EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
134 PM EDT SAT AUG 14 2004
VALID 12Z TUE AUG 17 2004 - 12Z SAT AUG 21 2004
...FINAL MODEL DISCUSSION...

A BLOCKY LATE SUMMER PATTERN AT HIGHER LATITUDES WILL MODIFY THIS
PERIOD AS A DEEP CLOSED LOW IN THE ERN GLF AK WEAKENS AND
RETROGRADES WWD WHILE A SUB ARCTIC VORTEX DROPS SWD BETWEEN TWO
STRONG MID LEVEL RIDGES IN TO CENTRAL CANADA. AGAIN A VERY
ANOMALOUS PATTERN WITH HTS WELL BELOW NORMAL. SWD OVER SRN CONUS A
MEAN SEPARATE MORE SRN STREAM TROF WILL WORK EWD OUT OF THE
SOUTHWEST TO THE MS VALLEY WHERE IT WILL PARTIALLY PHASEE WITH THE
DEEP MEAN TROF NWD IN THE SRN CANADIAN PLAINS. THIS RESULTS IN
RAISING HTS OVER THE SERN SEABOARD AND ADJACENT CARRIBEAN.

...ATLC TROPICS...
CENTRAL AND ERN ATLC TROPICS BECOMING QUITE ACTIVE WITH TWO
CURRENT SYSTEMS WITH TROPICAL DEPRESSION 5 AND T.S. DANIELLE BOTH
FORECAST TO BECOME HURCNS IN A FEW DAYS. MOST MEDIUM RANGE MODEL
GUIDANCE AT THIS TIME HAS DANIELLE TURNING WELL NWD IN THE OPEN
ATLC. T.D. 5 FORECAST TO COME S OF THE GREATER ANTILLES TO NR THE
YUCATAN CHANNEL BY DAY 5 THU POSSIBLY THREATENING SRN OR SERN
GULFMEX NEXT WEEKEND. ANOTHER WRN AFRICAN DISTURBANCE SEEN BY
LONGER TERM MODEL RUNS COMING INTO THE CENTRAL TROP ATLC...MUCH
MORE UNCERTAIN AT THAT TIME RANGE BUT LONGER TERM TREND OF
GFS/ECMWF IS TO RAISE W ATLC/CARIB HTS WHILE GFS INDICATES THIS AS
A POTENTIALLY STRONG SYSTEM FOR SEVERAL MODEL RUNS. SEE LATEST NHC
ADVISORIES AND DISCUSSIONS.
ROSENSTEIN

GRAPHICS AVAILABLE AT www.HPC.NCEP.NOAA.GOV