Preliminary Forecasts
Issued by NWS

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FXUS02 KWNH 250508
PREEPD

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
107 AM EDT FRI JUL 25 2014

VALID 12Z MON JUL 28 2014 - 12Z FRI AUG 01 2014

...ANOTHER SHOT OF COOL AIR TO PUSH ALL THE WAY TO THE GULF COAST
NEXT WEEK...

...OVERVIEW AND GUIDANCE PREFERENCES...

ANOTHER WELL-ADVERTISED HIGH-AMPLITUDE MERIDIONAL EVENT...
SUPPORTED BY A STRONG TROUGH/RIDGE/TROUGH TRIPLET OVER THE NORTH
PACIFIC... WILL PORTEND MUCH BELOW AVERAGE TEMPERATURES FOR THE
CENTRAL/EASTERN STATES WHILE THE WEST RETAINS ITS GRIP ON SUMMER
/OR PERHAPS THE OTHER WAY AROUND/. THE DETERMINISTIC MODELS AND
MULTI-CENTER ENSEMBLES HAVE BEEN IN RATHER GOOD SYNOPTIC AGREEMENT
AND EVEN ALIGN CLOSER THAN AVERAGE ON SOME DETAILS... MAKING A
MULTI-MODEL/ENSEMBLE BLEND A WORTHWHILE STARTING POINT.
DIFFERENCES ARISE BY THE END OF NEXT WEEK AS TO HOW QUICKLY
HEIGHTS RISE THROUGH THE GREAT LAKES AS THE UPPER LOW LIFTS
NORTHWARD THROUGH QUEBEC. THE 18Z GFS/GEFS LAG BEHIND THE 12Z
ECMWF/ECENS MEAN. ONE DETERMINING FACTOR WILL BE A ROBUST CLOSED
LOW DESCENDING OUT OF THE POLAR REGION THROUGH NUNAVUT... WHERE
THE MODELS NOTORIOUSLY HAVE TROUBLE IN THE MEDIUM RANGE. WEIGHTED
THE ECENS MEAN MORE BY THE END OF THE PERIOD DUE TO ITS STABILITY
IN THE DAY 7 TIME FRAME.

...SENSIBLE WEATHER HIGHLIGHTS...

THE SENSIBLE WEATHER ANOMALIES SHOULD SHOW UP POINTEDLY ACROSS THE
SOUTHERN HIGH PLAINS INTO THE ARKLATEX WHERE DAYTIME HIGHS ARE
LIKELY TO RUN FAR BELOW NORMAL IN THE OVERRUNNING ZONE NORTH OF
THE POLAR FRONT--MUCH LIKE THE EVENT ABOUT A WEEK AGO. HEAVY RAIN
WILL AGAIN BE POSSIBLE FROM NW TX/OK SOUTHEASTWARD WED-FRI. ALSO
LIKE THE EVENT FROM MID MONTH... THE FAR WEST LOOKS SCORCHING HOT
WITH TEMPERATURES ONCE AGAIN LIKELY TO REACH OR EXCEED THE CENTURY
MARK IN EASTERN WASHINGTON AND THE ADJACENT LOWLANDS OF IDAHO.
ADDITIONALLY... THE MONSOON SHOULD SEND ENOUGH MID-LEVEL MOISTURE
NORTHWARD TO FUEL HIGH-BASED THUNDERSTORMS THROUGHOUT MUCH OF THE
PARCHED FAR WEST--A CRITICAL CONCERN FOR WILDLAND FIRES.


FRACASSO/CISCO

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