Prognostic Meteorological Discussion
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000
FXUS02 KWBC 241619
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1218 PM EDT WED AUG 24 2016

VALID 12Z SAT AUG 27 2016 - 12Z WED AUG 31 2016

...A TROPICAL WAVE CURRENTLY BEING MONITORED BY THE NATIONAL
HURRICANE CENTER COULD BRING STRONG WINDS AND HEAVY RAINS TO
FLORIDA AND LOCATIONS ALONG THE GULF COAST...BUT THE FORECAST
REMAINS VERY UNCERTAIN...


...PATTERN OVERVIEW...

THE MAIN FOCUS ACROSS THE EASTERN HALF OF THE NATION THIS WEEKEND
AND INTO EARLY NEXT WEEK WILL WITH AN UPPER RIDGE HOLDING STRONG
OVER THE MID-ATLANTIC STATES AND A DEVELOPING TROPICAL SYSTEM
WHICH HAS THE POTENTIAL TO TRACK ACROSS SOUTHERN FLORIDA AND INTO
THE GULF OF MEXICO (PLEASE REFER TO THE NATIONAL HURRICANE CENTER
FOR THE LATEST INFORMATION ON THIS FEATURE...WWW.NHC.NOAA.GOV).
IN THE WEST...ATTENTION WILL BE WITH ANOTHER UPPER TROUGH
RELOADING IN THE NORTHWEST EARLY NEXT WEEK...AND BETWEEN THE
RELOADING TROUGH IN THE WEST AND RIDGE OVER THE MID-ATLANTIC
REGION...SHORTWAVE ENERGY CROSSING THE NORTH CENTRAL U.S. THIS
WEEKEND COULD HELP PRESS A SURFACE LOW AND COLD FRONT TROUGH THE
UPPER MISSISSIPPI VALLEY AND GREAT LAKES.


...UNCERTAINTY ASSESSMENT...

MODELS ARE SHOWING AN UNUSUALLY LARGE AMOUNT OF SPREAD WITH THE
DETAILS OF THE MEDIUM RANGE FORECAST...ESPECIALLY WHEN COMPARING
RECENT RUNS OF THE DETERMINISTIC GFS AND ECMWF OVER THE
SOUTHEASTERN CORNER OF THE NATION.  THE ECMWF HAS BEEN
CONSISTENTLY STRONGER WITH THE UPPER RIDGE OVER THE MID-ATLANTIC
STATES AND MUCH STRONGER/FASTER TO TRACK A POSSIBLE TROPICAL
SYSTEM INTO THE GULF OF MEXICO...WHILE THE GFS HAS GENERALLY BEEN
WEAKER WITH UPPER RIDGE AND LESS AGGRESSIVE WITH ANY TROPICAL
DEVELOPMENT.  SINCE THE LATEST RUNS OF THE UKMET AND CMC SUGGESTS
A SOLUTION CLOSER TO THE ECMWF...ALTHOUGH NOT AS STRONG...THE WPC
DAY 3-7 WAS WEIGHTED MORE HEAVILY ON ECMWF/ECMWF ENSEMBLE MEAN
GUIDANCE RATHER THAN GFS/GEFS MEAN SOLUTIONS.
HOWEVER...CONSIDERING THE UNUSUALLY LARGE AMOUNT OF SPREAD WITH
INDIVIDUAL ENSEMBLE MEMBERS AND EVEN SIGNIFICANT RUN-TO-RUN JUMPS
WITH THE EXACT TRACK/DEPTH OF THE POSSIBLE DEVELOPING TROPICAL
SYSTEM...THE FORECAST REMAINS EXTREMELY UNCERTAIN.  AGAIN...PLEASE
REFER TO THE NATIONAL HURRICANE CENTER FOR THE LATEST INFORMATION
ON THIS FEATURE.


...WEATHER HIGHLIGHTS...

STRONG WINDS AND HEAVY RAINS WILL BE POSSIBLE WITH THE POTENTIAL
TROPICAL SYSTEM...AND FLORIDA AND LOCATIONS ALONG THE GULF COAST
SHOULD CONTINUE TO CLOSELY MONITOR THE LATEST FORECASTS.  PERIODS
OF HEAVY RAIN AND THUNDERSTORMS WILL BE POSSIBLE ACROSS THE
MIDDLE/UPPER MISSISSIPPI VALLEY AND GREAT LAKES THIS
WEEKEND...AHEAD OF THE SHORTWAVE CROSSING THE NORTH CENTRAL U.S..
IN TERMS OF TEMPERATURES ACROSS THE NATION...UPPER RIDGING HOLDING
STRONG OVER THE MID-ATLANTIC STATES SHOULD KEEP TEMPERATURES ABOVE
NORMAL...WHILE TEMPERATURES SHOULD RETURN TO NEAR OR BELOW NORMAL
AS THE TROUGH RELOADS OVER THE NORTHWESTERN U.S. EARLY NEXT WEEK.



GERHARDT







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