Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4
483
FXUS02 KWBC 141600
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1100 AM EST SUN FEB 14 2016

VALID 12Z WED FEB 17 2016 - 12Z SUN FEB 21 2016

THE 14/00Z ECENS/NAEFS MEANS AND DETERMINISTIC GFS PROVIDE THE
BASELINE FOR THE NATIONAL FORECAST BLEND TODAY.

FOUND LITTLE REASON TO ALTER THE CURRENT MEDIUM RANGE
FORECAST...OR DEVIATE FROM THE CURRENT FORECAST PHILOSOPHY.
PACIFIC INFLUENCES BEGIN TO SWEEP FROM WEST TO EAST AND WILL
MAINTAIN A "PROGRESSIVENESS" ACROSS THE LOWER 48 --- EAST OF THE
DIVIDE.

AROUND THE DAY6-DAY7 POINT... UPPER-LEVEL RIDGING BEGINS TO
REBUILD WEST OF THE DIVIDE AND STRENGTHENS CONSIDERABLY ALONG THE
WEST COAST. AND DOWNSTREAM---TROUGHING (A MID-LEVEL NORTHWEST
FLOW) BEGINS TO REFORM AND CARVE ACROSS THE MISSOURI VALLEY.

THE DEEP-LAYERED RIDGE FORMING IN THE WEST --- BRINGS AN END TO
THE "PROGRESSIVENESS" OF THE PACIFIC INFLUENCE AND MILDER FLOW
EAST OF THE CONTINENTAL DIVIDE ---AND DEFLECTS/DIRECTS --- THE
`PROGRESSIVE` EAST PAC ENERGY NORTH AND NORTHWESTWARD ALONG 130W
--- AND BACK INTO THE GULF OF ALASKA/ALASKA PANHANDLE.

THE 14/00Z DETERMINISTIC GFS/ECMWF WERE VERY REASONABLE SOLUTIONS
THROUGH DAY 5. AND IN PRINCIPLE --- IDENTIFY AND ADEQUATELY
MAINTAIN A DECENT CONSENSUS WITH RESPECT TO THE NEXT PACIFIC FRONT
AND RESULTANT SURFACE CYCLOGENESIS THAT EXITS THE CENTRAL
CONTINENTAL DIVIDE OF NORTH AMERICA. THIS SURFACE CYCLONE TRACK
(ESSENTIALLY FOR DESCRIPTIVE PURPOSES) WILL FOLLOW THE ENTIRE
COURSE OF THE MISSOURI RIVER (DAYS 5-6) AND ARC NORTHEASTWARD INTO
IOWA...MINNESOTA AND WISCONSIN.

WHERE THE GREAT LAKES REGION AND LOWER 48 FORECASTS ARE CONCERNED
--- THOUGHT THE GFS SEEMS TO HANDLE THE NATURE OF THIS SYSTEM ON
DAY 6 --- FROM A SYNOPTIC-SCALE SYSTEM FRONT `POINT OF VIEW` ---
AND IN A `MANNER` THAT FITS THE ENTIRE ENSEMBLE PACKAGE.

THE SYSTEM SHOULD HAVE A WELL-DEFINED WARM FRONT AND LOW-LEVEL
THERMAL STRUCTURE THAT SUSTAINS A BROAD ... ALMOST SPRING-LIKE
SOUTHWEST WIND AND TEMPERATURE `FEEL` ACROSS THE NATION`S MID
SECTION FROM NORTHEAST TEXAS TO THE EASTERN LAKES.

THE PATTERN DOES LOOK RATHER `DRY`. THE LOGIC BEING --- IT WILL
NOT BE A `FOUR CORNERS LOW`.

GIVEN THE TRAJECTORY OF THIS PARTICULAR PACIFIC TROUGH --- THE
BULK OF ITS ENERGY AND MOISTURE MUST TRAVERSE THE LOWER 48`S
NORTHERN DIVIDE ... AND DOES NOT APPEAR TO TAP THE WESTERN GULF OF
MEXICO FOR THE LOW-LEVEL MOISTURE AND/OR GET SUPPORT FROM
MID-LEVEL DYNAMICS ASSOCIATED WITH A SOUTHERN JET AXIS.

ANTICIPATE THIS AIRMASS TO SPREAD NORTHEASTWARD AND ENCOMPASSES
ALL OF THE LOWER HALF OF THE MS VALLEY FOR DAYS 4-5 --- UNTIL THE
SURFACE CYCLONE MOVES INTO ONTARIO. LIKEWISE...ITS COLD FRONT AND
ITS CANADIAN AIRMASS ---INITIATES A PRE-FRONTAL WIND SHIFT --- AND
SUCCESSION OF TEMPERATURE AND DEW POINT FALLS. THIS COLD FRONT
SHOULD SPREAD ACROSS THE EASTERN THIRD OF THE NATION DURING THE
DAY 6-7 TIME FRAME.

VOJTESAK







$$





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