000
FXUS64 KHGX 172330 AAA
AFDHGX
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
630 PM CDT SAT MAY 17 2008
.AVIATION...
UPPER LOW IS FORECAST TO MOVE SLOWLY EAST TOWARDS THE AREA AND
GRADUALLY WEAKEN TONIGHT AND SUNDAY MORNING. MID LEVEL CLOUDINESS
WILL PERSIST THROUGH 15Z SUNDAY FOLLOWED BY CLEARING SKIES AS THE
TROUGH SHIFTS EAST OF THE TERMINALS. HAVE MAINTAINED -RA IN THE TAFS
THROUGH 04Z...HOWEVER PRECIP SHOULD REMAIN TOO LIGHT TO IMPACT
FLYING CONDITIONS. LIGHT AND VARIABLE WINDS EXPECTED TONIGHT...
FOLLOWED BY A WEST/SOUTHWEST WIND AROUND 10 KTS SUNDAY. PATCHY
GROUND FOG WILL AFFECT RURAL TERMINALS 08-14Z SUNDAY.
35
&&
.DISCUSSION...
A WEAK SHORTWAVE TROUGH CONTINUES TO PUSH THROUGH SE TX TODAY
KEEPING THICK CLOUD COVER IN PLACE. SOME AREAS HAVE SEEN SPOTS OF
RAIN BUT DRIER AIR IN THE BOUNDARY LAYER HAS ALLOWED FOR VIRGA
INSTEAD. THE BOUNDARY LAYER HAS MOISTENED JUST ENOUGH FOR A FEW
SPOTS OF RAIN WHERE LIFT IS STRONGEST. BROAD UPPER LEVEL LOW
CONTINUES TO SPIN OVER W TX PER UPPER AIR ANALYSIS AND WATER
VAPOR IMAGERY. SHORT RANGE MODELS ARE CONSISTENT WITH BRINGING
THIS UPPER LOW ACROSS CENTRAL AND N TX THIS EVENING AND TONIGHT.
MEANWHILE A JET STREAK EMBEDDED IN A MUCH BROADER SYNOPTIC TROUGH
OVER THE DESERT SW SHOULD DEVELOP ANOTHER CUT OFF LOW DURING THE
DAY SUNDAY INTO MONDAY. THIS LEAVES MAINLY NW FLOW ALOFT OVER SE
TX INTO MONDAY. THE CUTOFF REMAINS OVER THE BAJA AND NW MEX
THROUGH THE MIDDLE OF THE WEEK.
THE FORECAST FOR THE EARLY PART OF THE COMING WEEK REMAINS
RELATIVELY UNCHANGED. THE FORECAST DOES KEEP SOME SLIGHT RAIN
CHANCES FOR THE CURRENT ACTIVITY BUT A DRY FORECAST IS EXPECTED
THROUGH THE MIDDLE OF THE WEEK. SUMMER TIME HIGH TEMPERATURES
LOOK TO TAKE OVER MAINLY MONDAY AND TUESDAY. SW BOUNDARY LAYER
FLOW UP TO 850MB WILL DOMINATE MONDAY AND TUESDAY. THIS SHOULD
ALLOW FOR 850MB TEMPS AROUND 20C AND SUPPORT HIGH TEMPS IN THE
LOW TO MID 90S BOTH DAYS. WEDNESDAY MAY NOT BE QUITE AS WARM BUT
LOW 90S FOR HIGH TEMPS WILL CERTAINLY BE POSSIBLE FOR SE TX. LOW
LEVEL FLOW BACKS WITH TIME GIVEN THE APPROACH OF THE CUTOFF LOW
FROM MEX. BOTH THE 12Z GFS AND ECMWF SHEAR THE LOW OUT WITH A
BROAD SHORTWAVE MOVING THROUGH THE AREA WED NIGHT INTO THU. THERE
REMAINS QUITE A BIT OF UNCERTAINTY IN THIS TIMING AS WELL AS THE
EXTENT OF ANY CONVECTION. MID LEVEL CAPPING WILL BE STRONG WITH
850MB TEMPS NEAR 20C STILL AND 700MB TEMPS NEAR 10-12C. GIVEN THE
CAP...WILL LEAVE POPS OUT OF THE FORECAST FOR NOW...BUT THIS
COULD CERTAINLY CHANGE IN THE NEXT COUPLE OF FORECAST CYCLES.
IN THE FAR EXTENDED RANGE...BOTH THE GFS AND ECWMF DEVELOP A
STRONG CUTOFF LOW OVER THE ROCKIES AND GREAT BASIN. THIS LOW
SINKS SOUTH THU INTO FRI ALLOWING FOR SW UPPER LEVEL FLOW. GULF
MOISTURE IS EXPECTED TO REALLY INCREASE DURING THIS TIME WHICH
WILL HELP WITH CONVECTIVE POSSIBILITIES. GIVEN A MORE SUMMER TIME
PATTERN...CONVECTION BECOMES MORE UNCERTAIN TO FORECAST. THROUGH
THE END OF THE WEEK THE UPPER LEVEL LOW BECOMES FULLY CUT OFF AND
MOVES THROUGH THE DESERT SW INTO MEX. THIS CERTAINLY SET UP A
PATTERN FOR MORE TYPICAL DIURNAL THUNDERSTORM ACTIVITY.
39/OVERPECK
&&
.MARINE...
NOT A WHOLE LOT OF CHANGES MADE TO THE FORECAST. STILL ANTICIPATE
LIGHT WINDS TONIGHT FOLLOWED BY STRENGTHENING SOUTHWEST WINDS ON
SUNDAY IN RESPONSE TO THE PASSAGE OF THE UPPER LOW/TROF. SOUTH WINDS
SHOULD COME BACK BY MONDAY IN THE WAKE OF THIS SYSTEM. THE ONSHORE
FLOW INCREASES AROUND MIDWEEK AND CONTINUES THROUGH THE END OF THE
WEEK AS PRESSURE LOWER TO OUR NORTHWEST. THIS PERSISTENT ONSHORE
FLOW AND A DEEPENING FETCH OFF THE GULF WILL PROBABLY BRING US TO
CAUTION/ADVISORY CONDITIONS BY MIDWEEK. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 61 88 63 93 70 / 10 0 0 0 0
HOUSTON (IAH) 61 89 67 92 73 / 10 0 0 0 0
GALVESTON (GLS) 69 84 73 85 78 / 10 0 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...42
