Small Craft Advisory 848, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
100 PM ADT FRI OCT 12 2007

.MODEL DISCUSSION...
MODELS STILL STRUGGLING EVEN IN THE VERY SHORT TERM. THE LOW IN THE
NORTHERN GULF IS HANDLED DIFFERENTLY BY THE NAM AND GFS...POSSIBLY
DUE TO RESOLUTION DIFFERENCES...MORE ON THIS BELOW. ON THE WEEKEND A
LOW TRAVERSING THE BERING SEA HAS BEEN (AND STILL IS) GIVING THE
MODELS A CASE OF THE WAFFLES.

.ANALYSIS AND UPPER LEVELS...
STEERING LOW OVER THE BERING STRAIT WITH A SYSTEM IN THE ARCTIC
PORTION OF THE JET OVER THE ALEUTIANS...AND A SYSTEM IN THE
SUB-TROPICAL PORTION BOMBING OUT IN THE NORTHERN GULF. THE BULK OF
THE MOISTURE IS RIDING THE SUB-TROPICAL JET INTO SOUTHEAST ALASKA
WITH AN OFFSHOOT PULLING INTO SOUTHEAST ALASKA WITH THE WARM FRONT.

.SHORT TERM FORECAST...
THE GULF LOW IS PROVIDING AN INTERESTING FORECAST CHALLENGE. THE GFS
AND ECMWF HAVE ONE LARGE LOW CENTER THAT WILL TIGHTEN UP AND PUSH
WEST OF MIDDLETON ISLAND TONIGHT. THE NAM HAS TWO LOWS. ONE OFF THE
EAST COAST OF KODIAK AND THE OTHER EAST OF IT AT ABOUT 140 DEGREES
WEST LONGITUDE. IT STRENGTHENS THE FURTHER EAST LOW AND BRINGS IT
NORTHWESTWARD OVER MIDDLETON ISLAND TONIGHT AND DISSIPATES THE LOW
NEAR KODIAK. THE NAM SOLUTION WOULD CONTINUE STORM CONDITIONS IN THE
NORTHERN GULF UNTIL AROUND MIDNIGHT AND THE GFS/ECMWF SOLUTION ENDS
THE STORMS SIX HOURS EARLIER. IT IS POSSIBLE THE NAM IS ON TO
SOMETHING HERE DUE TO ITS HIGHER RESOLUTION. ON THE OTHER SIDE OF
THE COINT...THE NAM HAS NOT HAD A VERY GOOD TRACK RECORD LATELY.
THIS SYSTEM WILL BE WATCHED CLOSELY TO SEE WHICH MODEL TO FOLLOW.

BOTH SOLUTIONS INDICATE THAT THE LOW WILL MOVE INLAND LATE SATURDAY.
COLD ADVECTION BEHIND THE LOW GIVES A DECENT CHANCE OF SNOW FOR THE
ANCHORAGE BOWL LATE SATURDAY THROUGH SUNDAY. AMOUNTS UP TO A COUPLE
OF INCHES WILL BE MENTIONED IN THE ZONES.

THE BERING SEA LOW FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT HAS BEEN
GIVING THE MODELS FITS FOR THE LAST FEW DAYS. HOWEVER...THERE IS A
RAY OF HOPE WITH THE 12Z MODEL RUNS. THE GFS AND ECMWF AGREE NICELY
ON LOCATION AND STRENGTH THROUGH SUNDAY NIGHT. STILL UNCERTAINTY AS
THE NAM AND UKMET ARE NOT SO AGREEABLE.

.LONG TERM FORECAST...
WITH MODEL STRUGGLES IN THE EARLIER PERIODS...CONFIDENCE IN THE
FORECAST FOR NEXT WEEK IS NOT VERY HIGH. PERSISTENCE AND CLIMATOLOGY
ARE GOOD BETS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM WARNING 120.
         GALE WARNING 125 170 172 175 176.
FIRE WEATHER...NONE.

LUDWIG OCT 07