Small Craft Advisory 898, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM ADT THU OCT 25 2007

.MODEL DISCUSSION...NCEP/UKMET MODEL INITIALIZATIONS AND FORECAST
THROUGH 60-72 HOURS REASONABLE. CONSISTENCY PROBLEMS ARISE BEYOND 72
HOURS WITH LOW COMPLEX MOVING NEAR THE WESTERN ALEUTIANS SUN. THE GFS
MODEL TENDS TO DEVELOP THIS CENTER TAKING IT JUST SOUTH OF ADAK IN
THE 960S MON SUN MORNING. THIS IS A MAJOR SHIFT FROM THE PREVIOUS RUN
WHICH HAS A 990 MB MUCH FURTHER TO THE SE. GFS ENSEMBLE MEMBERS WOULD
NOT SUPPORT A CENTER ANYWHERE NEAR 965 MB. THE 12Z EC CARRIES A 968
MB CENTER NEAR 51N 178E SUN AFTERNOON. THINKING THAT LOW CENTER WILL
BE DEEPER THEN OLD GFS RUN BUT NOT AS DEEP AS CURRENT GFS/EC RUNS. SO
FOR NOW WILL LEAN TOWARD GFS POSITIONS BEYOND 72 HOURS...BUT RAISE
THE PRESSURE AND LOWER THE WIND MAGNITUDES.

.EAST...MAIN CONCERN WITH WIND. STRONG OCCLUDED FRONT EXTENDING
ACROSS SW ALASKA...KODIAK...TO A TRIPLE POINT IN THE SOUTHERN
OFFSHORE FORECAST ZONE...MOVES INLAND OVER SOUTHCENTRAL
ALASKA/NORTHERN GULF COAST EARLY FRI MORNING. STRONG PRESSURE
GRADIENTS AND RESULTANT WINDS ACROSS MUCH OF THE EASTERN FORECAST
AREA WILL DIMINISH SOME AFTER THE FRONT MOVES INLAND TONIGHT. WIND
WARNING CONDITIONS THROUGH ZONES 101 AND 125 SHOULD VERIFY THIS
AFTERNOON AND EVENING...BEFORE DIMINISHING OVERNIGHT. WARMING OVER
SOUTHCENTRAL TONIGHT MAY BE A LITTLE OVER DONE IN THE SUSITINA
VALLEY. TEMPS PROBABLY WILL HOLD BELOW FREEZING IN THE NORTHERN
VALLEY...SO WITH THE ONSET OF SW FLOW IN THE MID LEVELS SNOW AMOUNTS
MAY BE A CONCERN FOR TONIGHT. UNSTABLE CONDITIONS WILL PREVAIL OVER
MUCH OF THE EAST AS FRONTAL PASSAGE FRI MORNING SO LOOK FOR RAIN/SNOW
SHOWERS TO BE THE GENERAL RULE.

.WEST....THE ARCTIC FRONTAL BOUNDARY THIS AFTERNOON EXTENDS ACROSS SW
ALASKA FROM PAHP...PASM...TO ALONG THE TAYLOR MOUNTAINS THIS
AFTERNOON. EXPECT WILL SOME BOUNDARY TO MOVE A LITTLE FURTHER NORTH
TONIGHT. HOWEVER...THE COLD AIR WILL REMAIN TRAPPED IN THE KUSKOKWIM
VALLEY THROUGH TONIGHT. THAT SAID...MAY SEE POCKETS OF LIGHT FREEZING
RAIN THROUGH TONIGHT MIXED IN WITH SNOW. OVER BRISTOL SHOULD DROP
THROUGH LATE THIS AFTERNOON/EARLY EVENING AS OCCLUDED FRONT MOVES
NORTH AND EAST. LOW COMPLEX OVER THE EASTERN BERING SEA WILL CONTINUE
SHOWERS IN THE REGION THROUGH SAT. OLD LOW CENTER OVER THE WESTERN
ALEUTIANS WILL MOVE TO THE WESTERN AK PEN SAT MORNING. EXPECT
NORTHERLY GALES ON THE BACKSIDE OF THIS CENTER AS IT MOVES ACROSS THE
ALEUTIANS. CONFIDENCE LEVEL IS NOT VERY HIGH OVER THE ALEUTIANS/PEN
BEYOND SAT NIGHT AS DISCUSSED IN MODEL ANALYSIS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING ZONES 101 AND 111.
MARINE...STORM 120 GALES 130 132 172 175 176 185.

RMC OCT 07