Preliminary Forecasts
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12
000
FXUS02 KWNH 170501
PREEPD

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
100 AM EDT WED SEP 17 2014

VALID 12Z SAT SEP 20 2014 - 12Z WED SEP 24 2014


...HEAVY RAIN THREAT FOR THE SOUTHERN AND CENTRAL PLAINS...


THE GLOBAL NUMERICAL MODELS INDICATE THAT THE FLOW ACROSS CENTRAL
NORTH AMERICA AT THE MEDIUM RANGE WILL BREAK INTO LARGE EDDIES
OVER THE UNITED STATES, WITH AN ENERGETIC, WAVY POLAR JET ACROSS
CANADA. THE PROGRESSIVE TROUGHS IN THE POLAR WESTERLIES ARE LIKELY
TO DIP INTO THE NORTHERN UNITED STATES THROUGH THE PERIOD, THEIR
BASES SPLITTING OFF DURING THE PEAKS OF THEIR AMPLIFICATIONS.
WHERE THESE SPLITS OCCUR VIS-A-VIS POCKETS OF TROPICAL AIR
MEANDERING ABOUT THE SOUTH OF THE UNITED STATES--DRIFTING CHUNKS
OF SUPERMOIST AIR ORIGINATING FROM EITHER FORMER HURRICANES
(ODILE) OR PSEUDO-TROPICAL LOWS (THE CIRCULATION EAST OF
FLORIDA)--IS NOT AN EASY CALL. THE STRONG CORRELATION BETWEEN THE
12Z/16 ECENS AND NAEFS MEANS AFFORDS AT LEAST A STABLE BASE FROM
WHICH TO BUILD THE SYNOPTIC DETAILS OF THE FORECAST. THE BEST BET
FOR SOAKING RAINFALL APPEARS TO BE THE SLICE OF THE PLAINS FROM
KANSAS TO TEXAS--THE REGION WHERE THE MID-LEVEL CORE OF THE
REMNANTS OF ODILE ARE MOST LIKELY TO LODGE IN THE COMPLEX HAND OFF
BETWEEN THE SPLIT STREAMS.


CISCO

$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.