Red Flag Warning 3, NWS Guam

AREA FORECAST DISCUSSION...RESENT
NATIONAL WEATHER SERVICE TIYAN GU
753 AM CHST SAT FEB 21 2015

RETRANSMITTED TO PLACE ON THE WEB

.SYNOPSIS...
PGUA WSR-88D SHOWS ALMOST NO SHOWERS WITHIN THE MARIANAS WATERS.
THE VAD WIND PROFILE REVEALS NORTHEAST WINDS OF 8 TO 18 KNOTS
THROUGH THE LOWEST 5 THOUSAND FEET OF THE AIR.

&&

.DISCUSSION...
SIGNIFICANT RAINFALL FAILED TO MATERIALIZE YESTERDAY AS THE SHEAR
LINE MOVED OVER THE MARIANAS...AT LEAST AT THE AIRPORT WHICH IS
THE OFFICIAL TOTAL. AS WINDS PICK UP... THIS WILL MAKE FIRE
WEATHER ALL THE MORE THE MAIN FORECAST PROBLEM THE NEXT FEW DAYS.
DEWPOINTS WERE GETTING TO BE A FEW DEGREES TOO HIGH SO WENT AHEAD
AND REFRESHED THEM FROM THE GFS40. THIS WAS STILL TOO HIGH SO
APPLIED A DELTA ACROSS THE ENTIRE GFS40 RUN. THEY ARE NOW ROUGHLY
IN LINE WITH OBS AND STILL SHOW THE SLOW INCREASE THAT THE MODEL
HAD. INHERITED GRIDS WERE EXTREMELY DRY AND FOR NOW SAW NO REASON
TO CHANGE THAT. THE ECMWF-HIRES MAINTAINS THE DRY STANCE IT HAS
BEEN PUSHING AND THE GFS40 IS NOW SUBSTANTIALLY LESS GENEROUS WITH
RAINFALL ALSO.

&&

.MARINE...
LARGE NORTH SWELL FROM A STORM THAT RECENTLY MOVED OFF JAPAN WILL
COMBINE WITH WIND WAVES THROUGH MONDAY OR TUESDAY. TOGETHER THEY
ARE JUST ENOUGH TO REQUIRE HIGH SURF AND SMALL CRAFT ADVISORIES.
THE ADVISORIES ARE EXPECTED TO PEAK SUNDAY THROUGH MONDAY THEN
SUBSIDE ON TUESDAY.

&&

.FIRE WEATHER...
EXTREMELY DRY WEATHER RECENTLY HAS COMBINED WITH AFTERNOON
RELATIVE HUMIDITIES IN THE 40S TO FURTHER DRY OUT VEGETATION AND
FUELS. WINDS WILL PICK UP TODAY...GFS75 AND ECMWF-HIRES SHOW
WINDS MEETING CRITERIA TODAY SO AM UPGRADING THE WATCH TO A
WARNING. GFS40 SHOWED LOWER WINDS OVER GUAM BUT THIS COULD BE AN
ARTIFACT OF THE AFFECT OF TOPOGRAPHY IN THE MODEL ITSELF SO
INCREASED WINDS SLIGHTLY TO COUNTERACT THIS EFFECT.

&&

.CLIMATE...
RAINFALL FOR FEBRUARY SO FAR IS AT AN IMPRESSIVE 1.8 PERCENT OF
NORMAL. ALSO...WE ARE NOW AT 11 DAYS WITH NO MEASURABLE RAIN. THIS
HAS ONLY HAPPENED 8 OTHER TIMES IN THE LAST 58 YEARS. AND...IF IT
KEEPS UP MUCH LONGER...WE WILL BE IN A GOOD POSITION TO CHALLENGE
THE ALL TIME RECORD MINIMUM FEBRUARY RAINFALL OF 0.31 INCHES SET
IN 1960.

&&

.EASTERN MICRONESIA...
VERY DRY CONDITIONS JUST UPSTREAM OF MAJURO WILL MOVE OVER THE
MARSHALL ISLANDS TODAY ALLOWING FOR FOR A CLEARING TREND TO BEGIN.
SHOWERS WILL BE LIMITED TONIGHT AND SUNDAY FOR MAJURO AND WILL
INCREASE MARGINALLY MONDAY AS A WEAK DISTURBANCE PASSES OVER THE
REGION. LATEST STREAM LINE ANALYSIS SHOWS A SURFACE TROUGH OVER
THE MARSHALL ISLANDS. THE TROUGH WILL MOVE TOWARD KOSRAE TODAY
BRINGING INCREASED CLOUD COVER LATER TODAY THROUGH SUNDAY. GFS
MODEL IS A BIT AGGRESSIVE IN GIVING KOSRAE SCATTERED SHOWERS
TONIGHT AND SATURDAY SO MAINTAINED ISOLATED COVERAGE DURING THIS
TIME. OTHERWISE...A MAINLY DRY TRADE-WIND PATTERN WILL PREVAIL
FROM LATE SUNDAY THROUGH THE MIDDLE OF NEXT WEEK. DRY CONDITIONS
WILL CONTINUE FOR POHNPEI THROUGH AT LEAST SUNDAY NIGHT. A SHEAR
LINE IS PROGGED TO APPROACH POHNPEI WATERS MONDAY BUT SCATTERED
SHOWERS SHOULD STAY JUST TO THE NORTH.

RESIDUAL LONG-PERIOD NORTH SWELL WILL MAINTAIN THE POTENTIAL FOR
MINOR INUNDATION AT MAJURO ATOLL THROUGH THIS AFTERNOON. INUNDATION
THREAT SHOULD BE GREATLY DIMINISHED BY THIS EVENING AS SWELL
CONTINUES TO STEADILY SUBSIDE.

&&

.WESTERN MICRONESIA...
DRIER CONDITIONS ARE BEGINNING TO FILTER INTO CHUUK WATERS FROM
THE EAST AS A BROAD SURFACE TROUGH PROGRESSES TOWARDS YAP STATE.
THE SHEAR LINE THAT IS PROGGED TO STALL TO THE NORTH OF POHNPEI
MONDAY MAY HAVE A GREATER IMPACT AT CHUUK WITH SCATTERED SHOWERS
MORE OF A POSSIBILITY ESPECIALLY TUESDAY. A DRY PATTERN WILL
CONTINUE AT YAP AND PALAU BEFORE THE SURFACE TROUGH TO THE EAST
BEGINS TO AFFECT THESE LOCATIONS SUNDAY. MODELS HAVE BEEN FAIRLY
CONSISTENT IN BRINGING SCATTERED SHOWERS AND SOME THUNDERSTORMS TO
YAP SUNDAY AND SUNDAY NIGHT AND SUNDAY NIGHT AND MONDAY TO KOROR.
ACTIVE WEATHER SHOULD MOVE NORTH OF KOROR BY TUESDAY BUT COULD
REMAIN OVER YAP POSSIBLY INTO TUESDAY.

SEAS WILL GRADUALLY BUILD ACROSS YAP STATE AND PALAU OVER THE NEXT
COUPLE OF DAYS IN RESPONSE TO STRONGER TRADE WINDS TO THE NORTHEAST.
THIS MAY BRING SURF BACK UP TO ADVISORY LEVELS SUNDAY NIGHT ON YAP.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...RED FLAG WARNING FROM 10 AM THIS MORNING TO 6 PM CHST TUESDAY
     FOR GUZ001.

     SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 PM CHST
     TUESDAY FOR GUZ001>004.

     HIGH SURF ADVISORY FROM 10 AM THIS MORNING TO 6 PM CHST TUESDAY
     FOR GUZ001>004.

MARIANAS WATERS...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO
     6 PM CHST TUESDAY FOR PMZ151>154.

&&

STANKO/WILLIAMS