Prognostic Meteorological Discussion
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FXUS02 KWBC 281558
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1158 AM EDT TUE JUL 28 2015

VALID 12Z FRI JUL 31 2015 - 12Z TUE AUG 04 2015

...MODEL/UNCERTAINTY ASSESSMENT...

WPC MEDIUM RANGE SURFACE FRONTS/PRESSURES AND 500 MB PROGS ALONG
WITH THE 2.5KM SENSIBLE WEATHER GRIDS HAVE BEEN PRIMARILY DERIVED
FROM REASONABLY WELL CLUSTERED GUIDANCE FROM THE 06 UTC GFS/GEFS
MEAN AND 00 UTC ECMWF/ECMWF ENSEMBLE MEAN.

THE 06 UTC GFS/GEFS MEAN HAVE TRENDED CLOSER TO THE MORE RUN TO
RUN CONSISTENT 00 UTC ECMWF/ECMWF ENSEMBLE MEAN. PRIOR RUNS OF THE
GFS AND FOR THAT MATTER THE CANADIAN AND RESPECTIVE ENSEMBLES
SHOWED LESS THAN STELLAR RUN TO RUN CONTINUITY.
GUIDANCE SOLUTION CONVERGENCE CAN BE A GOOD PREDICTOR OF
PREDICTABILITY. THIS IS ESPECIALLY THE CASE WHEN THE FLOW PATTERN
SUPPORTS BETTER FRONTAL CONVECTIVE ORGANIZATION THAN TYPICALLY THE
CASE FOR THE SEASON AND THERE IS A LACK OF TROPICAL SYSTEMS TO
SHAKE UP THE FLOW. ACCORDINGLY...WOULD CHARACTERIZE WEATHER
PREDICTABILITY ACROSS OUR FINE NATION AS ABOVE AVERAGE.

...PATTERN OVERVIEW AND SENSIBLE WEATHER HIGHLIGHTS/THREATS...

MID-UPPER LEVEL RIDGING EXTENDS FROM THE W-CENTRAL US. EXPECT
CONTINUED MONSOONAL ACTIVTY ON THE MOISTURE PLUMED WRN PERIPHERY
THROUGH THE SWRN US AND INTERMOUNTAIN W/ROCKY STATES. PACIFIC AND
NRN STREAM IMPULSES RUNNING AROUND AND OVERTOP THE RIDGE TEND TO
DIG SEWD DOWNSTREAM UNDERNEATH A CLOSED E-CENTRAL CANADIAN VORTEX
ALOFT AND INTO A SPLIT ERN US TROUGH POSITION. ENERGY ACROSS THE
US NRN/NERN TIER WILL FORCE SEVERAL CONVECTION FOCUSING FRONTAL
SYSTEMS OVER THE REGION. MID-LOWER LATITUDE ENERGIES WILL
MEANWHILE FOCUS WAVY FRONTAL ORGANIZATION AND DEEPER MOISTURE TO
FUEL LOCALLY HEAVY CONVECTIVE DOWNPOURS FAR DOWN INTO THE SRN/SERN
US.

SCHICHTEL

$$





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