FXUS64 KBRO 251501
AFDBRO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
859 AM CST FRI DEC 25 2009
.DISCUSSION...VIOLENT CLASH OF WARM AND COLD...MOIST AND DRY...NOW
IN FULL BATTLE OVER THE OH VLY/GREAT LAKES/NRN PLAINS. THIS IS THE
SECOND OF TWO SYSTEMS THIS DECEMBER THAT HAS CAUSED A GREAT DEAL
OF PROBLEMS FOR THE EASTERN SEABOARD AND NOW THE NRN
PLAINS...GREAT LAKES AND NRN PORTIONS OF THE NEW ENGLAND STATES.
OUR REGION WILL EXPERIENCE HIGH CLOUDINESS AND MAX TEMPS TO NEAR
60 AS INSOLATION WILL NEED TO PULL AMS UP FM MRNG LOWS IN THE MID
30S NORTHERN VLY...LOW 40S ALONG THE RIO GRANDE RIVER.
ONLY COSMETIC CHANGES NEEDED TO RID FCST OF MRNG WORDING.
&&
.PREV DISCUSSION.../ISSUED 329 AM CST FRI DEC 25 2009/CLOUDINESS
BEGINNING TO STREAM OVER DEEP SOUTH TEXAS FROM MEXICO WITHIN A
SOUTHWEST-TO-NORTHEAST MID-LEVEL FLOW. CLOUDS SHOULD INCREASE
THROUGHOUT TODAY...WITH ISOLATED PRECIPITATION POSSIBLE AFTER
MIDNIGHT TONIGHT AS A SURFACE TROUGH OF LOW PRESSURE DEVELOPS
ALONG THE LOWER TEXAS COAST. AS A CLOSED LOW MORPHS FROM THE
TROUGH...PRECIPITATION SHOULD INCREASE IN COVERAGE SATURDAY...
WITH THE BEST OPPORTUNITY FOR RAINFALL OCCURRING OVER THE ADJACENT
COASTAL WATERS AND EASTERN AND CENTRAL PORTIONS OF THE BRO CWFA.
LOW QUICKLY MOVES NORTHEAST...ALLOWING RAINFALL TO BRIEFLY END
SATURDAY NIGHT BEFORE BRIEFLY RESUMING FOR EARLY SUNDAY DUE TO
WEAK OVERRUNNING SCENARIO. TRANQUIL WEATHER EXPECTED FOR MONDAY
WITH SURFACE HIGH PRESSURE IN CLOSE PROXIMITY TO THE RIO GRANDE
VALLEY...BUT FORMATION OF ANOTHER COASTAL TROUGH/CLOSED LOW
RESULTS IN A MORE INTENSE OVERRUNNING SITUATION FOR TUESDAY AND
WEDNESDAY. WEATHER IMPROVES FOR THURSDAY AS HIGH PRESSURE AND
DRIER AIR SETTLE INTO DEEP SOUTH TEXAS. IN THE MEANTIME...MERRY
CHRISTMAS...FELIZ NAVIDAD.
&&
.MARINE...AFTER QUITE A BLOW FROM CHRISTMAS EVE DAY INTO EARLY THIS
CHRISTMAS MORNING...WINDS AND SEAS ARE QUICKLY RAMPING DOWN AS HIGH
PRESSURE BRIEFLY SETTLES ACROSS THE AREA TODAY. BUOY 20 IS STILL
HANGING ON NEAR SMALL CRAFT WIND CONDITIONS AROUND 20 KNOTS WITH
SEAS SUBSIDING TO JUST ABOVE 7 FEET. SLIGHTLY HIGHER GUSTS CONTINUE
AT THE TEXAS A&M BUOY /42045/ ABOUT 40 NM EAST OF SPI...STILL 27
KNOTS LAST CHECK.
FOR THE MID MORNING UPDATE WILL LET THE NEARSHORE AND LAGUNA
ADVISORIES EXPIRE BUT HAVE EXTENDED THE 20-60NM LEGS UNTIL THE
AFTERNOON PACKAGE WHEN WINDS SHOULD BE 15 KNOTS WITH A FEW GUSTS AND
SEAS DOWN TO 5 OR 6 FEET.
NO OTHER CHANGES TO REST OF FORECAST AT THIS TIME. WIND FORECAST A
BIT TRICKY NEARSHORE LATER TONIGHT AND SATURDAY GIVEN PROXIMITY OF
DEVELOPING INVERTED TROUGH NEAR THE COAST...AND REINFORCING HIGH
PRESSURE ARRIVING SATURDAY NIGHT AND SUNDAY WILL PROBABLY TICK WINDS
BACK INTO ADVISORY /20 KNOT/ LAND AND BRING SEAS ABOVE 7 FEET ONCE
AGAIN.
&&
.AVIATION...GOOD FLYING DAY UNDERWAY WITH ONLY AN INCREASE AND
THICKENING OF CIRRUS AT OR ABOVE 25000 FEET AND LOW LEVEL WINDS
CONTINUING TO DECREASE QUICKLY. VFR CONDITIONS SHOULD CONTINUE THIS
EVENING AND OVERNIGHT...BUT LOWER DECKS WILL ARRIVE PERHAPS REACHING
MVFR NEAR THE COAST BY DAYBREAK SATURDAY. THEREAFTER...THINGS
PROGRESS DOWNHILL AS CEILINGS LOWER IN RESPONSE TO COASTAL TROUGH
AND SOME LIGHT RAIN AND/OR DRIZZLE WILL PROBABLY ARRIVE BEFORE 18Z
SATURDAY. MORE DETAILS ON THE 12-18Z DECEMBER 26TH FORECAST WITH THE
AFTERNOON UPDATE.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 62 49 64 52 / 0 10 50 10
BROWNSVILLE 65 50 63 49 / 0 10 50 10
HARLINGEN 62 47 63 49 / 0 10 50 10
MCALLEN 62 48 63 48 / 0 10 40 10
RIO GRANDE CITY 62 43 63 43 / 0 10 30 0
SOUTH PADRE ISLAND 63 48 65 51 / 0 10 60 10
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR GMZ170-
175.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 9 AM CST THIS MORNING FOR
GMZ130-132-135.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
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