Preliminary Forecasts
Issued by NWS

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FXUS02 KWNH 260519
PREEPD

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
118 AM EDT SUN JUN 26 2016

VALID 12Z WED JUN 29 2016 - 12Z SUN JUL 03 2016

...OVERVIEW AND GUIDANCE EVALUATION/PREFERENCES...

MODELS AND ENSEMBLES REMAIN IN VERY GOOD OVERALL AGREEMENT THROUGH
THE END OF THE WEEK WITH THE LARGE SCALE CONUS PATTERN. RIDGING IN
THE WEST WILL EASE A BIT AS THE TROUGH IN THE EAST RELOADS THROUGH
THE GREAT LAKES. THE PAC NW WILL SEE SOME LOWER HEIGHTS ENCROACH
INTO THE REGION BUT THE MODELS SHOW THE GREATEST DIVERGENCE HERE
NEXT WEEKEND. UNTIL THEN, A CONSENSUS BLEND OF THE 12Z/18Z GFS AND
12Z GEFS AND ECMWF/ECENS MEAN OFFERED A GOOD STARTING POINT. BY
NEXT SAT/SUN, THE 12Z GFS WAS ON THE QUICKER SIDE OF THE ENSEMBLES
WITH TROUGHING INTO THE PAC NW, WELL AHEAD OF ITS MEAN, WHILE THE
ECMWF WAS ON THE SLOWER SIDE DUE TO A DIFFERENT CONFIGURATION
UPSTREAM. LEFT OUT THE 12Z GFS FOR NEXT SUN/D7 WHICH RESULTED IN
MAINTAINING THE RIDGE AXIS THROUGH ID/MT.


...SENSIBLE WEATHER HIGHLIGHTS...

PRECIPITATION WILL FOCUS NEAR THREE AREAS - THE FIRST ALONG/AHEAD
OF THE LEAD FRONTAL BOUNDARY EXITING THE EAST COAST WEDNESDAY BUT
HUNG UP THROUGH THE SOUTHEAST AND BACK TO THE WEST, THE SECOND
WITH THE NEXT FRONT THROUGH THE GREAT LAKES, AND THE THIRD IN IN
THE INTERIOR WEST DUE TO AN INCREASE IN MOISTURE AS THE MONSOON
STARTS TO GET GOING. BEST CHANCES FOR HEAVIEST RAIN LIE IN THE
SOUTHERN PLAINS AS SMALL SHORTWAVES RIDE OUT OF THE ROCKIES AND
OVER/ALONG THE SURFACE BOUNDARY AND THEN BACK INTO THE FOUR
CORNERS REGION BUT ESPECIALLY COLORADO WHICH HAS BEEN A RATHER
PERSISTENT SIGNAL IN THE MODELS/ENSEMBLES. LIGHTER RAIN IS
EXPECTED WITH THE NORTHERN STREAM GREAT LAKES FRONT THU-SAT DUE TO
LIMITED MOISTURE (THANKS TO THE PRECEDING FRONT).


FRACASSO

$$




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