317
FXUS64 KHGX 271149
AFDHGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
649 AM CDT THU MAR 27 2025
..NEW AVIATION
SYNOPSIS
ISSUED AT 225 AM CDT THU MAR 27 2025
SCATTERED TO WIDESPREAD SHOWERS WITH LOCALLY HEAVY RAINFALL WILL
BE POSSIBLE THROUGH FRIDAY AFTERNOON WITH PERIODS OF LULLS IN THE
SHOWER ACTIVITY EXPECTED.
- LIGHT TO MODERATE RAINFALL HAS ALREADY OCCURRED ACROSS THE SW
PORTION OF THE REGION WITH TOTALS OF .8-1.5"
- SOME ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE THROUGH THE AFTERNOON TODAY, AN INCREASE IN COVERAGE
AND INTENSITY IS EXPECTED THIS EVENING THROUGH FRIDAY MORNING -
ESPECIALLY ACROSS THE SW PORTIONS OF THE REGION (PARTICULARLY
AROUND MATAGORDA BAY)
- A FLOOD WATCH IS IN EFFECT FOR JACKSON, MATAGORDA, BRAZORIA,
WHARTON, COLORADO AND FORT BEND COUNTIES THROUGH FRIDAY
AFTERNOON
- STORM TOTAL RAINFALL THROUGH FRIDAY WILL BE GENERALLY UP 2-5",
HOWEVER ISOLATED HIGHER AMOUNTS UP TO 9" WILL BE POSSIBLE
WITHIN THE WATCH AREA
- OVERALL MINOR URBAN AND SMALL STREAM FLOODING IS EXPECTED, BUT
A FEW INSTANCES OF FLASH FLOODING IS POSSIBLE - WITH TONIGHT
INTO FRIDAY MORNING BEING THE MAIN WINDOW OF CONCERN
- CANNOT OUT RULE AN ISOLATED STRONG TO SEVERE THUNDERSTORM OR
TWO DEVELOPING THIS AFTERNOON OR FRIDAY AFTERNOON
FOWLER
SHORT TERM
(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 225 AM CDT THU MAR 27 2025
THE RAIN HAS ARRIVED AND WILL BE STICKING AROUND THROUGH THE REST
OF THE SHORT TERM PERIOD. A LARGE UPPER-LEVEL TROUGH IS SWINGING
THROUGH NORTHERN MEXICO INTO TEXAS THIS MORNING AND A SHORTWAVE
TROUGH OUT AHEAD OF THIS SYSTEM IS WHAT IS TRIGGERING THE
WIDESPREAD SHOWERS WE HAVE SEEN OVER OUR SOUTHWESTERN COUNTIES
SINCE AROUND SUNSET LAST NIGHT. MRMS QPE HAS RAIN TOTALS THROUGH
2AM GENERALLY AROUND .75" TO 1" ACROSS JACKSON, MATAGORDA,
WHARTON, AND COLORADO COUNTIES WITH SOME POCKETS OF HIGHER TOTALS
NEARING 1.5-2". THIS WIDESPREAD LIGHT TO MODERATE SHOWER ACTIVITY
WILL PERSIST THROUGH THIS MORNING ALONG AND SOUTH OF I-10, BUT CAM
GUIDANCE IS INDICATING THE SHOWERS WILL BECOME MORE ISOLATED TO
SCATTERED (RATHER THAN THE WIDESPREAD/STRATIFORM RAIN WE ARE
SEEING OVERNIGHT), BUT THE COVERAGE EXPANDS FURTHER NORTH INTO
THE BRAZOS VALLEY AND EVEN TO THE PINEY WOODS BY THE MID
AFTERNOON. THE MAIN TROUGH AXIS IS EXPECTED TO MOVE THROUGH OUR
REGION TONIGHT THROUGH FRIDAY AFTERNOON INCREASING NOT ONLY THE
COVERAGE OF THE SHOWER ACTIVITY, BUT ALSO THE INTENSITY. CAM
GUIDANCE VARIES ON EXACTLY WHERE THE HEAVIEST RAINFALL WILL OCCUR
(MAINLY DUE TO MESOSCALE INTERACTIONS THAT ARE HARD TO PREDICT
THIS FAR OUT), BUT THERE CONTINUES TO BE A BETTER CONSENSUS THAT
THE MODERATE TO HEAVY RAINFALL TONIGHT WILL OCCUR SOUTH OF I-10,
BUT WEST OF I-45 WITH THE AREAS AROUND MATAGORDA BAY HAVING THE
HIGHEST CHANCES. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE
POSSIBLE FOR MUCH OF THE REGION THROUGH FRIDAY AFTERNOON AS THE
UPPER LEVEL DISTURBANCE SLOWLY MOVES THROUGH. WE FINALLY GET TO BE
ON THE BACKSIDE OF THE TROUGH FRIDAY EVENING LEADING TO AN END OF
THE PRECIPITATION (ON LAND, IT MAY LINGER OVER THE GULF WATERS
INTO FRIDAY NIGHT).
THE FLOOD WATCH HAS BEEN EXPANDED TO NOW INCLUDE COLORADO AND FORT
BEND COUNTIES AND HAS BEEN EXTENDED THROUGH 00Z SATURDAY (FRIDAY
EVENING). NO BIG CHANGES IN THE RAINFALL TOTALS EXPECTED THROUGH
THE EVENT: GENERALLY UP TO 2-5" WITH ISOLATED HIGHER AMOUNTS OF UP
TO 9" WITHIN THE WATCH AREA IS EXPECTED. NOW, GROUND SOILS ARE
PARTICULARLY DRY WITH D1-D3 DROUGHT BEING EXPERIENCED ACROSS THE
WATCH AREA WITH 3-HR FFG AROUND 4". SO, THERE IS GOING TO NEED TO
BE A DECENT AMOUNT OF RAIN TO OVERCOME THESE DRY GROUNDS.
RAIN RATES COULD BE AS HIGH AS 1-2" PER HOUR WITHIN SOME OF THE
STRONGER STORMS TONIGHT INTO FRIDAY, AND THERE IS ALSO POTENTIAL
FOR SOME TRAINING STORMS. IF THESE TWO THINGS HAPPEN TO OCCUR AT
THE SAME TIME, THEN WE MAY BE ABLE TO EXCEED THE HIGH FFG.
OVERALL, MINOR/NUISANCE FLOODING OF LOW-LYING OR POOR DRAINAGE
AREAS IS EXPECTED - BUT SOME INSTANCES OF FLASH FLOODING CANNOT BE
OUT RULED WITHIN THE WATCH AREA. THERE IS SOME BUST POTENTIAL
WHERE THE AXIS OF HEAVY RAINFALL THIS EVENING THROUGH FRIDAY
MORNING SETS UP OVER THE COASTAL WATERS AND AREAS INLAND SEE MUCH
LESS RAINFALL.
WPC HAS EXPANDED THE MODERATE RISK OF EXCESSIVE RAINFALL (LEVEL
3/4 - CORRESPONDING TO AT LEAST A 40% CHANCE OF EXCEEDING FFG
WITHIN A 25 MILES OF A POINT) TO INCLUDE MOST OF JACKSON COUNTY,
WESTERN HALF OF MATAGORDA COUNTY, AND A PORTION OF SOUTHERN
WHARTON COUNTY. A SLIGHT RISK (LEVEL 2 OF 4) EXTENDS UP TO US-290
AND DOWN THROUGH EASTERN BRAZORIA COUNTY, AND A MARGINAL RISK
(LEVEL 1 OF 4) IN THE BRAZOS VALLEY DOWN THROUGH THE HOUSTON METRO
AND GALVESTON COUNTY. FOR FRIDAY, THE HOUSTON METRO AND AREAS TO
THE SOUTH AND EAST ARE IN A SLIGHT RISK WITH THE REST OF THE AREA
IN A MARGINAL RISK.
SPC HAS ALSO A MARGINAL RISK (LEVEL 1 OF 5) TODAY AND TOMORROW FOR
PORTIONS OF THE REGION FOR ISOLATED STRONG TO SEVERE
THUNDERSTORMS CAPABLE OF PRODUCING STRONG WIND GUSTS AND HAIL (AND
POSSIBLY EVEN A QUICK, WEAK TORNADO) - BUT THE PRIMARY WEATHER
CONCERN THROUGH FRIDAY WILL BE THE LOCALIZED HEAVY RAINFALL
POTENTIAL.
OVERCAST SKIES WILL KEEP TEMPERATURES FAIRLY SEASONAL DURING THE
DAYTIME TODAY AND FRIDAY WITH HIGHS IN THE LOW TO MID 70S, BUT MILD
OVERNIGHT TEMPERATURES WITH LOWS IN THE MID TO UPPER 60S.
FOWLER
LONG TERM
(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 225 AM CDT THU MAR 27 2025
AFTER A WET SHORT TERM, THE LONG TERM IS LOOKING FAIRLY DRY WITH
JUST SOME SLIGHT CHANCES OF SHOWERS IN THE PINEY WOODS SUNDAY AND
AGAIN MIDWEEK NEXT WEEK DUE TO A PASSING DISTURBANCES TO THE
NORTH. THE MAIN HEADLINE THIS WEEKEND INTO NEXT WEEK WILL BE THE
INCREASING TEMPERATURES AND HUMIDITY WITH DAYTIME HIGH
TEMPERATURES REACHING THE MID TO UPPER 80S (EVEN REACHING 90
DEGREES BY WEDNESDAY) AND OVERNIGHT LOWS IN THE MID 60S TO LOW
70S.
FOWLER
AVIATION
(12Z TAF ISSUANCE)
ISSUED AT 625 AM CDT THU MAR 27 2025
VFR CONDITIONS WILL PREVAIL THROUGH THE DAY TODAY WITH SCT LOW
LEVEL CLOUDS AROUND 2000-4000FT WITH OVC HIGH LEVEL CLOUDS AROUND
10000FT. WIDESPREAD LIGHT RAIN SHOWERS WITH ISOLATED AREAS OF
MODERATE RAINFALL WILL CONTINUE THROUGH THE DAY TODAY WITH AN
INCREASE IN COVERAGE AND INTENSITY EXPECTED TONIGHT THROUGH FRIDAY
AFTERNOON. HEAVY RAINFALL MAY REDUCE VISIBILITY DOWN TO 2-4MI AT
TIMES. CIGS ARE EXPECTED TO DECREASE TO AROUND 1500FT BY THIS
EVENING AND CONTINUE THROUGH FRIDAY MORNING WITH SOME ISOLATED
LOWER CIGS DOWN TO 700FT POSSIBLE LATE TONIGHT. WHILE SOME
ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON, CHANCES FOR TS
DOES NOT INCREASE UNTIL FRIDAY. SOUTHEASTERLY WINDS AROUND 8-12KT
WILL PREVAIL TODAY WITH GUSTS TO 20-25KT POSSIBLE DOWN ALONG THE
COAST TONIGHT INTO FRIDAY MORNING.
FOWLER
MARINE
ISSUED AT 225 AM CDT THU MAR 27 2025
THE FORECAST THROUGH FRIDAY NIGHT / SATURDAY MORNING IS VERY
COMPLEX, FEATURING HIGHER THAN NORMAL UNCERTAINTY. FIRST, LET'S TALK
ABOUT WHAT WE KNOW. FIRST, WE KNOW THERE WILL BE PERIODS OF RAIN AND
THUNDERSTORMS. SECOND, WE KNOW THAT WINDS WILL GENERALLY BE MODERATE
TO FRESH OUT OF THE EAST TO SOUTHEAST. IN ADDITION, WE ALSO KNOW
THAT SEAS WILL BUILD. OUR CURRENT FORECAST HAS WINDS OVER THE BAYS
AND GULF AVERAGING ~15-20KTS THROUGH FRIDAY NIGHT. WINDS WITHIN
THUNDERSTORMS WILL LIKELY BE HIGHER. BUT THE REAL WILD CARD IN THE
FORECAST CONCERNS POTENTIAL FOR STRONG WINDS WELL OUTSIDE OF THESE
THUNDERSTORMS. THIS IS BECAUSE WE ARE LIKELY TO SEE LARGER CLUSTERS
OF STRONG THUNDERSTORMS CALLED MESOSCALE CONVECTIVE SYSTEMS (MCS)
WHICH RESULT IN LOCALIZED PRESSURE PERTURBATIONS, STEEPENING THE
GRADIENT IN THE VICINITY OF THE STORM. THEREFORE, BE ADVISED THAT
THERE COULD PERIODS OF MUCH HIGHER WINDS EVEN IF YOUR LOCATION IS
NOT DIRECTLY HIT BY A THUNDERSTORM.
SELF
HYDROLOGY
ISSUED AT 225 AM CDT THU MAR 27 2025
PRECEDING LOW RIVER LEVELS BEFORE THIS RAIN EVENT WILL LIKELY
LIMIT ANY SIGNIFICANT RIVER FLOODING OVER THE NEXT COUPLE OF DAYS.
HOWEVER, SOME GAUGES ALONG THE LAVACA/NAVIDAD MAY REACH ACTION
(BANKFULL) OR EVEN MINOR STAGE WITH SOME RISES OF OTHER AREA
RIVERS POSSIBLE BY FRIDAY AFTERNOON. CHECK WITH THE WEST GULF RFC
AND AT WATER.WEATHER.GOV FOR THE LATEST RIVER FORECASTS.
FOWLER
PRELIMINARY POINT TEMPS/POPS
COLLEGE STATION (CLL) 70 62 73 64 / 90 90 90 40
HOUSTON (IAH) 74 66 75 66 / 70 70 90 60
GALVESTON (GLS) 74 67 74 67 / 50 70 90 70
HGX WATCHES/WARNINGS/ADVISORIES
TX...FLOOD WATCH THROUGH FRIDAY EVENING FOR TXZ210-226-227-235>237-
335>337-436-437.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH THIS EVENING FOR
GMZ330-335-350-355-370-375.
SHORT TERM...FOWLER
LONG TERM....FOWLER
AVIATION...FOWLER
MARINE...SELF
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