Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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000
FXUS64 KHGX 081625
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1025 AM CST MON FEB 8 2016

...HIGH FIRE DANGER TODAY...

.DISCUSSION...
CONDITIONS REMAIN VERY FAVORABLE FOR DANGEROUS FIRE WEATHER
CONDITIONS TODAY. RH VALUES ARE ALREADY BELOW 20 PERCENT IN
SEVERAL LOCATIONS WIND GUSTS ARE APPROACHING 30 MPH. GROUND
FUELS ARE FAIRLY DRY AS WELL SO WILL MAINTAIN THE RED FLAG
WARNING FOR ALL OF SE TX. NOT SURE SUSTAINED WINDS WILL REACH 25
MPH OVER THE NE ZONES TODAY BUT WILL MAINTAIN THE WIND ADVISORY
FOR CONSISTENCY WITH NEIGHBORS. NOT MUCH OF A WARM UP EXPECTED
THIS AFTN WITH WEAK COLD AIR ADVECTION AND MIXING FROM STRONG
WINDS. 12Z SOUNDINGS SUPPORT MAX TEMPS IN THE UPPER 50S TO LOWER
60S AND CURRENT FCST SUPPORTS THESE VALUES. HAVE TWEAKED SKY GRIDS
TO SHOW MORE CIRRUS FOR THIS AFTN BUT OTHER THAN THAT...THE
PREVIOUS FCST IS IN GOOD SHAPE. CAN`T STATE THIS ENOUGH...IF
WORKING WITH FLAMMABLE MATERIAL TODAY...PLEASE BE CAREFUL. 43


&&

.PREV DISCUSSION... /ISSUED 613 AM CST MON FEB 8 2016/

AVIATION...
VFR CONDITIONS TO PREVAIL FOR NEXT 24 HOURS. A COLD FRONT MOVED
ACROSS THE AREA EARLY THIS MORNING. SKIES BEHIND THE FRONT SHOULD
BE MOSTLY SUNNY WITH SOME SCATTERED HIGH CLOUDS. WINDS WILL BE
FROM THE NORTH AT 15 TO 25 KNOTS FOR MUCH OF THE DAY TODAY...
DECREASING TO 5 TO 10 KNOTS OVERNIGHT TONIGHT.

ACCORDING TO THE KHGX VAD WIND PROFILE WINDS AT 020 ARE FROM THE
NORTH AT 35 TO 40 KNOTS. 44

PREV DISCUSSION... /ISSUED 423 AM CST MON FEB 8 2016/

DISCUSSION...
AT 10Z...SFC ANALYSIS SHOWS HIGH PRESSURE OVER THE TX PANHANDLE
PUSHING INTO TEXAS WITH A COLD FRONT MOVING THROUGH SE TX. WINDS
HAVE SHIFTED TO THE NW ACROSS THE AREA AND SHOULD INCREASE LATER
THIS MORNING AS THE PRESSURE GRADIENT INCREASES. SFC DEWPOINTS
WERE ALREADY IN THE TEENS TO LOW 20S ACROSS N TX AND N CENTRAL TX.
THIS AIRMASS SHOULD MOVE INTO SE TX LATER TODAY. LATEST WATER
VAPOR IMAGERY AND 500MB ANALYSIS SHOW UPPER LEVEL PATTERN
CONSISTENT WITH MODEL GUIDANCES FROM THE LAST COUPLE OF DAYS.
NAMELY A DEEP TROUGH HAS FORMED OVER THE GREAT LAKES WITH A TROUGH
AXIS ROTATING THROUGH TEXAS. BROAD UPPER LEVEL RIDGE HAS FORMED
OVER THE PACIFIC COAST WITH STRONG N/NW FLOW ALOFT THROUGH THE
PLAINS AND TEXAS.

IN WHAT SHOULD BE A RATHER QUIET WEATHER WEEK...THE MAIN CONCERN
WILL BE IMPACTS FROM CRITICAL FIRE WEATHER CONDITIONS FOR TODAY.
AS MENTIONED BEFORE THERE IS ALREADY A DRY AIRMASS ADVECTING INTO
THE AREA FROM N TX. DEWPOINTS IN THE LOW 20S COULD END UP BEING
CLOSER TO 10F WITH DEEP MIXING IN THE BOUNDARY LAYER. FORECAST
SOUNDINGS SHOW A MIXED LAYER UP FROM THE SURFACE TO 850MB. BOTH
THE NAM/GFS SHOW MORE THAN 40 KNOTS OF WIND AT 850MB WHICH COULD
MIX DOWN IN THE FORM OF WIND GUSTS. WIND AT 925MB IS A LITTLE LESS
BUT STILL SUPPORTIVE OF SUSTAINED WINDS NEAR 20 MPH DURING THE
EARLY AFTERNOON WITH GUSTS NEAR 30 MPH. A WIND ADVISORY FOR THE
AREA LOOKS REASONABLE GIVEN THESE CONDITIONS.

MAX TEMPS TODAY ARE FORECAST TO REACH THE UPPER 50S TO LOW 60S.
THE CHALLENGE WITH THE TEMPERATURE FORECAST WILL BE HOW MUCH COLD
ADVECTION REALLY OCCURS. TEMPS AT 850MB DROP FROM 3C-5C DOWN TO 0C
TO -2C BY LATE AFTERNOON. THE CHALLENGE WILL BE IF COLD ADVECTION
IS ENOUGH TO OFFSET DAY TIME HEATING AND MIXING. AS SUCH SHOULD
LOW DEWPOINTS BE ACHIEVED WITH SLIGHTLY HIGHER MAX TEMPS THAN
FORECAST...RELATIVE HUMIDITY LEVELS COULD DROP BELOW 15 PERCENT
FOR THE AFTERNOON. RIGHT NOW 14 TO 20 PERCENT RELATIVE HUMIDITY IS
FORECAST. THIS COMBINED WITH THE GUSTY WINDS EXPECTED AND
CURED/DRY VEGETATION SUPPORT THE POTENTIAL FOR RAPID FIRE GROWTH
AND A HIGH FIRE DANGER. FOR THIS REASON A RED FLAG WARNING HAS
BEEN ISSUED FOR TODAY. THIS IS THE FIRST RED FLAG WARNING ISSUED
SINCE JANUARY 21 2014.

OVERALL THERE IS NOT A LOT OF CHANGE IN THE FORECAST PATTERN FOR
THE WEEK. UPPER LEVEL TROUGH REMAINS OVER THE EASTERN THIRD OF THE
U.S. WHILE RIDGING OVER THE PACIFIC COAST BECOMES A BIT MORE
PROGRESSIVE AND MOVES EAST INTO THE ROCKIES BY THE WEEKEND. COLD
AIRMASS THE NEXT COUPLE OF DAYS SHOULD MODIFY WED/THU/FRI AS
925-850MB FLOW BECOMES W/SW ALLOWING BOUNDARY LAYER TEMPS TO
INCREASE. WARMING IS NOT AS DRAMATIC AS IN PREVIOUS FORECASTS BUT
STILL NOTICABLE JUMP IN MAX TEMPS INTO THE 70S. NEXT COLD FRONT
LOOKS TO PUSH THROUGH FRI NIGHT INTO SATURDAY WHICH WILL KNOCK
TEMPS DOWN A FEW DEGREES FOR THE WEEKEND. THAT SAID BOTH GFS/ECMWF
ENSEMBLE MOS NUMBERS SHOW QUITE A BIT OF VARIANCE AND 5 DEGREE
STANDARD DEVIATIONS SO FAIRLY LOW CONFIDENCE IN TEMPERATURE
FORECAST FOR THE EXTENDED.

39

MARINE... A DRY COLD FRONT MOVED OFF THE COAST THIS MORNING WITH
NORTH WINDS EXPECTED TO QUICKLY STRENGTHEN TO ADVISORY LEVELS
BETWEEN 4 AND 6 AM. ADVISORY CONDITIONS WILL REMAIN OVER THE BAY AND
GULF WATERS THROUGH THIS AFTERNOON. HOWEVER...WINDS WILL GRADUALLY
WEAKEN TO CAUTION LEVELS OVER THE BAYS. HIGH PRESSURE EXPANDING OVER
THE WATERS FROM SOUTH TEXAS WILL LOOSEN THE SURFACE PRESSURE
GRADIANT AND BACK OFFSHORE WINDS AROUND TO THE WEST AND NORTHWEST
FROM LATE WEDNESDAY INTO THURSDAY.  A LARGE RIDGE OF HIGH PRESSURE
OVER THE GREAT LAKES REGION WILL ENSURE THAT A LIGHT ONSHORE FLOW
AND 2 TO 4 FOOT SEAS HEIGHTS CONTINUE INTO THE WEEKEND. 44

FIRE WEATHER...
A VERY DRY AIR MASS BEHIND THIS MORNINGS COLD FRONT WILL GENERATE
ELEVATED FIRE WEATHER CONDITIONS. AVERAGE AFTERNOON RH VALUES TO
FALL TO THE MID-TEENS OVER THE ENTIRE (NON-COASTAL) FORECAST AREA.
NORTHWEST WINDS WILL BE BETWEEN 15 TO 20 MPH WITH FREQUENT GUSTS
TO 25 MPH. GIVEN THE WELL CURED FUELS ACROSS THE REGION THIS WILL
BE THE FIRST TIME WE HAVE HAD THESE INGREDIENTS OF AVAILABLE
FUEL/STRONG WINDS/LOW RH COME TOGETHER IN NEARLY TWO YEARS. A RED
FLAG WARNING IS IN EFFECT FROM THIS MORNING THROUGH 7 PM TONIGHT.
44

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      58  34  61  40  68 /   0   0   0   0   0
HOUSTON (IAH)              60  36  61  41  68 /   0   0   0   0   0
GALVESTON (GLS)            60  42  58  48  63 /   0   0   0   0   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...     WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
     ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
     COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
     HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
     MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
     WALLER...WASHINGTON...WHARTON.

GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
     FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.

     SMALL CRAFT SHOULD EXERCISE CAUTION FROM 6 PM CST THIS EVENING
     THROUGH THIS EVENING FOR THE FOLLOWING ZONES: GALVESTON
     BAY...MATAGORDA BAY.

     SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE
     FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
     CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
     MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
     TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
     FREEPORT OUT 20 NM.

&&

$$

DISCUSSION...43


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