Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center

 
 

 

Follow the Weather Prediction Center on Facebook Follow the Weather Prediction Center on Twitter
NCEP Quarterly Newsletter
WPC Home
Analyses and Forecasts
   National High & Low
   WPC Discussions
   Surface Analysis
   Days ½-2½ CONUS
   Days 3-7 CONUS
   Days 4-8 Alaska
   QPF
   PQPF
   Flood Outlook
   Winter Weather
   Storm Summaries
   Heat Index
   Air Quality
   Tropical Products
   Daily Weather Map
   GIS Products
Current Watches/
Warnings

Satellite and Radar Imagery
   Satellite Images
   National Radar
Product Archive
WPC Verification
   QPF
   Medium Range
   Model Diagnostics
   Event Reviews
International Desks
Development and Training
   Development
WPC Overview
   About the WPC
   Staff
   WPC History
   Accomplishments
   Other Sites
   FAQs
Meteorological Calculators
Contact Us
   About Our Site
 
USA.gov is the U.S. Government's official web portal to all federal, state, and local government web resources and services.
 
Extended Forecast Discussion
 
(Caution: Version displayed is not the latest version. - Issued 1559Z Oct 31, 2014)
 
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
 
Abbreviations and acronyms used in this product
 
Geographic Boundaries -  Map 1: Color  Black/White       Map 2: Color  Black/White


EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1159 AM EDT FRI OCT 31 2014

VALID 12Z MON NOV 03 2014 - 12Z FRI NOV 07 2014

...VERY HEAVY PCPN PATTERN ON TAP FOR THE S-CENTRAL AND NWRN US
NEXT WEEK...

...PATTERN OVERVIEW AND GUIDANCE/UNCERTAINTY ASSESSMENTS...

WPC SURFACE FRONTS/PRESSURE AND 500 MB PROGS ALONG WITH ASSOCIATED
HPCGUIDE HIGH RESOLUTION SENSIBLE WEATHER GRIDS HAVE BEEN
PRIMARILY DERIVED FROM A BLEND OF THE 06 UTC GFS ENSEMBLE MEAN AND
THE REASONABLY COMPATABLE 00 UTC ECMWF/NAEFS ENSEMBLE MEANS. AN
ENSEMBLE MEAN FORECAST APPROACH WAS USED IN PART DUE TO LESS THAN
STELLAR DETERMINISTIC MODEL RUN TO RUN VARIANCE. GUIDANCE THOUGH
DOES SEEM TO BE CONVERGING UPON A MORE COMMON MID-LARGER SCALE
SOLUTION...BOLSTERING FORECAST CONFIDENCE... ESPECIALLY WITH HEAVY
PCPN THREATS FOR THE S-CENTRAL AND NWRN US NEXT WEEK.

THE WPC SOLUTION LEANS ON THE MORE AMPLIFIED SIDE OF THE FULL
ENVELOPE OF SOLUTIONS FOR BOTH THE NRN AND SRN STREAMS...FOLLOWING
FROM LEAD-IN WATER VAPOR IMAGERY LOOP ANALYSIS...OVERALL GUIDANCE
TRENDS/BIASES...AND RECENT FLOW HISTORY. 


...SENSIBLE WEATHER HIGHLIGHTS...

AMPLIFIED YET STEADILY PROGRESSIVE MID-UPPER LATITUDE FLOW
SUPPORTS SEVERAL FRONTAL SYSTEM PUSHES FROM THE CENTRAL TO ERN US
NEXT WEEK WITH MODEST PCPN. ENSEMBLE MEANS ARE MODESTLY MORE
AMPLIFIED THAN THE DETERMINISTIC GFS/ECMWF OVER TIME IN THIS
PATTERN. HOWEVER...A BIGGER THREAT TRAILS BACK AND LINGERS OVER
THE S-CENTRAL US WHERE SLOWER MOVING BOUNDARIES AND POTENTIAL SRN
STREAM MID-UPPER LEVEL TROUGH SUPPORT WORKING SLOWLY FROM THE SWRN
US/MEXICO MAY COMBINE WITH DEEPER GULF OF MEXICO MOISTURE INFLOW
THAT MAY BE FURTHER ENHANCED TO SOME FACTOR BY MID-UPPER LEVEL
MOISTURE FED UP FROM ERN PAC TS VANCE. FYI...THE EXPERIMENTAL
PARELLEL 06 UTC GFS HAS TRENDED MORE IN LINE WITH THE 00 UTC ECMWF
IN THE SRN STREAM NEXT WEEK.

MEANWHILE...ENERGETIC MID-UPPER LATITUDE FLOW ALSO FAVORS A
PROLONGED HEAVY PCPN PATTERN FOR THE NWRN US WHERE A MOIST FETCH
WITH EACH SYSTEM APPROACH/PASSAGE IS SIGNIFICANTLY ENHANCED BY
TOPOGRAPHY.

SCHICHTEL