FXUS64 KEWX 090540
AFDEWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1140 PM CST TUE DEC 8 2009
.AVIATION...
WIDESPREAD LIFR/VLIFR CIGS/FOG ACROSS S CENTRAL TX AHEAD OF A COLD
FRONT MOVING SWD INTO CENTRAL TX. THE COLD FRONT WILL MOVE THRU
THE HILL COUNTRY AND S CENTRAL TX BETWEEN 09Z AND 14Z WITH A WEAK
DRY LINE PRECEDING THE FRONT. CONDITIONS WILL IMPROVE RAPIDLY
BEHIND THE COLD FRONT AS THE DRIER AIR DISPERSES THE FOG. VFR
CONDITIONS WILL PREVAIL DURING THE DAY WEDNESDAY AND WEDNESDAY
EVENING AS A DRY RIDGE OF HIGH PRESSURE BUILDS INTO THE AREA.
VARIABLE WINDS NW WINDS OF 5 AHEAD OF THE FRONT...WITH WINDS
SHIFTING TO N-NELY AT 15-20 KNOTS AND GUSTY BEHIND THE FRONT.
&&
.PREV DISCUSSION... /ISSUED 1106 PM CST TUE DEC 8 2009/
UPDATE...
EXTEND FOG TO THE WEST.
DISCUSSION...
FOG HAS SPREAD FARTHER WEST INTO DEL RIO. UPDATED TO ADD PATCHY
FOG TO WESTERN COUNTIES. DON'T EXPECT IT TO BECOME DENSE OUT THERE.
PREV DISCUSSION... /ISSUED 945 PM CST TUE DEC 8 2009/
UPDATE...
DENSE FOG ADVISORY ISSUED.
DISCUSSION...
FOG HAS GOTTEN DENSE IN SPOTS ESPECIALLY IN UVALDE AND MEDINA
COUNTIES. HAVE ISSUED A DENSE FOG ADVISORY FOR THE SOUTHERN AND
EASTERN COUNTIES UNTIL 4 AM. EXPECT DRIER AIR TO ADVECT IN FROM THE
NORTH WHICH SHOULD HELP DISSIPATE FOG BY THEN. FOG WILL DISSIPATE
FROM NORTHWEST TO SOUTHEAST.
PREV DISCUSSION... /ISSUED 813 PM CST TUE DEC 8 2009/
UPDATE...
FOG STARTING TO FORM.
DISCUSSION...
FOG IS FORMING ACROSS THE SOUTHERN AND EASTERN PART OF THE CWA.
EXPECT THIS TO LAST THROUGH THE NIGHT AND EXPAND A BIT FARTHER
WESTWARD. HAVE UPDATED TO BRING FOG INTO THE FORECAST EARLIER THAN
PREVIOUSLY ANTICIPATED.
PREV DISCUSSION... /ISSUED 608 PM CST TUE DEC 8 2009/
AVIATION...
THE CLEARING LINE STALLED NEAR A KSAT-KHYI-KAUS LINE AT 23Z AND
WILL NOT MOVE MUCH FURTHER EAST. IFR-MVFR CIGS WILL PREVAIL
GENERALLY EAST OF I35 AND LOWER WITH TIME ALONG WITH FOG
DEVELOPING AS A COLD IN NORTH TX CONTINUES SOUTHWARD INTO THE
HILL COUNTRY AFTER MIDNIGHT. AREAS OF IFR/LIFR VSBYS ARE LIKELY
AHEAD OF THE COLD FRONT BEFORE SUNRISE...ESPECIALLY ALONG AND EAST
OF I35. THE COLD FRONT WILL DISSIPATE THE FOG AND LOW CIGS FROM
THE NORTH AND WEST BY SUNRISE BECOMING VFR ALL AREAS BY BETWEEN
14Z AND 16Z. NLY WINDS OF 10-20 KNOTS WILL BLOW BEHIND THE COLD
FRONT ON WEDNESDAY WITH GUSTS OF 20-25 KNOTS.
PREV DISCUSSION... /ISSUED 326 PM CST TUE DEC 8 2009/
DISCUSSION...
A STRONG STORM SYSTEM OVER THE CENTRAL US BROUGHT STRONG WESTERLY
WINDS INTO WEST TX TO DISRUPT THE FRONTAL INVERSION AND CLEAR AWAY
MOST OF THE CLOUD COVER OVER SOUTH CENTRAL TX LATE THIS AFTERNOON.
AFTERNOON WINDS ARE MUCH LIGHTER IN THIS AREA THAN THEY HAVE BEEN
OVER WEST CENTRAL TX. TIME IS RUNNING OUT FOR THE LOW CLOUDS TO
CLEAR EAST OF THE ESCARPMENT AND THE CLOUDS AND FOG ARE LIKELY TO
DEVELOP AGAIN. A COLD FRONT MOVES INTO THE AREA AROUND DAYBREAK
WEDNESDAY WHICH SHOULD FINISH THE JOB CLEARING THE LOW CLOUDS AND
MOISTURE. THE FRONT IS OF AVERAGE STRENGTH IN TERMS OF PRESSURE
AND WIND BUT IS CARRYING AIR THAT WILL BE MODIFIED BY ABUNDANT
SNOW AND ICE COVER TO THE NORTH.
THE ZONAL PATTERN CONTINUES ALOFT SO RELATIVELY MILD DAY
INFLUENCED BY SUNSHINE TOMORROW SHOULD BE FOLLOWED BY A FAIRLY
COLD NIGHT. THEN THE ZONAL PATTERN BRINGS THE RETURN OF CLOUDS TO
SUPPORT PERSISTENT COOL CONDITIONS THROUGH THE WEEKEND AS
OVERRUNNING PRECIP RETURNS BY FRIDAY. A SHORTWAVE LOCATED NEAR 20N
135W SHOULD TRACK INTO THE AREA BY THIS TIME WITH GOOD RAIN
CHANCES FRIDAY FOCUSED HIGHEST TOWARD THE COAST. THIS IMPULSE IS
EXPECTED TO BE FAIRLY WEAK WITH ONLY BRIEF STABILITY AND CLOUDS
QUICK TO RETURN OVER THE WEEKEND. THE NEXT UPSTREAM DISTURBANCE IN
THIS PROGRESSIVE PATTERN IS AGREED BY MOST MODELS TO BE STRONGER
AS IT REACHES THE AREA MONDAY INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 41 54 33 53 43 / - 0 - 10 20
AUSTIN BERGSTROM INTL AIRPORT 42 53 28 53 42 / - 0 - 10 20
NEW BRAUNFELS MUNI AIRPORT 43 58 32 55 45 / - 0 - 10 20
BURNET MUNI AIRPORT 37 49 29 51 41 / - 0 - 10 20
DEL RIO INTL AIRPORT 45 66 42 58 47 / 0 0 - 10 10
GEORGETOWN MUNI AIRPORT 39 52 30 51 42 / - 0 - 10 20
HONDO MUNI AIRPORT 42 62 33 56 45 / - 0 - 10 20
SAN MARCOS MUNI AIRPORT 42 54 31 54 43 / - 0 - 10 20
LA GRANGE - FAYETTE REGIONAL 44 55 32 55 46 / 10 - - 10 20
SAN ANTONIO INTL AIRPORT 42 60 34 55 47 / - 0 - 10 20
STINSON MUNI AIRPORT 43 61 34 56 47 / - 0 - 10 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 4 AM CST WEDNESDAY FOR THE FOLLOWING
COUNTIES: ATASCOSA...BASTROP...BEXAR...CALDWELL...COMAL...DE WITT...
DIMMIT...FAYETTE...FRIO...GONZALES...GUADALUPE...HAYS...KARNES...
LAVACA...LEE...MEDINA...TRAVIS...UVALDE...WILLIAMSON...WILSON...
ZAVALA.
&&
$$
05/01
