODUCE RAIN CHANCES FRIDAY
EVENING/OVERNIGHT, BUT BY IN LARGE FRIDAY WILL BE A BENIGN AND
PLEASANT DAY, AT LEAST COMPARED TO WHAT'S COMING...
A SHORTWAVE OVER THE SOUTHERN PLAINS WILL PUSH A STRONG COLD FRONT
THROUGH SE TEXAS ON SATURDAY. TIMING WITH THIS FRONT REMAINS THE
SAME, ENTERING THE BRAZOS VALLEY EARLY SATURDAY MORNING THEN PUSHING
OFF THE COAST BY THE AFTERNOON. SHOWERS/THUNDERSTORMS WILL BE
POSSIBLE ALONG/AHEAD OF THE FRONT, WITH GUSTY NORTH/NORTHEAST WINDS
DEVELOPING IN IT'S WAKE. COLD AIR FILTERS IN BEHIND THIS SYSTEM,
WITH LOWS TEMPERATURES FOR SUNDAY MORNING CURRENTLY FORECASTED TO BE
IN THE UPPER 20S/30S INLAND AND LOWER 40S ALONG THE COAST. WIND
CHILL WILL PUT APPARENT TEMPERATURES IN THE UPPER TEENS/UPPER 20S
INLAND AND LOWER 30S NEAR THE COAST EARLY THAT MORNING.
WHILE WE'LL WARM ABOVE FREEZING DURING THE DAY (HIGHS IN THE 40S
AREA-WIDE), A DEEP UPPER LEVEL LOW OVER THE HUDSON BAY (CANADA) WILL
PUSH A STRONG 1050MB SURFACE HIGH INTO THE NORTHERN PLAINS/GREAT
BASIN ON SUNDAY. THIS FRIGID ARCTIC AIRMASS WILL FILL IN ACROSS THE
MUCH OF THE CONUS OVERNIGHT INTO NEXT WEEK, BRINGING EVEN COLDER
CONDITIONS TO SE TEXAS. LOW TEMPERATURES FOR MONDAY & TUESDAY
MORNING ARE CURRENTLY FORECASTED TO BE IN THE 20S INLAND TO LOWER
30S ALONG THE COAST. HARD FREEZE CONDITIONS (TEMPS 24 OR LOWER) WILL
BE POSSIBLE IN AREAS NORTH OF I-10, AND ESPECIALLY SO ACROSS THE
BRAZOS VALLEY/PINEY WOODS AREA, WHERE NBM PROBABILITIES SHOW HIGH
CONFIDENCE (70-90% CHANCE) FOR REACHING HARD FREEZE TEMPERATURES.
WIND CHILL TEMPERATURES ARE FORECASTED TO BE IN THE 20S TO LOWER
TEENS. LREF ENSEMBLE PROBABILITIES STILL SUGGEST THAT THERE IS A LOW
TO MEDIUM (35%) CHANCE OF WIND CHILLS HITTING SINGLE DIGITS OVER THE
FAR NORTHERN REACHES OF OUR CWA EARLY TUESDAY MORNING. UNCERTAINTY
GROWS BEYOND THE 7 DAY FORECAST, THOUGH AT PRESENT WE MAY HAVE TO
WAIT TILL THE SECOND HALF OF THE WEEK TO SEE TEMPERATURES WARM UP
AGAIN.
WITH THESE COLD CONDITIONS COMES THE QUESTION OF WINTER
PRECIPITATION, AND IT APPEARS AS THOUGH THE CONDITIONS ARE LOOKING
FAVORABLE FOR IT'S DEVELOPMENT. A COASTAL TROUGH IS STILL PROGGED TO
FORM NEAR THE DEEP S TEXAS/MEXICO COASTLINE ON MONDAY, PROVIDING
INFLUX OF MOISTURE ACROSS THE TEXAS COASTAL BEND. PACIFIC MOISTURE
FILLING IN ALOFT, 700-850MB FRONTOGENESIS AND A SHORTWAVE TROUGH
PASSING OVER TEXAS WILL PROVIDE THE NECESSARY COMPONENTS FOR
PRECIPITATION. LREF, GFS AND ECMWF ENSEMBLES ALL SHOW A MORE
DISTINCT CLUSTERING OF QPF BEGINNING ON MONDAY, PROVIDING HIGHER
CONFIDENCE IN PRECIPITATION. COMPARED TO YESTERDAY, GUIDANCE DOES
APPEAR A TAD WARMER ALOFT, WITH ENSEMBLE MEANS SHOWING 500MB
TEMPERATURES IN THE RANGE OF -14 TO -19. DYNAMIC ENSEMBLE SOUNDINGS
STILL KEEP MOST OF THE TEMPERATURE PROFILE BELOW ZERO, THOUGH THE
UPPER END OF THE IQR HAS SHIFTED ABOVE THE FREEZING MARK.
DETERMINISTIC SOUNDINGS STILL SHOWS SIGNS OF SEEDER-FEEDER PROCESSES
OCCURING, BUT ALSO FEATURE A STRONGER WARM NOSE ALOFT.
THE MAIN TAKEAWAY IS THAT WE NOW HAVE MEDIUM TO HIGH CONFIDENCE (40-
50% CHANCE) THAT WINTRY PRECIPITATION WILL OCCUR OVER SOUTHEAST
TEXAS DURING THE FIRST HALF OF NEXT WEEK. ALL WINTER PRECIPITATION
TYPES ARE STILL ON THE TABLE RIGHT NOW, BUT BROADLY SPEAKING
GUIDANCE AND THE NBM SEEM TO STILL FAVOR SNOW AS THE DOMINANT PRECIP
TYPE. AREAS NORTH OF THE I-10 ARE MORE LIKELY TO SEE SNOW/MIX OF
SLEET. AREAS TO THE SOUTH MAY SEE A MIX OF SNOW/SLEET/FREEZING RAIN
AND POTENTIALLY LIQUID RAIN RIGHT ALONG THE BARRIER
ISLANDS/NEARSHORE WATERS. AS FOR HOW MUCH SNOW/SLEET/ICE,
UNCERTAINTY IS TOO HIGH TO PUT A SPECIFIC AMOUNT ON IT JUST YET.
BROADLY SPEAKING, IT'S MORE SNOW TO THE NORTH AND MORE ICE TO THE
SOUTH. WE'LL HAVE A BETTER IDEA OF "HOW MUCH" OVER THE NEXT FEW
DAYS, BUT FOR NOW WE SHOULD PREPARE FOR SOME ACCUMULATING WINTER
PRECIPITATION.
AVIATION
(18Z TAF ISSUANCE)
ISSUED AT 1156 AM CST WED JAN 15 2025
AREAS OF SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE THROUGH
THIS EVENING AS A SYSTEM OF LOW PRESSURE CONTINUES TO SUPPLY LOW
LEVEL MOISTURE WHILE AN UPPER LEVEL TROUGH MOVES ACROSS THE
SOUTHERN PLAINS. THIS MAY RESULT IN PERIODS OF MVFR VIS/CIGS,
MAINLY FOR SITES SOUTH OF CXO. LATER THIS AFTERNOON INTO THIS
EVENING, RAINFALL WILL EBB FROM NORTH TO SOUTH AS DRIER AIR
FILTERS IN FROM THE NORTH. CLOUD DECKS ARE EXPECTED TO SCATTER OUT
DURING THE OVERNIGHT HOURS, WITH MUCH OF THE REGION UNDER CLEAR
SKIES BY SUNRISE. EXPECT LIGHT N WINDS TONIGHT INTO THU.
24
MARINE
ISSUED AT 433 AM CST WED JAN 15 2025
A COASTAL TROUGH WILL BRING SCATTERED SHOWERS/STORMS, EAST/NORTHEAST
WINDS OF 15 TO 25 KNOTS AND SEAS OF 3 TO 6 FEET THROUGH LATE
TONIGHT. THIS WILL WARRANT CAUTION FLAGS AND OCCASIONALLY SMALL
CRAFT ADVISORIES THROUGH EARLY THURSDAY. DURING THIS TIME FRAME, LOW
TIDE LEVELS ARE EXPECTED ACROSS THE BAYS, WHICH MAY MAKE NAVIGATION
DIFFICULT IN SOME SPOTS. SOUTHERLY WINDS RETURN FRIDAY MORNING AND
STRENGTHEN OVERNIGHT AHEAD OF THE NEXT COLD FRONT. THIS STRONG COLD
FRONT SHOULD PUSH OFFSHORE SOMETIME SATURDAY AFTERNOON, BRINGING
SHOWERS/STORMS AS IT PASSES THEN GUSTY NORTHERLY WINDS AND HIGH SEAS
IN IT'S WAKE. COLD ARCTIC AIR WILL WORKS ITS WAY TO THE COAST ON
SUNDAY INTO NEXT WEEK. CHANCES OF A HARD FREEZE OCCURING AROUND
GALVESTON BAY NEXT WEEK ARE LOW (20-35%). EVEN HIGHER WINDS AND SEAS
ARE LOOKING MORE LIKELY FOR NEXT WEEK AS A COASTAL TROUGH DEVELOPS
OFFSHORE.
PRELIMINARY POINT TEMPS/POPS
COLLEGE STATION (CLL) 57 35 62 40 / 10 0 0 0
HOUSTON (IAH) 54 39 62 42 / 40 20 0 0
GALVESTON (GLS) 55 46 58 50 / 70 40 0 0
HGX WATCHES/WARNINGS/ADVISORIES
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 9 PM CST THIS EVENING
FOR GMZ330.
SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR GMZ350-355.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR GMZ370-375.
SHORT TERM...LUCHS
LONG TERM....03
AVIATION...COTTO (24)
MARINE...03
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