Prognostic Meteorological Discussion
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000
FXUS02 KWBC 240643
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
242 AM EDT THU JUL 24 2014

VALID 12Z SUN JUL 27 2014 - 12Z THU JUL 31 2014

...OVERVIEW AND MODEL GUIDANCE...

IN MOST RESPECTS MODEL/ENSEMBLE GUIDANCE HAS SETTLED INTO BETTER
THAN AVERAGE AGREEMENT AND CONTINUITY AS THE PATTERN BECOMES
DOMINATED BY A LARGE SCALE AND HIGHLY AMPLIFIED WRN RIDGE/ERN
TROUGH.  WHAT DIFFS REMAIN ARE RELATIVELY SMALL IN SCALE LEADING
TO PREFS TOWARD MAINTAINING A GENERAL BLEND OF LATEST
MODEL/ENSEMBLE MEAN SOLNS... IN THIS CASE THE 18Z GFS/GEFS MEAN
AND 12Z ECMWF/ECMWF MEAN.  THE RESULTING BLEND LEANS MORE TOWARD
THE MEANS WITH GRTLKS TO ERN CANADA LOW PRESSURE AS THE 12Z ECMWF
IS SLOWER THAN CONSENSUS WITH THE SFC LOW AFTER SUN AND THE GFS
COULD RUN A TAD FAST BY TUE.  THE NEW 00Z GFS/UKMET/CMC REMAIN
FASTER THAN THE 12Z ECMWF TO VARYING DEGREES.

WITHIN THE AMPLIFYING ERN TROUGH THE MDLS/ENSMEANS STILL INDICATE
THAT MID LVL HGTS SHOULD REACH UP TO AT LEAST 2.5-3.O STDEVS BELOW
NORMAL... WITH THE CORE OF LOWEST ANOMALIES TRACKING FROM THE
GRTLKS/OH VLY INTO THE CNTRL APLCHNS EARLY-MID PERIOD BEFORE
WEAKENING SOMEWHAT AND DRIFTING S/SW THEREAFTER AS THE SRN PART OF
THE TROUGH CONTINUES TO AMPLIFY BUT THE NRN-CNTRL PART BEGINS TO
FILL.  THE OVERALL TROUGH AXIS MAY RETROGRADE A LITTLE LATE IN THE
PERIOD AS A WRN ATLC RIDGE BUILDS TOWARD THE ERN CANADIAN
MARITIMES.  MEANWHILE HGTS MAY REACH 2.0-2.5 STDEVS ABOVE NORMAL
IN THE SRN PART OF THE SRN ROCKIES/SOUTHWEST UPR HIGH.


...SENSIBLE WEATHER HIGHLIGHTS...

AHEAD OF THE WELL BELOW NORMAL TEMPS SPREADING ACROSS MOST OF THE
CNTRL-ERN STATES... GRTLKS/ERN CANADA LOW PRESSURE AND TRAILING
FRONT WILL BRING AREAS OF RNFL/TSTMS TO THE ERN STATES INTO EARLY
NEXT WEEK.  BY MIDWEEK THE FRONT AND ITS ASSOC RNFL SHOULD SETTLE
JUST OFF THE EAST COAST AND NEAR THE GULF COAST THEN BACK THROUGH
THE SRN PLAINS.  POTENTIAL REMAINS FOR LOW LVL UPSLOPE FLOW TO
ENHANCE RNFL OVER PARTS OF CO/NM WHILE ONE OR MORE IMPULSES ALOFT
IN NWLY FLOW MAY PROVIDE ADDED FOCUS FOR ONE OR MORE AREAS OF
LOCALLY HVY CONVECTION EXTENDING SEWD THROUGH THE SRN PLAINS.
COOLEST MAX TEMP ANOMALIES OF 10-15F BELOW NORMAL ARE MOST LIKELY
TO EXTEND FROM THE NRN TIER INTO THE APLCHNS SUN-TUE WITH PSBL
CLOUDS/RNFL KEEPING DAYTIME READINGS BELOW NORMAL TO A SIMILAR
EXTENT OVER THE S-CNTRL PLAINS BY TUE-THU.  MIN TEMPS MAY REACH AS
LOW AS 10F OR SO BELOW NORMAL ONE OR MORE DAYS OVER THE OH VLY/TN
VLY/APLCHNS TUE-THU.  ON THE OTHER HAND EXPECT MOST AREAS OVER THE
WEST TO SEE ABOVE AVERAGE TEMPS WITH LOCALIZED MAX ANOMALIES UP TO
PLUS 10F OR SO OVER THE NORTHWEST AND PSBLY BROADER COVERAGE OF
SIMILAR ANOMALIES FOR MINS.  SHRTWV ENERGY EMBEDDED WITHIN SWLY
FLOW ALOFT BETWEEN THE WRN RIDGE AND A NERN PAC TROUGH MAY
GENERATE ONE OR MORE EPISODES OF SCT CONVECTION.

RAUSCH

$$





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