Preliminary Forecasts
Issued by NWS

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FXUS02 KWNH 300538
PREEPD

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
137 AM EDT WED JUL 30 2014

VALID 12Z SAT AUG 02 2014 - 12Z WED AUG 06 2014

...OVERVIEW AND GUIDANCE PREFERENCES...

AMPLIFIED RIDGE/TROUGH IS STILL FORECAST TO RELAX IN THE MEDIUM
RANGE... BUT OTHERWISE MAINTAIN ITS ORIENTATION. THE MODELS AND
ENSEMBLE MEMBERS CONTINUE TO FORM A RELATIVELY GOOD CLUSTER
THROUGH THE WEEKEND AS THE TROUGH WEAKENS OVER THE GREAT LAKES AND
OH VALLEY... THOUGH THE UKMET/ECMWF/ECENS MEMBERS CONTINUE TO BE A
BIT QUICKER TO RAISE HEIGHTS OVER IN/OH AS IT LIFTS A VORT MAX
INTO THE NORTHEAST WHILE THE GFS/GEFS AND CANADIAN RUNS DIG IT A
BIT FARTHER SOUTH. SPLIT THE DIFFERENCE SINCE THESE SMALLER
DETAILS HAVE HAD LITTLE CONTINUITY OVER THE PAST SEVERAL DAYS. BY
NEXT WEEK... ENERGY INITIALLY UP NEAR ALASKA IN THE SHORT TERM
SHOULD SLIDE THROUGH NW ONTARIO AND DIG INTO QUEBEC AND NORTHERN
NEW ENGLAND. ECMWF HAS BEEN MORE CONSISTENT ON TIMING THAN THE
GFS... BUT THE GFS LIES CLOSER IN AMPLITUDE TO THE ENSEMBLE
CONSENSUS /THE ECMWF BEING AMONG THE DEEPEST 10 PERCENT OF
ENSEMBLE MEMBERS/. SPLIT THE DIFFERENCE BETWEEN THE GEFS AND ECENS
MEANS AS CONFIDENCE IS LOW IN ANY DETAILS THAT WILL AFFECT THIS
EVOLUTION. OVERALL... CONFIDENCE IS AT LEAST AVERAGE.


...SENSIBLE WEATHER HIGHLIGHTS...

THE LINGERING SFC BOUNDARY ALONG THE I-10 AND 95 CORRIDORS WILL BE
A FOCUS FOR RAINFALL... BUT NOT CONTINUOUS... INSTEAD BEING DRIVEN
BY THE DIURNAL CYCLE AS WELL AS WEAK BUT IMPORTANT SHORTWAVES
MOVING THROUGH THE LONGWAVE TROUGH. THAT BOUNDARY SHOULD WASH OUT
FIRST IN THE GULF AND THEN EVENTUALLY BY MIDWEEK AS THE NORTHERN
STREAM ENERGY AND ITS ASSOCIATED COLD FRONT PUSH INTO THE
NORTHEAST... WITH ANOTHER PUSH OF MODESTLY COOL AIR.

IN THE WEST... MONSOONAL MOISTURE SHOULD REACH A PEAK... PER PW
VALUES... LATE THIS WEEKEND IN THE SW AND THEN AROUND TUE/D6
FARTHER NORTH IN UT/NV. TEMPERATURES WILL REMAIN NEAR TO ABOVE
NORMAL IN THE PAC NW... BUT TEMPERED A BIT IN THE FOUR CORNERS
REGION AMID DAILY SHOWERS/STORMS.


FRACASSO

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