Scientific Forecast Discussion

      
000
FXUS64 KHGX 231147
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
547 AM CST SUN NOV 23 2008

.UPDATE...
VFR CEILINGS WILL LOWER TO MVFR OVER MOST SITES THIS MORNING...
THE EXCEPTION TOWARD THE COAST. RADAR AND REPORTS INDICATE
SPRINKLES WERE OCCURRING AND WILL GO WITH VICINITY SHOWERS.
CEILINGS WILL LOWER AS A WARM FRONT MOVES NORTHWARD ACROSS THE
AREA DURING THE AFTERNOON AND EVENING. THE EXCEPTION FOR MVFR
CEILINGS THIS EVENING WILL BE AT KGLS AND KLBX TOWARD AND ALONG
THE COAST. IFR CONDITIONS ARE POSSIBLE AFTER 06Z TONIGHT WELL
INLAND. 

40

&&

.PREV DISCUSSION... /ISSUED 329 AM CST SUN NOV 23 2008/ 

DISCUSSION...
WARM AIR ADVECTION IS UNDERWAY AND A SMATTERING OF SHOWERS HAS
BEGUN TO DEVELOP. GFS PW VALUES LOOK A LITTLE HIGH WHEN COMPARED
TO GPS VALUES AND THE NAM SEEMS MORE REFLECTIVE OF CURRENT
CONDITIONS. THE NAM...CAN AND ECMWF CONTINUE TO TREND BEST RAIN
CHANCES OVER THE WESTERN HALF OF THE CWA. THE GFS IS THE OUTLIER
WITH HEAVIER RAINFALL TOTALS OVER THE ENTIRE CWA. WILL GO WITH THE
CONSENSUS WHICH FAVORS THE DRIER SOLUTION TODAY. SCATTERED SHOWERS
WILL CONTINUE OVERNIGHT AS WAA PERSISTS. A COLD FRONT WILL CROSS
THE REGION ON MONDAY AFTERNOON. AGAIN...THE GFS IS THE MOST
AGGRESSIVE WITH RAIN CHANCES ALONG THE FRONT. HAVE GONE WITH A
BLEND OF MODEL SOLUTIONS...LEANING TOWARD THE ECMWF. STRONG
DOWNGLIDE ON MON NITE AND TUES WILL YIELD CLEARING SKIES AND WEAK
HIGH PRESSURE BUILDING INTO TEXAS WILL BRING COOLER TEMPERATURES.
MOISTURE LEVELS BEGIN TO INCREASE ON WEDNESDAY AND THERE SHOULD BE
AN INCREASE IN MID/HIGH LEVEL CLOUDS. MOISTURE IS DEEP ENOUGH ON
THURSDAY TO GET SCATTERED SHOWERS. AN UPPER LEVEL TROUGH WILL PUSH
EAST ACROSS THE SOUTHERN PLAINS THURSDAY NIGHT AND FRIDAY. THE
TROUGH IS NOT AS DEEP AS FORECAST YESTERDAY AND IS NEUTRAL OR
SLIGHTLY POSITIVELY TILTED. WILL TEMPER ENTHUSIASM A BIT WITH
REGARD TO RAIN CHANCES THU/THU NITE. A COLD FRONT WILL CROSS THE
REGION LATE FRIDAY OR FRIDAY NIGHT. THE ECMWF IS SLOWER WITH FRONT
AND HAS THE FRONT CROSSING THE AREA EARLY SATURDAY. THE CANADIAN
AND GFS ARE IN GOOD AGREEMENT WITH THE FRONT ON FRIDAY. NOT SURE
WHICH MODEL HAS THE BEST HANDLE ON THINGS AS RUN TO RUN
CONSISTENCY HAS BEEN RATHER POOR SO WILL CARRY POPS INTO SATURDAY
MORNING AND FINE TUNE AS THE EVENT GETS CLOSER.

MARINE...
CONFIDENCE IN THE MODEL SOLUTION IS MODERATE AT BEST. THE NAM AND 
GFS BOTH DIFFER IN WHEN THE COLD FRONT WILL PUSH OFF THE COAST ON 
MONDAY. KEPT THE CURRENT FORECAST BUT THINK THAT THE NAM MAY PAN OUT 
IN THE LONG RUN GIVEN ITS BETTER HANDLING OF THE QPF AND MOISTURE 
OVER THE INLAND AREAS. OTHERWISE...SCEC CONDITIONS MAY WELL DEVELOP 
TONIGHT AND EARLY MONDAY AHEAD OF THE PREFRONTAL TROUGH. THE 
GRADIENT WILL RELAX AFTER SUNRISE MONDAY. THE AIRMASS BEHIND THE 
FRONT APPEARS TO BE MODIFIED ENOUGH TO NOT HAVE A LARGE CONTRAST 
BETWEEN THE WATER AND AIR TEMPERATURE...AND CONSEQUENTLY SCA 
CONDITIONS DO NOT LOOK TO DEVELOP.

THE EXTENDED PORTION OF THE FORECAST IS EVEN MORE UP IN THE AIR 
GIVEN THE DIFFERENCES IN THE MODELS. FOR NOW THE WINDS WILL RELAX 
TUESDAY AND NOT INCREASE AGAIN UNTIL THURSDAY.

40

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      69  61  72  44  70 /  30  30  30  10  10 
HOUSTON (IAH)              70  64  74  46  69 /  30  30  50  10  10 
GALVESTON (GLS)            70  68  74  58  69 /  30  30  50  10  10 

&&

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

$$

DISCUSSION...43
AVIATION/MARINE...40