PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
959 AM EDT SUN MAY 11 2008
 
VALID 12Z THU MAY 15 2008 - 12Z SUN MAY 18 2008
 

UPDATED PRELIM MEDIUM RANGE DISCUSSION

THE 06Z/11 GFS AND 00Z/11 ECMWF ENSEMBLE MEAN WERE CHOSEN IN A
50-50 BLEND FOR THE UPDATED PRELIM GRAPHICS. THEY APPEARED TO BEST
REPRESENT THE CENTER OF THE ENVELOPE BETWEEN THE GFS FAMILY OF
SOLUTIONS...FEATURING A HIGHLY AMPLIFIED WRN CANADIAN
RIDGE/CENTRAL AND SRN HIGH PLAINS TROF...AND THE ECMWF FAMILY OF
SOLUTIONS...WHICH SHOW A WEAKER BUT STILL STRONG WRN RIDGE AND AN
EWD-DISPLACED BUT STILL AMPLIFIED ERN CONUS TROF. SOME OF THE
DIFFERENCES HERE ARE THAT THE GFS AND ITS ENSEMBLE MEMBERS DUMP
MORE ENERGY INTO A SRN BRANCH OF WESTERLIES ACROSS THE SWRN
STATES/THE SRN PLAINS AS ENERGY ROUNDS THE VERY STRONG W COAST
RIDGE....WHILE THE ECMWF AND ITS ENSEMBLES MEAN DROP MORE  NRN
STREAM ENERGY FARTHER E INTO AN ERN LONGWAVE TROF ALONG 85W.

MORE HEAVY PRECIPITATION IS EXPECTED FROM THE SERN PLAINS EWD THRU
THE LOWER MS VLY TO THE MID ATLANTIC/SERN STATES ALONG A WAVY
FRONT BY THE LATTER PORTION OF THIS WORKWEEK. UNDER ANOMALOUSLY
LOW UPPER HEIGHTS...MID MAY MAY FEEL MORE LIKE MARCH OVER THE GRT
LAKES REGION NEXT WEEKEND.  


 
CISCO