Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KHGX 230251
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
851 PM CST MON DEC 22 2014

.UPDATE...
TWO PRIMARY CONCERNS WITH THE FORECAST UPDATE TONIGHT...FOG /SOME
POTENTIALLY DENSE/ AND TIMING SHOWERS AND THUNDERSTORMS ASSOCIATED
WITH INCOMING FRONT.

SURFACE ANALYSIS AS OF 7 PM PLACED THE COLD FRONT SURGING THROUGH
TEXAS ROUGHLY ALONG A TEXARKANA TO TEMPLE TO OZONA TO CARLSBAD NM
LINE...WITH SURFACE PRESSURE RISES BEHIND THE FRONT ON THE ORDER
OF 2 TO 3 MB OVER THE PAST 3 HOURS. THE COLDER AIR ASSOCIATED WITH
THIS FRONT IS LAGGING BEHIND THIS BOUNDARY A BIT AS 30S AND 40S
OOZE INTO THE TEXAS PANHANDLE AND WESTERN OKLAHOMA ...WITH LITTLE
IMMEDIATE CHANGE IN TEMPERATURES BOTH AHEAD AND BEHIND THE FRONT
IN THE MID TO UPPER 50S TO NEAR 60. BECAUSE OF THIS LAG IN COLDER
AIR...LOW TEMPERATURES IN THE LOW 50S IN CENTRAL TEXAS TO LOW 60S
ALONG THE COAST SHOULD BE ON TRACK. PRESENT TIMING FOR THE COLD
FRONT HAS IT ENTERING THE HOUSTON METRO AREA AROUND 7-9 AM TUESDAY
MORNING.

BOTH INLAND AND COASTAL AREAS ARE AT RISK FOR AT LEAST PATCHY FOG
DEVELOPMENT TONIGHT. GENERALLY CLEAR SKIES AND LIGHT WINDS ALONG
AND SOUTH OF THE HIGHWAY 59 CORRIDOR HAVE SET THE STAGE FOR A
RADIATION FOG EVENT...WITH SEVERAL COASTAL COUNTIES ALREADY
REPORTING REDUCED VISIBILITIES FROM FOG. LATEST RAP/HRRR RUNS
SHOW FOG CONTINUING TO DEVELOP ALONG AND SOUTH OF HIGHWAY 59
OVERNIGHT AND THE PREVIOUS FORECAST UPDATE HANDLES THIS
ANTICIPATED DEVELOPMENT WELL. MAIN QUESTION WILL BE HOW DENSE FOG
WILL ACTUALLY GET /VISIBILITY AT KBYY HAS ALREADY DROPPED BELOW 1
MILE/. WILL CONTINUE TO MONITOR TRENDS FOR POTENTIAL DENSE FOG
ADVISORY LATER TONIGHT. FOR MORE INFORMATION REGARDING THE UPDATE
TO THE MARINE FORECAST...PLEASE SEE THE MARINE DISCUSSION APPENDED
BELOW.

REGARDING RAIN CHANCES...REGIONAL RADAR MOSAIC AS OF 830 PM
SHOWED A COMPLEX OF SHOWERS AND THUNDERSTORMS OVER THE PERMIAN
BASIN DEVELOPING ALONG AND BEHIND THE FRONT. 00Z MODEL DATA
CONTINUES TO TRICKLE IN BUT THE LATEST SOLUTIONS STILL INDICATE
THAT THIS ACTIVITY WILL CONTINUE TO SPREAD EAST TOWARDS SOUTHEAST
TEXAS AS THE ASSOCIATED UPPER LEVEL SYSTEM MOVES ACROSS THE STATE.
RAIN CHANCES WILL BEGIN INCREASING ALONG AND BEHIND THE PASSAGE OF
THE FRONT TONIGHT BUT BEST FORCING FOR RAIN DEVELOPMENT WILL BE
ALONG THE 850 MB FRONT...DELAYING HIGHEST RAIN CHANCES AROUND 3-6
HOURS AFTER FRONTAL PASSAGE. CURRENT FORECAST HANDLES THE
EVOLUTION OF TOMORROW/S RAIN...INCREASING FROM WEST TO EAST DURING
THE DAY AS THE UPPER LEVEL TROUGH PASSES...FAIRLY WELL AND NO
CHANGES WERE MADE TO ONGOING RAIN CHANCES.

HUFFMAN

&&

.MARINE...
SURFACE DEW PTS ARE IN THE MID 60S AND WATER TEMPS ARE NEAR 60.
SOME PATCHY SEA FOG DEVELOPED NEAR GALVESTON EARLIER AND FEEL SOME
PATCHY FOG COULD PLAGUE MARINE AREAS OFF AND ON THROUGH TUESDAY
AFTERNOON. NOT SURE HOW WIDESPREAD OR DENSE THE FOG WILL BECOME SO
WILL JUST CALL FOR AREAS OF FOG AND WATCH TRENDS.

A STRONG COLD FRONT SHOULD REACH MATAGORDA BAY BY EARLY
AFTERNOON...GALVESTON BAY AROUND 3 PM AND CROSS THE COASTAL WATERS
BY 6 PM. NORTHWEST WINDS WILL INCREASE RAPIDLY IN THE WAKE OF THE
FRONT AND SPEEDS SHOULD EXCEED 20 KNOTS OVER THE ENTIRE MARINE
AREA BY 00Z WITH OCCASIONAL GUSTS TO GALE FORCE. A SMALL CRAFT
ADVISORY HAS BEEN ISSUED FOR THE MARINE AREAS FOR LATE TUESDAY
AFTERNOON THROUGH TUESDAY NIGHT. THE STRONG OFFSHORE FLOW WILL
DRIVE WATER OUT OF GALVESTON BAY AND FEEL THE UPPER REACHES OF
GALVESTON BAY NEAR MORGANS PT AND MANCHESTER WILL SUFFER FROM LOW
WATER ISSUES. A LOW WATER ADVISORY MAY BE REQUIRED LATE TUESDAY
NIGHT INTO WEDNESDAY. MODERATE TO STRONG WINDS WILL PREVAIL ON
WEDNESDAY BEFORE SPEEDS BEGIN TO DECREASE WEDNESDAY NIGHT. AN
ONSHORE FLOW WILL REDEVELOP THURSDAY AND STRENGTHEN ON FRIDAY.
ANOTHER COLD FRONT WILL CROSS THE MARINE AREA ON SATURDAY NIGHT.
43

&&

.PREV DISCUSSION... /ISSUED 619 PM CST MON DEC 22 2014/

DISCUSSION...
SEE 00Z AVIATION DISCUSSION.

AVIATION...
VFR CONDS WILL PREVAIL AT MOST TAF SITES THROUGH 06Z WITH SKY
CONDS TRANSITIONING TO MVFR AHEAD OF A COLD FRONT. KGLS HAD A
BRIEF BOUT WITH LOW CIGS EARLIER IN THE EVENING ASSOCIATED WITH
SOME SEA FOG JUST OFF THE COAST. FCST SOUNDINGS SHOW A REASONABLY
DEEP SATURATE LAYER THAT FEEL SOME LIGHT RAIN WILL BE POSSIBLE
ALONG AND BEHIND TUESDAYS COLD FRONT. CIGS WILL ALSO LOWER TO
IFR/LIFR IN THE WAKE OF THE FRONT. WINDS WILL BECOME STRONG IN THE
WAKE OF THE FRONT AS WELL SO WILL CARRY A GUST GROUP AGAIN. VFR
CONDS EXPECTED TO GRADUALLY RETURN AFTER 00Z WED. 43

PREV DISCUSSION... /ISSUED 535 PM CST MON DEC 22 2014/

UPDATE...
QUICK UPDATE TO GRIDS TO ADD MENTION OF PATCHY FOG FOR COASTAL
AREAS THIS EVENING WHERE AFTERNOON VISIBLE SATELLITE AND
GALVESTON WEBCAMS SHOW A LOW STRATUS DECK/FOG BANK SITTING JUST
OFFSHORE. GUIDANCE DEPICTS WINDS BACKING FROM THE SOUTHWEST TO THE
SOUTHEAST DURING THE OVERNIGHT HOURS AND EXPANDED FOG MENTION TO
INLAND AREAS AS THIS OCCURS...WITH AREAS OF FOG LIKELY DEVELOPING
ALONG THE COAST COURTESY CONTINUED LOW LEVEL MOISTURE ADVECTION.

HUFFMAN

PREV DISCUSSION... /ISSUED 355 PM CST MON DEC 22 2014/

DISCUSSION...
QUITE A LOT MORE SUN ACROSS SE TX TODAY THAN THERE HAS BEEN THESE
LAST FEW DAYS...WITH TEMPERATURES RESPONDING ACCORDINGLY. NOT TOO
MANY CHANGES WITH THE FCST AS MODELS REMAIN IN FAIRLY GOOD AGREE-
MENT WITH THE TIMING OF THE ADVERTISED STRONG COLD FRONT. HOWEVER
WE ARE SEEING HINTS THAT A PRE-FRONTAL TROF DURING THE OVERNIGHT/
VERY EARLY TUES MORNING HRS WILL HELP TO SHIFT WINDS/LIMIT MOIST-
URE FOR WHEN THE OFFICIAL COLD FRONT ARRIVES. NOT TOO COMFORTABLE
WITH LOWERING POPS TOO MUCH ATTM...GIVEN THE STRONG LIFT WITH THE
FRONT ITSELF SO WILL KEEP WITH THE MOSTLY CHC POPS ALREADY IN THE
GRIDS FOR FROPA.

NICE COOL DOWN PROGGED IN THE WAKE OF THIS FRONT BY TUES NIGHT AS
THE AIRMASS BUILDS DOWN OFF THE NRN PLAINS. COOL/DRY WX WEDS WITH
LIGHT/MOD CAA WILL GIVE WAY TO WARMING TEMPS/RETURN OF ONSHORE BY
THURS (CHRISTMAS DAY) AS HIGH PRESSURE MOVES OFF TO THE EAST. EX-
TENDED MODELS KEEPING WITH THE STEADY PARADE OF FAST MOVING UPPER
LEVEL LONGWAVE TROFS ACROSS THE U.S. FOR THE REST OF THE WEEK (ON
INTO NEXT WEEK). THIS SHOULD TRANSLATE TO A SERIES OF COLD FRONTS
FOR SE TX DURING THIS TIMEFRAME (ONE FRI THEN ANOTHER NEXT TUES).
ALL IN ALL A FAIRLY TYPICAL EL NINO PATTERN FOR US. 41

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      53  57  37  53  35 /  20  40  10  10   0
HOUSTON (IAH)              58  61  40  54  36 /  20  40  20  10   0
GALVESTON (GLS)            63  65  45  54  44 /  10  30  10  10   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 3 PM TUESDAY TO 6 AM CST WEDNESDAY FOR
     THE FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM FREEPORT
     TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
     FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM.

     SMALL CRAFT ADVISORY FROM 6 PM TUESDAY TO 6 AM CST WEDNESDAY FOR
     THE FOLLOWING ZONES: GALVESTON BAY...WATERS FROM HIGH
     ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
     FREEPORT OUT 20 NM.

&&

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.