Wind Advisory 51, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
1100 AM AKDT FRI JUL 18 2008

.SHORT RANGE...MAJOR UPR LOW MAIN CENTER IS OVER BETHEL THIS
MORNING WITH A SECOND CENTER DEVELOPING NEAR MIDDLETON ISL.
INTERESTINGLY THE COLDEST TEMP AT 500 HPA IS KODIAK -27C AS PER
THE 12Z RAOB. CERTAINLY THE ENERGY WILL BE FOCUSED IN THE EASTERN
LOW CENTER. MONDO JET 250 MB 12Z DUE WEST FROM ALMOST THE S TIP
OF KOREA TO AN EXIT JUST OFF SITKA. WITH THE COLD AIR ALF WE
AGREE WITH THE MID SHIFTS IDEA TO SELECT PROG WITH MOST
DEVELOPMENT IN THE UPR LEFT QUAD ERGO THE EASTERN GULF.

MOST INTENSE PROBLEM OF THE DAY IS NOT THE NEAR GALE WINDS IN
JULY BUT THE QPF AND HENCE HYDRO PROBLEMS. BY MIDDAY TODAY NEW
JET AXIS SW UP TO 100 KT OVR PAGS. THERE HAS BEEN A FAIRLY GOOD
CONNECTION TO THE TROPICS BACK IN THE WESTERN PACIFIC. AMOUNTS
FORECASTED ARE HIGHLY MODEL DEPENDENT. 12Z NAM-40 SELECTED AS THE
BEST DEPICTION FOR QPF AND DEVELOPING WAVE ON THE FRONT WHICH
WILL BE 997 MB JUST OFF CAPE SPENCER 12Z SAT. LOOKED AT THE 700
MB FLOW FOR THE STRAIGHT SHOT OF MOISTURE GOING UP LYNN CANAL TO
DUMP IN THE SKAGWAY-TAIYA RIVER AREA FOR PROBLEMS. WILL DECIDE
LATER IN THE SHIFT FOR HOW MUCH FLOODING. WET COOL AND SOMEWHAT
WINDY WEEKEND. COULD WE PLEASE HAVE A SUMMER?

.LONG RANGE...MAJOR RUN-TO-RUN MODEL VARIABILITY NOW BEING
EXHIBITED BY ECMWF AS WELL AS GFS. FORECAST CONFIDENCE ON TIMING
AND INTENSITY OF SURFACE PRESSURE AND WIND FIELDS LOW FOR THE
EXTENDED RANGE FORECAST PERIOD. STILL LOOKS LIKE A FAIRLY WET
WEEK BUT MODELS ARE NOW SUGGESTING A LONGER BREAK IN THE PRECIP
BEGINNING EARLY NEXT WEEK. FORECAST CONFIDENCE IN PRECIP FROM DAY
4 ONWARD NOW MODERATE.

ENSEMBLE MEANS FOR GFS...ECMWF...AND CANADIAN ALL TENDING TO WASH
OUT MAJOR FEATURES AND THIS IS ADDRESSED BY HPC. OPTED FOR A
BLEND OF UKMET...GFS AND CURRENT GRIDS AND SPECIFICALLY EXCLUDED
ECMWF TODAY DUE TO A 997MB BULLS EYE LOW IN THE EAST-CENTRAL GULF
ON 24/25 JULY THAT WAS NOT THERE YESTERDAY.

TROPICAL MOISTURE TAP WILL CONTINUE FROM THE END OF THE SHORT
RANGE PERIOD INTO EARLY NEXT WEEK. MOISTURE SOURCE FOR THE SECOND
HALF OF THE WEEK LOOKS MORE LIKE THE BERING SEA. A LARGE UPPER
LEVEL LOW OVER THE WESTERN INTERIOR WILL DRAW DOWN COLD UPPER AIR
FROM THE ARCTIC AND...AS IT TURNS THE CORNER OVER THE
ALEUTIANS...PICK UP GULF MOISTURE BEFORE ARRIVING OVER THE
PANHANDLE. CERTAINLY NOT EXPECTING SNOW AT LOWER ELEVATIONS...BUT
SIGNIFICANTLY COLDER MID AND UPPER LEVEL TEMPERATURES ARE ON THE
WAY SO SNOW LEVELS WILL BE COMING DOWN.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR
PKZ011>013-021-022-031>036-041>043-051-052.

JCC/FRITSCH/BOWLEY