000
FXUS64 KHGX 192053
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
353 PM CDT SUN MAY 19 2013

.DISCUSSION...
SE TX WAS UNDER A SOUTHWESTERLY FLOW ALOFT AS A BROAD UPPER LEVEL
LOW CONTINUED TO DEVELOP OVER THE PLAINS AND ROCKIES. THE LOW WILL
DEEPEN AS IT MOVES INTO THE UPPER MISSISSIPPI VALLEY OVER THE NEXT
FEW DAYS. AS IT DOES...THE MODELS PUSH AN UPPER LEVEL TROUGH
ACROSS NORTHERN AND CENTRAL TEXAS TUESDAY NIGHT AND WEDNESDAY. AS
THE TROUGH MOVES OVERHEAD...CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL INCREASE ACROSS SE TX. A DRIER PERIOD IS THEN EXPECTED AS AN
UPPER LEVEL HIGH PRESSURE RIDGE DEVELOPS OVER TEXAS AND THE
NORTHWESTERN GULF OF MEXICO.

IN THE SHORT TERM...ANOTHER BREEZY DAY IS IN STORE FOR SE TX ON
MONDAY AS A TIGHT SURFACE PRESSURE GRADIENT WILL PERSIST OVER THE
AREA. THE MODEL FORECAST SOUNDINGS CONTINUE TO SHOW A DECENT CAP
IN PLACE. EVEN THOUGH SOME OF THE MODELS WERE BRINGING IN A BIT OF
QPF...FELT THAT A MORE LIKELY SCENARIO WILL BE A REPEAT OF THE
LAST TWO DAYS WITH THE EARLY MORNING CLOUD COVER DISSIPATING
DURING THE MID AND LATE MORNING. CONTINUED THE SLIGHT CHANCE FOR
RAIN ON TUESDAY.

FOR TUESDAY NIGHT AND WEDNESDAY...THE GFS FORECAST THE TROUGH TO
BE FURTHER TO THE NORTH THAN THE GFS. THE GFS AND NAM BUFR MODEL
FORECAST SOUNDINGS BOTH ERODE THE CAP TUESDAY NIGHT AND WEDNESDAY
AS THE SHORTWAVE TROUGH MOVES ACROSS THE AREA. THE MODEL SOUNDINGS
ARE ALSO FORECASTING SLIGHTLY DRIER CONDITIONS THAN THEY WERE
YESTERDAY. PW/S ARE NOW FORECASTED TO REACH BETWEEN 1.5 AND 1.7
INCHES. FELT THAT THE BETTER CHANCES FOR STRONG STORMS WILL BE
MORE OVER NORTH TEXAS...BUT STILL CANNOT RULE OUT AN ISOLATED
STRONG OR SEVERE STORM OVER THE NORTHERN HALF OF THE FORECAST
AREA. BECAUSE OF THE SLIGHTLY CONFLICTING STRENGTHS OF THE UPPER
LEVEL TROUGH BETWEEN THE GFS AND ECMWF...DECIDED TO KEEP THE RAIN
CHANCES THE SAME TUESDAY THROUGH WEDNESDAY EVENING.

FOR THE LAST PART OF THE FORECAST...THE UPPER LEVEL RIDGE WILL
HELP WARM UP THE AIR MASS BY THE END OF THE WEEK AND THROUGH THE
WEEKEND. FELT THAT THE PREVIOUS FORECAST OF TEMPERATURES ABOVE THE
GUIDANCE WAS ON TRACK.

40

&&

.MARINE...
MODERATE ONSHORE FLOW WILL CONTINUE THROUGH AT LEAST MONDAY AND
WILL CARRY A SMALL CRAFT SHOULD EXERCISE CAUTION FOR ALL THE
WATERS. WIND SPEEDS WILL GRADUALLY DROP OFF TOWARD MID WEEK.

46

&&

.PREV DISCUSSION... /ISSUED 1237 PM CDT SUN MAY 19 2013/

DISCUSSION...
UPDATED AVIATION DISCUSSION.

AVIATION...
MAINLY CLEAR CONDITIONS AT THE TAF SITES CURRENTLY WITH A GUSTY
SOUTH WIND. THERE ARE A FEW CLOUDS COMING IN OFF THE GULF...NOT
SURE CLOUD HEIGHTS ON THOSE...BUT WILL KNOW SHORTLY AS THEY COME
ASHORE. LOW CEILINGS FROM LAST NIGHT...WITH GENERALLY 1000 TO
1500 FOOT DECK...MIXED OUT BETWEEN 13 UTC AND 15 UTC...OR 08 TO 10
CDT...THIS MORNING. TONIGHT...WITH SIMILAR FLOW PATTERN AND
MOISTURE PROFILES...EXPECT SIMILAR SCENARIO WITH THE FORMATION OF
A STRATUS DECK AFTER SUNSET. IN ANYTHING...LOW DECK COULD DEVELOP
AN HOUR OR TWO EARLIER...GIVEN LACK OF CIRRUS THAT WE HAD LAST
NIGHT...AND HAVE INDICATED THAT IN THE TAF. MONDAY...SHOULD SEE
LOWER DECK MIX OUT AGAIN...ABOUT THE SAME TIMING. 46

PREV DISCUSSION... /ISSUED 1041 AM CDT SUN MAY 19 2013/

DISCUSSION...
THE 12Z SOUNDINGS SHOW A GOOD CAP OVERHEAD OF SE TX THIS MORNING.
LOW CLOUDS TRAPPED UNDER THE CAP WERE DISSIPATING AT 10 AM AND
EXPECT MOSTLY SUNNY CONDITIONS BY MIDDAY...ALTHOUGH SOME
CLOUDINESS MAY LINGER AT THE IMMEDIATE COAST INTO THE EARLY
AFTERNOON PERIOD. THE SURFACE TO 700 MB RIDGE WAS KEEPING A FAIRLY
DRY AIR MASS IN PLACE OVER THE FORECAST AREA AS WELL. THE MODEL
FORECAST SOUNDINGS DO ERODE MUCH OF THE CAP...BUT THERE WILL STILL
BE ENOUGH OF AN INVERSION ABOVE 850 MB TO LIKELY KEEP CONVECTION
FROM DEVELOPING. DO LIKE THE CURRENT FORECAST WHICH GOES ABOVE THE
GUIDANCE FOR THE AFTERNOON TEMPERATURES. THE SMOKE AND HAZE
APPEARS TO BE LESS THAN YESTERDAY AND WOULD EXPECT THIS GIVEN THAT
THE DEEP LAYER RIDGE HAS NOT MOVED INTO THE NORTH CENTRAL AND
EASTERN GULF OF MEXICO.

THE CURRENT FORECAST LOOKS ON TRACK AND NO CHANGES ARE PLANNED AT
THIS TIME.

40

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      73  92  73  91  73 /  10  10  10  20  40
HOUSTON (IAH)              75  91  74  90  73 /  10  10  10  20  30
GALVESTON (GLS)            75  79  75  80  73 /  10  10  10  10  20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH LATE TONIGHT FOR THE
     FOLLOWING ZONES: GALVESTON BAY...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...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
     WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.

&&

$$

DISCUSSION...40
AVIATION/MARINE...46